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Sample records for aespoe hard rock

  1. Aespoe hard rock laboratory Sweden

    International Nuclear Information System (INIS)

    The aim of the new Aespoe hard rock laboratory is to demonstrate state of the art of technology and evaluation methods before the start of actual construction work on the planned deep repository for spent nuclear fuel. The nine country OECD/NEA project in the Stripa mine in Sweden has been an excellent example of high quality international research co-operation. In Sweden the new Aespoe hard rock laboratory will gradually take over and finalize this work. SKB very much appreciates the continued international participation in Aespoe which is of great value for the quality efficiency, and confidence in this kind of work. We have invited a number of leading experts to this first international seminar to summarize the current state of a number of key questions. The contributions show the great progress that has taken place during the years. The results show that there is a solid scientific basis for using this knowledge on site specific preparation and work on actual repositories. (au)

  2. Aespoe hard rock laboratory. Annual report 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2010 is given below

  3. Aespoe Hard Rock Laboratory. Annual Report 2011

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2011 is given below

  4. Aespoe Hard Rock Laboratory. Annual Report 2011

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-03-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2011 is given below.

  5. Aespoe hard rock laboratory. Annual report 2010

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2010 is given below

  6. Aespoe Hard Rock Laboratory. Annual Report 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-06-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. The work performed at Aespoe HRL during 2006 is in this report described in six chapters: Geo-science - experiments, analysis and modelling to increase the knowledge of the surrounding rock; Natural barriers - experiments, analysis and modelling to increase the knowledge of the repository barriers under natural conditions; Engineered barriers - demonstration of technology for and function of important engineered parts of the repository barrier system; Aespoe facility - operation, maintenance, data management, monitoring, public relations etc; Environmental research; and finally, International co-operation.

  7. Aespoe Hard Rock Laboratory. Annual Report 2006

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. The work performed at Aespoe HRL during 2006 is in this report described in six chapters: Geo-science - experiments, analysis and modelling to increase the knowledge of the surrounding rock; Natural barriers - experiments, analysis and modelling to increase the knowledge of the repository barriers under natural conditions; Engineered barriers - demonstration of technology for and function of important engineered parts of the repository barrier system; Aespoe facility - operation, maintenance, data management, monitoring, public relations etc; Environmental research; and finally, International co-operation

  8. Aespoe Hard Rock Laboratory Annual report 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-09-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Aespoe HRL has been in operation since 1995 and the associated research, development, and demonstration tasks, have so far attracted considerable interest. A summary of work performed at Aespoe HRL during 2003 is given below. Seven organisations from six countries participated in the co-operation at Aespoe HRL during 2003 in addition to SKB. Most of the organisations are interested in groundwater flow, radionuclide transport and rock characterisation. Several of the organisations are participating in the experimental work as well as in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. SKB is through Repository Technology co-ordinating three EC contracts and takes part in several EC projects of which the representation in five projects is channelled through Repository Technology. SKB takes also part in work within the IAEA framework.

  9. Aespoe Hard Rock Laboratory Annual report 2003

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. Aespoe HRL has been in operation since 1995 and the associated research, development, and demonstration tasks, have so far attracted considerable interest. A summary of work performed at Aespoe HRL during 2003 is given below. Seven organisations from six countries participated in the co-operation at Aespoe HRL during 2003 in addition to SKB. Most of the organisations are interested in groundwater flow, radionuclide transport and rock characterisation. Several of the organisations are participating in the experimental work as well as in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. SKB is through Repository Technology co-ordinating three EC contracts and takes part in several EC projects of which the representation in five projects is channelled through Repository Technology. SKB takes also part in work within the IAEA framework

  10. Aespoe hard rock laboratory. Annual report 1992

    International Nuclear Information System (INIS)

    The Aespoe hard rock laboratory is being constructed in preparation for the deep geological repository of spent fuel in Sweden. This Annual report 1992 for the Aespoe hard rock laboratory contains an overview of the work conducted. Present work is focused on verification of pre-investigation methods and development of the detailed investigation methodology. Construction of the facility and investigation of the bedrock are being carried out in parallel. December 1992 1925 m of the tunnel has been excavated to a depth of 255 m below surface. An important and integrated part of the work is further refinement of conceptual and numerical models for groundwater flow and radionuclide migration. This work is carried out in cooperation with seven organizations from six countries that participate in the project. (25 refs.)

  11. Aespoe Hard Rock Laboratory. Annual Report 2009

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2009 is given below. Geoscience Geoscientific research is a basic activity at Aespoe HRL. The aim of the current studies is to develop geoscientific models of the Aespoe HRL and increase the understanding of the rock mass properties as well as knowledge of applicable methods of measurement. A main task within the geoscientific field is the development of the Aespoe Site Descriptive Model (SDM) integrating information from the different fields. The main activities in the geoscientific fields have been: (1) Geology evaluation of geological mapping techniques leading to the decision to develop a SKB mapping system and finalization of the mapping of rock surfaces in the new tunnel, (2) Hydrogeology monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics finalised the field tests on thermally-induced spalling in deposition holes and evaluated the effect of counterforce in the deposition holes. Natural barriers At Aespoe HRL

  12. Aespoe Hard Rock Laboratory. Annual Report 2009

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2009 is given below. Geoscience Geoscientific research is a basic activity at Aespoe HRL. The aim of the current studies is to develop geoscientific models of the Aespoe HRL and increase the understanding of the rock mass properties as well as knowledge of applicable methods of measurement. A main task within the geoscientific field is the development of the Aespoe Site Descriptive Model (SDM) integrating information from the different fields. The main activities in the geoscientific fields have been: (1) Geology evaluation of geological mapping techniques leading to the decision to develop a SKB mapping system and finalization of the mapping of rock surfaces in the new tunnel, (2) Hydrogeology monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics finalised the field tests on thermally-induced spalling in deposition holes and evaluated the effect of counterforce in the deposition holes. Natural barriers At Aespoe HRL, experiments are

  13. Aespoe Hard Rock Laboratory. Annual Report 2001

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The bedrock with available fractures and fracture zones, its properties and on-going physical, chemical and biological processes which affect the integrity of the engineered barriers and the transport of radionuclides are denoted the natural barriers of a deep repository. Experiments are performed at Aespoe HRL at conditions that are expected to prevail at repository depth, with the aim to increase the knowledge of the long term function of the repository barriers. Another aim with the Aespoe HRL is testing of models for groundwater flow, radionuclide migration, chemical and biological processes. The programme for the testing of models includes evaluation of the usefulness and reliability of different models and the development and testing of methods for determination of parameters required as input to conceptual and numerical models. Ongoing projects are Tracer Retention Understanding Experiments, Long Term Diffusion Experiment, Radionuclide Retention Experiment, Microbial Project, Colloid Project, and Matrix Water Chemistry Experiments. The activities at Aespoe HRL include the evaluation of the usefulness and reliability of different calculation models and the development and testing of methods for determination of parameters required as input to the models. An important part of this work is performed in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, an international co-operation project. The work within the Tasks 4 and 5 were reported during 2001

  14. Aespoe Hard Rock Laboratory. Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-06-15

    The Aespoe Hard Rock Laboratory (HRL), in the Simpevarp area in the municipality of Oskarshamn constitutes an important part of SKB's work with the design and construction of a deep geological repository for final disposal of spent nuclear fuel. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its associated research, as well as in the development and demonstration tasks. Most of the research is focused on processes of importance for the long-term safety of a final repository for spent nuclear fuel. Demonstration addresses the performance of the engineered barriers and practical means of constructing and operating a repository for spent fuel. To meet the overall time schedule for SKB's RD and D work, the following stage goals were initially defined for the work at the Aespoe HRL: 1. Verify pre-investigation methods. Demonstrate that investigations on the ground surface and in boreholes provide sufficient data on essential safety-related properties of the rock at repository level. 2. Finalise detailed investigation methodology. Refine and verify the methods and the technology needed for characterisation of the rock in the detailed site investigations. 3. Test models for description of the barrier functions at natural conditions. Further develop, and at repository depth, test methods and models for description of groundwater flow, radionuclide migration and chemical conditions during operation of a repository and after closure. 4. Demonstrate technology for and function of important

  15. Aespoe Hard Rock Laboratory. Annual Report 2005

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL), in the Simpevarp area in the municipality of Oskarshamn constitutes an important part of SKB's work with the design and construction of a deep geological repository for final disposal of spent nuclear fuel. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its associated research, as well as in the development and demonstration tasks. Most of the research is focused on processes of importance for the long-term safety of a final repository for spent nuclear fuel. Demonstration addresses the performance of the engineered barriers and practical means of constructing and operating a repository for spent fuel. To meet the overall time schedule for SKB's RD and D work, the following stage goals were initially defined for the work at the Aespoe HRL: 1. Verify pre-investigation methods. Demonstrate that investigations on the ground surface and in boreholes provide sufficient data on essential safety-related properties of the rock at repository level. 2. Finalise detailed investigation methodology. Refine and verify the methods and the technology needed for characterisation of the rock in the detailed site investigations. 3. Test models for description of the barrier functions at natural conditions. Further develop, and at repository depth, test methods and models for description of groundwater flow, radionuclide migration and chemical conditions during operation of a repository and after closure. 4. Demonstrate technology for and function of important parts of the

  16. Aespoe Hard Rock Laboratory. Annual Report 2008

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. The main activities in the geoscientific fields have been: (1) Geology - completion of the feasibility study concerning geological mapping techniques and mapping of rock surfaces in the new tunnel, (2) Hydrogeology - monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field tests to evaluate the counterforce needed to prevent thermally-induced spalling in deposition holes. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. A number of large-scale field experiments and supporting activities concerning Engineered barriers are carried out at Aespoe HRL. The experiments focus on different aspects of engineering technology and performance testing: The Prototype Repository is a demonstration of the integrated function of the repository and provides a full-scale reference for tests of predictive models concerning individual components as well as the complete repository system; The Long Term Test of Buffer Material (Lot-experiment) aims at validating models and hypotheses concerning physical properties in a bentonite buffer material and of related processes regarding microbiology, radionuclide transport, copper corrosion and gas transport; The objective of the project Alternative Buffer

  17. Aespoe Hard Rock Laboratory. Annual Report 2008

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. The main activities in the geoscientific fields have been: (1) Geology - completion of the feasibility study concerning geological mapping techniques and mapping of rock surfaces in the new tunnel, (2) Hydrogeology - monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field tests to evaluate the counterforce needed to prevent thermally-induced spalling in deposition holes. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. A number of large-scale field experiments and supporting activities concerning Engineered barriers are carried out at Aespoe HRL. The experiments focus on different aspects of engineering technology and performance testing: The Prototype Repository is a demonstration of the integrated function of the repository and provides a full-scale reference for tests of predictive models concerning individual components as well as the complete repository system; The Long Term Test of Buffer Material (Lot-experiment) aims at validating models and hypotheses concerning physical properties in a bentonite buffer material and of related processes regarding microbiology, radionuclide transport, copper corrosion and gas transport; The objective of the project Alternative

  18. Aespoe Hard Rock Laboratory. Annual Report 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-09-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site for a deep repository. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create an opportunity for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The bedrock with available fractures and fracture zones, its properties and on-going physical, chemical and biological processes which affect the integrity of the engineered barriers and the transport of radionuclides are denoted the natural barriers of a deep repository. Experiments are performed at Aespoe HRL at conditions that are expected to prevail at repository depth, with the aim to increase the knowledge of the long term function of the repository barriers. Another aim with the Aespoe HRL is testing of models for groundwater flow, radionuclide migration, chemical and biological processes. The programme for the testing of models includes evaluation of the usefulness and reliability of different models and the development and testing of methods for determination of parameters required as input to conceptual and numerical models. Ongoing projects are Tracer Retention Understanding Experiments, Long Term Diffusion Experiment, Radionuclide Retention Experiment, Microbial Project, Colloid Project, and Matrix Water Chemistry Experiments. The activities at Aespoe HRL include the evaluation of the usefulness and reliability of different calculation models and the development and testing of methods for determination of parameters required as input to the models. An important part of this work is performed in the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, an international co-operation project. The work within the Tasks 4 and 5 were reported

  19. Aespoe Hard Rock Laboratory. Annual Report 2009

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. Aespoe HRL is located in the Simpevarp area in the municipality of Oskarshamn. One of the fundamental reasons behind SKB's decision to construct an underground laboratory was to create opportunities for research, development and demonstration in a realistic and undisturbed rock environment down to repository depth. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995 and considerable international interest has been shown in its research, as well as in the development and demonstration tasks. A summary of the work performed at Aespoe HRL during 2009 is given below. Geoscience Geoscientific research is a basic activity at Aespoe HRL. The aim of the current studies is to develop geoscientific models of the Aespoe HRL and increase the understanding of the rock mass properties as well as knowledge of applicable methods of measurement. A main task within the geoscientific field is the development of the Aespoe Site Descriptive Model (SDM) integrating information from the different fields. The main activities in the geoscientific fields have been: (1) Geology evaluation of geological mapping techniques leading to the decision to develop a SKB mapping system and finalization of the mapping of rock surfaces in the new tunnel, (2) Hydrogeology monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics finalised the field tests on thermally-induced spalling in deposition holes and evaluated the effect of counterforce in the deposition holes. Natural barriers At Aespoe HRL

  20. Aespoe Hard Rock Laboratory. Annual Report 2008

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-15

    The Aespoe Hard Rock Laboratory (HRL) is an important part of SKB's work with the design and construction of a deep geological repository for the final disposal of spent nuclear fuel. The main activities in the geoscientific fields have been: (1) Geology - completion of the feasibility study concerning geological mapping techniques and mapping of rock surfaces in the new tunnel, (2) Hydrogeology - monitoring and storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field tests to evaluate the counterforce needed to prevent thermally-induced spalling in deposition holes. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. A number of large-scale field experiments and supporting activities concerning Engineered barriers are carried out at Aespoe HRL. The experiments focus on different aspects of engineering technology and performance testing: The Prototype Repository is a demonstration of the integrated function of the repository and provides a full-scale reference for tests of predictive models concerning individual components as well as the complete repository system; The Long Term Test of Buffer Material (Lot-experiment) aims at validating models and hypotheses concerning physical properties in a bentonite buffer material and of related processes regarding microbiology, radionuclide transport, copper corrosion and gas transport; The objective of the project Alternative

  1. Aespoe Hard Rock Laboratory. Annual report 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The surface and borehole investigations and the research work performed in parallel with construction have provided a thorough test of methods for investigation and evaluation of bedrock conditions for construction of a deep repository. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The experimental results of the first tracer test with sorbing radioactive tracers have been obtained. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. The manufacturing of the CHEMLAB probe was completed during 1996, and the first experiments were started early in 1997. During 1997 three experiments on diffusion in bentonite using {sup 57}Co, {sup 114}Cs,{sup 85}Sr, {sup 99}Tc, and {sup 131}I were conducted. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. The characterization of the rock mass in the area of the prototype repository is in progress. The objectives of the Demonstration of Repository Technology are to develop, test, and demonstrate methodology and equipment for encapsulation and deposition of spent nuclear fuel. The demonstration of handling and deposition will be made in a new drift. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full scale plug. The backfill and rock will be instrumented with about 230 transducers for measuring the thermo-hydro-mechanical processes. The

  2. Aespoe Hard Rock Laboratory. Annual report 1997

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The surface and borehole investigations and the research work performed in parallel with construction have provided a thorough test of methods for investigation and evaluation of bedrock conditions for construction of a deep repository. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The experimental results of the first tracer test with sorbing radioactive tracers have been obtained. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. The manufacturing of the CHEMLAB probe was completed during 1996, and the first experiments were started early in 1997. During 1997 three experiments on diffusion in bentonite using 57Co, 114Cs,85Sr, 99Tc, and 131I were conducted. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. The characterization of the rock mass in the area of the prototype repository is in progress. The objectives of the Demonstration of Repository Technology are to develop, test, and demonstrate methodology and equipment for encapsulation and deposition of spent nuclear fuel. The demonstration of handling and deposition will be made in a new drift. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full scale plug. The backfill and rock will be instrumented with about 230 transducers for measuring the thermo-hydro-mechanical processes. The Retrieval Test is aiming at

  3. Aespoe Hard Rock Laboratory Annual Report 1999

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The TRUE -1 experiment including tests with sorbing radioactive tracers in a single fracture over a distance of about 5 m has been completed. Diffusion and sorption in the rock matrix is the dominant retention mechanism over the time scales of the experiments. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. In total six boreholes have been drilled into the experimental volume located at the 450 m level. The Long-Term Diffusion Experiment is intended as a complement to the dynamic in-situ experiments and the laboratory experiments performed in the TRUE Programme. Diffusion from a fracture into the rock matrix will be studied in situ. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. A new site for the CHEMLAB experiments was selected and prepared during 1999. All future experiment will be conducted in the J niche at 450 m depth. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. Characterisation of the rock mass in the area of the Prototype repository is completed and the six deposition holes have been drilled. The Backfill and

  4. Aespoe Hard Rock Laboratory Annual Report 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-08-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. The TRUE -1 experiment including tests with sorbing radioactive tracers in a single fracture over a distance of about 5 m has been completed. Diffusion and sorption in the rock matrix is the dominant retention mechanism over the time scales of the experiments. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. In total six boreholes have been drilled into the experimental volume located at the 450 m level. The Long-Term Diffusion Experiment is intended as a complement to the dynamic in-situ experiments and the laboratory experiments performed in the TRUE Programme. Diffusion from a fracture into the rock matrix will be studied in situ. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. A new site for the CHEMLAB experiments was selected and prepared during 1999. All future experiment will be conducted in the J niche at 450 m depth. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and instrumented. Characterisation of the rock mass in the area of the Prototype repository is completed and the six deposition holes have been drilled. The Backfill and

  5. Aespoe Hard Rock Laboratory. Status Report. April - June 2007

    Energy Technology Data Exchange (ETDEWEB)

    2007-07-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2005- 2010 are presented in SKB's RDandD-Programme 2004 /SKB 2004/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2007/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the second quarter 2007

  6. Aespoe Hard Rock Laboratory. Status Report May - August 2010

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RD and D-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2010/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2010

  7. Aespoe Hard Rock Laboratory. Status Report May - August 2009

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2009

  8. Aespoe Hard Rock Laboratory. Status Report. September - December 2009

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2009

  9. Aespoe Hard Rock Laboratory. Status Report. January - April 2010

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2010

  10. Aespoe hard rock laboratory. Annual report 2000

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory constitutes an important component of SKB's work to design, construct, and implement a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of selected repository sites. The retention effect of the rock has been studied by tracer tests in the Tracer Retention Understanding Experiments (TRUE) and the TRUE Block Scale (TRUE BS). These tests are supplemented by the new Long Term Diffusion Experiment (LTDE). During year 2000 the field experiments of TRUE BS (50 m scale) were completed and preparations made for the LTDE (migration through a fracture wall and into the rock), including boring of approximately 10 m deep hole with 300 mm diameter. Laboratory investigations have difficulties in simulating natural conditions and need supplementary field studies to support validation exercises. A special borehole probe, CHEMLAB, has therefore been designed for different kinds of validation experiments where data can be obtained representative for the in-situ properties of groundwater at repository depth. During 2000 migration experiments were made with actinides (Am, Np and Pu) in CHEMLAB 2, the simplified supplement to CHEMLAB 1. Colloids of nuclides as well as of bentonite might affect the migration of released radionuclides and a separate project was planned during 2000 to assess the existence, stability and mobility of colloids. The development of numerical modelling tools continues with the general objective to improve the numerical models in terms of flow and transport and to update the site-scale and laboratory scale models for the Aespoe HRL. The Matrix Fluid Chemistry project aims at determining the origin and age of matrix fluids and the experiment has been designed to sample matrix fluids from predetermined, isolated borehole sections by specialised equipment. The Aespoe HRL also has the task to demonstrate and perform full scale tests of the function of different components of the

  11. Aespoe Hard Rock Laboratory. Annual report 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. Experiments with sorbing radioactive tracers have been completed in a single fracture over a distance of about 5 m. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. Breakthrough of sorbing tracers in the TRUE-I tests is retarded more strongly than would be expected based on laboratory data alone. Results are consistent for all tracers and tracer tests. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. The total duration of the project is approximately 4.5 years with a scheduled finish at the end of the year 2000. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. The project Degassing of groundwater and two phase flow was initiated to improve our understanding of observations of hydraulic conditions made in drifts and interpretation of experiments performed close to drifts. The analysis performed so far shows that the experimentally observed flow reductions indeed are consistent with the degassing hypothesis. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and

  12. Aespoe Hard Rock Laboratory. Annual report 1998

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. The Tracer Retention Understanding Experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models that are intended to be used in the licensing of a deep repository for spent fuel. Experiments with sorbing radioactive tracers have been completed in a single fracture over a distance of about 5 m. These tests have been subject to blind predictions by the Aespoe Task Force on groundwater flow and transports of solutes. Breakthrough of sorbing tracers in the TRUE-I tests is retarded more strongly than would be expected based on laboratory data alone. Results are consistent for all tracers and tracer tests. The main objective of the TRUE Block Scale Experiment is to increase understanding and our ability to predict tracer transport in a fracture network over spatial scales of 10 to 50 m. The total duration of the project is approximately 4.5 years with a scheduled finish at the end of the year 2000. The REX project focuses on the reduction of oxygen in a repository after closure due to reactions with rock minerals and microbial activity. Results show that oxygen is consumed within a few days both for the field and laboratory experiments. The project Degassing of groundwater and two phase flow was initiated to improve our understanding of observations of hydraulic conditions made in drifts and interpretation of experiments performed close to drifts. The analysis performed so far shows that the experimentally observed flow reductions indeed are consistent with the degassing hypothesis. The Prototype Repository Test is focused on testing and demonstrating repository system function. A full-scale prototype including six deposition holes with canisters with electric heaters surrounded by highly compacted bentonite will be built and

  13. Aespoe Hard Rock Laboratory Annual Report 1994

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory is being constructed as part of the preparations for the deep geological repository of spent nuclear fuel in Sweden. The annual report 1994 contains an overview of the work conducted. Present work is focused on verification of pre-investigation methods and development of detailed investigation methodology which is applied during tunnel construction. Construction of the facility and detailed characterization of the bedrock are performed in parallel. Excavation of the main access tunnel was completed during 1994 and at the end of the year only minor excavation work remained. The last 400 m of the main tunnel, which has a total length of 3600 m, was excavated by a 5 m diameter boring machine. The tunnel reaches a depth of 450 m below ground. Preparations for the operating phase have started and detailed plans have been prepared for several experiments. Nine organizations, including SKB, from eight countries are now participating in the work at the laboratory. 50 refs, 28 figs

  14. Aespoe hard rock laboratory. Annual report 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-06-01

    The Aespoe Hard Rock Laboratory constitutes an important component of SKB's work to design, construct, and implement a deep geological repository for spent nuclear fuel and to develop and test methods for characterisation of selected repository sites. The retention effect of the rock has been studied by tracer tests in the Tracer Retention Understanding Experiments (TRUE) and the TRUE Block Scale (TRUE BS). These tests are supplemented by the new Long Term Diffusion Experiment (LTDE). During year 2000 the field experiments of TRUE BS (50 m scale) were completed and preparations made for the LTDE (migration through a fracture wall and into the rock), including boring of approximately 10 m deep hole with 300 mm diameter. Laboratory investigations have difficulties in simulating natural conditions and need supplementary field studies to support validation exercises. A special borehole probe, CHEMLAB, has therefore been designed for different kinds of validation experiments where data can be obtained representative for the in-situ properties of groundwater at repository depth. During 2000 migration experiments were made with actinides (Am, Np and Pu) in CHEMLAB 2, the simplified supplement to CHEMLAB 1. Colloids of nuclides as well as of bentonite might affect the migration of released radionuclides and a separate project was planned during 2000 to assess the existence, stability and mobility of colloids. The development of numerical modelling tools continues with the general objective to improve the numerical models in terms of flow and transport and to update the site-scale and laboratory scale models for the Aespoe HRL. The Matrix Fluid Chemistry project aims at determining the origin and age of matrix fluids and the experiment has been designed to sample matrix fluids from predetermined, isolated borehole sections by specialised equipment. The Aespoe HRL also has the task to demonstrate and perform full scale tests of the function of different components of

  15. Aespoe Hard Rock Laboratory. Annual Report 2007

    International Nuclear Information System (INIS)

    The main activities in the geoscientific fields have been: (1) Geology - besides mapping of rock surfaces and drill cores a feasibility study concerning geological mapping techniques is performed, (2) Hydrogeology - completion of the modelling work for the detailed hydro-structural model for the -450 m level and monitoring/storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field work to determine the stress levels at which core disking occur followed by numerical modelling. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The experiments are related to the rock, its properties and in situ environmental conditions. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. An important goal is to demonstrate technology for and the function of important parts of the repository system. This implies translation of current scientific knowledge and state-of- the-art technology into engineering practice applicable in a real repository. It is important that development, testing and demonstration of methods and procedures are conducted under realistic conditions and at an appropriate scale. A number of large-scale field

  16. Aespoe Hard Rock Laboratory. Annual Report 2007

    Energy Technology Data Exchange (ETDEWEB)

    2007-04-15

    The main activities in the geoscientific fields have been: (1) Geology - besides mapping of rock surfaces and drill cores a feasibility study concerning geological mapping techniques is performed, (2) Hydrogeology - completion of the modelling work for the detailed hydro-structural model for the -450 m level and monitoring/storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field work to determine the stress levels at which core disking occur followed by numerical modelling. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The experiments are related to the rock, its properties and in situ environmental conditions. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. An important goal is to demonstrate technology for and the function of important parts of the repository system. This implies translation of current scientific knowledge and state-of- the-art technology into engineering practice applicable in a real repository. It is important that development, testing and demonstration of methods and procedures are conducted under realistic conditions and at an appropriate scale. A number of large-scale field

  17. Aespoe Hard Rock Laboratory Annual Report 2004

    International Nuclear Information System (INIS)

    At Aespoe HRL, methods for characterising a suitable site for a deep repository are being developed and tested. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995. Most of the research is focused on processes of importance for the long-term safety of a future deep repository. To meet the overall time schedule for SKB's RDandD work, the following stage goals were initially defined for the work at the Aespoe HRL. 1. Verify pre-investigation methods. Demonstrate that investigations on the ground surface and in boreholes provide sufficient data on essential safety-related properties of the rock at repository level. 2. Finalise detailed investigation methodology. Refine and verify the methods and the technology needed for characterisation of the rock in the detailed site investigations. 3. Test models for description of the barrier functions at natural conditions. Further develop and at repository depth test methods and models for description of groundwater flow, radionuclide migration, and chemical conditions during operation of a repository and after closure. 4. Demonstrate technology for and function of important parts of the repository system. Test, investigate and demonstrate on full-scale different components of importance for the long-term safety of a deep repository and to show that high quality can be achieved in design, construction, and operation of repository components. Stage goals 1 and 2 have been concluded at Aespoe HRL and the tasks have been transferred to the Site Investigation Department of SKB which performs site investigations at two sites, Simpevarp/Laxemar in the municipality of Oskarshamn and Forsmark in the municipality of Oesthammar. In order to reach present goals the following important tasks are performed at the Aespoe HRL: Develop, test, evaluate and demonstrate

  18. Aespoe Hard Rock Laboratory Annual Report 2004

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-08-01

    At Aespoe HRL, methods for characterising a suitable site for a deep repository are being developed and tested. The underground part of the laboratory consists of a tunnel from the Simpevarp peninsula to the southern part of Aespoe where the tunnel continues in a spiral down to a depth of 460 m. Aespoe HRL has been in operation since 1995. Most of the research is focused on processes of importance for the long-term safety of a future deep repository. To meet the overall time schedule for SKB's RDandD work, the following stage goals were initially defined for the work at the Aespoe HRL. 1. Verify pre-investigation methods. Demonstrate that investigations on the ground surface and in boreholes provide sufficient data on essential safety-related properties of the rock at repository level. 2. Finalise detailed investigation methodology. Refine and verify the methods and the technology needed for characterisation of the rock in the detailed site investigations. 3. Test models for description of the barrier functions at natural conditions. Further develop and at repository depth test methods and models for description of groundwater flow, radionuclide migration, and chemical conditions during operation of a repository and after closure. 4. Demonstrate technology for and function of important parts of the repository system. Test, investigate and demonstrate on full-scale different components of importance for the long-term safety of a deep repository and to show that high quality can be achieved in design, construction, and operation of repository components. Stage goals 1 and 2 have been concluded at Aespoe HRL and the tasks have been transferred to the Site Investigation Department of SKB which performs site investigations at two sites, Simpevarp/Laxemar in the municipality of Oskarshamn and Forsmark in the municipality of Oesthammar. In order to reach present goals the following important tasks are performed at the Aespoe HRL: Develop, test, evaluate and

  19. Aespoe Hard Rock Laboratory. Annual Report 2007

    Energy Technology Data Exchange (ETDEWEB)

    2007-04-15

    The main activities in the geoscientific fields have been: (1) Geology - besides mapping of rock surfaces and drill cores a feasibility study concerning geological mapping techniques is performed, (2) Hydrogeology - completion of the modelling work for the detailed hydro-structural model for the -450 m level and monitoring/storage of data in the computerised Hydro Monitoring System, (3) Geochemistry - sampling of groundwater in the yearly campaign and for specific experiments and (4) Rock Mechanics - field work to determine the stress levels at which core disking occur followed by numerical modelling. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. At Aespoe HRL, experiments are performed under the conditions that are expected to prevail at repository depth. The experiments are related to the rock, its properties and in situ environmental conditions. The aim is to provide information about the long-term function of natural and repository barriers. Experiments are performed to develop and test methods and models for the description of groundwater flow, radionuclide migration, and chemical conditions at repository depth. The programme includes projects which aim to determine parameter values that are required as input to the conceptual and numerical models. An important goal is to demonstrate technology for and the function of important parts of the repository system. This implies translation of current scientific knowledge and state-of- the-art technology into engineering practice applicable in a real repository. It is important that development, testing and demonstration of methods and procedures are conducted under realistic conditions and at an appropriate scale. A number of large-scale field

  20. Aespoe Hard Rock Laboratory. Annual Report 2002

    International Nuclear Information System (INIS)

    The Aespoe HRL was opened in 1994 as a research centre and underground laboratory. The experiments performed in Aespoe HRL are related to the rock, its properties, and in situ environmental conditions. Tests of models for groundwater flow, radionuclide migration and chemical/biological processes are some of the main purposes of the Aespoe HRL. The programme includes projects with the aim to evaluate the usefulness and reliability of different models and to develop and test methods for determination of parameters required as input to conceptual and numerical models. The retardation in rock is studied at different experiment scales in a programme called Tracer Retention Understanding Experiments (TRUE). The Long Term Diffusion Experiment constitutes a complement to performed diffusion and sorption laboratory experiments, and is a natural extension of the experiments conducted as part of the TRUE experiments. Radionuclide retention experiments are carried out with the aim to confirm result from laboratory experiments in situ, where conditions representative for the properties of groundwater at repository depth prevail. In CHEMLAB 1 two kinds of experiments to study the influence of radiolysis on the mobility of technetium in bentonite were started in the end of 2002. Experiments to study migration of actinides in natural fractures in drill cores are being carried out in CHELMAB 2. The findings of potential transport of solutes by colloids and access to more sensitive instruments for colloid measurements motivated a Colloid Project at Aespoe HRL. There are presently four specific microbial process areas identified that are of importance for proper repository functions and that are studied in the Microbe Project. The process areas are; biomobilisation of radionuclides, bioimmobilisation of radionuclides, microbial effects on the chemical stability, and microbial corrosion of copper. The main objectives of the Matrix Fluid Chemistry experiment are to understand the

  1. Aespoe Hard Rock Laboratory. Annual report 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The Aespoe HRL has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. Geoscientific investigations on Aespoe and nearby islands began 1986. Since then, bedrock conditions have been investigated by several deep boreholes. The Aespoe research village has been built and extensive underground construction work has been undertaken in parallel with comprehensive research. This has resulted in a thorough test of methods for investigation and evaluation of bedrock conditions for construction of a deep repository. The objective of the ZEDEX project is to compare the mechanical disturbance to the rock for excavation by tunnel boring and blasting. The results indicate that the role of the EDZ as a preferential pathway to radionuclide transport is limited to the damaged zone. The tracer retention understanding experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models. During 1996 a series of tracer experiments in radially converging and dipole flow configuration have been performed. A special borehole probe has been designed for different kinds of retention experiments where data can be obtained representative for the in situ properties of groundwater at repository depth. The prototype repository test is focused on testing and demonstrating repository system function, and includes backfill and plug tests and demonstration of methods for deposition and retrieval of canisters in a new tunnel at the 420 m level. The long term tests of buffer material aim to validate models of buffer performance and at quantifying clay buffer alteration processes at adverse conditions. 80 refs, 53 figs, 16 tabs.

  2. Aespoe Hard Rock Laboratory. Annual report 1996

    International Nuclear Information System (INIS)

    The Aespoe HRL has been constructed as part of the preparations for the deep geological repository for spent nuclear fuel in Sweden. Geoscientific investigations on Aespoe and nearby islands began 1986. Since then, bedrock conditions have been investigated by several deep boreholes. The Aespoe research village has been built and extensive underground construction work has been undertaken in parallel with comprehensive research. This has resulted in a thorough test of methods for investigation and evaluation of bedrock conditions for construction of a deep repository. The objective of the ZEDEX project is to compare the mechanical disturbance to the rock for excavation by tunnel boring and blasting. The results indicate that the role of the EDZ as a preferential pathway to radionuclide transport is limited to the damaged zone. The tracer retention understanding experiments are made to gain a better understanding of radionuclide retention in the rock and create confidence in the radionuclide transport models. During 1996 a series of tracer experiments in radially converging and dipole flow configuration have been performed. A special borehole probe has been designed for different kinds of retention experiments where data can be obtained representative for the in situ properties of groundwater at repository depth. The prototype repository test is focused on testing and demonstrating repository system function, and includes backfill and plug tests and demonstration of methods for deposition and retrieval of canisters in a new tunnel at the 420 m level. The long term tests of buffer material aim to validate models of buffer performance and at quantifying clay buffer alteration processes at adverse conditions. 80 refs, 53 figs, 16 tabs

  3. Aespoe hard rock laboratory. Current research projects 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    In 1986 SKB decided to construct the Aespoe Hard Rock Laboratory (HRL) in order to provide an opportunity for research, development and demonstration in a realistic and undisturbed underground rock environment down to the depth planned for the future deep repository. The focus of current and future work is on development and testing of site characterization methods, verification of models describing the function of the natural and engineered barriers and development, testing, and demonstration of repository technology. The program has been organised so that all important steps in the development of a repository are covered, in other words the Aespoe HRL constitutes a `dress rehearsal` for the Swedish deep geological repository for spent fuel and other long-lived waste. Geoscientific investigations on Aespoe and nearby islands began in 1986. Aespoe was selected as the site for the laboratory in 1988. Construction of the facility, which reaches a depth of 460 m below the surface, began in 1990 and was completed in 1995. A major milestone had been reached in 1996 with the completion of the pre-investigation and construction phases of the Aespoe HRL. The comprehensive research conducted has permitted valuable development and verification of site characterization methods applied from the ground surface, boreholes, and underground excavations. The results of this research are summarised in the book `Aespoe Hard Rock Laboratory - 10 years of Research` published by SKB in 1996. The Operating Phase of the Aespoe HRL began in 1995 and is expected to continue for 15-20 years, that is until the first stage of the development of the Swedish deep geological repository for spent nuclear fuel is expected to be completed. A number of research projects were initiated at the start of the Operating Phase. Most of these projects have made substantial progress since then and important results have been obtained. The purpose of this brochure is to provide a brief presentation of the

  4. Aespoe hard rock laboratory. Current research projects 1998

    International Nuclear Information System (INIS)

    In 1986 SKB decided to construct the Aespoe Hard Rock Laboratory (HRL) in order to provide an opportunity for research, development and demonstration in a realistic and undisturbed underground rock environment down to the depth planned for the future deep repository. The focus of current and future work is on development and testing of site characterization methods, verification of models describing the function of the natural and engineered barriers and development, testing, and demonstration of repository technology. The program has been organised so that all important steps in the development of a repository are covered, in other words the Aespoe HRL constitutes a 'dress rehearsal' for the Swedish deep geological repository for spent fuel and other long-lived waste. Geoscientific investigations on Aespoe and nearby islands began in 1986. Aespoe was selected as the site for the laboratory in 1988. Construction of the facility, which reaches a depth of 460 m below the surface, began in 1990 and was completed in 1995. A major milestone had been reached in 1996 with the completion of the pre-investigation and construction phases of the Aespoe HRL. The comprehensive research conducted has permitted valuable development and verification of site characterization methods applied from the ground surface, boreholes, and underground excavations. The results of this research are summarised in the book 'Aespoe Hard Rock Laboratory - 10 years of Research' published by SKB in 1996. The Operating Phase of the Aespoe HRL began in 1995 and is expected to continue for 15-20 years, that is until the first stage of the development of the Swedish deep geological repository for spent nuclear fuel is expected to be completed. A number of research projects were initiated at the start of the Operating Phase. Most of these projects have made substantial progress since then and important results have been obtained. The purpose of this brochure is to provide a brief presentation of the

  5. Aespoe Hard Rock Laboratory. Status Report May - August 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RD and D-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2010/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2010.

  6. Aespoe Hard Rock Laboratory. Status Report. September - December 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-04-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. In September 2010, the plans for SKB's research and development of technique during the period 2011-2016 were presented in SKB's RDandD-Programme 2010 /SKB 2010a/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report and the information valid for 2010 is given in /SKB 2010b/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2010

  7. Aespoe Hard Rock Laboratory. Status Report. September - December 2010

    International Nuclear Information System (INIS)

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. In September 2010, the plans for SKB's research and development of technique during the period 2011-2016 were presented in SKB's RDandD-Programme 2010 /SKB 2010a/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report and the information valid for 2010 is given in /SKB 2010b/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2010

  8. Aespoe Hard Rock Laboratory. Status Report October - December 2008

    Energy Technology Data Exchange (ETDEWEB)

    2009-03-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2008/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the fourth quarter of 2008.

  9. Aespoe Hard Rock Laboratory. Status Report. January - April 2010

    Energy Technology Data Exchange (ETDEWEB)

    2010-10-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2010

  10. Aespoe Hard Rock Laboratory. Status Report. July - September 2008

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2008/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the third quarter of 2008.

  11. Aespoe Hard Rock Laboratory. Status Report May - August 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-11-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period May to August 2009.

  12. Aespoe Hard Rock Laboratory. Status Report. September - December 2009

    Energy Technology Data Exchange (ETDEWEB)

    2010-05-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period September to December 2009

  13. Aespoe Hard Rock Laboratory. Status Report January - April 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-09-15

    The Aespoe Hard Rock Laboratory (HRL) constitutes an important part of SKB's work to design and construct a geological repository for spent nuclear fuel and to develop and test methods for characterisation of a suitable site. The plans for SKB's research and development of technique during the period 2008-2013 are presented in SKB's RDandD-Programme 2007 /SKB 2007/. The information given in the RDandD-Programme related to Aespoe HRL is annually detailed in the Aespoe HRL Planning Report /SKB 2009/. This Aespoe HRL Status Report is a collection of the main achievements obtained during the period January to April 2009.

  14. Aespoe Hard Rock Laboratory. Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    The Aespoe HRL was opened in 1994 as a research centre and underground laboratory. The experiments performed in Aespoe HRL are related to the rock, its properties, and in situ environmental conditions. Tests of models for groundwater flow, radionuclide migration and chemical/biological processes are some of the main purposes of the Aespoe HRL. The programme includes projects with the aim to evaluate the usefulness and reliability of different models and to develop and test methods for determination of parameters required as input to conceptual and numerical models. The retardation in rock is studied at different experiment scales in a programme called Tracer Retention Understanding Experiments (TRUE). The Long Term Diffusion Experiment constitutes a complement to performed diffusion and sorption laboratory experiments, and is a natural extension of the experiments conducted as part of the TRUE experiments. Radionuclide retention experiments are carried out with the aim to confirm result from laboratory experiments in situ, where conditions representative for the properties of groundwater at repository depth prevail. In CHEMLAB 1 two kinds of experiments to study the influence of radiolysis on the mobility of technetium in bentonite were started in the end of 2002. Experiments to study migration of actinides in natural fractures in drill cores are being carried out in CHELMAB 2. The findings of potential transport of solutes by colloids and access to more sensitive instruments for colloid measurements motivated a Colloid Project at Aespoe HRL. There are presently four specific microbial process areas identified that are of importance for proper repository functions and that are studied in the Microbe Project. The process areas are; biomobilisation of radionuclides, bioimmobilisation of radionuclides, microbial effects on the chemical stability, and microbial corrosion of copper. The main objectives of the Matrix Fluid Chemistry experiment are to understand the

  15. Aespoe Hard Rock Laboratory. Planning Report for 2011

    International Nuclear Information System (INIS)

    This report presents the planned activities for the year 2011. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2010, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Background information on the projects is given in the Annual Report as well as findings and results

  16. Aespoe Hard Rock Laboratory. Annual Report 1995

    International Nuclear Information System (INIS)

    The construction of the laboratory was completed during 1995 and the operating phase has now begun. During the construction data has been collected from the tunnel and boreholes drilled from the tunnel. Results from these investigations have been reported and a comprehensive evaluation is in progress. The results will be used to design the site characterization program for the deep repository. Ten organizations from nine countries participate in the work at the laboratory. An important part of the cooperative work is performed within the framework of the task force on groundwater flow and transport of solutes. An evaluation has been made of the long term pumping test which was performed at Aespoe some years ago. It showed that the modelling tools that exist today have the ability to give a three-dimensional description of groundwater flow at a site like Aespoe. The task force will perform predictive modelling of the tracer experiments performed within the TRUE project. Characterization of the experimental site for TRUE and preparations for the tracer tests were completed during 1995. Tests of the engineering barriers have been started with the test of technology for backfilling of deposition tunnels. 55 refs, 36 figs, 7 tabs

  17. Aespoe Hard Rock Laboratory. Planning Report for 2011

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    This report presents the planned activities for the year 2011. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2010, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Background information on the projects is given in the Annual Report as well as findings and results.

  18. Aespoe Hard Rock Laboratory. Planning Report for 2010

    International Nuclear Information System (INIS)

    This report presents the planned activities for the year 2010. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2007, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Thereby the Status Reports may concentrate on work in progress and refers to this Planning Report for scope of work over the year. Background information on the projects is given in the Annual Report as well as findings and results

  19. Aespoe Hard Rock Laboratory. Planning Report for 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-02-15

    This report presents the planned activities for the year 2009. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2007, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Thereby the Status Reports may concentrate on work in progress and refers to this Planning Report for scope of work over the year. Background information on the projects is given in the Annual Report as well as findings and results.

  20. Aespoe Hard Rock Laboratory. Planning Report for 2010

    Energy Technology Data Exchange (ETDEWEB)

    2010-05-15

    This report presents the planned activities for the year 2010. The report is revised annually and details the programme carried out in the Aespoe Hard Rock Laboratory as described in SKB's Research, Development and Demonstration Programme 2007, and serves as a basis for the management of the laboratory. The role of the Planning Report is to present the plans and scope of work for each project. Thereby the Status Reports may concentrate on work in progress and refers to this Planning Report for scope of work over the year. Background information on the projects is given in the Annual Report as well as findings and results

  1. Aespoe Hard Rock Laboratory. The TASS-tunnel. Geological mapping

    Energy Technology Data Exchange (ETDEWEB)

    Hardenby, Carljohan (Vattenfall Power Consultant AB (Sweden)); Sigurdsson, Oskar (HAskGeokonsult AB (Sweden))

    2010-12-15

    The project entitled 'Sealing of tunnel at great depth' (Fintaetning av tunnel paa stort djup) needed a new tunnel in an area as undisturbed as possible and with cross-cutting water-bearing structures. The new tunnel, which was given the name TASS, was excavated on the -450 m level of SKB's Aespoe Hard Rock Laboratory (Aespoe HRL). The length of the tunnel is approximately 80 m and the theoretical tunnel area 19 m2. As is the case with all the other tunnels of the Aespoe HRL, the new tunnel has been geologically mapped. In addition, laser scanning combined with digital photography has been carried out. The tunnel was also used to test various types of explosives, borehole layouts and drilling techniques. The geological mapping of tunnel floor, walls and roof took place on four major occasions when a halt was made in tunnel excavation to allow for various tests. Before the mapping started on these occasions, laser scanning took place. The tunnel faces were mapped after each round (drilling, blasting and unloading). The present report describes the geological features of the tunnel and briefly how the laser scanning was performed. Water-bearing structures have been compared to similar structures in the neighbouring tunnels. The rock type names used here follow the old established Aespoe HRL nomenclature. Narrow (<0.1 m wide) dykes are normally mapped as fracture fillings. The dominating rock type is Aespoe diorite, which constitutes some 90 % of the rock mass. It is mostly mapped as fresh rock. . Minor constituents of the rock mass are fine-grained granite, hybrid rock, pegmatite, quartz veins/lenses and undifferentiated mafic rock. The mapping of fractures and deformation zones considers a number of parameters such as number of fractures, open/healed, width, length, description of fracture surfaces (roughness, planarity, etc), fracture filling, alteration and water. The deformation zones are discriminated into two main categories (&apos

  2. Swedish hard rock laboratory. Evaluation of 1988 year preinvestigations and description of the target area, the island of Aespoe

    International Nuclear Information System (INIS)

    The site investigations for the Swedish Hard Rock Laboratory have been focussed on the southern part of the Aespoe island. Geological, geohydrological and chemical investigations have been made in three deep boreholes on Aespoe. The results are used to evaluate previous predictions of the properties of the rock mass and to set up new predictions, more detailed than the previous ones. At the southern part of Aespoe a basic rock type called the Aespoe diorite dominates at the depths of 300-600 m. The hydraulic conducticity is lower here than in the surrounding Smaaland Granite. The groundwater chemistry in contact with the Aespoe Diorite has a high iron content. The methods and techniques used for the investigations have been optimized and integrated. During the drilling operation both hydraulic tests and groundwater sampling were performed. (authors)

  3. The colloid investigations conducted at the Aespoe Hard Rock Laboratory during 2000-2004

    Energy Technology Data Exchange (ETDEWEB)

    Laaksoharju, Marcus [Geopoint AB, Stockholm (Sweden); Wold, Susanna [Royal Inst. of Tech., Stockholm (Sweden). School of Chemical Science and Engineering, Nuclear Chemistry] (eds.)

    2005-12-15

    In 2000, SKB decided to initiate an international colloid project at the Aespoe Hard Rock Laboratory in Sweden. The objectives of the colloid project are to: (i) study the role of bentonite as a colloid source, (ii) verify the background colloid concentration at Aespoe HRL and, (iii) investigate the potential for colloid formation/transport in natural groundwater concentrations. The experimental concepts for the colloid project are: laboratory experiments with bentonite, background field measurements of natural colloids, borehole specific bentonite colloid stability experiments and a fracture specific transport experiment. The activities concerning the laboratory experiments and background field measurements are described in this work; the other activities are ongoing or planned. The following conclusions were made: The bentonite colloid stability is strongly dependent on the groundwater ionic strength. Natural colloids are organic degradation products such as humic and fulvic acids, inorganic colloids (clay, calcite, iron hydroxide) and microbes. Microbes form few but large particles and their concentration increase with increasing organic carbon concentrations. The small organic colloids are present in very low concentrations in deep granitic groundwater. The concentrations can be rather high in shallow waters. The colloid concentration decreases with depth and salinity, since colloids are less stable in saline waters. The colloid content at Aespoe is less than 300 ppb. The colloid content at repository level is less than 50 ppb. The groundwater variability obtained in the boreholes reflects well the natural groundwater variability along the whole HRL tunnel.

  4. Aespoe Hard Rock Laboratory. Sensor Data Report No 23

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Johannesson, Lars-Erik (Clay Technology AB (Sweden))

    2010-11-15

    The Prototype Repository Test consists of two sections. The installation of the first Section of Prototype Repository was made during summer and autumn 2001 and Section 2 was installed in spring and summer 2003. This report presents data from measurements in the Prototype Repository during the period 20010917-20100601. The report is organized so that the actual measured results are shown in Appendix 1-10, where Appendix 8 deals with measurements of canister displacements (by AITEMIN), Appendix 9 deals with geo-electric measurements in the backfill (by GRS), Appendix 10 deals with stress and strain measurement in the rock (by AaF) and Appendix 11 deals with measurement of water pressure in the rock (by VBB/VIAK). The main report and Appendix 1-7 deal with the rest of the measurements. Section 1. The following measurements are made in the bentonite in each of the two instrumented deposition holes in Section 1 (1 and 3): Temperature is measured in 32 points, total pressure in 27 points, pore water pressure in 14 points and relative humidity in 37 points. Temperature is also measured by all relative humidity gauges. Every measuring point is related to a local coordinate system in the deposition hole. The following measurements are made in the backfill in Section 1. Temperature is measured in 20 points, total pressure in 18 points, pore water pressure in 23 points and relative humidity in 45 points. Temperature is also measured by all relative humidity gauges. Furthermore, water content is measured by an electric chain in one section. Every measuring point is related to a local coordinate system in the tunnel. The following measurements are made on the surface of the canisters in Section 1: Temperature is measured every meter along two fiber optic cables. Furthermore, displacements of the canister in hole 3 are measured with 6 gauges. The following measurements are made in the rock in Section 1: Temperature is measured in 37 points in boreholes in the floor. Water

  5. Experiments at the Aespoe Hard Rock Laboratory[Information for the general public

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-12-01

    A dress rehearsal is being held in preparation for the construction of a deep repository for spent nuclear fuel at SKB's underground Hard Rock Laboratory (HRL) on Aespoe, outside Oskarshamn. Here we can test different technical solutions on a full scale and in a realistic environment. The Aespoe HRL is also used for field research. We are conducting a number of experiments here in collaboration with Swedish and international experts. In the Zedex experiment we have compared how the rock is affected around a drill-and-blast tunnel versus a bored tunnel. In a new experiment we will investigate how much the rock can take. A narrow pillar between two boreholes will be loaded to the point that the rock's ultimate strength is exceeded (Aespoe Pillar Stability Experiment). In the Demo Test we are demonstrating emplacement of the copper canisters and the surrounding bentonite in the deposition holes. In the Prototype Repository we study what long-term changes occur in the barriers under the conditions prevailing in a deep repository. Horizontal deposition: Is it possible to deposit the canisters horizontally without compromising safety? Backfill and Plug Test: The tunnels in the future deep repository for spent nuclear fuel will be filled with clay and crushed rock and then plugged. Canister Retrieval Test: If the deep repository should not perform satisfactorily for some reason, we want to be able to retrieve the spent fuel. The Lot test is intended to show how the bentonite behaves in an environment similar to that in the future deep repository. The purpose of the TBT test is to determine how the bentonite clay in the buffer is affected by high temperatures. Two-phase flow means that liberated gas in the groundwater flows separately in the fractures in the rock. This reduces the capacity of the rock to conduct water. Lasgit: By pressurizing a canister with helium, we can measure how the gas moves through the surrounding buffer. Colloid Project: Can very small

  6. SITE-94. Geochemical characterization of Simpevarp ground waters near the Aespoe Hard Rock Laboratory

    International Nuclear Information System (INIS)

    The present report analyzes the geochemical data in order to evaluate collection and interpretation techniques that will be used to site the repository and to assess its safety. Ground waters near the Aespoe Hard Rock Laboratory (HRL) may be grouped into five chemically and isotopically distinct water types, on the basis of their deuterium and chloride contents: 1) recent waters, 2) 5 g/L chloride waters, 3) deep waters, 4) seawater imprint waters, and 5) glacial melt waters. The sampled ground waters show a progressive change from a predominantly NaHCO3 composition at shallow depth to a CaCl2-rich composition at depth. Despite the proximity of the Baltic, relatively few of the sampled ground waters contain any evidence of a seawater component. This finding, together with the rather shallow depths at which saline waters were found, indicates that Aespoe island is presently in a regional ground-water discharge area. The chemical and isotopic composition of the sampled waters also indicates that local recharge of dilute recent waters occurs only down to shallow depths (generally less than 100 in). The Aespoe ground waters are sulfidic and do not presently contain any dissolved oxygen. Measured EH values are generally near -300 mV, and on average are only about 50 mV lower than EH values calculated from the sulfide/sulfate couple. Maintenance of reducing conditions, such as presently found at the Aespoe HRL, is an important consideration in assessing the performance of nuclear waste disposal sites. Measurements of dissolved radon and of uranium concentrations in fracture-fill materials were used to calculate an average effective flow-wetted surface area of 3.1 m2 per liter of water for the Aespoe site. Estimation of flow-wetted surface areas is essential in determining the importance of matrix diffusion and surface sorption processes for radionuclide release calculations. The Rn calculation technique shows promise in helping narrow the possible range of values that

  7. Aespoe Hard Rock Laboratory. Evaluation of scaling records for TASA access tunnel

    International Nuclear Information System (INIS)

    This report presents the result of a project accomplished during the summer 2009. It introduces a method to estimate the magnitude, mass distribution and cause of scaled blocks by tunnel mapping and evaluation of scaling data records. These issues are important for understanding the impact of the excavation method on the surrounding rock mass during excavation of the planned underground repository for spent nuclear fuel. The project includes mapping of the 3120 m drill and blast excavated part of the TASA access tunnel in the Aespoe Hard Rock Laboratory (HRL). In addition it includes development of a method for evaluation of the collected material together with scaling data records from the Site Characterization Database (SICADA). An interview has also been held with Erik Gabrielsson, who has been in charge of tunnel maintenance at Aespoe for many years. The mapping focused on to identify size and cause of areas with significant overbreaks in the tunnel roof. By distributing documented scaled volume in a tunnel section on several mapped overbreak areas in the same section it is possible to reconstruct the size of scaled blocks. The observed overbreak areas have been categorized in five different area types, depending on the cause of scaling: two geologically induced, one blast induced, one induced from a combination of geology and blasting and one unable to place in any category. For the calculated mass distribution the number of observations is declining with increasing block mass. 11% of the total blocks exceeding 400 Kg and 75% of the scaled blocks weights under 200 Kg. Most of the blocks are however lighter with 34% weighting 50 Kg or less. There is a relation between the mapped area type and the size distribution among the mapped overbreak areas. For example the areas caused by the end of blasting rounds are more frequently appearing then the other types but most of them are small in relation to the others The impression achieved from the tunnel mapping is

  8. Large scale gas injection test (Lasgit) performed at the Aespoe Hard Rock Laboratory. Summary report 2008

    Energy Technology Data Exchange (ETDEWEB)

    Cuss, R.J.; Harrington, J.F.; Noy, D.J. (British Geological Survey (United Kingdom))

    2010-02-15

    This report describes the set-up, operation and observations from the first 1,385 days (3.8 years) of the large scale gas injection test (Lasgit) experiment conducted at the Aespoe Hard Rock Laboratory. During this time the bentonite buffer has been artificially hydrated and has given new insight into the evolution of the buffer. After 2 years (849 days) of artificial hydration a canister filter was identified to perform a series of hydraulic and gas tests, a period that lasted 268 days. The results from the gas test showed that the full-scale bentonite buffer behaved in a similar way to previous laboratory experiments. This confirms the up-scaling of laboratory observations with the addition of considerable information on the stress responses throughout the deposition hole. During the gas testing stage, the buffer was continued to artificially hydrate. Hydraulic results, from controlled and uncontrolled events, show that the buffer continues to mature and has yet to reach full maturation. Lasgit has yielded high quality data relating to the hydration of the bentonite and the evolution in hydrogeological properties adjacent to the deposition hole. The initial hydraulic and gas injection tests confirm the correct working of all control and data acquisition systems. Lasgit has been in successful operation for in excess of 1,385 days

  9. Large scale gas injection test (Lasgit) performed at the Aespoe Hard Rock Laboratory. Summary report 2008

    International Nuclear Information System (INIS)

    This report describes the set-up, operation and observations from the first 1,385 days (3.8 years) of the large scale gas injection test (Lasgit) experiment conducted at the Aespoe Hard Rock Laboratory. During this time the bentonite buffer has been artificially hydrated and has given new insight into the evolution of the buffer. After 2 years (849 days) of artificial hydration a canister filter was identified to perform a series of hydraulic and gas tests, a period that lasted 268 days. The results from the gas test showed that the full-scale bentonite buffer behaved in a similar way to previous laboratory experiments. This confirms the up-scaling of laboratory observations with the addition of considerable information on the stress responses throughout the deposition hole. During the gas testing stage, the buffer was continued to artificially hydrate. Hydraulic results, from controlled and uncontrolled events, show that the buffer continues to mature and has yet to reach full maturation. Lasgit has yielded high quality data relating to the hydration of the bentonite and the evolution in hydrogeological properties adjacent to the deposition hole. The initial hydraulic and gas injection tests confirm the correct working of all control and data acquisition systems. Lasgit has been in successful operation for in excess of 1,385 days

  10. Aespoe Hard Rock Laboratory. Final report of the first stage of the tracer retention understanding experiments

    Energy Technology Data Exchange (ETDEWEB)

    Winberg, A. [Conterra AB, Uppsala (Sweden); Andersson, Peter [Geosigma AB, Uppsala (Sweden); Hermanson, Jan [Golder Grundteknik, Solna (Sweden); Byegaard, Johan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry; Cvetkovic, V. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Water Resources Engineering; Birgersson, Lars [Kemakta Konsult AB, Stockholm (Sweden)

    2000-03-15

    The first stage of the Tracer Retention Understanding Experiments (TRUE) was performed as a SKB funded project. The overall objectives of TRUE are to develop the understanding of radionuclide migration and retention in fractured rock, to evaluate the realism in applied model concepts, and to assess whether the necessary input data to the models can be collected from site characterisation. Further, to evaluate the usefulness and feasibility of different model approaches, and finally to provide in situ data on radionuclide migration and retention. The strive for address with multiple approaches is facilitated through a close collaboration with the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. The TRUE programme is a staged programme which addresses various scales from laboratory (< 0.5 m), detailed scale (< 10 m) and block scale (10-50 m). The First TRUE Stage was performed in the detailed scale with the specific objectives of providing data and conceptualising the investigated feature using conservative and sorbing tracers. Further, to improve methodologies for performing tracer tests, and to develop and test a methodology for obtaining pore volume/aperture data from epoxy resin injection, excavation and subsequent analyses. The experimental site is located at approximately 400 m depth in the northeastern part of the Aespoe Hard Rock Laboratory. The identification of conductive fractures and the target feature has benefited from the use of BIPS borehole TV imaging combined with detailed flow logging. The assessment of the conductive geometry has been further sustained by cross-hole pressure interference data. The investigated target feature (Feature A) is a reactivated mylonite which has later undergone brittle deformation. The feature is oriented northwest, along the principal horizontal stress orientation, and is a typical conductor for Aespoe conditions. Hydraulic characterisation shows that the feature is relatively well isolated

  11. SITE-94. Geochemical characterization of Simpevarp ground waters near the Aespoe Hard Rock Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Glynn, P.D.; Voss, C.I. [US Geological Survey, Reston, VA (United States)

    1999-09-01

    The present report analyzes the geochemical data in order to evaluate collection and interpretation techniques that will be used to site the repository and to assess its safety. Ground waters near the Aespoe Hard Rock Laboratory (HRL) may be grouped into five chemically and isotopically distinct water types, on the basis of their deuterium and chloride contents: 1) recent waters, 2) 5 g/L chloride waters, 3) deep waters, 4) seawater imprint waters, and 5) glacial melt waters. The sampled ground waters show a progressive change from a predominantly NaHCO{sub 3} composition at shallow depth to a CaCl{sub 2}-rich composition at depth. Despite the proximity of the Baltic, relatively few of the sampled ground waters contain any evidence of a seawater component. This finding, together with the rather shallow depths at which saline waters were found, indicates that Aespoe island is presently in a regional ground-water discharge area. The chemical and isotopic composition of the sampled waters also indicates that local recharge of dilute recent waters occurs only down to shallow depths (generally less than 100 in). The Aespoe ground waters are sulfidic and do not presently contain any dissolved oxygen. Measured E{sub H} values are generally near -300 mV, and on average are only about 50 mV lower than E{sub H} values calculated from the sulfide/sulfate couple. Maintenance of reducing conditions, such as presently found at the Aespoe HRL, is an important consideration in assessing the performance of nuclear waste disposal sites. Measurements of dissolved radon and of uranium concentrations in fracture-fill materials were used to calculate an average effective flow-wetted surface area of 3.1 m{sup 2} per liter of water for the Aespoe site. Estimation of flow-wetted surface areas is essential in determining the importance of matrix diffusion and surface sorption processes for radionuclide release calculations. The Rn calculation technique shows promise in helping narrow the

  12. Aespoe hard rock laboratory. Field investigation methodology and instruments used in the preinvestigation phase, 1986-1990

    International Nuclear Information System (INIS)

    The Aespoe hard rock laboratory project started in 1986. The pre-investigation phase, 1986-1990, involved extensive field measurements from the surface as well as from boreholes, aimed at characterizing the rock formation with regard to geology, geohydrology, hydrochemistry and rock mechanics. The field investigation methodology used in the project was based on experience from and developments during the previous SKB study site investigation programme. However, in some respects the techniques were changed or modified. Major changes have been possible due to a new drilling technique, telescope-type drilling. This report describes the logistics of the investigation programme, characterized to a large extent by multi-purpose planning and performance of the activities in order to optimize the use of available resources; time, personnel and equipment. Preliminary hydraulic testing and groundwater sampling were conducted during the drilling of each borehole. When the drilling was completed an extensive set of singlehole investigations were carried out: geophysical logging, borehole radar, hydraulic tests of different kinds, water sampling and rock stress measurements. Multipackers were installed in the boreholes as soon as possible after the borehole investigations. The system enables monitoring of groundwater pressure, water sampling and groundwater flow measurements to be performed by means of dilution tests and tracer injection. Boreholes with such equipment were used as observation holes during interference pumping tests and long term hydraulic and tracer tests. The monitoring programme will continue during the subsequent phases of construction and operation of the Aespoe hard rock laboratory. (83 refs., 94 figs.) (au)

  13. Towards a new generation of flow and transport models for the Aespoe Hard Rock Laboratory. Main results from the project Aespoe models 2005

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Urban (ed.) (Computer-aided Fluid Engineering AB (CFE AB), SE-602 10 Norrkoeping (Sweden)); Vidstrand, Patrik (Bergab AB, Goeteborg (Sweden)); Neretnieks, Ivars (Dept. of Chemical Engineering and Technology, Royal Inst. of Technology, Stockholm (Sweden)); Wallin, Bill (Geokema, Lidingoe (Sweden))

    2008-05-15

    This report constitutes the outcome of a project called 'Aespoe models 2005'. The main objective of the project has been to provide a first step towards a new generation of numerical models of flow and transport, for the Aespoe HRL. In order to achieve this goal, work has been carried out along three parallel lines; discussion of basic concepts, compilation and analysis of data and model applications. A number of sub tasks are reported as appendices in the report. In fact, these appendices represent the main achievements of the project: an analysis of fracture properties, compilation of isotope and chemical data, dispersion and mixing in fractured rocks and model results. The conclusion of the project is that significant contributions to a new generation of Aespoe models have been obtained. It has further been demonstrated that working numerical simulations are up and running. Recommendations are provided for the continued work

  14. Towards a new generation of flow and transport models for the Aespoe Hard Rock Laboratory. Main results from the project Aespoe models 2005

    International Nuclear Information System (INIS)

    This report constitutes the outcome of a project called 'Aespoe models 2005'. The main objective of the project has been to provide a first step towards a new generation of numerical models of flow and transport, for the Aespoe HRL. In order to achieve this goal, work has been carried out along three parallel lines; discussion of basic concepts, compilation and analysis of data and model applications. A number of sub tasks are reported as appendices in the report. In fact, these appendices represent the main achievements of the project: an analysis of fracture properties, compilation of isotope and chemical data, dispersion and mixing in fractured rocks and model results. The conclusion of the project is that significant contributions to a new generation of Aespoe models have been obtained. It has further been demonstrated that working numerical simulations are up and running. Recommendations are provided for the continued work

  15. Aespoe Hard Rock Laboratory. Characterisation methods and instruments. Experiences from the construction phase

    International Nuclear Information System (INIS)

    This report describes the different investigation methods used during the Aespoe HRL construction phase which commenced 1990 and ended 1995. The investigation methods are described with respect to performance, errors, uncertainty and usefulness in determined, analysed and/or calculated parameter values or other kind of geoscientific information. Moreover, other comments of the different methods, like those related to the practical performance of the measurements or tests are given. The practical performance is a major task as most of the investigations were conducted in parallel with the construction work. Much of the wide range of investigations carried out during the tunnelling work required special efforts of the personnel involved. Experiences and comments on these operations are presented in the report. The pre-investigation methods have been evaluated by comparing predictions based on pre-investigation models with data and results from the construction phase and updated geoscientific models. In 1997 a package of reports describe the general results of the pre-investigations. The investigation methods are in this report evaluated with respect to usefulness for underground characterisation of a rock volume, concerning geological, geohydrological, hydrochemical and rock mechanical properties. The report describes out opinion of the methods after the construction phase, i.e. the same platform of knowledge as for the package of reports of 1997. The evaluation of usefulness of the underground investigation methods are structured according to the key issues used for the preinvestigation modelling and predictions, i.e. Geological-structural model, Groundwater flow (hydrogeology), Groundwater chemistry (hydrochemistry), Transport of solutes and Mechanical stability models (or rock mechanics). The investigation methods selected for the different subjects for which the predictions were made are presented. Some of the subjects were slightly modified or adjusted during

  16. Aespoe Hard Rock Laboratory. Characterisation methods and instruments. Experiences from the construction phase

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-12-15

    This report describes the different investigation methods used during the Aespoe HRL construction phase which commenced 1990 and ended 1995. The investigation methods are described with respect to performance, errors, uncertainty and usefulness in determined, analysed and/or calculated parameter values or other kind of geoscientific information. Moreover, other comments of the different methods, like those related to the practical performance of the measurements or tests are given. The practical performance is a major task as most of the investigations were conducted in parallel with the construction work. Much of the wide range of investigations carried out during the tunnelling work required special efforts of the personnel involved. Experiences and comments on these operations are presented in the report. The pre-investigation methods have been evaluated by comparing predictions based on pre-investigation models with data and results from the construction phase and updated geoscientific models. In 1997 a package of reports describe the general results of the pre-investigations. The investigation methods are in this report evaluated with respect to usefulness for underground characterisation of a rock volume, concerning geological, geohydrological, hydrochemical and rock mechanical properties. The report describes out opinion of the methods after the construction phase, i.e. the same platform of knowledge as for the package of reports of 1997. The evaluation of usefulness of the underground investigation methods are structured according to the key issues used for the preinvestigation modelling and predictions, i.e. Geological-structural model, Groundwater flow (hydrogeology), Groundwater chemistry (hydrochemistry), Transport of solutes and Mechanical stability models (or rock mechanics). The investigation methods selected for the different subjects for which the predictions were made are presented. Some of the subjects were slightly modified or adjusted during

  17. Aespoe Hard Rock Laboratory. Final report of the first stage of the tracer retention understanding experiments

    International Nuclear Information System (INIS)

    The first stage of the Tracer Retention Understanding Experiments (TRUE) was performed as a SKB funded project. The overall objectives of TRUE are to develop the understanding of radionuclide migration and retention in fractured rock, to evaluate the realism in applied model concepts, and to assess whether the necessary input data to the models can be collected from site characterisation. Further, to evaluate the usefulness and feasibility of different model approaches, and finally to provide in situ data on radionuclide migration and retention. The strive for address with multiple approaches is facilitated through a close collaboration with the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes. The TRUE programme is a staged programme which addresses various scales from laboratory (22Na+ 47Ca2+ ≅ 85Sr2+ 86Rb+ ≅ 133Ba2+ The field tracer tests, using essentially the same cocktail of sorbing tracers as in the laboratory, were found to show the same relative sorbtivity as seen in the laboratory. A test using 137Cs showed that after termination of the test, some 63% of the injected activity remained sorbed in the rock. The interpretation of the in situ tests with sorbing tracers was performed using the LaSAR approach, developed as a part of the TRUE project. In this approach the studied flow path is viewed as a part of an open fracture. Key processes are spatially variable advection and mass transfer. The evaluation shows that laboratory diffusion data are not representative for in situ conditions, and that a close fit between field and modelled breakthrough is obtained only when a parameter group which includes diffusion is enhanced with a factor varying between 32-50 for all tracers and experiments (except for Cs) and 137 for Cs. Our interpretation is that the enhancement is mainly due to higher diffusivity/porosity and higher sorption in the part of the altered rim zone of the feature which is accessible over the time scales of the in

  18. New developments of the Integrated Stress Determination Method and application to the Aespoe Hard Rock Laboratory, Sweden

    International Nuclear Information System (INIS)

    This thesis presents new developments of the Integrated Stress Determination Method (ISDM) with application to the Aespoe Hard Rock Laboratory (HRL), Oskarshamn, Sweden. The new developments involve a 12-parameter representation of the regional stress field in the rock mass. The method is applicable to data from hydraulic fracturing, hydraulic tests on pre-existing fractures (HTPF), and overcoring data from CSIR- and CSIRO-type of devices. When hydraulic fracturing/HTPF data are combined with overcoring data, the former may be used to constrain the elastic parameters, i.e. the problem involves 14 model parameters. The Swedish Nuclear Fuel and Waste Management Co. (SKB), have conducted a vast amount of rock stress measurements at the Aespoe HRL since the late 1980s. However, despite the large number of stress measurement data collected in this limited rock volume, variability in the stress field exists. Not only does the result vary depending on measuring technique, e.g. overcoring data indicated larger stress magnitudes compared to hydraulic fracturing data; the results are also affected by existing discontinuities, indicated by non-linear stress magnitudes and orientations versus depth. The objectives for this study are therefore threefold: (1) find explanations to the observed differences between existing hydraulic and overcoring stress data at the Aspo HRL; (2) explain the non-linear stress distribution indicated by existing stress data; and (3) apply the ISDM, including the new developments, based on the results obtained in step 1 and 2. To evaluate the observed differences between existing hydraulic and overcoring stress data, a detailed re-interpretation was conducted. Several measurement-related uncertainties were identified and corrected for when possible, which effectively reduced the discrepancies between the hydraulic and overcoring measuring results. Modeling studies managed by SKB have shown that the redistribution of the stresses at Aespoe HRL to a

  19. Aespoe Hard Rock Laboratory. Studies of factors that affect and controls the Excavation Damaged/Disturbed Zone

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, Martin; Baeckstroem, Ann; Quanhong Feng (AaF - Berg och Maetteknik, Stockholm (Sweden)); Berglund, Johan (Vattenfall Power Consultant, Stockholm (Sweden)); Johansson, Malin; Mas Ivars, Diego (Itasca Geomekanik AB, Solna (Sweden)); Olsson, Mats (SweBefo, Stockholm (Sweden))

    2009-07-15

    A tunnel was developed at the Aespoe Hard Rock Laboratory (HRL) in 2003 purposely for a large in-situ rock mechanics experiment, the Aespoe Pillar Stability Experiment (APSE). The tunnel had a large height/width ratio with a circular floor, primarily to control the stress situation around the tunnel and concentrate the stresses under the floor. An extensive set of data for understanding the Excavation Damaged Zone (EDZ) was collected within section 47 of the tunnel. It consist of the blast design, blast sequences, convergence measurements during excavation, geological mapping of tunnel and cores, 3D-laser scanning of the tunnel geometry etc. Furthermore, in 2006, ultrasonic measurements along eight boreholes were carried out in order to estimate the extent of the EDZ in the tunnel. The collection of all these different information provides an opportunity to evaluate the mechanical damages caused by the excavation work. The overall aim with this project is to give feed-back to future planning of tunnelling on issues of importance for requirements with respect to minimising the EDZ in crystalline rock from the drill and blast method. A combination of the mapped geological features (tunnel and cores) and the geometry of the blasted tunnel obtained from the 3D-laser scanning were used to build a 3D model of the geology with emphasis on the geometry of the natural fractures. The rock mechanic response to the tunnelling was evaluated in a numerical model including the as-built geometry in combination with the 3D model of the geology. The modelling of the rock mechanical processes of importance for the EDZ could be calibrated against actual measurements. From observed changes in the ultrasonic wave velocity along the boreholes it was found that the locations of the velocity changes corresponded well with the location of the mapped fractures in the drill cores. This indicates that EDZ can be detected using the ultrasonic method with high accuracy. Furthermore, the

  20. Aespoe Hard Rock Laboratory. Analysis of fracture networks based on the integration of structural and hydrogeological observations on different scales

    International Nuclear Information System (INIS)

    Fracture networks at Aespoe have been studied for several rock types exhibiting different degrees of ductile and brittle deformation, as well as on different scales. Mesoscopic fault systems have been characterised and classified in an earlier report, this report focuses mainly on fracture networks derived on smaller scales, but also includes mesoscopic and larger scales. The TRUE-1 block has been selected for detailed structural analysis on a small scale due to the high density of relevant information. In addition to the data obtained from core materials, structural maps, BIP data and the results of hydro tests were synthesised to derive a conceptual structural model. The approach used to derive this conceptual model is based on the integration of deterministic structural evidence, probabilistic information and both upscaling and downscaling of observations and concepts derived on different scales. Twelve fracture networks mapped at different sites and scales and exhibiting various styles of tectonic deformation were analysed for fractal properties and structural and hydraulic interconnectedness. It was shown that these analysed fracture networks are not self-similar. An important result is the structural and hydraulic interconnectedness of fracture networks on all scales in the Aespoe rocks, which is further corroborated by geochemical evidence. Due to the structural and hydraulic interconnectedness of fracture systems on all scales at Aespoe, contaminants from waste canisters placed in tectonically low deformation environments would be transported - after having passed through the engineered barriers -from low-permeability fractures towards higher permeability fractures and may thus eventually reach high-permeability features

  1. Aespoe Hard Rock Laboratory. Analysis of fracture networks based on the integration of structural and hydrogeological observations on different scales

    Energy Technology Data Exchange (ETDEWEB)

    Bossart, P. [Geotechnical Inst. Ltd., Bern (Switzerland); Hermanson, Jan [Golder Associates, Stockholm (Sweden); Mazurek, M. [Univ. of Bern (Switzerland)

    2001-05-01

    Fracture networks at Aespoe have been studied for several rock types exhibiting different degrees of ductile and brittle deformation, as well as on different scales. Mesoscopic fault systems have been characterised and classified in an earlier report, this report focuses mainly on fracture networks derived on smaller scales, but also includes mesoscopic and larger scales. The TRUE-1 block has been selected for detailed structural analysis on a small scale due to the high density of relevant information. In addition to the data obtained from core materials, structural maps, BIP data and the results of hydro tests were synthesised to derive a conceptual structural model. The approach used to derive this conceptual model is based on the integration of deterministic structural evidence, probabilistic information and both upscaling and downscaling of observations and concepts derived on different scales. Twelve fracture networks mapped at different sites and scales and exhibiting various styles of tectonic deformation were analysed for fractal properties and structural and hydraulic interconnectedness. It was shown that these analysed fracture networks are not self-similar. An important result is the structural and hydraulic interconnectedness of fracture networks on all scales in the Aespoe rocks, which is further corroborated by geochemical evidence. Due to the structural and hydraulic interconnectedness of fracture systems on all scales at Aespoe, contaminants from waste canisters placed in tectonically low deformation environments would be transported - after having passed through the engineered barriers -from low-permeability fractures towards higher permeability fractures and may thus eventually reach high-permeability features.

  2. The Aespoe Hard Rock Laboratory: Final evaluation of the hydrogeochemical pre-investigations in relation to existing geologic and hydraulic conditions

    International Nuclear Information System (INIS)

    The Swedish Nuclear Fuel and Management Company (SKB) is currently excavating the access tunnel to an underground experimental laboratory, the Aespoe Hard Rock Laboratory, planned to be located some 500 m below the island of Aespoe which is located in the Simpevarp area, southeast Sweden. The construction of an underground laboratory forms part of the overall SKB strategy to test, not only the construction techniques for deep excavation, but also the various methods and protocols required to obtain a three-dimensional model of the geology and groundwater flow and chemistry, within a fractured crystalline bedrock similar to that envisaged for the final disposal of spent fuel. Aespoe was chosen because it geologically represents a variety of typical crystalline bedrock environments. The hydrogeochemical activities described and interpreted in this report form part of the initial pre-investigation phase (from the surface to around 1000 metres depth) aimed at siting the laboratory, describing the natural hydrogeological and hydrogeochemical conditions in the bedrock and predicting the changes that will occur during excavation and construction of the laboratory. Hydrogeochemical interpretation has therefore been closely integrated with the hydrogeological investigations and other disciplines of major influence, in particular, bedrock geology and geochemistry and fracture mineralogy and chemistry. A large section of this report has been devoted to the detailed investigation of each individual zone hydraulically selected, tested and sampled for hydrogeochemical characterization. The data have been used to describe the chemistry and origin of the Aespoe groundwaters, models have been developed to illustrate groundwater mixing and standard geochemical modelling approaches have been employed to understand rock/water interaction processes. An attempt has been made to integrate the hydrogeochemical information with known geological and hydrogeological parameters to construct a

  3. Aespoe Hard Rock Laboratory. Prototype Repository. Sensors data report (Period 010917-091201) Report No: 22

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Johannesson, Lars-Erik (Clay Technology AB, Lund (Sweden))

    2009-12-15

    The Prototype Repository Test consists of two sections. The installation of the first Section of Prototype Repository was made during summer and autumn 2001 and Section 2 was installed in spring and summer 2003. This report presents data from measurements in the Prototype Repository during the period 010917-091201. The report is organized so that the actual measured results are shown in Appendix 1-10, where Appendix 8 deals with measurements of canister displacements (by AITEMIN), Appendix 9 deals with geo-electric measurements in the backfill (by GRS), Appendix 10 deals with stress and strain measurement in the rock (by AaF) and Appendix 11 deals with measurement of water pressure in the rock (by VBB/VIAK). The main report and Appendix 1-7 deal with the rest of the measurements.

  4. Aespoe Hard Rock Laboratory. Prototype Repository. Sensors data report (Period 010917-090601) Report No: 21

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Johannesson, Lars-Erik (Clay Technology AB, Lund (Sweden))

    2009-07-15

    The Prototype Repository Test consists of two sections. The installation of the first Section of Prototype Repository was made during summer and autumn 2001 and Section 2 was installed in spring and summer 2003. This report presents data from measurements in the Prototype Repository during the period 010917-090601. The report is organized so that the actual measured results are shown in Appendix 1-10, where Appendix 8 deals with measurements of canister displacements (by AITEMIN), Appendix 9 deals with geo-electric measurements in the backfill (by GRS), Appendix 10 deals with stress and strain measurement in the rock (by BBK) and Appendix 11 deals with measurement of water pressure in the rock (by VBB/VIAK). The main report and Appendix 1-7 deal with the rest of the measurements.

  5. Aespoe Hard Rock Laboratory. Prototype Repository. Sensors data report (Period 010917-081201) Report No: 20

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Johannesson, Lars-Erik (Clay Technology AB, Lund (Sweden))

    2009-03-15

    The Prototype Repository Test consists of two sections. The installation of the first Section of Prototype Repository was made during summer and autumn 2001 and Section 2 was installed in spring and summer 2003. This report presents data from measurements in the Prototype Repository during the period 010917-081201. The report is organized so that the actual measured results are shown in Appendix 1-10, where Appendix 8 deals with measurements of canister displacements (by AITEMIN), Appendix 9 deals with geo-electric measurements in the backfill (by GRS), Appendix 10 deals with stress and strain measurement in the rock (by BBK) and Appendix 11 deals with measurement of water pressure in the rock (by VBB/VIAK). The main report and Appendix 1-7 deal with the rest of the measurements.

  6. SITE-94. Natural elemental mass movement in the vicinity of the Aespoe Hard Rock Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.M.; Smith, G.M.; Towler, P.A.; Savage, D. [QuantiSci, Melton Mowbray (United Kingdom)

    1997-05-01

    The primary objective of this study is to quantify natural elemental fluxes at a location exhibiting typical characteristics of a site for a spent fuel repository in Sweden. The relevant pathways are considered to be: Groundwater transport; Glacial erosion; Non-glacial weathering; River transport. Calculations are made of elemental mass fluxes from a volume of rock equivalent to that which would hold a KBS-3 style repository. In addition, the radioactive flux associated with the natural series radionuclide mass fluxes from the repository are also calculated. These can be compared directly to performance assessment predictions of the releases from a repository. 88 refs, 13 figs, 24 tabs.

  7. SITE-94. Natural elemental mass movement in the vicinity of the Aespoe Hard Rock Laboratory

    International Nuclear Information System (INIS)

    The primary objective of this study is to quantify natural elemental fluxes at a location exhibiting typical characteristics of a site for a spent fuel repository in Sweden. The relevant pathways are considered to be: Groundwater transport; Glacial erosion; Non-glacial weathering; River transport. Calculations are made of elemental mass fluxes from a volume of rock equivalent to that which would hold a KBS-3 style repository. In addition, the radioactive flux associated with the natural series radionuclide mass fluxes from the repository are also calculated. These can be compared directly to performance assessment predictions of the releases from a repository. 88 refs, 13 figs, 24 tabs

  8. Aespoe Hard Rock Laboratory. Prototype Repository. Analyses of microorganisms, gases and water chemistry in buffer and backfill, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Lydmark, Sara (Microbial Analytics Sweden AB (Sweden))

    2010-09-15

    The Prototype repository is an international project to build and study a full-scale model of the planned Swedish final repository for spent nuclear fuel. The Prototype repository differs from a real storage in that it is drained. For example, this makes the swelling pressure lower in the Prototype repository compared with a real storage. The project is being conducted at the Aespoe Hard Rock Laboratory (HRL) in crystalline rock at a depth of approximately 450 m. A monitoring programme is investigating the evolution of the water chemistry, gas, and microbial activity at the site, and one of the specific aims is to monitor the microbial consumption of oxygen in situ in the Prototype repository. This document describes the results of the analyses of microbes, gases, and chemistry inside and outside the Prototype in 2009. Hydrogen, helium, nitrogen, oxygen, carbon monoxide, carbon dioxide, methane, ethane, and ethene were analysed in the following sampling points in the Prototype repository: KBU10001, KBU10002, KBU10004, KBU10006, KBU10008, KFA01 and KFA04. Where the sampling points in the Prototype delivered pore water, the water was analysed for amount of ATP (i.e., the biovolume), cultivable heterotrophic aerobic bacteria (CHAB), sulphate-reducing bacteria (SRB), methane-oxidizing bacteria (MOB), autotrophic acetogens (AA) and in some cases iron-reducing bacteria (IRB). Cultivation methods were also compared with qPCR molecular techniques to evaluate these before next year's decommission of the Prototype repository. The collected pore water from the Prototype repository was subject to chemistry analysis (as many analyses were conducted as the amount of water allowed). In addition, groundwater from two borehole sections in the rock surrounding the Prototype was analysed regarding its gas composition, microbiology and redox. Chemistry data from a previous investigation of the groundwater outside the Prototype repository were compared with the pore water

  9. Aespoe Hard Rock Laboratory Canister Retrieval Test. Microorganisms in buffer from the Canister Retrieval Test - numbers and metabolic diversity

    International Nuclear Information System (INIS)

    'Canister Retrieval Test' (CRT) is an experiment that started at Aespoe Hard Rock Laboratory (HRL) 2000. CRT is a part of the investigations which evaluate a possible KBS-3 storage of nuclear waste. The primary aim was to see whether it is possible or not to retrieve a copper canister after storage under authentic KBS-3 conditions. However, CRT also provided a unique opportunity to investigate if bacteria survived in the bentonite buffer during storage. Therefore, in connection to the retrieval of the canister microbiological samples were extracted from the bentonite buffer and the bacterial composition was studied. In this report, microbiological analyses of a total of 66 samples at the C2, R10, R9 and R6 levels in the bentonite from CRT are presented and discussed. By culturing bacteria from the bentonite in specific media the following bacterial parameters were investigated: The total amount of culturable heterotrophic aerobic bacteria, sulphate-reducing bacteria, and bacteria that produce the organic compound acetate (acetogens). The biovolume in the bentonite was determined by detection of the ATP content. In addition, bacteria from the bentonite were cultured in different sulphate-reducing media. In these cultures, the presence of the biotic compounds sulphide and acetate was investigated, since these have potentially negative effect on the copper canister in a KBS-3 repository. The results were to some extent compared to density, water content, and temperature data provided by Clay Technology AB. The results showed that 100-102 viable sulphate-reducing and acetogenic bacteria and 102-104 heterotrophic aerobic bacteria g-1 bentonite were present after five years of storage in the rock. Bacteria with several morphologies could be found in the cultures with bentonite. The most bacteria were detected in the bentonite buffer close to the rock but in a few samples also in bentonite close to the copper canister. When the presence of bacteria in the bentonite is

  10. Aespoe Hard Rock Laboratory Canister Retrieval Test. Microorganisms in buffer from the Canister Retrieval Test - numbers and metabolic diversity

    Energy Technology Data Exchange (ETDEWEB)

    Lydmark, Sara; Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden))

    2011-03-15

    'Canister Retrieval Test' (CRT) is an experiment that started at Aespoe Hard Rock Laboratory (HRL) 2000. CRT is a part of the investigations which evaluate a possible KBS-3 storage of nuclear waste. The primary aim was to see whether it is possible or not to retrieve a copper canister after storage under authentic KBS-3 conditions. However, CRT also provided a unique opportunity to investigate if bacteria survived in the bentonite buffer during storage. Therefore, in connection to the retrieval of the canister microbiological samples were extracted from the bentonite buffer and the bacterial composition was studied. In this report, microbiological analyses of a total of 66 samples at the C2, R10, R9 and R6 levels in the bentonite from CRT are presented and discussed. By culturing bacteria from the bentonite in specific media the following bacterial parameters were investigated: The total amount of culturable heterotrophic aerobic bacteria, sulphate-reducing bacteria, and bacteria that produce the organic compound acetate (acetogens). The biovolume in the bentonite was determined by detection of the ATP content. In addition, bacteria from the bentonite were cultured in different sulphate-reducing media. In these cultures, the presence of the biotic compounds sulphide and acetate was investigated, since these have potentially negative effect on the copper canister in a KBS-3 repository. The results were to some extent compared to density, water content, and temperature data provided by Clay Technology AB. The results showed that 100-102 viable sulphate-reducing and acetogenic bacteria and 102-104 heterotrophic aerobic bacteria g-1 bentonite were present after five years of storage in the rock. Bacteria with several morphologies could be found in the cultures with bentonite. The most bacteria were detected in the bentonite buffer close to the rock but in a few samples also in bentonite close to the copper canister. When the presence of bacteria in the

  11. Aespoe Hard Rock Laboratory - feasibility and usefulness of site investigation methods. Experiences from the pre-investigation phase

    Energy Technology Data Exchange (ETDEWEB)

    Almen, K.E. [ed.] [KEA GEO-Konsult (Sweden); Olsson, Paer [SKANSKA, (Sweden); Rhen, I. [VBB VIAK AB, Malmoe (Sweden); Stanfors, R. [RS Consulting, (Sweden); Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1994-08-01

    One of the main goals set up by SKB for the Aespoe HRL project is to `test the quality and appropriateness of different methods for characterizing the bedrock with respect to conditions of importance for a final repository`. An extensive investigation programme was carried out during the projects pre-investigation phase that in part was based in experience from SKBs previous site investigations and in part entailed the testing of new or other unestablished methods. Previous technical reports have described the methods that have been used and the results, models and predictions that have been produced. All the methods used are discussed in the present report in terms of how they have contributed in different analysis stages to the total geoscientific characterization of the rock at Aespoe. The usefulness of each method for modelling and prediction in different scales is evaluated, and aspects of the practical execution of the methods under different conditions are discussed. The report sheds light on the importance of dividing large investigation programmes such as this one into suitable stages to get an opportunity to evaluate the results obtained and plan in detail the investigations in the next stage. Furthermore, the way in which the characterization/modelling work in different geometric scales has been done for the different investigation stages is discussed, along with whether this has been found to be a suitable approach. The importance of pursuing an interdisciplinary strategy throughout the pre-investigation process cannot be overemphasized. For the planning, execution, analysis and reporting of the results of the pre-investigations, this has been guaranteed by an organization in which an interdisciplinary group has been in charge of the investigations, together with the project manager. 52 refs, numerous tabs and figs.

  12. Aespoe Hard Rock Laboratory. Prototype repository. Analyses of microorganisms, gases, and water chemistry in buffer and backfill, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Lydmark, Sara [Microbial Analytics Sweden AB, Moelnlycke (Sweden)

    2011-06-15

    The prototype repository (hereafter, 'Prototype') is an international project to build and study a fullscale model of the planned Swedish final repository for spent nuclear fuel. However, the Prototype differs from a real storage in that it is drained, which makes the swelling pressure lower in the Prototype than in a real storage facility. The heat from the radioactive decay is simulated by electrical heaters. The project is being conducted at the Aespoe Hard Rock Laboratory (HRL) in crystalline rock at a depth of approximately 450 m. A monitoring programme is investigating the evolution of the water chemistry, gas, and microbial activity at the site, and a specific aim is to monitor the microbial consumption of oxygen in situ in the Prototype. This document describes the results of the analyses of microbes, gases, and chemistry inside the Prototype in 2010. Hydrogen, helium, nitrogen, oxygen, carbon monoxide, carbon dioxide, methane, ethane, and ethene were analysed at the following sampling points in the Prototype: KBU10001, KBU10002, KBU10004, KBU10008, and KFA04. Where the sampling points in the Prototype delivered pore water, the water was analysed for amount of ATP (i.e. the biovolume), culturable heterotrophic aerobic bacteria (CHAB), sulphate-reducing bacteria (SRB), methane-oxidizing bacteria (MOB), and iron-reducing bacteria (IRB). The pore water collected from the Prototype was subject to as many chemical analyses as the amount of water allowed. Chemical analyses were also performed on pore water from two additional sampling points, KBU10005 and KBU10006. Chemical data from a previous investigation of the groundwater outside the Prototype were compared with the pore water chemistry. The improved sampling and analysis protocols introduced in 2007 worked very well. The International Progress Report (IPR) 08-01 (Eriksson 2008) revealed that many of the hydrochemical sampling points differ greatly from each other. The 16 sampling points were

  13. Bacterial sulphate reduction and mixing processes at the Aespoe Hard Rock Laboratory indicated by groundwater δ34S isotope signatures

    International Nuclear Information System (INIS)

    This report includes data mostly obtained from δ34S isotope measurements of groundwater at the Aespoe Island and one sampling from the Laxemar site, southeastern Sweden, during tunnel construction. Early sampling at Aespoe (up to 1992), before tunnel excavation, indicates a groundwater system with multiple sulphur sources. The isotope changes over time in the dissolved sulphate were studied during a sampling campaign in the monitoring phase from 1993 to 1995. A total of 88 samples were collected by SKB between 1992 and 1995 from core-drilled surface boreholes and from boreholes drilled in the tunnel (34 of these samples were collected from the tunnel boreholes). The results of the analyses have been the focus of discussion of the isotope changes with time in the dissolved sulphate (SO42-). The results indicate that the sulphur isotope signatures in the dissolved sulphate of the groundwater and those from fracture-filling sulphides at Aespoe originate from multiple sulphur sources in the groundwater at Aespoe and Laxemar. The data may be grouped as follows: a) typically homogeneous marine signatures of dissolved SO42- are observed, with δ34S values of approximately +21 per mille CDT at intermediate depths of approximately 100-250 m; b) dissolved sulphate in the groundwater at greater depths (below 600 m) with average values of approximately +10 per mille CDT; and c) a dissolved SO42- originating from a mixture of these sulphur sources (100-600m), although there is a difference between a mixture and modification by reduction. Reduced sulphur with low δ34S values is also recorded in fracture-filling sulphides, with δ34S values of approximately 0 to -10 per mille CDT. This may contribute to small changes in the isotope signature of the dissolved SO42-, probably by sulphide oxidation in the past. The changes in the δ34S isotope data for dissolved SO42- over the 1992-1996 period suggest a complex situation, indicating both sulphate reduction by sulphate

  14. Aespoe Hard Rock Laboratory. Temperature Buffer Test. Sensors data report (Period 030326-080701) Report No:12

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Aakesson, Mattias; Hoekmark, Harald (Clay Technology AB, Lund (Sweden))

    2008-07-01

    TBT (Temperature Buffer Test) is a joint project between SKB/ANDRA and supported by ENRESA (modeling) and DBE (instrumentation), which aims at understanding and modeling the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test is carried out in Aespoe HRL in a 8 meters deep and 1.75 m diameter deposition hole, with two heaters (3 m long, 0.6 m diameter), surrounded by a MX 80 bentonite buffer and a confining plug on top anchored with 9 rods. It was installed during spring 2003. Two buffer arrangements are being investigated: - The lower heater is surrounded by bentonite in the usual way, allowing the temperature of the bentonite to exceed 100 deg C locally. - The higher heater is surrounded by a ring of sand acting as thermal protection for the bentonite, the temperature of which is kept below 100 deg C. The canisters were heated with 1500 W power from day 15 to day 1171, when the power was raised to 1600 W. Around day 1700, the power was by steps raised in the lower heater to 2000 W and reduced in the upper heater to 1000 W. This report presents data from the measurements in the Temperature Buffer Test from 030326 to 080701 (26 March 2003 to 01 July 2008). The following measurements are made in the bentonite: Temperature is measured in 92 points, total pressure in 29 points, pore water pressure in 8 points and relative humidity in 35 points. Temperature is also measured by all gauges as an auxiliary measurement used for compensation. The following additional measurements are done: temperature is measured in 40 points in the rock, in 11 points on the surface of each canister and in 6 points inside each canister. The force on the confining plug is measured in 3 of the 9 rods and its vertical displacement is measured in three points. The water inflow and water pressure in the outer sand filter is also measured. Temperature and total pressure measurements

  15. Aespoe Hard Rock Laboratory. Temperature Buffer Test. Sensors data report (Period 030326-080701) Report No:12

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza; Aakesson, Mattias; Hoekmark, Harald (Clay Technology AB, Lund (Sweden))

    2008-07-01

    TBT (Temperature Buffer Test) is a joint project between SKB/ANDRA and supported by ENRESA (modeling) and DBE (instrumentation), which aims at understanding and modeling the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test is carried out in Aespoe HRL in a 8 meters deep and 1.75 m diameter deposition hole, with two heaters (3 m long, 0.6 m diameter), surrounded by a MX 80 bentonite buffer and a confining plug on top anchored with 9 rods. It was installed during spring 2003. Two buffer arrangements are being investigated: - The lower heater is surrounded by bentonite in the usual way, allowing the temperature of the bentonite to exceed 100 deg C locally. - The higher heater is surrounded by a ring of sand acting as thermal protection for the bentonite, the temperature of which is kept below 100 deg C. The canisters were heated with 1500 W power from day 15 to day 1171, when the power was raised to 1600 W. Around day 1700, the power was by steps raised in the lower heater to 2000 W and reduced in the upper heater to 1000 W. This report presents data from the measurements in the Temperature Buffer Test from 030326 to 080701 (26 March 2003 to 01 July 2008). The following measurements are made in the bentonite: Temperature is measured in 92 points, total pressure in 29 points, pore water pressure in 8 points and relative humidity in 35 points. Temperature is also measured by all gauges as an auxiliary measurement used for compensation. The following additional measurements are done: temperature is measured in 40 points in the rock, in 11 points on the surface of each canister and in 6 points inside each canister. The force on the confining plug is measured in 3 of the 9 rods and its vertical displacement is measured in three points. The water inflow and water pressure in the outer sand filter is also measured. Temperature and total pressure measurements

  16. Bacterial sulphate reduction and mixing processes at the Aespoe Hard Rock Laboratory indicated by groundwater delta34S isotope signatures

    Energy Technology Data Exchange (ETDEWEB)

    Wallin, Bill (Geokema AB (Sweden))

    2011-04-15

    This report includes data mostly obtained from delta34S isotope measurements of groundwater at the Aespoe Island and one sampling from the Laxemar site, southeastern Sweden, during tunnel construction. Early sampling at Aespoe (up to 1992), before tunnel excavation, indicates a groundwater system with multiple sulphur sources. The isotope changes over time in the dissolved sulphate were studied during a sampling campaign in the monitoring phase from 1993 to 1995. A total of 88 samples were collected by SKB between 1992 and 1995 from core-drilled surface boreholes and from boreholes drilled in the tunnel (34 of these samples were collected from the tunnel boreholes). The results of the analyses have been the focus of discussion of the isotope changes with time in the dissolved sulphate (SO{sub 4}{sup 2-}). The results indicate that the sulphur isotope signatures in the dissolved sulphate of the groundwater and those from fracture-filling sulphides at Aespoe originate from multiple sulphur sources in the groundwater at Aespoe and Laxemar. The data may be grouped as follows: a) typically homogeneous marine signatures of dissolved SO{sub 4}{sup 2-} are observed, with delta34S values of approximately +21 per mille CDT at intermediate depths of approximately 100-250 m; b) dissolved sulphate in the groundwater at greater depths (below 600 m) with average values of approximately +10 per mille CDT; and c) a dissolved SO{sub 4}{sup 2-} originating from a mixture of these sulphur sources (100-600m), although there is a difference between a mixture and modification by reduction. Reduced sulphur with low delta34S values is also recorded in fracture-filling sulphides, with delta34S values of approximately 0 to -10 per mille CDT. This may contribute to small changes in the isotope signature of the dissolved SO{sub 4}{sup 2-}, probably by sulphide oxidation in the past. The changes in the delta34S isotope data for dissolved SO{sub 4}{sup 2-} over the 1992-1996 period suggest a

  17. Aespoe hard rock laboratory. Evaluation and conceptual modelling based on the pre-investigations 1986-1990

    International Nuclear Information System (INIS)

    The investigations have been grouped to several geometric scales under the disciplines of geology, geohydrology and groundwater chemistry, transport of solutes and mechanical stability. Geological mapping and geophysical measurements have been made both on a regional and on a site scale. On the site scale additional surface measurements, drilling of 35 percussion boreholes and 19 cored boreholes was made. The results of the geological investigations show that the Aespoe bedrock is a complex mixture between Smaaland granite, Aespoe diorite and fine grained granite. Hydraulic and chemical data was collected from existing well records within the Kalmar County. Hydraulic conductivity measurement and interference pumping tests were made in the core drilled holes and to some extent in the percussion holes. The hydraulic conductors are basically the fracture zones, but one of the most important is a NNW striking system of single fractures which is difficult to distinguish geologically. The chemical conditions of the groundwater and the fracture minerals form water bearing sections of the core drilled holes have been examined. Water samples were collected from percussion boreholes. The groundwater can be divided into three categories. Fresh water down to approximately 50 m depth. Mixed fresh and seawater 50-100 m, present and/or relict seawater 100-500 m and old (relict) seawater below a depth of 500 m. An important task in the evaluations is to set up 'conceptual models'. These models are the basis for calculation of the ambient groundwater situation and the way in which the hydrological regime will change during the excavation of the laboratory. In order to allow for different levels of detail the conceptual models are established on different scales. The geometrical scales chosen are 500 m, 50 m and 5 m. (au)

  18. Long term test of buffer material at the Aespoe Hard Rock Laboratory, LOT project. Final report on the A2 test parcel

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Olsson, Siv; Dueck, Ann; Birgersson, Martin; Nilsson, Ulf; Hernan-Haakansson, Tania (Clay Technology AB, Lund (Sweden)); Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden); Goeteborg Univ., Dept. of Cell and Molecular Biology, Goeteborg (Sweden)); Nilsson, Sara; Eriksen, Trygve E. (School of Chemical Science and Engineering, Nuclear chemistry, Royal Inst. of Tech., Stockholm (Sweden)); Rosborg, Bo (Rosborg Consulting, Nykoeping (Sweden))

    2009-11-15

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, are expected to result in minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory (HRL) are focused on identifying and quantifying such mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks with a diameter of 30 cm, and gauges for temperature, total pressure, water pressure and humidity. Electrical heaters placed inside the copper tube are used to simulate the power from the decaying spent fuel. Three parcels are exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and four parcels to adverse conditions (maximum temperature below approx140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (>5 years) and long term tests (>10 years). The present report concerns the A2 test parcel, which was a medium term test exposed to adverse conditions. Cu-coupons, 60Co tracers, bacteria and specific chemical substances were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at test site and the bentonite material was sampled for specified analyses performed by nine different laboratories in five countries. The main aspects of the various tests and analyses may be summarized in the following items: - physical

  19. Long term test of buffer material at the Aespoe Hard Rock Laboratory, LOT project. Final report on the A2 test parcel

    International Nuclear Information System (INIS)

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, are expected to result in minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory (HRL) are focused on identifying and quantifying such mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks with a diameter of 30 cm, and gauges for temperature, total pressure, water pressure and humidity. Electrical heaters placed inside the copper tube are used to simulate the power from the decaying spent fuel. Three parcels are exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and four parcels to adverse conditions (maximum temperature below ∼140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (>5 years) and long term tests (>10 years). The present report concerns the A2 test parcel, which was a medium term test exposed to adverse conditions. Cu-coupons, 60Co tracers, bacteria and specific chemical substances were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at test site and the bentonite material was sampled for specified analyses performed by nine different laboratories in five countries. The main aspects of the various tests and analyses may be summarized in the following items: - physical properties

  20. Aespoe Hard Rock Laboratory. Aespoe Task Force on Engineered Barrier System. Modelling of THM-coupled processes for benchmark 2.2 with the code GeoSys/RockFlow

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Thomas; Kunz, Herbert (Federal Inst. for Geosciences and Natural Resources, Hannover (Germany))

    2010-02-15

    In 2004 the Swedish Nuclear Fuel and Waste Management Co. (SKB) initiated the project 'Task Force on Engineered Barrier Systems'. This project has the objective to verify the feasibility of modelling THM-coupled processes (task 1) and gas migration processes (task 2) in clay-rich buffer materials. The tasks are performed on the basis of appropriate benchmarks. This report documents the modelling results of the THM-benchmark 2.2 - the Canister Retrieval Test - using the code GeoSys/RockFlow. The Temperature Buffer Test which was performed in the immediate vicinity of the Canister Retrieval Test is included in the model. Especially the heat transport requires the handling of the problem in 3-D. Due to limitations imposed by post-processing different spatial discretisations of the model had to be used during the processing of the benchmark. The calculated temperatures agree well with measured data. Concerning hydraulic parameters the values of permeability and tortuosity were varied in the calculations. The time necessary to saturate the buffer is very sensitive to both of these values. In comparison to thermal and hydraulic processes the model only has limited capacity to predict the measured evolution of total pressure

  1. Aespoe Pillar Stability Experiment. Geology and mechanical properties of the rock in TASQ

    Energy Technology Data Exchange (ETDEWEB)

    Staub, Isabelle [Golder Associates AB, Uppsala (Sweden); Andersson, J. Christer; Magnor, Bjoern

    2004-03-01

    oxidized brittle-ductile shear zone striking along the drift dipping to the south-east. The zone is present in the experiment volume but is less pronounced there than in the rest of the drift. The zone is not assessed to give large enough changes in the geology to hazard the outcome of the experiment. The major concern has been the possibility of shearing along the zone in the pillar that would give stress re-distributions resulting in stresses too low to initiate brittle failure. The convergence measurements and the back calculation of those resulted in changes of the stress tensor and Young's modulus of the rock mass. The magnitudes and bearings of the principal stresses are in principal the same as the ones compiled from the extensive rock stress measurement made in the vicinity of the drift. However the numerical modelling resulted in changes of the dips. The new tensor has only horizontal and vertical stresses where the second principal stress is vertical. The derived Young's modulus is approximately 20% higher than what earlier has been predicted for the rock mass. The reason in this case is though likely that the convergence measurements were accidentally performed in a rock mass with extremely low fracture frequency. The few fractures likely give a more rigid rock mass than what's generally observed at Aespoe. The confirmation of the stress magnitudes by the back calculations is positive for the project. These stresses are concentrated by the drift shape and the large boreholes creating the pillar. A concern in the early part of the project was the risk that the in-situ stresses should be too low to increase the stresses high enough for initiation of spalling. This would have resulted in that very high temperatures would have been needed to expand the rock to initiate spalling which could have been hard to handle. The extensive laboratory tests are assessed to have given a good data set of the intact rock properties. The uniaxial and triaxial tests

  2. Hydrogeological pre-modelling exercises. Assessment of impact of the Aespoe Hard Rock Laboratory. Sensitivities of palaeo-hydrogeology. Development of a local near-surface Hydro-DFN for KLX09B-F. Site descriptive modelling SDM-Site Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, Lee; Jackson, Peter; Joyce, Steve; Roberts, David; Shevelan, John; Swift, Ben (Serco Assurance, Harwell (GB)); Gylling, Bjoern; Marsic, Niko (Kemakta Konsult AB, Stockholm (SE)); Hermanson, Jan; Oehman, Johan (Golders Associates (SE))

    2007-12-15

    Numerical modelling has been used to investigate the potential impact of the Aespoe HRL on regional groundwater flow and hydro-geochemistry in the Laxemar study area. The numerical models have been adapted for this application from the ones use in the site-descriptive modelling (SDM) and SR-Can assessment modelling based on Laxemar version 1.2. In order to test the robustness of the simulation results, sensitivities were studied with respect to different flow boundary conditions and the hydraulic properties of the Quaternary deposits, particularly those beneath the sea around the Aespoe island. The simulations show that the Aespoe HRL has a local effect on the groundwater situation. Typically, in the simulations, the rock under the Aespoe island, the bays around it and the Aevroe area (mainly western part of the islands of Aevroe, Mjaelen and Haaloe) are influenced. In the sensitivity study, visualisations of the drawdown caused by the HRL tunnel system show small differences in the results for head versus flux top boundary conditions, little sensitivity to a change in the surface infiltration rate, but most sensitivity to the contact between the sea and the bedrock beneath the seabed sediments. For all simulation cases considered, results suggest that the Aespoe HRL has not been in operation sufficiently long to have affected the chemistry of samples collected at Laxemar and Simpevarp, though there is some possibility that Aevroe samples have been altered, at least for boreholes in the western part of Aevroe, Mjaelen and Haaloe. The distribution of flow and discharge areas around the bay at Aespoe is clearly affected by the HRL for all cases. Using the drawdown in percussion drilled boreholes around Aespoe as an interference test suggests that there is a partial reduction in the hydraulic contact between the sea and the groundwater system in the bedrock beneath. It is recommended that the conclusions about appropriate hydraulic properties for Quaternary sediments

  3. Aespoe Hard Rock Laboratory. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between October 2007 and March 2008

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, D.; Haycox, J.; Pettitt, W.S. (Applied Seismology Consultants, Shrewsbury (United Kingdom))

    2008-12-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The experiment has been designed to simulate a disposal tunnel in a real deep repository environment for storage of high-level radioactive waste. The test consists of a 90 m long, 5 m diameter subhorizontal tunnel excavated in dioritic granite. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and pore pressures induced from tunnel sealing.

  4. Aespoe Hard Rock Laboratory. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between April 2008 and September 2008

    International Nuclear Information System (INIS)

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation [Pettitt et al., 1999], and during stages of canister heating and tunnel pressurisation [Haycox et al., 2005a and 2005b; Haycox et al., 2006a and 2006b; Zolezzi et al., 2007 and Duckworth et al., 2008]. Further information on this monitoring can be found in Appendix I. This report covers the period between 1st April 2008 and 30th September 2008 and is the seventh instalment of the 6-monthly processing and interpretation of the results from the experiment

  5. Aespoe Hard Rock Laboratory. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between April 2008 and September 2008

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, D.; Haycox, J.; Pettitt, W.S. (Applied Seismology Consultants, Shrewsbury (United Kingdom))

    2009-03-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation [Pettitt et al., 1999], and during stages of canister heating and tunnel pressurisation [Haycox et al., 2005a and 2005b; Haycox et al., 2006a and 2006b; Zolezzi et al., 2007 and Duckworth et al., 2008]. Further information on this monitoring can be found in Appendix I. This report covers the period between 1st April 2008 and 30th September 2008 and is the seventh instalment of the 6-monthly processing and interpretation of the results from the experiment.

  6. Session: Hard Rock Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Tennyson, George P. Jr.; Dunn, James C.; Drumheller, Douglas S.; Glowka, David A.; Lysne, Peter

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five presentations: ''Hard Rock Penetration - Summary'' by George P. Tennyson, Jr.; ''Overview - Hard Rock Penetration'' by James C. Dunn; ''An Overview of Acoustic Telemetry'' by Douglas S. Drumheller; ''Lost Circulation Technology Development Status'' by David A. Glowka; ''Downhole Memory-Logging Tools'' by Peter Lysne.

  7. Rock-hard coatings

    NARCIS (Netherlands)

    Muller, M.

    2007-01-01

    Aircraft jet engines have to be able to withstand infernal conditions. Extreme heat and bitter cold tax coatings to the limit. Materials expert Dr Ir. Wim Sloof fits atoms together to develop rock-hard coatings. The latest invention in this field is known as ceramic matrix composites. Sloof has sign

  8. The interaction of sorbing and non-sorbing tracers with different Aespoe rock types. Sorption and diffusion experiments in the laboratory scale

    Energy Technology Data Exchange (ETDEWEB)

    Byegaard, J.; Johansson, Henrik; Skaalberg, M. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry; Tullborg, E.L. [Terralogica AB, Graabo (Sweden)

    1998-11-01

    Laboratory experiments studying the sorption and diffusivity of different tracers in Aespoe Hard Rock Laboratory (Aespoe HRL) site specific conditions have been performed. The experiments were conducted by applying both the batch sorption and the through diffusion technique. The investigation was focused on slightly sorbing tracers, i e, alkaline metals (Na{sup +}, Rb{sup +} and Cs{sup +}) and alkaline earth metals (Ca{sup 2+}, Sr{sup 2+} and Ba{sup 2+}), but some presumed non-sorbing species have also been included. The dominating generic rock material from Aespoe HRL, Aespoe-diorite and fine-grained granite, were used as well as some altered wall rock and mylonite from the Feature A fracture, the fracture where in situ migration studies have been performed. Synthetic groundwater was used; similar to the high saline groundwater found at the 350m level at Aespoe HRL and at the Feature A site. The results of batch experiments show that the sorption of the tracers increase in the order NaAespoe-diorite than for the fine-grained granite which is explained by the much higher concentration of biotite in Aespoe diorite than in fine-grained granite. In the altered material the biotite has been transformed to chlorite and a lower sorptivity is shown for those material compared to the fresh diorite and granite, respectively. Attempts to explain the sorption and desorption results to a surface sorption - diffusion model are presented. The diffusion results show that the tracers were retarded in the same order as was expected from the measured batch sorption coefficients. Furthermore, the largest size fraction was the most

  9. Aespoe HRL - Geoscientific evaluation 1997/1. Overview of site characterization 1986-1995

    International Nuclear Information System (INIS)

    Geological investigations for the Aespoe Hard Rock Laboratory in the region around Aespoe began in 1986. Aespoe was selected as the laboratory site in 1988 and construction of the underground facility started in october 1990. Construction of the laboratory was completed in the summer of 1995. This report gives a comprehensive compilation of the different investigations performed during the pre-investigation phase 1986-1990 and the excavation phase 1990-1995. The information is mainly compiled in CAD-generated maps, tables and illustrations in which the reader can gather information concerning the scope of work as well as references to more detailed reports for further study. 325 refs., 85 figs

  10. Rock stability considerations for siting and constructing a KBS-3 repository. Based on experiences from Aespoe HRL, AECL's URL, tunnelling and mining

    International Nuclear Information System (INIS)

    Over the past 25 years the international nuclear community has carried out extensive research into the deep geological disposal of nuclear waste in hard rocks. In two cases this research has resulted in the construction of dedicated underground research facilities: SKB's Aespoe Hard Rock Laboratory, Sweden and AECL's Underground Research Laboratory, Canada. Both laboratories are located in hard rocks considered representative of the Fennoscandian and Canadian Shields, respectively. This report is intended to synthesize the important rock mechanics findings from these research programs. In particular the application of these finding to assessing the stability of underground openings. As such the report draws heavily on the published results from the SKB's ZEDEX Experiment in Sweden and AECL's Mine- by Experiment in Canada. The objectives of this report are to: 1. Describe, using the current state of knowledge, the role rock engineering can play in siting and constructing a KBS-3 repository. 2. Define the key rock mechanics parameters that should be determined in order to facilitate repository siting and construction. 3. Discuss possible construction issues, linked to rock stability, that may arise during the excavation of the underground openings of a KBS-3 repository. 4. Form a reference document for the rock stability analysis that has to be carried out as a part of the design works parallel to the site investigations. While there is no unique or single rock mechanics property or condition that would render the performance of a nuclear waste repository unacceptable, certain conditions can be treated as negative factors. Outlined below are major rock mechanics issues that should be addressed during the siting, construction and closure of a nuclear waste repository in Sweden in hard crystalline rock. During the site investigations phase, rock mechanics information will be predominately gathered from examination and testing of the rock core and mapping of the

  11. Rock stability considerations for siting and constructing a KBS-3 repository. Based on experiences from Aespoe HRL, AECL's URL, tunnelling and mining

    Energy Technology Data Exchange (ETDEWEB)

    Martin, C.D. [Univ. of Alberta, Edmonton (Canada); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Soederhaell, J. [VBB VIAK AB, Stockholm (Sweden)

    2001-12-01

    Over the past 25 years the international nuclear community has carried out extensive research into the deep geological disposal of nuclear waste in hard rocks. In two cases this research has resulted in the construction of dedicated underground research facilities: SKB's Aespoe Hard Rock Laboratory, Sweden and AECL's Underground Research Laboratory, Canada. Both laboratories are located in hard rocks considered representative of the Fennoscandian and Canadian Shields, respectively. This report is intended to synthesize the important rock mechanics findings from these research programs. In particular the application of these finding to assessing the stability of underground openings. As such the report draws heavily on the published results from the SKB's ZEDEX Experiment in Sweden and AECL's Mine- by Experiment in Canada. The objectives of this report are to: 1. Describe, using the current state of knowledge, the role rock engineering can play in siting and constructing a KBS-3 repository. 2. Define the key rock mechanics parameters that should be determined in order to facilitate repository siting and construction. 3. Discuss possible construction issues, linked to rock stability, that may arise during the excavation of the underground openings of a KBS-3 repository. 4. Form a reference document for the rock stability analysis that has to be carried out as a part of the design works parallel to the site investigations. While there is no unique or single rock mechanics property or condition that would render the performance of a nuclear waste repository unacceptable, certain conditions can be treated as negative factors. Outlined below are major rock mechanics issues that should be addressed during the siting, construction and closure of a nuclear waste repository in Sweden in hard crystalline rock. During the site investigations phase, rock mechanics information will be predominately gathered from examination and testing of the rock core and

  12. Rock mechanics for hard rock nuclear waste repositories

    International Nuclear Information System (INIS)

    The mined geologic burial of high level nuclear waste is now the favored option for disposal. The US National Waste Terminal Storage Program designed to achieve this disposal includes an extensive rock mechanics component related to the design of the wastes repositories. The plan currently considers five candidate rock types. This paper deals with the three hard rocks among them: basalt, granite, and tuff. Their behavior is governed by geological discontinuities. Salt and shale, which exhibit behavior closer to that of a continuum, are not considered here. This paper discusses both the generic rock mechanics R and D, which are required for repository design, as well as examples of projects related to hard rock waste storage. The examples include programs in basalt (Hanford/Washington), in granitic rocks (Climax/Nevada Test Site, Idaho Springs/Colorado, Pinawa/Canada, Oracle/Arizona, and Stripa/Sweden), and in tuff

  13. Aespoe HRL - Geoscientific evaluation 1997/5. Models based on site characterization 1986-1995

    International Nuclear Information System (INIS)

    The pre-investigations for the Aespoe Hard Rock Laboratory were started in 1986 and involved extensive field measurements, aimed at characterizing the rock formations with regard to geology, geohydrology, hydrochemistry and rock mechanics. Predictions for the excavation phase were made prior to excavation of the laboratory which was started in the autumn of 1990. The predictions concern five key issues: lithology and geological structures, groundwater flow, hydrochemistry, transport of solutes and mechanical stability. During 1996 the results from the pre-investigations and the excavation of the Aespoe Hard Rock Laboratory were evaluated and were compiled in geological, mechanical stability, geohydrological, groundwater chemical and transport-of-solutes models. The model concepts and the models of 1996 are presented in this report. The model developments from the pre-investigation phase up to the models made 1996 are also presented briefly

  14. Aespoe HRL - Geoscientific evaluation 1997/5. Models based on site characterization 1986-1995

    Energy Technology Data Exchange (ETDEWEB)

    Rhen, I. [ed.; Gustafsson, Gunnar [VBB Viak AB, Goeteborg (Sweden); Stanfors, R. [RS Consulting, Lund (Sweden); Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1997-10-01

    The pre-investigations for the Aespoe Hard Rock Laboratory were started in 1986 and involved extensive field measurements, aimed at characterizing the rock formations with regard to geology, geohydrology, hydrochemistry and rock mechanics. Predictions for the excavation phase were made prior to excavation of the laboratory which was started in the autumn of 1990. The predictions concern five key issues: lithology and geological structures, groundwater flow, hydrochemistry, transport of solutes and mechanical stability. During 1996 the results from the pre-investigations and the excavation of the Aespoe Hard Rock Laboratory were evaluated and were compiled in geological, mechanical stability, geohydrological, groundwater chemical and transport-of-solutes models. The model concepts and the models of 1996 are presented in this report. The model developments from the pre-investigation phase up to the models made 1996 are also presented briefly. 317 refs, figs, tabs.

  15. Ototraumatic effects of hard rock music.

    Science.gov (United States)

    Reddell, R C; Lebo, C P

    1972-01-01

    Temporary and permanent shifts in auditory thresholds were found in 43 hard rock musicians and temporary shifts were also observed in some listeners. The threshold shifts involved all of the conventional puretone test frequencies. Custom-fitted polyvinyl chloride ear protectors were found to be effective in prevention of these noise-induced hearing losses.

  16. Perception of the Hard Rock Brand by Czech University Students

    OpenAIRE

    Polák, Ivan

    2010-01-01

    The goal of this thesis is to understand perception of the Hard Rock brand in the Czech Republic among university students. Hard Rock Cafe Prague is a combination of a restaurant, bar, and rock club operated by the hospitality corporation Hard Rock International. The studied segment can be seen as a group of potential customers in long term, and this research should identify opportunities for growth of Czech guests. The thesis presents the process and results of Hard Rock brand research on th...

  17. Design for rock grouting based on analysis of grout penetration. Verification using Aespoe HRL data and parameter analysis

    International Nuclear Information System (INIS)

    the relationship between grout penetration and grouting time to derive theoretically based stop criteria for real grouting work. Verify the theory by using the field data from the grouting experiment at the 450 m level in the Aespoe HRL. Analyze the difference between the grouting result based on theoretically based stop criteria and that based on empirically based stop criteria. Evaluate the effect of variations in grouting parameters such as grouting pressure and grout materials. The further developed grouting theory includes models for increasing the grouting pressure and changing the grout mix and the capacity of grouting equipment. The theory focuses on deriving theoretically based stop criteria for real grouting work. The further developed theory was verified by comparing the calculated result with the measured result of the grouting experiment at the 450 m level of the Aespoe HRL. It was concluded that the further developed theory is well verified and is applicable to grouting design and analysis, even though there is still room for further improvement. The difference between the grouting results based on three types of stop criteria - one based on grout flow, one on grout take, and the third on grout penetration - has been analyzed for 1D and 2D flows. Three types of hypothetical rock masses with different permeabilities are used for the calculation. In both the 1D and 2D cases, great differences were found between the results derived from the three stop criteria. In general, grouted volume and grouting time for the 2D case were much higher than those for the 1D case. The results show the importance of choosing the theoretically based stop criteria based on the estimated flow dimension of the fracture system in order to avoid inadequate or uneconomical grouting. The parameter studies were conducted to show the effect of variation in grouting parameters. As a result of the parameter studies, it was found that the grouting time and the final grouting flow depend

  18. Aespoe HRL - Geoscientific evaluation 1997/2. Results from pre-investigation and detailed site characterization. Summary report

    International Nuclear Information System (INIS)

    The work at Aespoe Hard rock laboratory provides an important scientific and technical basis for implementing and operating a future deep repository in Sweden. A milestone has now been reached with the completion of the pre investigation and construction phases at Aespoe HRL. The present data base at Aespoe HRL is one of the most comprehensive data bases in the world for crystalline rock properties, containing data from a large number of investigation methods from the surface down to 1700 m below ground level. Site characterization in conjunction with construction work has basically confirmed the pre-construction models. The site characterization has been a realistic 'dress rehearsal' that is invaluable for planning and execution of surface and underground characterization of sites for the deep repository for spent nuclear fuel in Sweden

  19. Mining technology development for hard rock excavation

    International Nuclear Information System (INIS)

    A research facility has been established in the granitic gneiss of the CSM Experimental Mine at Idaho Springs, Colorado, for the purpose of evaluating/developing mining, geologic and geotechnical procedures appropriate for use in establishing nuclear waste repositories in hard rock. An experimental room has been excavated using careful blasting procedures. The extent and magnitude of blast damage is being evaluated. Structural geology is being mapped to assess continuity

  20. Interactions of trace elements with fracture filling minerals from the Aespoe Hard Rock Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Landstroem, O. [Studsvik Eco and Safety AB, Nykoeping (Sweden); Tullborg, E.L. [Terralogica AB (Sweden)

    1995-06-01

    This report focuses on the distribution of stable elements and natural radionuclides (e.g. REEs, Th, Ra, Sr and Cs) in natural fracture systems. They have been redistributed by natural processes in the past; mobilization, transport and deposition of which the latter is manifested as `enrichments` of the elements in fracture fillings. Fillings dominated by Fe-oxyhydroxide, calcite and clay minerals show the highest concentrations. Precipitates from different fractures show large variations in concentration levels of trace elements, REE patterns, and activity and activity ratios of natural radionuclides, reflecting variations in physical, chemical and hydrological properties of the fractures. The incorporation of REEs, Sr, Th and U in calcite is significant. The precipitation rate influences the amount of Sr incorporated and probably other elements as well. Clay minerals have high sorption capacity and are important in the retention of Cs and Sr as well as of REEs, Th, U and Ra. The importance of clay minerals in radionuclide retention is emphasized by the results from this study, even small amounts of clay minerals in fractures and fracture zones can significantly influence the radionuclide migration. Accurate determination of quantities and types of clay minerals is therefore very important for radionuclide migration modelling. 58 refs, 14 figs, 12 tabs.

  1. Real-time monitoring of copper corrosion at the Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Rosborg, Bo; Pan, Jinshan [Div. Corrosion Science, Royal Institute of Technology, Drottning Kristinas vaeg 51, SE - 100 44 Stockholm (Sweden); Eden, David [InterCorr International, Inc., 14503 Bammel-N Houston, Suite 300, Houston, TX 77014 (United States); Karnland, Ola [Clay Technology AB, Ideon Research Center, SE - 223 70 Lund (Sweden); Werme, Lars [Svensk Kaernbraenslehantering AB, P.O. Box 5864, SE - 102 40 Stockholm (Sweden)

    2004-07-01

    In Sweden the principal strategy for high-level radioactive waste disposal is to enclose the spent nuclear fuel in tightly sealed copper canisters that are embedded in bentonite clay about 500 m down in the Swedish bed-rock. Initially, a limited amount of air will be left in a repository after emplacement. The entrapped oxygen will be consumed through reactions with minerals in the rock and the bentonite and also through microbial activity. After the oxygen has been consumed in the repository, after a few hundred years at the very most, corrosion will be controlled completely by the supply of dissolved sulphide to the canister. The present work concerns the oxic period after emplacement. The main hypothesis is that the average corrosion rate of the canister under oxic conditions will be less than 7 {mu}m/year, and that pitting will only be possible under these conditions. The Aespoe Hard Rock Laboratory offers a realistic environment for different experiments and tests under the conditions that will prevail in a deep repository. Real-time monitoring of copper corrosion is presently performed with polarization resistance, harmonic distortion analysis and electrochemical noise techniques. The first two techniques are used to derive information regarding the general corrosion rate and the third to derive information regarding localized corrosion. In order to support these measurements at Aespoe, laboratory work is also performed at the Royal Institute of Technology in Stockholm using the very same corrosion monitoring equipment and also other equipment and techniques. Copper coupons are also exposed at Aespoe. Results from the work at Aespoe and in Stockholm are presented with an emphasis on the gained information concerning localized corrosion. The recorded corrosion rates at Aespoe are well below the value given above, and the recorded localization factors are interpreted as indicating only a slight tendency to local attack. (authors)

  2. TOPOGRAPHIC SITE RESPONSE AT HARD ROCK SITES

    Science.gov (United States)

    Yong, A. K.; Hough, S. E.

    2009-12-01

    Site (material impedance) and topographic (geometric form) effects are known to be key factors that influence seismic ground motions. To characterize site effects, Yong et al. (2009) developed a terrain-based Vs30 prediction model using an automated classification method (Iwahashi and Pike, 2007) that relied on taxonomic criteria (slope gradient, local convexity and surface texture) developed from geomorphometry to identify 16 terrain types from a 1-km spatial resolution (SRTM30 data) digital elevation model of California. On the basis that the underlying framework for this model contains parameters (esp., local convexity) which aptly describe the geometry (i.e., base to height ratio) of relief features that are known to also control the behavior of ground motions (Bouchon, 1973), we extend our investigation to study topographic effects. Focusing on sites that would generally be considered “hard rock,” the classification scheme distinguishes 7 separate terrain types ranging from “moderately eroded mountains” to “well dissected alpine summits.” Observed 1-Hz amplification factors at Southern California Seismographic Network sites reveal a weak but systematic correlation with these 7 terrain types. Significant scatter is also found within each terrain type; typical standard deviations of logarithmic amplification factors are 0.2-0.3. Considering stations that have high amplification factors, we find some that have apparently been misclassified due to data resolution limitations. Many of the remaining stations with higher than expected amplifications are located on or near topographic peaks or ridges. The unusually high amplification factors at hard-rock sites, typically factors of 1.5-2, can most plausibly be explained as a topographic effect.

  3. A site scale analysis of groundwater flow and salinity distribution in the Aespoe area

    International Nuclear Information System (INIS)

    The objective of the study is to develop, calibrate and apply a numerical simulation model of the Aespoe area. An area of 1.8 x 1.8 km2, centred around the Aespoe Hard Rock Laboratory (HRL), gives the horizontal extent of the model. In the vertical direction the model follows the topography at the upper boundary and has a lower boundary at 1000 metres below sea level. The model is based on a mathematical model that includes equations for the Darcy velocities, mass conservation and salinity distribution. Gravitational effects are thus fully accounted for. A regional groundwater model was used to generate boundary conditions for vertical and bottom boundaries. Transmissivities of fracture zones and conductivities for the rock in between, as used in the model, are based on field data. An extensive calibration of the model is carried out, using data for natural conditions (i.e. prior to the construction of the Aespoe HRL), drawdowns from a pump test and data collected during the excavation of the tunnel. A satisfactory agreement with field data is obtained by the calibration. Main results from the model include vertical and horizontal sections of flow, salinity and hydraulic head distributions for natural conditions and for completed tunnel. A sensitivity study, where boundary conditions and material properties are modified, is also carried out. The model is also used to describe some characteristic features of the site like infiltration rates, flux statistics at a depth of 450 metres, salinity of inflows to the tunnel and flow and salinity distributions in fracture zones. The general conclusion of the study is that the model developed can simulate the conditions at Aespoe, both natural and with Aespoe HRL present, in a realistic manner

  4. Cutting capacity of PDC cutters in very hard rock

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An experimental programm of investigating the cutting capacity of PDC flat cutters in very hard rock has been performed.Experiments include both the cutting of PDC fixed at different angles on the granite core or bar and linear cutting with different static thrust on the block of granite.The effects of the rough degree of rock surface,cutting angles,and static thrust on the cutting capacity of PDC in very hard rock were investigated and analyzed.The results show that the single mode of rotary drilling using PDC cutters is not applied for very hard rocks.

  5. Aespoe modelling task force - experiences of the site specific flow and transport modelling (in detailed and site scale)

    International Nuclear Information System (INIS)

    The Aespoe Task Force on modelling of groundwater flow and transport of solutes was initiated in 1992. The Task Force shall be a forum for the organisations supporting the Aespoe Hard Rock Laboratory Project to interact in the area of conceptual and numerical modelling of groundwater flow and solute transport in fractured rock. Much emphasis is put on building of confidence in the approaches and methods in use for modelling of groundwater flow and nuclide migration in order to demonstrate their use for performance and safety assessment. The modelling work within the Task Force is linked to the experiments performed at the Aespoe Laboratory. As the first Modelling Task, a large scale pumping and tracer experiment called LPT2 was chosen. This was the final part of the characterisation work for the Aespoe site before the construction of the laboratory in 1990. The construction of the Aespoe HRL access tunnel caused an even larger hydraulic disturbance on a much larger scale than that caused by the LPT2 pumping test. This was regarded as an interesting test case for the conceptual and numerical models of the Aespoe site developed during Task No 1, and was chosen as the third Modelling Task. The aim of Task 3 can be seen from two different perspectives. The Aespoe HRL project saw it as a test of their ability to define a conceptual and structural model of the site that can be utilised by independent modelling groups and be transformed to a predictive groundwater flow model. The modelling groups saw it as a means of understanding groundwater flow in a large fractured rock volume and of testing their computational tools. A general conclusion is that Task 3 has served these purposes well. Non-sorbing tracers tests, made as a part of the TRUE-experiments were chosen as the next predictive modelling task. A preliminary comparison between model predictions made by the Aespoe Task Force and the experimental results, shows that most modelling teams predicted breakthrough from

  6. 2D and 3D modelling of magnetic and resistivity data from Aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Mattsson, Haakan (GeoVista AB, Luleaa (Sweden))

    2011-05-15

    This report presents results from modelling of geophysical data. Ground magnetic and geo electric data were collected in 1988 as part of the pre-investigations carried out before the construction of the Aespoe Hard Rock Laboratory (HRL). The work presented in this report is an evaluation of the magnetic and geo electric data with the focus on estimating variations in geometry and dip of some of the possible deformation zones indicated in lineament interpretations presented earlier. This was done by 2D forward magnetic modelling, 2D forward resistivity modelling and 3D inversion of the magnetic data. The specific aims of this work are: 1. Produce magnetic 2D forward models across 12 selected linked lineaments. 2. Produce a 3D susceptibility model of the entire data set of Aespoe. 3. Use 2D forward resistivity modelling to produce electric anomaly response diagrams for a dipole-dipole survey across low resistivity zones with various dips. The results of the modelling work will mainly be used as supportive information for deterministic geological modelling of deformation zones and rock units in the vicinity of the Aespoe HRL. The results of the 2D forward modelling of magnetic data show geologically reasonable solutions, and in most cases it is possible to make reliable estimates of the width and orientation of the cause of the targeted lineament. The possible deformation zones generally dip steeply (80 deg-90 deg) and have a width of c. 30-50 m. In some cases the modelled lineament has a diffuse character with low amplitude, which makes the model solution uncertain. Two 3D susceptibility models were created by use of inversion of the ground magnetic data; one coarse model of the entire Island of Aespoe and one more detailed model of the south-eastern peninsula of the Island, covering the volume of the Aespoe HRL. The two models fit nicely to the measured data and they are geologically realistic. It is possible to identify well-defined bodies (rock volumes) of

  7. Sulphate reduction in the Aespoe HRL tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, G. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Geology; Laaksoharju, M. [ed.; Skaarman, C. [GeoPoint AB, Sollentuna (Sweden); Pedersen, K. [Goeteborg Univ. (Sweden). Dept. of Genetics, Microbiology and Molecular Biology; Rhen, I. [VBB Viak (Sweden); Tullborg, E.L. [Terralogica AB (Sweden); Wallin, B. [Geokema AB (Sweden); Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1995-12-01

    Evidence and indications of sulphate reduction based on geological, hydrogeological, groundwater, isotope and microbial data gathered in and around the Aespoe Hard Rock Laboratory tunnel have been evaluated. This integrated investigation showed that sulphate reduction had taken place in the past but is most likely also an ongoing process. Anaerobic sulphate-reducing bacteria can live in marine sediments, in the tunnel sections under the sea and in deep groundwaters, since there is no access to oxygen. The sulphate-reducing bacteria seem to thrive when the Cl{sup -} concentration of the groundwater is 4000-6000 mg/l. Sulphate reduction is an in situ process but the resulting hydrogen-sulphide rich water can be transported to other locations. A more vigorous sulphate reduction takes place when the organic content in the groundwater is high (>10 mg/l DOC) which is the case in the sediments and in the groundwaters under the sea. Some bacteria use hydrogen as an electron donor instead of organic carbon and can therefore live in deep environments where access to organic material is limited. The sulphate-reducing bacteria seem to adapt to changing flow situations caused by the tunnel construction relatively fast. Sulphate reduction seems to have occurred and will probably occur where conditions are favourable for the sulphate-reducing bacteria such as anaerobic brackish groundwater with dissolved sulphate and organic carbon or hydrogen. 59 refs, 37 figs, 6 tabs.

  8. Sulphate reduction in the Aespoe HRL tunnel

    International Nuclear Information System (INIS)

    Evidence and indications of sulphate reduction based on geological, hydrogeological, groundwater, isotope and microbial data gathered in and around the Aespoe Hard Rock Laboratory tunnel have been evaluated. This integrated investigation showed that sulphate reduction had taken place in the past but is most likely also an ongoing process. Anaerobic sulphate-reducing bacteria can live in marine sediments, in the tunnel sections under the sea and in deep groundwaters, since there is no access to oxygen. The sulphate-reducing bacteria seem to thrive when the Cl- concentration of the groundwater is 4000-6000 mg/l. Sulphate reduction is an in situ process but the resulting hydrogen-sulphide rich water can be transported to other locations. A more vigorous sulphate reduction takes place when the organic content in the groundwater is high (>10 mg/l DOC) which is the case in the sediments and in the groundwaters under the sea. Some bacteria use hydrogen as an electron donor instead of organic carbon and can therefore live in deep environments where access to organic material is limited. The sulphate-reducing bacteria seem to adapt to changing flow situations caused by the tunnel construction relatively fast. Sulphate reduction seems to have occurred and will probably occur where conditions are favourable for the sulphate-reducing bacteria such as anaerobic brackish groundwater with dissolved sulphate and organic carbon or hydrogen. 59 refs, 37 figs, 6 tabs

  9. Prediction of rock brittleness using nondestructive methods for hard rock tunneling

    Directory of Open Access Journals (Sweden)

    Rennie B. Kaunda

    2016-08-01

    Full Text Available The material and elastic properties of rocks are utilized for predicting and evaluating hard rock brittleness using artificial neural networks (ANN. Herein hard rock brittleness is defined using Yagiz' method. A predictive model is developed using a comprehensive database compiled from 30 years' worth of rock tests at the Earth Mechanics Institute (EMI, Colorado School of Mines. The model is sensitive to density, elastic properties, and P- and S-wave velocities. The results show that the model is a better predictor of rock brittleness than conventional destructive strength-test based models and multiple regression techniques. While the findings have direct implications on intact rock, the methodology can be extrapolated to rock mass problems in both tunneling and underground mining where rock brittleness is an important control.

  10. Prediction of rock brittleness using nondestructive methods for hard rock tunneling

    Institute of Scientific and Technical Information of China (English)

    Rennie B. Kaunda; Brian Asbury

    2016-01-01

    The material and elastic properties of rocks are utilized for predicting and evaluating hard rock brit-tleness using artificial neural networks (ANN). Herein hard rock brittleness is defined using Yagiz’ method. A predictive model is developed using a comprehensive database compiled from 30 years’ worth of rock tests at the Earth Mechanics Institute (EMI), Colorado School of Mines. The model is sensitive to density, elastic properties, and P-and S-wave velocities. The results show that the model is a better predictor of rock brittleness than conventional destructive strength-test based models and mul-tiple regression techniques. While the findings have direct implications on intact rock, the methodology can be extrapolated to rock mass problems in both tunneling and underground mining where rock brittleness is an important control.

  11. Electron accelerator for tunneling through hard rock

    International Nuclear Information System (INIS)

    Earlier work demonstrated that intense sub-microsecond bursts of energetic electrons cause significant pulverization and spalling of a variety of rock types. The spall debris generally consists of sand, dust, and small flakes. If carried out at rapid repetition rate, this can lead to a promising technique for increasing the speed and reducing the cost of underground excavation of tunnels, mines, and storage spaces. The conceptual design features of a Pulsed Electron Tunnel Excavator capable of tunneling approximately ten times faster than conventional drill/blast methods are presented with primary emphasis on the electron accelerator and only a brief description of the tunneling aspects. Of several candidate types of accelerators, a linear induction accelerator producing electron pulses (5 MV, 5 kA, 1.0 μs = 25 kJ) at a 360 Hz rate was selected for the conceptual example. This provides the required average electron beam power output of 9 MW. The feasibility of such an accelerator is discussed

  12. Aespoe HRL - Geoscientific evaluation 1997/4. Results from pre-investigation and detailed site characterization. Comparison of predictions and observations. Hydrogeology, groundwater chemistry and transport of solutes

    Energy Technology Data Exchange (ETDEWEB)

    Rhen, I.; Gustafson, Gunnar [VBB Viak AB, Goeteborg (Sweden); Wikberg, P. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1997-06-01

    The pre-investigations for the Aespoe Hard Rock Laboratory were started in 1986 and involved extensive field measurements, aimed at characterizing the rock formations with regard to geology, hydrogeology, hydrochemistry and rock mechanics. Prior to the excavation in 1990 predictions were made for the excavation phase concerning: geology, ground water flow and chemistry, transport of solutes and mechanical stability. This report presents a comparison between these predictions and the observations made during the excavation. Also, investigation methods for the 700-2874 m sections of the tunnel are evaluated. 157 refs, 190 figs, 37 tabs.

  13. Aespoe HRL - Geoscientific evaluation 1997/4. Results from pre-investigation and detailed site characterization. Comparison of predictions and observations. Hydrogeology, groundwater chemistry and transport of solutes

    International Nuclear Information System (INIS)

    The pre-investigations for the Aespoe Hard Rock Laboratory were started in 1986 and involved extensive field measurements, aimed at characterizing the rock formations with regard to geology, hydrogeology, hydrochemistry and rock mechanics. Prior to the excavation in 1990 predictions were made for the excavation phase concerning: geology, ground water flow and chemistry, transport of solutes and mechanical stability. This report presents a comparison between these predictions and the observations made during the excavation. Also, investigation methods for the 700-2874 m sections of the tunnel are evaluated

  14. Performance Assessment of Hard Rock TBM and Rock Boreability Using Punch Penetration Test

    Science.gov (United States)

    Jeong, Ho-Young; Cho, Jung-Woo; Jeon, Seokwon; Rostami, Jamal

    2016-04-01

    Rock indentation tests are often called punch penetration tests and are known to be related to penetration rates of drilling equipment and hard rock tunnel boring machines (TBMs). Various indices determined from analysis of the force-penetration plot generated from indentation tests have been used to represent the drillability, boreability, and brittleness of rocks. However, no standard for the punch penetration test procedure or method for calculating the related indices has been suggested or adopted in the rock mechanics community. This paper introduces new indices based on the punch test to predict the performance of hard rock TBMs. A series of punch tests was performed on rock specimens representing six rock formations in Korea with different dimensions, i.e., the core specimens had different lengths and diameters. Of the indices obtained from the punch tests, the peak load index and mean load index showed good correlations with the cutting forces measured in full-scale linear cutting machine tests on the same rock types. The indices also showed good linear correlations with the ratio of uniaxial strength to Brazilian tensile strength, which indicates the brittleness of rock. The scale effect of using core specimens was investigated, and a preferred dimension for the punch test specimens is proposed. This paper also discusses the results of the punch test and full-scale rock cutting tests using LCM. The results of this study confirm that the proposed indices from the punch tests can be used to provide a reliable prediction of the cutting forces that act on a disc cutter. The estimated cutting forces can then be used for optimization of cutter-head design and performance prediction of hard rock TBMs.

  15. Handling and final disposal of nuclear waste. Hard Rock Laboratory

    International Nuclear Information System (INIS)

    The purpose of the Hard Rock Laboratory is to provide an opportunity for research and development in a realistic and undisturbed underground rock environment down to the depth planned for the future repository. The R and D work in the underground laboratory has the following main goals: To test the quality and appropriateness of different methods for characterizing the bedrock with respect to conditions of importance for a final repository. To refine and demonstrate methods for how to adapt a repository to the local properties of the rock in connection with planning and construction. And, finally, to collect material and data of importance for the safety of the future repository and for confidence in the quality of the safety assessments 13 figs, 3 tabs

  16. 76 FR 70644 - Special Local Regulations; Seminole Hard Rock Winterfest Boat Parade, New River and Intracoastal...

    Science.gov (United States)

    2011-11-15

    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulations; Seminole Hard Rock Winterfest... the New River and the Intracoastal Waterway in Fort Lauderdale, Florida during the Seminole Hard Rock... the Coast Guard did not receive necessary information about the Seminole Hard Rock Winterfest...

  17. Aespoe Hard Rock Laboratory. The use of focused ion beams for structural characterisation of bentonite. A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Wegden, Marie; Kristiansson, Per (Division of Nuclear Physics, Lund Inst. of Technology (Sweden)); Svensson, Daniel; Sjoeland, Anders (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden))

    2009-07-01

    Bentonite clay is planned to be used in the KBS-3 concept for future nuclear high level waste (HLW) repository in Sweden. In the concept the spent nuclear fuel is placed in an iron insert, which is encapsulated in a copper canister. The copper canister is embedded in compacted bentonite and deposited at 500 m depth in granite bedrock. The compacted bentonite will act as a buffer material, giving mechanical support for the copper canister, reducing water movements and capturing potentially escaping radionuclides. Bentonite contains high amounts of smectite minerals (most common is montmorillonite), which are swelling clay minerals. The smectite minerals are layered and have the ability to store water in its structure. This is done by intercalating water between the layers and expanding the interlayer distance. The exceptional swelling capacity makes bentonite a suitable buffer material that works as a sealant and barrier. Heterogeneity in the material, compaction and in swelling may result in porosity, both on the nano- and micrometre scale. This may affect the permeability of the clay and may mediate the transport of radionuclides, cations and corrosion products. The aim of this work is to investigate the feasibility of using common ion beam techniques for structural characterisation of bentonite, including studying the mineral composition and the coarse porosity. The analytical techniques used were scanning transmission ion microscopy (STIM), particle-induced X-ray emission (PIXE) and elastic p-p scattering, performed at the Lund Nuclear Microprobe. On-axis STIM analysis was performed in order to measure and map the areal mass density of the sample. Since it was impossible to differentiate an increase in thickness from an area of higher mass density, as well as discerning depth variations, the STIM analysis was also performed in tomographic mode, in an attempt to obtain 3D structural information. The tomographic reconstruction showed that the bentonite had an interesting internal structure, with micrometre-sized features indicating both accessory minerals and potential pores. PIXE analysis was performed subsequently for investigation and mapping of the element distribution in the samples. From these element maps, the different mineral phases and regions suitable for further analysis could be identified. Finally hydrogen analysis was performed with the elastic p-p scattering method, in order to measure the water content in the sample. This method can be useful in further examinations of bentonite, if the variation in porosity is to be studied as a function of the degree of water saturation. This work demonstrates that, in a combination, PIXE, hydrogen analysis and microtomography with the STIM technique, can provide unique information on the internal structure and element distribution in a microscopic bentonite sample. Removal of water from the clay sample will change the clay structure and porosity due to the dehydration of the interlayer space and is hence problematic, however in this feasibility study this problem is neglected.

  18. Probabilistic Analysis of the Hard Rock Disintegration Process

    Directory of Open Access Journals (Sweden)

    K. Frydrýšek

    2008-01-01

    Full Text Available This paper focuses on a numerical analysis of the hard rock (ore disintegration process. The bit moves and sinks into the hard rock (mechanical contact with friction between the ore and the cutting bit and subsequently disintegrates it. The disintegration (i.e. the stress-strain relationship, contact forces, reaction forces and fracture of the ore is solved via the FEM (MSC.Marc/Mentat software and SBRA (Simulation-Based Reliability Assessment method (Monte Carlo simulations, Anthill and Mathcad software. The ore is disintegrated by deactivating the finite elements which satisfy the fracture condition. The material of the ore (i.e. yield stress, fracture limit, Young’s modulus and Poisson’s ratio, is given by bounded histograms (i.e. stochastic inputs which better describe reality. The results (reaction forces in the cutting bit are also of stochastic quantity and they are compared with experimental measurements. Application of the SBRA method in this area is a modern and innovative trend in mechanics. However, it takes a long time to solve this problem (due to material and structural nonlinearities, the large number of elements, many iteration steps and many Monte Carlo simulations. Parallel computers were therefore used to handle the large computational needs of this problem. 

  19. Numerical simulation for rheological characteristics of alternating distribution of soft and hard rock layers

    Institute of Scientific and Technical Information of China (English)

    HAN Bing; WANG Zhi-yin; DING Xiu-li; XU Ping

    2006-01-01

    The difficulty of selecting appropriate rheological model and parameters for the alternating distribution of soft and hard rock layers was often encountered due to the unhomogeneity, discontinuity and anisotropy of rock mass. The Burgers and generalized Kelvin models were applied to the soft and hard rock respectively and the rheological parameters were obtained based on the method of optimum separation. By using the simulated code FLAC3D, the stability of surrounding rocks of a certain underground plant was analyzed. The effect of surface load and weakening the parameters intensity of argillaceous and bioclastic interlayers between soft and hard rock on rheological behavior of layer composite rock mass was investigated. The results indicate that the rheological characteristics of soft and hard rock layer in composite rock mass can be described well with above two rheological models.

  20. Comparison of the SKI, SKB, and SKN geological and structural models of the Aespoe area

    Energy Technology Data Exchange (ETDEWEB)

    Tiren, S.A. [Geosigma AB, Uppsala (Sweden)

    1996-06-01

    Three sets of geological and structural models produced by three different groups are compared. The same set of basic data has been available to each of the groups. The models, all of which are 2 by 2 km by 1 km deep - or smaller, are based entirely on surface-based investigations. The modelled area is centered on the island of Aespoe, where SKB has built the Hard Rock Laboratory (HRL) in plutonic bedrock at a depth of 500 m. SKB (Swedish Nuclear Fuel and Waste Management Co) has recorded the basic data during the period 1986 to 1991, before starting the underground work. One of the main tasks in the SKB characterization of the HRL rock mass was to predict which of the geological structures will have the greatest rock-mechanical and hydraulic significance. The National Board for Spent Nuclear Fuel (SKN) constructed alternative models in 1992 to verify the SKB model. However, the SKN models were subsequently modified and converted into a hydrogeological model. The Swedish Nuclear Inspectorate (SKI) chose Aespoe as a hypothetical site for storage of nuclear waste in their SITE 94 project. The objective of the project is to assist SKI in their future review of SKB`s application for a license to dispose of spent nuclear fuel underground. The agreement of the three models is found to be best where the density of information is greatest. The main difference between the two geological models is related to the inferred effects of block faulting on the rock type distribution. The correlation of moderately to gently inclined zones between the models is relatively poor at depth. 46 refs, 30 figs, 18 tabs.

  1. Research on the Hard-Rock Breaking Mechanism of Hydraulic Drilling Impact Tunneling

    OpenAIRE

    Risheng Long; Shaoni Sun; Zisheng Lian

    2015-01-01

    In order to realize the rapid hard-rock tunneling in a safe, highly effective, and economic manner, the hydraulic drilling impact hard-rock tunneling (HDIHT) technology and method were introduced based on the theories of rock mechanics and hydraulic impact. The key parameters, including drilling radius and impact distance, were researched to reveal the stress behavior during HDIHT process. The Von Mises equivalent stress and its principal stress components were analyzed, and the breaking mech...

  2. Pillar Design in the Hard Rock Mines of South Africa

    Directory of Open Access Journals (Sweden)

    D.F. Malan

    2012-12-01

    Full Text Available This paper gives an overview of the difficulties associated with the design of hard rock pillars in South African mines. Recent examples of large scale pillar collapses in South Africa suggest that these were caused by weak partings which traversed the pillars. Currently two different methods are used to determine the strength of pillars, namely, empirical equations derived from back analyses of failed and stable cases and numerical modeling tools using appropriate failure criteria. It is illustrated in the paper that both techniques have their limitations and additional work is required to obtain a better understanding of pillar strength.Empirical methods based on observations of pillar behaviour in a given geotechnical setting are popular and easy to use, but care should be exercised that the results are not inappropriately extrapolated beyond the environment in which they are established. An example is the Hedley and Grant formula (derived for the Canadian uranium mines that has been used for many years in the South African platinum and chrome mines (albeit with some adaptation of the K-value. Very few collapses have been reported in South Africa for layouts designed using this formula, suggesting that in some cases it might yield estimates of pillar strength that are too conservative.As an alternative, some engineers strongly advocate the use of numerical techniques to determine pillar strength. A close examination unfortunately reveals that these techniques also rely on many assumptions. An area where numerical modeling is invaluable, however, is to determine pillar stresses accurately and to study specific pillar failure mechanisms, such as the influence of weak partings on pillar strength.

  3. Experimental study on large diameter drilling in hard rock annular coring

    Institute of Scientific and Technical Information of China (English)

    Yinzhu WU; Guochun YANG; Wenchen WANG

    2008-01-01

    Based on analyzing method of large diameter hard rock drilling at home and abroad, the authors proposed a set of drilling of large diameter hard rock annular coring in low energy consumption, low cost and high efficiency. The prototype of drilling tools was designed and was made. The experimental result of the prototype indicates that this plan and technology are feasible and reach the anticipated object of design. A set of drilling tools has been offered for the constructs of large diameter hard rock coring.

  4. IMPACT OF ROCK HARDNESS ON FRAGMENTATION BY HYDRAULIC HAMMER AND CRUSHING IN JAW CRUSHER

    Directory of Open Access Journals (Sweden)

    Trpimir Kujundžić

    2008-12-01

    Full Text Available The physical and mechanical characteristics of intact rocks depend on the way of their formation, sustained deformations and the process of wearing a specific rock has been exposed to. These characteristics have a rather high influence on the technological process of extraction and dressing of mineral raw materials. However, the mechanical characteristics of rocks due to use of explosives for their extraction in the open pit have a more significant impact. The rock blocks extracted by blasting which are larger than the opening of the primary crusher are usually fragmented by hydraulic hammer. The paper presents the results of the testing of impact of rock hardness on fragmentation of rocks by means of hydraulic hammer and during crushing in jaw crusher. The testing was carried out on the rock samples from five quarries. According to the obtained results the hardness has a considerably larger impact on the fragmentation energy by hydraulic hammer than on the crushing energy in jaw crusher.

  5. Dynamic design method for deep hard rock tunnels and its application

    Directory of Open Access Journals (Sweden)

    Xia-Ting Feng

    2016-08-01

    Full Text Available Numerous deep underground projects have been designed and constructed in China, which are beyond the current specifications in terms of scale and construction difficulty. The severe failure problems induced by high in situ stress, such as rockburst, spalling, damage of deep surrounding rocks, and time-dependent damage, were observed during construction of these projects. To address these problems, the dynamic design method for deep hard rock tunnels is proposed based on the disintegration process of surrounding rocks using associated dynamic control theories and technologies. Seven steps are basically employed: (i determination of design objective, (ii characteristics of site, rock mass and project, and identification of constraint conditions, (iii selection or development of global design strategy, (iv determination of modeling method and software, (v preliminary design, (vi comprehensive integrated method and dynamic feedback analysis, and (vii final design. This dynamic method was applied to the construction of the headrace tunnels at Jinping II hydropower station. The key technical issues encountered during the construction of deep hard rock tunnels, such as in situ stress distribution along the tunnels, mechanical properties and constitutive model of deep hard rocks, determination of mechanical parameters of surrounding rocks, stability evaluation of surrounding rocks, and optimization design of rock support and lining, have been adequately addressed. The proposed method and its application can provide guidance for deep underground projects characterized with similar geological conditions.

  6. Aespoe HRL. Experiences of blasting of the TASQ tunnel

    International Nuclear Information System (INIS)

    A new tunnel was developed at the Aespoe Hard Rock Laboratory (AHRL) during the spring and summer 2003. The tunnel was specially designed for a rock mechanics experiment, the Aespoe Pillar Stability Experiment (APSE). In this pillar experiment there was a high demand to initiate high in-situ stresses and therefore the tunnel was designed with a large height/ width ratio and with a circular floor. There were high requirements on bore hole precision and of a minimized EDZ (Excavation damaged zone) in the pillar area. This included a maximum borehole deviation of 10 mm/m, a maximum overbreak due to the lookout angle of 0.3 m and an EDZ of 0.3 m. To make a charge control feasible cartridged explosives was prescribed. The initiation was made with Nonel. The last three rounds used electronic initiation to enable studies of possibility to further reduce the EDZ. The collar of the tunnel was very close to installations and shaft and it was very important to avoid fly-rock and vibrations. Special types of stemming were used as well as steel plates and rubber mats. The excavation works was divided in three different phases. The first phase of the tunnel was an ordinary 26 m2 tunnel. After approximately 30 m a ramp separated the tunnel section into a top heading and a bench, total 33 m2. After the last top heading round was excavated and the roof had been reinforced with fibre reinforced shotcrete the bench was taken out with horizontal holes as the third phase. The drilling precision was very good and 95% of all half-pipes fulfilled the demands. The total amount of visible half-pipes in the APSE-tunnel was high and indicated a successful smooth blasting. The EDZ was examined further by cutting slots in the wall and roof. Existing cracks appear very clearly when a dye penetrant is sprayed on the cleaned surface. A typical crack pattern consists of blast cracks, induced cracks (cracks from the distressing caused by blasting) and natural cracks. The maximum crack length in the

  7. Incoherent SSI Analysis of Reactor Building using 2007 Hard-Rock Coherency Model

    International Nuclear Information System (INIS)

    Many strong earthquake recordings show the response motions at building foundations to be less intense than the corresponding free-field motions. To account for these phenomena, the concept of spatial variation, or wave incoherence was introduced. Several approaches for its application to practical analysis and design as part of soil-structure interaction (SSI) effect have been developed. However, conventional wave incoherency models didn't reflect the characteristics of earthquake data from hard-rock site, and their application to the practical nuclear structures on the hard-rock sites was not justified sufficiently. This paper is focused on the response impact of hard-rock coherency model proposed in 2007 on the incoherent SSI analysis results of nuclear power plant (NPP) structure. A typical reactor building of pressurized water reactor (PWR) type NPP is modeled classified into surface and embedded foundations. The model is also assumed to be located on medium-hard rock and hard-rock sites. The SSI analysis results are obtained and compared in case of coherent and incoherent input motions. The structural responses considering rocking and torsion effects are also investigated

  8. Aespoe Pillar Stability Experiment. Final coupled 3D thermo-mechanical modeling. Preliminary particle mechanical modeling

    International Nuclear Information System (INIS)

    SKB is planning to perform a large-scale pillar stability experiment called APSE (Aespoe Pillar Stability Experiment) at Aespoe HRL. The study is focused on understanding and control of progressive rock failure in hard crystalline rock and damage caused by high stresses. The elastic thermo-mechanical modeling was carried out in three dimensions because of the complex test geometry and in-situ stress tensor by using a finite-difference modeling software FLAC3D. Cracking and damage formation were modeled in the area of interest (pillar between two large scale holes) in two dimensions by using the Particle Flow Code (PFC), which is based on particle mechanics. FLAC and PFC were coupled to minimize the computer resources and the computing time. According to the modeling the initial temperature rises from 15 deg C to about 65 deg C in the pillar area during the heating period of 120 days. The rising temperature due to thermal expansion induces stresses in the pillar area and after 120 days heating the stresses have increased about 33% from the excavation induced maximum stress of 150 MPa to 200 MPa in the end of the heating period. The results from FLAC3D model showed that only regions where the crack initiation stress has exceeded were identified and they extended to about two meters down the hole wall. These could be considered the areas where damage may occur during the in-situ test. When the other hole is pressurized with a 0.8 MPa confining pressure it yields that 5 MPa more stress is needed to damage the rock than without confining pressure. This makes the damaged area in some degree smaller. High compressive stresses in addition to some tensile stresses might induce some AE (acoustic emission) activity in the upper part of the hole from the very beginning of the test and are thus potential areas where AE activities may be detected. Monitoring like acoustic emissions will be measured during the test execution. The 2D coupled PFC-FLAC modeling indicated that

  9. New Rock Abrasivity Test Method for Tool Life Assessments on Hard Rock Tunnel Boring: The Rolling Indentation Abrasion Test (RIAT)

    Science.gov (United States)

    Macias, F. J.; Dahl, F.; Bruland, A.

    2016-05-01

    The tunnel boring machine (TBM) method has become widely used and is currently an important presence within the tunnelling industry. Large investments and high geological risk are involved using TBMs, and disc cutter consumption has a great influence on performance and cost, especially in hard rock conditions. Furthermore, reliable cutter life assessments facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory tests for rock abrasivity assessments are needed. A new abrasivity test method by rolling disc named Rolling Indentation Abrasion Test (RIAT) has been developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods. Wear by rolling contact on intact rock samples is introduced and several rock types, covering a wide rock abrasiveness range, have been tested by RIAT. The RIAT procedure indicates a great ability of the testing method to assess abrasive wear on rolling discs. In addition and to evaluate the newly developed RIAT test method, a comprehensive laboratory testing programme including the most commonly used abrasivity test methods and the mineral composition were carried out. Relationships between the achieved results from conventional testing and RIAT results have been analysed.

  10. Research on definition of hard rock shear wave velocity of site for nuclear power plant

    International Nuclear Information System (INIS)

    Background: The definition of hard rock shear wave velocity is one of the most critical issues in the work of site selection. Purpose: To make a definition of hard rock site on which the model can be assumed as fixed-base condition, a series of research had been done. Several possible hard rock site soil models were developed. Methods: Shear wave velocity of hard rock had been assumed from 1100 m/s to 3200 m/s. For each case, free field analysis and soil structure analysis had been performed. And responses in soil and key nodes of structure were compared. Results: In free field analysis, responses of models that shear wave velocity below 2400 m/s decreased a lot. In SSI analysis, structure responses didn't change much when shear wave velocity was above 2400 m/s. Conclusions: 2400 m/s was the lowest shear wave velocity for hard rock site for fixed-base assumption. (authors)

  11. An Estimation Method of Stress in Soft Rock Based on In-situ Measured Stress in Hard Rock

    Institute of Scientific and Technical Information of China (English)

    LI Wen-ping; LI Xiao-qin; SUN Ru-hua

    2007-01-01

    The law of variation of deep rock stress in gravitational and tectonic stress fields is analyzed based on the Hoek-Brown strength criterion. In the gravitational stress field, the rocks in the shallow area are in an elastic state and the deep, relatively soft rock may be in a plastic state. However, in the tectonic stress field, the relatively soft rock in the shallow area is in a plastic state and the deep rock in an elastic state. A method is proposed to estimate stress values in coal and soft rock based on in-situ measurements of hard rock. Our estimation method relates to the type of stress field and stress state. The equations of rock stress in various stress states are presented for the elastic, plastic and critical states. The critical state is a special stress state, which indicates the conversion of the elastic to the plastic state in the gravitational stress field and the conversion of the plastic to the elastic state in the tectonic stress field. Two cases studies show that the estimation method is feasible.

  12. The Fracture Influence on the Energy Loss of Compressed Air Energy Storage in Hard Rock

    Directory of Open Access Journals (Sweden)

    Hehua Zhu

    2015-01-01

    Full Text Available A coupled nonisothermal gas flow and geomechanical numerical modeling is conducted to study the influence of fractures (joints on the complex thermohydromechanical (THM performance of underground compressed air energy storage (CAES in hard rock caverns. The air-filled chamber is modeled as porous media with high porosity, high permeability, and high thermal conductivity. The present analysis focuses on the CAES in hard rock caverns at relatively shallow depth, that is, ≤100 m, and the pressure in carven is significantly higher than ambient pore pressure. The influence of one discrete crack and multiple crackson energy loss analysis of cavern in hard rock media are carried out. Two conditions are considered during each storage and release cycle, namely, gas injection and production mass being equal and additional gas injection supplemented after each cycle. The influence of the crack location, the crack length, and the crack open width on the energy loss is studied.

  13. A new technology for hard-rock tunneling based on drilling and hydraulic impact breaking

    Institute of Scientific and Technical Information of China (English)

    Long Risheng; Sun Shaoni; Lian Zisheng; Liao Yaoyao; Qin Xiaofeng

    2015-01-01

    In order to realize the safety, high efficiency and rapidity of hard rock tunneling, we propose the drilling&hydraulic impact hard-rock tunneling (DHIHT) technology and method. Based on the LS-DYNA explicit module and APDL programming, the key parameters of DHIHT, including drilling spacing and drilling radius, were investigated. The simulation results show that: the drilling spacing should not exceed 0.20 m-larger distances weaken the actual breaking effect;the best drilling radius is about 0.035 m, lar-ger or smaller distances would both decrease the effect of drilling-hole free surfaces. The field impact breaking experiments were conducted in Baitaizi township granite quarry, Jinzhou, Liaoning province, China. The experiment results indicate that DHIHT is a feasible method for hard-rock tunneling, but its efficiency still needs to be further optimized and improved.

  14. Outcrop Groundwater Prospecting, Drilling, and Well Construction in Hard Rocks in Semi-arid Regions

    OpenAIRE

    Chambel, António

    2014-01-01

    This chapter presents some recommendations for prospecting, drilling and well construction in hard rocks in semi-arid regions. Considering that these conditions are present in many countries where technology is not always available, the chapter concentrates on the most basic and simple methods to plan where best to drill and maximize success through the direct observation of rock types, weathering and fracturing. The advantage for the geologist and hydrogeologist in an arid or semi-arid envir...

  15. Choice of grouting method for jointed hard rock based on sealing time predictions

    OpenAIRE

    Dalmalm, Thomas

    2004-01-01

    This thesis concerns subjects related to the choice of agrouting method in a jointed hard rock mass. By calculating thetotal sealing time to reach the requested sealing level,different grouting methods could be compared and the mostfavourable chosen. A methodology, to calculate the sealing time for differentgrouting methods in different rock masses has been developed.Five main activities are included in the methodology; drilling,grouting, waiting, probing and re-grouting, which to differingde...

  16. Dynamics of ultrasonic percussive drilling of hard rocks

    Science.gov (United States)

    Wiercigroch, M.; Wojewoda, J.; Krivtsov, A. M.

    2005-02-01

    Ultrasonic percussive drilling with diamond-coated tools has been extensively studied under laboratory conditions on rocks such as sandstone, limestone, granite and basalt, in order to investigate the applicability of this technique to downhole drilling. An experimental set-up, a programme of work and example results are presented. The studies showed that an introduction of high-frequency axial vibration significantly enhances drilling rates compared to the traditional rotary type method. It has been found out that the material removal rate (MRR) as a function of static load has at least one maximum. Looking at the time histories of the measured drilling force, strong nonlinear effects have been observed, which were explained using simple nonlinear models. Among them, pure impact and impact with dry friction oscillators were used to provide an insight into the complex dynamics of ultrasonic percussive drilling. It is postulated that the main mechanism of the MRR enhancement is associated with high amplitudes of forces generated by impacts. Novel procedures for calculating MRR are proposed, explaining an experimentally observed fall of MRR at higher static loads.

  17. Groundwater Resources Potential in Hard Rock Terrain: A Multivariate Approach.

    Science.gov (United States)

    Earon, Robert; Dehkordi, S Emad; Olofsson, Bo

    2015-01-01

    Groundwater resources are limited and difficult to predict in crystalline bedrock due to heterogeneity and anisotropy in rock fracture systems. Municipal-level governments often lack the resources for traditional hydrogeological tests when planning for sustainable use of water resources. A new methodology for assessing groundwater resources potential (GRP) based on geological and topographical factors using principal component analysis (PCA) and analysis of variance (ANOVA) was developed and tested. ANOVA results demonstrated statistically significant differences in classed variable groups as well as in classed GRP scores with regard to hydrogeological indicators, such as specific capacity (SC) and transmissivity. Results of PCA were used to govern the weight of the variables used in the prediction maps. GRP scores were able to identify 79% of wells in a verification dataset, which had SC values less than the total dataset median. GRP values showed statistically significant correlations using both parametric (using transformed datasets) and non-parametric methods. The method shows promise for municipal or regional level planning in crystalline terrains with high levels of heterogeneity and anisotropy as a hydrogeologically and statistically based tool to assist in assessing groundwater resources. The methodology is executed in a geographic information systems environment, and uses often readily available data, such as geological maps, feature maps and topography, and thus does not require expensive and time-consuming aquifer tests. PMID:25214009

  18. Aespoe Pillar Stability Experiment. Final experiment design, monitoring results and observations

    International Nuclear Information System (INIS)

    The field part of the Aespoe Pillar Stability Experiment at the Aespoe Hard Rock Laboratory (HRL) was finished in 2004. The experiment was designed to induce and monitor the process of brittle failure, spalling, in a fractured rock mass under controlled conditions. The field part was successfully conducted and a large data set was obtained. This report presents the final design of the experiment, the results of the monitoring, and the observations made during the spalling process and when the spalled rock was removed. When heating of the rock was initiated the rock responded quickly. After only a few days the spalling process was activated in the notch, as indicated by the acoustic emission system, and shortly thereafter displacement readings were recorded. Contraction (radial expansion) of the rock was recorded by several instruments before the notch reached the instrument levels. This contraction is probably the result of a 3D re-distribution of the stresses. The temperature increase in the system was both slower and reached a steady state much earlier than predicted by the numerical models. The propagation of the notch was therefore halted after approximately one month of heating. The power to the electrical heaters was therefore doubled. Spalling then started up again, and in one month's time it had propagated to a depth of approximately five metres in the hole. A second steady state was now reached, but this time the heater power was kept constant for a while to let the rock settle before the confinement pressure was reduced from 700 kPa to 0 in decrements of 50 kPa. The rock mass response to the pressure drop was very limited until the pressure was lowered to approximately 200 kPa (the atmospheric pressure is not included in the given pressure values). Large displacements and a high acoustic emission hit frequency were then measured in the open hole. After the de-pressurization of the confined hole, the heaters were left on for approximately one week before

  19. Long-range spatial dependence in fractured rock. Empirical evidence and implications for tracer transport

    International Nuclear Information System (INIS)

    Nonclassical stochastic continuum models incorporating long-range spatial dependence are evaluated as models for fractured crystalline rock. Open fractures and fracture zones are not modeled explicitly in this approach. The fracture zones and intact rock are modeled as a single stochastic continuum. The large contrasts between the fracture zones and unfractured rock are accounted for by making use of random field models specifically designed for highly variable systems. Hydraulic conductivity data derived from packer tests in the vicinity of the Aespoe Hard Rock Laboratory form the basis for the evaluation. The Aespoe log K data were found to be consistent with a fractal scaling model based on bounded fractional Levy motion (bfLm), a model that has been used previously to model highly variable sedimentary formations. However, the data are not sufficient to choose between this model, a fractional Brownian motion model for the normal-score transform of log K, and a conventional geostatistical model. Stochastic simulations conditioned by the Aespoe data coupled with flow and tracer transport calculations demonstrate that the models with long-range dependence predict earlier arrival times for contaminants. This demonstrates the need to evaluate this class of models when assessing the performance of proposed waste repositories. The relationship between intermediate-scale and large-scale transport properties in media with long-range dependence is also addressed. A new Monte Carlo method for stochastic upscaling of intermediate-scale field data is proposed

  20. Aespoe Pillar Stability Experiment. Final 2D coupled thermo-mechanical modelling

    International Nuclear Information System (INIS)

    A site scale Pillar Stability Experiment is planned in the Aespoe Hard Rock Laboratory. One of the experiment's aims is to demonstrate the possibilities of predicting spalling in the fractured rock mass. In order to investigate the probability and conditions for spalling in the pillar 'prior to experiment' numerical simulations have been undertaken. This report presents the results obtained from 2D coupled thermo-mechanical numerical simulations that have been done with the Finite Element based programme JobFem. The 2D numerical simulations were conducted at two different depth levels, 0.5 and 1.5 m below tunnel floor. The in situ stresses have been confirmed with convergence measurements during the excavation of the tunnel. After updating the mechanical and thermal properties of the rock mass the final simulations have been undertaken. According to the modelling results the temperature in the pillar will increase from the initial 15.2 deg up to 58 deg after 120 days of heating. Based on these numerical simulations and on the thermal induced stresses the total stresses are expected to exceed 210 MPa at the border of the pillar for the level at 0.5 m below tunnel floor and might reach 180-182 MPa for the level at 1.5 m below tunnel floor. The stresses are slightly higher at the border of the confined hole. Upon these results and according to the rock mechanical properties the Crack Initiation Stress is exceeded at the border of the pillar already after the excavation phase. These results also illustrate that the Crack Damage Stress is exceeded only for the level at 0.5 m below tunnel floor and after at least 80 days of heating. The interpretation of the results shows that the required level of stress for spalling can be reached in the pillar

  1. Numerical analysis for heating and infiltration test at model deposition hole in underground hard rock laboratory

    International Nuclear Information System (INIS)

    Various insitu tests for the safety disposal of radioactive waste are conducted in the Swedish underground hard rock laboratory. Canister Retrieval Test (CRT) is a heating and infiltration test at a full-scale deposition hole. In this paper, we conducted thermo-hydro-mechanical coupled analysis for CRT and compared the results with measured data. The evolution of temperature and relative humidity and the profiles of bentonite's dry density were well reproduced by numerical analysis. Sensitivity analysis was also conducted in order to investigate the influence of hydraulic properties of surrounding rock mass on re-saturation behavior of bentonite in a deposition hole. (author)

  2. Estimating aquifer properties and distributed groundwater recharge in a hard-rock catchment of Udaipur, India

    Science.gov (United States)

    Machiwal, Deepesh; Singh, P. K.; Yadav, K. K.

    2016-09-01

    The present study determined aquifer parameters in hard-rock aquifer system of Ahar River catchment, Udaipur, India by conducting 19 pumping tests in large-diameter wells. Spreadsheet programs were developed for analyzing pumping test data, and their accuracy was evaluated by root mean square error (RMSE) and correlation coefficient (R). Histograms and Shapiro-Wilk test indicated non-normality (p value post-monsoon groundwater levels at 50 sites for years 2006-2008, and hence, logarithmic transformations were done. Furthermore, recharge was estimated using GIS-based water table fluctuation method. The groundwater levels were found to be influenced by the topography, presence of structural hills, density of pumping wells, and seasonal recharge. The results of the pumping tests revealed that the transmissivity (T) ranges from 68-2239 m2/day, and the specific yield (S y) varies from 0.211 to 0.51 × 10-5. The T and S y values were found reasonable for the hard-rock formations in the area, and the spreadsheet programs were found reliable (RMSE ~0.017-0.339 m; R > 0.95). Distribution of the aquifer parameters and recharge indicated that the northern portion with high ground elevations (575-700 m MSL), and high S y (0.08-0.25) and T (>600 m2/day) values may act as recharge zone. The T and S y values revealed significant spatial variability, which suggests strong heterogeneity of the hard-rock aquifer system. Overall, the findings of this study are useful to formulate appropriate strategies for managing water resources in the area. Also, the developed spreadsheet programs may be used to analyze the pumping test data of large-diameter wells in other hard-rock regions of the world.

  3. Groundwater resources in coastal hard rock terrains : Geostatistical and GIS approach

    OpenAIRE

    Dehkordi, S. Emad

    2009-01-01

    Stockholm archipelago is a combination of coastal and young glaciated conditions on hard rock geology with almost no primary porosity and very limited secondary porosity. Therefore the aquifer is both of limited capacity and exposed to salinity problem. In this context importance of fractures and soil cover is magnified. Lineaments are representatives of fractures in remote sensing. Fracture mapping in study area proves close correspondence between orientation of fractures and nearly located ...

  4. An accessible hydrogeological tool to monitor critical groundwater resources in hard-rock aquifers

    OpenAIRE

    Rohde, Melissa M.; Edmunds, W. Mike; Sharma, Somendra

    2015-01-01

    Groundwater resources are increasingly being relied on in rural areas for income generation and food security. However, there is currently a lack of simple, yet accessible hydrogeological tools to monitor critical groundwater resources, both for quantity and quality. This is particularly true in developing countries underlain by fractured hard rock aquifers, with low productivities. Electrical conductivity (EC) meters are presented here as an easy-to-use tool that can provide real-time data c...

  5. Release consequence analysis for a hypothetical geologic radioactive waste repository in hard rock

    International Nuclear Information System (INIS)

    This report makes an evaluation of the long-term behaviour of the wastes placed in a hard rock repository. Impacts were analyzed for the seven reference fuel cycles of WG 7. The reference repository for this study is for granitic rock or gneiss as the host rock. The descriptions of waste packages and repository facilities used in this study represent only one of many possible designs based on the multiple barriers concept. The repository's size is based on a nuclear economy producing 100 gigawatts of electricity per year for 1 year. The objective of the modeling efforts presented in this study is to predict the rate of transport of radioactive contaminants from the repository through the geosphere to the biosphere and thus determine an estimate of the potential dose to humans so that the release consequence impacts of the various fuel cycles can be compared. Currently available hydrologic, leach, transport, and dose models were used in this study

  6. The ICUTROC project - roadheaders for hard rock applications and influences on their cutting performance

    Energy Technology Data Exchange (ETDEWEB)

    Gehring, K.H.; Fuchs, M. [Voest Alpine Bergtechnik Zeltweg, Zeltweg (Austria)

    2002-07-01

    The main fields of application for roadheaders have been roadway drivage in coal mines and for mineral production. Their main field of application in tunnelling is in softer and partly friable rock formation. However, in longer tunnel sections excavators with high ripping forces have replaced roadheaders in many situations. The main arguments against roadheaders are: a sharp increase in excavation cost with increasing rock strength and increasing abrasivity; and greater risks in conditions which have not been, or could not be, investigated to a sufficient extent. To address these limitations, factors which could make roadheaders attractive for such conditions and could overcome existing technological difficulties have been investigated. Extension of the economic field of application in hard rock was found to be the most important and the most effective step forward. 9 refs., 13 figs., 11 tabs.

  7. A Coupled Thermo-Hydro-Mechanical Model of Jointed Hard Rock for Compressed Air Energy Storage

    Directory of Open Access Journals (Sweden)

    Xiaoying Zhuang

    2014-01-01

    Full Text Available Renewable energy resources such as wind and solar are intermittent, which causes instability when being connected to utility grid of electricity. Compressed air energy storage (CAES provides an economic and technical viable solution to this problem by utilizing subsurface rock cavern to store the electricity generated by renewable energy in the form of compressed air. Though CAES has been used for over three decades, it is only restricted to salt rock or aquifers for air tightness reason. In this paper, the technical feasibility of utilizing hard rock for CAES is investigated by using a coupled thermo-hydro-mechanical (THM modelling of nonisothermal gas flow. Governing equations are derived from the rules of energy balance, mass balance, and static equilibrium. Cyclic volumetric mass source and heat source models are applied to simulate the gas injection and production. Evaluation is carried out for intact rock and rock with discrete crack, respectively. In both cases, the heat and pressure losses using air mass control and supplementary air injection are compared.

  8. The Influence of Ephemeral Beaches on Alongshore Variability of Hard-rock Cliff Erosion

    Science.gov (United States)

    Vann Jones, E. C.; Rosser, N. J.; Brain, M.; Varley, S. J.

    2015-12-01

    The role of abrasion of rock cliffs is typically considered in the long-term presence of a beach. During monthly monitoring of hard rock cliff erosion along the North Yorkshire coast, UK, we have observed a number of small ephemeral beaches of highly variable duration and extent. The erosive significance of the temporary presence of sediment at the cliffs is unknown and we set out to examine whether observed alongshore variability in erosion can be linked to the presence of ephemeral beaches. We explore the temporal and spatial variability in sediment deposition and transport along a low-sediment rock coast foreshore, the controlling marine conditions and the effects on cliff erosion. We focus on a 500 m wide embayment set into 70 m high hard rock cliffs consisting of horizontally bedded Jurassic mudstone, shale, siltstone and sandstone. The bay has a wide, shallow gradient foreshore up to 300 m wide with highly variable topography. With the exception of an ephemeral beach (of widths up to approximately 150 m alongshore and 10 m cross-shore) the rock foreshore is typically sand-free, with failed material from the cliffs quickly removed from the cliff toe by the sea leaving only boulders. The high tidal range (6 m) and storm wave environment of the North Sea result in variable marine conditions at the site. We use magnetic sand tracers and a grid of foreshore and cliff face magnets to examine the sand transport across the foreshore and to identify the vertical extent of cliff face impacted by sand. We monitor the driving marine conditions on the foreshore using a network of current meters and wave pressure sensors. Erosion of the cliff face across the whole bay is monitored at high-resolution using terrestrial laser scanning to examine the spatial distribution of abrasion and the influence of the ephemeral beach.

  9. Application of the multi-rate diffusion approach in tracer test studies at Aespoe HRL. Final report

    International Nuclear Information System (INIS)

    This report summarizes an investigation into heterogeneous diffusivity and associated parameters within granitic rocks at the Aespoe Hard Rock Laboratory (HRL). Our tasks for this investigation were: (1) to assess the potential for either anomalous or multi-rate diffusion within Aespoe rocks; (2) to evaluate existing data relating to anomalous and multi-rate diffusion within Aespoe rocks; (3) to perform scoping calculations in support of a Long Term Diffusion Experiment (LTDE) design; and (4) to begin developing a mathematical and computer model for solute advection in the presence of anomalous matrix diffusion. In addition to carrying out these tasks, we also report on (5) the late-time behavior of breakthrough curves. First, in regard to the potential for anomalous and multi-rate diffusion and analyses of existing data, we find that (1) in a literature review of 100 column experiments in various types of rock and sediment, rate coefficients decrease with experimental observation time. This is precisely what would be expected of both multi-rate and anomalous diffusion. (2) Three sets of through-diffusion experiments in Fenno-Scandian granitic rock found decreasing effective diffusivity, De, with sample length, while one set did not. (3) Based on diffusivity and sorption data, and speculation on matrix block size variability, the total variability of Da/a2 may reasonably be expected to exceed 4 orders of magnitude. (4) Analyses of two-well tracer data completed to date are ambiguous with respect to multi-rate diffusion. Analyses of TRUE data are currently underway and may support multi-rate diffusion. Second, in regard to the potential consequences of multi-rate and anomalous diffusion on nuclear waste disposal, we found the following key points: (1) No single value of diffusivity can represent the diffusion process at all time- or length-scales if diffusion is truly anomalous, while a single value of diffusivity will represent diffusion adequately for some cases

  10. An accessible hydrogeological tool to monitor critical groundwater resources in hard-rock aquifers

    Directory of Open Access Journals (Sweden)

    Melissa M Rohde

    2015-10-01

    Full Text Available Groundwater resources are increasingly being relied on in rural areas for income generation and food security. However, there is currently a lack of simple, yet accessible hydrogeological tools to monitor critical groundwater resources, both for quantity and quality. This is particularly true in developing countries underlain by fractured hard rock aquifers, with low productivities. Electrical conductivity (EC meters are presented here as an easy-to-use tool that can provide real-time data collection to enhance routine groundwater monitoring in rural areas. A program was established within a fractured hard rock watershed for over a year in Rajasthan, India to determine the effectiveness and controls over EC as a monitoring tool. The initial groundwater quality in this region was largely influenced by rainfall, modified by evapotranspiration with recognizable input from water-rock interaction in the later months following the monsoon season. Chloride concentrations were linearly correlated with EC in all of the sampled groundwater, but the strength of the correlation attenuated in the months following the monsoon. Recharge rates were estimated using the chloride mass balance (CMB approach, and then compared to the recharge rates derived from using EC as a surrogate for in what is referred to here as the CMB-EC approach. Recharge rates estimated from the CMB and CMB-EC methods were statistically similar (p=0.44.

  11. Fault Rock Zones Characterisation - Final report. TRUE-1 Continuation Project

    Energy Technology Data Exchange (ETDEWEB)

    Winberg, Anders (ed.) (Conterra AB (Sweden))

    2010-11-15

    At the conclusion of the TRUE-1 and TRUE Block Scale experimental programmes at the Aespoe Hard Rock Laboratory one remaining identified uncertainty was the in situ internal structure of conductive structures, and in particular the in situ material properties of unconsolidated fault gouge of such conductive structures. With the aim of reducing these uncertainties an experimental program has been conducted at depth in the Aespoe Hard Rock Laboratory. Four conductive structures in the immediate vicinity of the Aespoe tunnel were identified for further study. Following basic geometrical and geological modelling based on tunnel observations, geological/ mineralogical and hydrogeological investigations in four boreholes at each site, epoxy resin was injected in selected packed off borehole sections containing the structure. Following a sufficient time for curing of the epoxy, the injected borehole 72 mm sections were overcored with a 300 mm core barrel. Customised techniques were employed to section the core in the borehole and for its retrieval out of the borehole. Following basic geological mapping, selected overcores were sectioned and were subject to image analysis to assess the pore structure using a variety of different descriptive geometrical attributes. In addition, an attempt was made to infer the porosity of the fault rock (including fault gouge) using binary images. Since analysis has been made on multiple slices of impregnated rock it is also possible to crudely map the 3D variability of a given entity. It was furthermore identified that porosity estimates, which range from some 10-70% are, apart from being dependent on the penetration of the epoxy, dependent on the resolution of the given image, the size of the averaging window, and the porosity components contained therein. The obtained quantifications of porosity can therefore only be regarded as ball-park relative porosities of a complete fault rock zones. It does not, however, provide firm

  12. Ancient microbial activity recorded in fracture fillings from granitic rocks (Äspö Hard Rock Laboratory, Sweden).

    Science.gov (United States)

    Heim, C; Lausmaa, J; Sjövall, P; Toporski, J; Dieing, T; Simon, K; Hansen, B T; Kronz, A; Arp, G; Reitner, J; Thiel, V

    2012-07-01

    Fracture minerals within the 1.8-Ga-old Äspö Diorite (Sweden) were investigated for fossil traces of subterranean microbial activity. To track the potential organic and inorganic biosignatures, an approach combining complementary analytical techniques of high lateral resolution was applied to drill core material obtained at -450 m depth in the Äspö Hard Rock Laboratory. This approach included polarization microscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS), confocal Raman microscopy, electron microprobe (EMP) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The fracture mineral succession, consisting of fluorite and low-temperature calcite, showed a thin (20-100 μm), dark amorphous layer lining the boundary between the two phases. Microscopic investigations of the amorphous layer revealed corrosion marks and, in places, branched tubular structures within the fluorite. Geochemical analysis showed significant accumulations of Si, Al, Mg, Fe and the light rare earth elements (REE) in the amorphous layer. In the same area, ToF-SIMS imaging revealed abundant, partly functionalized organic moieties, for example, C(x)H(y)⁺, C(x)H(y)N⁺, C(x)H(y)O⁺. The presence of such functionalized organic compounds was corroborated by Raman imaging showing bands characteristic of C-C, C-N and C-O bonds. According to its organic nature and the abundance of relatively unstable N- and O- heterocompounds, the organic-rich amorphous layer is interpreted to represent the remains of a microbial biofilm that established much later than the initial cooling of the Precambrian host rock. Indeed, δ¹³C, δ¹⁸O and ⁸⁷Sr/⁸⁶Sr isotope data of the fracture minerals and the host rock point to an association with a fracture reactivation event in the most recent geological past.

  13. SITE-94. Rock mechanics modelling for the stability and safety of a nuclear waste repository. Executive summary

    International Nuclear Information System (INIS)

    This summary presents an outline of the aims and problems involved in a rock mechanics study which is published in, so far, three separate technical reports. The objectives of the study were to investigate the mechanical influence of repository excavation, swelling pressure, thermal loading and glaciation on the stability and safety of a hypothetical nuclear waste repository, in both far-and near-field scales. The Aespoe Hard Rock Laboratory test site was used as the target site for regional and local geology, in situ stress data and material properties. 17 refs

  14. Deciphering groundwater potential zones in hard rock terrain using geospatial technology.

    Science.gov (United States)

    Dar, Imran A; Sankar, K; Dar, Mithas A

    2011-02-01

    Remote sensing and geographical information system (GIS) has become one of the leading tools in the field of groundwater research, which helps in assessing, monitoring, and conserving groundwater resources. This paper mainly deals with the integrated approach of remote sensing and GIS to delineate groundwater potential zones in hard rock terrain. Digitized vector maps pertaining to chosen parameters, viz. geomorphology, geology, land use/land cover, lineament, relief, and drainage, were converted to raster data using 23 m×23 m grid cell size. Moreover, curvature of the study area was also considered while manipulating the spatial data. The raster maps of these parameters were assigned to their respective theme weight and class weights. The individual theme weight was multiplied by its respective class weight and then all the raster thematic layers were aggregated in a linear combination equation in Arc Map GIS Raster Calculator module. Moreover, the weighted layers were statistically modeled to get the areal extent of groundwater prospects with respect to each thematic layer. The final result depicts the favorable prospective zones in the study area and can be helpful in better planning and management of groundwater resources especially in hard rock terrains. PMID:20364317

  15. Different spatial discretization methods of fault systems on heat transport processes in hard rock aquifers

    Science.gov (United States)

    Kruppa, Lisa; König, Christoph M.; Becker, Martin; Seidel, Torsten

    2016-04-01

    Most hard rock aquifers, which are important for geothermal use, contain fractures of different type and scale. These fault systems are of major significance for heat flow in the groundwater. The hydrogeological characterization of fault systems must therefore be part of any site investigation in hard rock aquifers and hydraulically important fault systems need to be appropriately represented in associated numerical models. This contribution discusses different spatial discretization methods of fault systems in three-dimensional groundwater models and their impact on the simulated groundwater flow field as well as density and viscosity dependent heat transport. The analysis includes a comparison of the convergence behavior and numerical stability of the different discretization methods. To ensure defendable results, the utilized numerical model SPRING was first verified against data from the Hydrocoin Level 1 Case 2 project. After verification, the software was used to evaluate the impact of different discretization strategies on steady-state and transient groundwater flow and transport model results. The results show a significant influence of the spatial discretization strategy on predicted flow rates and subsequent mass fluxes as well as energy balances.

  16. Geological-economic evaluation model for pithead heap-leaching uranium deposits of hard-rock

    International Nuclear Information System (INIS)

    By analyzing the technical flow of pithead heap-leaching uranium deposits of hard-rock type, the authors analyze its 14 cost items such as ore mining fee and major materials fee etc., and set up a geological-economic evaluation model. Under this geological-evaluation model a computer evaluating program is made in Ziyuan and Lujing uranium ore-fields. The results of static evaluation show that or mining fee is the main part and amortization of both building and equipment and major materials fee are the secondary parts in the total cost of pithead heap-leaching mining. The computer program may assist decision-making in the way of helping decision-makers to select scientificaly the average grade of ore in pithead heap-leaching mining under a total cost. (authors)

  17. Aespoe Pillar Stability Experiment. Acoustic emission and ultrasonic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Pettitt, Will; Young, R. Paul [Applied Seismology Consultants Ltd., Shrewsbury (United Kingdom)

    2005-12-15

    This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB staff. This document provides an in-depth summary of the AE and ultrasonic survey results for future reference. The pillar has been produced by excavating two 1.8 m diameter deposition holes 1 m apart. These were bored in 0.8 m steps using a Tunnel Boring Machine specially adapted for vertical drilling. The first deposition hole was drilled in December 2003. Preceding this a period of background monitoring was performed so as to obtain a datum for the results. The hole was then confined to 0.7 MPa internal over pressure using a specially designed water-filled bladder. The second deposition hole was excavated in March 2004. Heating of the pillar was performed over a two month period between ending in July 2004, when the confined deposition hole was slowly depressurised. Immediately after depressurisation the pillar was allowed to cool with cessation of monitoring occurring a month later. A total of 36,676 AE triggers were recorded over the reporting period between 13th October 2003 and 14th July 2004. Of these 15,198 have produced AE locations. The AE data set

  18. The information content of high-frequency seismograms and the near-surface geologic structure of "hard rock" recording sites

    Science.gov (United States)

    Cranswick, E.

    1988-01-01

    Due to hardware developments in the last decade, the high-frequency end of the frequency band of seismic waves analyzed for source mechanisms has been extended into the audio-frequency range (>20 Hz). In principle, the short wavelengths corresponding to these frequencies can provide information about the details of seismic sources, but in fact, much of the "signal" is the site response of the nearsurface. Several examples of waveform data recorded at "hard rock" sites, which are generally assumed to have a "flat" transfer function, are presented to demonstrate the severe signal distortions, including fmax, produced by near-surface structures. Analysis of the geology of a number of sites indicates that the overall attenuation of high-frequency (>1 Hz) seismic waves is controlled by the whole-path-Q between source and receiver but the presence of distinct fmax site resonance peaks is controlled by the nature of the surface layer and the underlying near-surface structure. Models of vertical decoupling of the surface and nearsurface and horizontal decoupling of adjacent sites on hard rock outcrops are proposed and their behaviour is compared to the observations of hard rock site response. The upper bound to the frequency band of the seismic waves that contain significant source information which can be deconvolved from a site response or an array response is discussed in terms of fmax and the correlation of waveform distortion with the outcrop-scale geologic structure of hard rock sites. It is concluded that although the velocity structures of hard rock sites, unlike those of alluvium sites, allow some audio-frequency seismic energy to propagate to the surface, the resulting signals are a highly distorted, limited subset of the source spectra. ?? 1988 Birkha??user Verlag.

  19. Assessment of site-scale hydrogeological modelling possibilities in crystalline hard rock for safety appraisal

    Energy Technology Data Exchange (ETDEWEB)

    Geier, J. [Cleanwater Hardrock Consulting, Corvallis, OR (United States); Luukkonen, A.

    2012-09-15

    This review describes the state-of-the-art in hydrogeological modelling for safety-case studies related to spent-fuel repositories in crystalline hard rock, focusing on issues of relevance for the KBS-3 disposal concept in Nordic environments. The review includes a survey of model capabilities and assumptions regarding groundwater flow processes, geological and excavation-related features, and boundary conditions for temperate, periglacial, and glacial climates. Modelling approaches are compared for research sites including the Stripa mine (Sweden), the Grimsel Test Site (Switzerland), the Whiteshell Underground Research Laboratory (Canada), the Aspo Hard Rock Laboratory and Simpevarp-Laxemar site (Sweden), the Forsmark site (Sweden), the Waste Isolation Pilot Plant site (USA), and Olkiluoto (Finland). Current hydrogeological models allow realistic representations, but are limited by availability of data to constrain their properties. Examples of calibrations of stochastic representations of heterogeneity are still scarce. Integrated models that couple flow and non-reactive transport are now well established, particularly those based on continuum representations. Models that include reactive transport are still mainly in the realm of research tools. Thus far, no single software tool allows fully coupled treatment of all relevant thermal, hydraulic, mechanical, and chemical transport processes in the bedrock, together with climate-related physical processes at the ground surface, and with explicit treatment of bedrock heterogeneity. Hence practical applications require combinations of models based on different simplifications. Key improvements can be expected in treatment of the unsaturated zone, simulation of heterogeneous infiltration at the surface, and hydromechanical coupling. Significant advances have already been made in the amounts and types of data that can be used in site-scale models, including large datasets to define topography and other surface

  20. Ellipticity of Rayleigh waves in basin and hard-rock sites in Northern Italy

    Science.gov (United States)

    Berbellini, Andrea; Morelli, Andrea; Ferreira, Ana M. G.

    2016-07-01

    We measure ellipticity of teleseismic Rayleigh waves at 95 seismic stations in Northern Italy, for wave period between 10 and 110 s, using an automatic technique and a large volume of high-quality seismic recordings from over 500 global earthquakes that occurred in 2008-2014. Northern Italy includes a wide range of crustal structures, from the wide and deep Po Plain sedimentary basin to outcropping sedimentary and crystalline rocks in the Northern Apennines and Alps. It thus provides an excellent case for studying the influence of shallow earth structure on polarization of surface waves. The ellipticity measurements show excellent spatial correlation with geological features in the region, such as high ellipticity associated with regions of low seismic velocity in the Po Plain and low ellipticity values in faster, hard rock regions in the Alps and Apennine mountains. Moreover, the observed ellipticity values also relate to the thickness of the basement, as highlighted by observed differences beneath the Alps and the Apennines. Comparison between observations and predicted ellipticity from a reference crustal model of the region show substantial fit, particularly for T ˜ 38 s data. Discrepancy for shorter wave period suggests that slight modifications of the model are needed, and that the ellipticity measurements could help to better constrain the shallow crustal structure of the region. Predictions for the Po Plain are larger than the observations by a factor of four or more and transition from retrograde to prograde Rayleigh wave motion at the surface for periods of T ˜ 10-13 s is predicted for seismic stations in the plain. Analysis of corresponding real data indicates a possible detection of teleseismic prograde particle motion, but the weak teleseismic earthquake signals are mixed with ambient noise signals at the predicted, short, transition periods. Detection of the period of polarity inversion from the joint analysis of earthquake and ambient noise

  1. Hitherto unknown shear rupture mechanism as a source of instability in intact hard rocks at highly confined compression

    Science.gov (United States)

    Tarasov, Boris G.

    2014-05-01

    Today, frictional shear resistance along pre-existing faults is considered to be the lower limit on rock shear strength for confined conditions corresponding to the seismogenic layer. This paper introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. In the new mechanism, the rock failure associated with consecutive creation of small slabs (known as ‘domino-blocks') from the intact rock in the rupture tip is driven by a fan-shaped domino structure representing the rupture head. The fan-head combines such unique features as: extremely low shear resistance, self-sustaining stress intensification, and self-unbalancing conditions. Due to this the failure process caused by the mechanism is very dynamic and violent. This makes it impossible to directly observe and study the mechanism and can explain why the mechanism has not been detected before. This paper provides physical motivation for the mechanism, based upon side effects accompanying the failure process. Physical and mathematical models of the mechanism presented in the paper explain unique and paradoxical features of the mechanism. The new shear rupture mechanism allows a novel point of view for understanding the nature of spontaneous failure processes in hard rocks including earthquakes.

  2. A new diamond bit for extra-hard, compact and nonabrasive rock formation

    Institute of Scientific and Technical Information of China (English)

    王佳亮; 张绍和

    2015-01-01

    A new impregnated diamond bit was designed to solve the slipping problem when impregnated diamond bit was used for extra-hard, compact, and nonabrasive rock formation. Adding SiC grits into matrix, SiC grits can easily be exfoliated from the surface of the matrix due to weak holding-force with matrix, which made the surface non-smooth. ThreeФ36/24 mm laboratorial bits were manufactured to conduct a laboratory drilling test on zirconiacorundum refractory brick. The laboratory drilling test indicates that the abrasive resistance of the bit work layer is proportional to the SiC concentation. The higher the concentration, the weaker the abrasive resistance of matrix. The new impregnated diamond bit was applied to a mining area drilling construction in Jiangxi province, China. Field drilling application indicates that the ROP (rate of penetration) of the new bit is approximately two to three times that of the common bits. Compared with the common bits, the surface of the new bit has typical abrasive wear characteristics, and the metabolic rate of the diamond can be well matched to the wear rate of the matrix.

  3. Hard Rock Café Colombia, ejemplo de una franquicia exitosa

    Directory of Open Access Journals (Sweden)

    Julián Besedicheck Prieto

    2008-11-01

    Full Text Available La incursión y expansión de restaurantes y cadenas hoteleras en Colombia ha generado distintas oportunidades de negocio; por lo tanto, es importante analizar desde distintas ópticas este fenómeno, porque éste puede ser una solución empresarial para muchas compañías, inversionistas y personas. Con el auge del comercio internacional y la apertura económica en Colombia han ingresado un gran número de empresas al mercado nacional bajo distintas figuras, dentro de éstas se encuentra la franquicia, que ha permitido el ingreso de compañías de la industria de restaurantes como McDonald’s, Burger King, TGI Fridays, entre otras. En el siguiente artículo se observará una breve muestra del funcionamiento y desarrollo del restaurante Hard Rock Café Bogotá, desde su primer contacto con la casa matriz hasta su apertura y sus eventos durante los últimos 6 años.

  4. Hard Rock Café Colombia, ejemplo de una franquicia exitosa

    Directory of Open Access Journals (Sweden)

    Julian Besedicheck Prieto

    2008-11-01

    Full Text Available La incursión y expansión de restaurantes y cadenas hoteleras en Colombia ha generado distintas oportunidades de negocio; por lo tanto, es importante analizar desde distintas ópticas este fenómeno, porque éste puede ser una solución empresarial para muchas compañías, inversionistas y personas. Con el auge del comercio internacional y la apertura económica en Colombia han ingresado un gran número de empresas al mercado nacional bajo distintas figuras, dentro de éstas se encuentra la franquicia, que ha permitido el ingreso de compañías de la industria de restaurantes como McDonald’s, Burger King, TGI Fridays, entre otras.En el siguiente artículo se observará una breve muestra del funcionamiento y desarrollo del restaurante Hard Rock Café Bogotá, desde su primer contacto con la casa matriz hasta su apertura y sus eventos durante los últimos 6 años.

  5. A self propelled drilling system for hard-rock, horizontal and coiled tube drilling

    Energy Technology Data Exchange (ETDEWEB)

    Biglin, D.; Wassell, M.

    1997-12-31

    Several advancements are needed to improve the efficiency and reliability of both hard rock drilling and extended reach drilling. This paper will present a Self Propelled Drilling System (SPDS) which can grip the borehole wall in order to provide a stable platform for the application of weight on bit (WOB) and resisting the reactive torque created by the downhole drilling motor, bit and formation interaction. The system will also dampen the damaging effects of drill string vibration. This tool employs two hydraulically activated anchors (front and rear) to grip the borehole wall, and a two-way thrust mandrel to apply both the drilling force to the bit, and a retraction force to pull the drill string into the hole. Forward drilling motion will commence by sequencing the anchor pistons and thrust mandrel to allow the tool to walk in a stepping motion. The SPDS has a microprocessor to control valve timing, sensing and communication functions. An optional Measurement While Drilling (MWD) interface can provide two-way communication of critical operating parameters such as hydraulic pressure and piston location. This information can then be telemetered to the surface, or used downhole to autonomously control system parameters such as anchor and thrust force or damping characteristics.

  6. Aespoe Pillar Stability Experiment. Modelling of fracture development of APSE by FRACOD

    International Nuclear Information System (INIS)

    An in-situ experiment has started at Aespoe HRL to investigate the stability of a pillar between two closely located boreholes of deposition hole scale. This full-scale experiment is named the Aespoe Pillar Stability Experiment (APSE). One of the holes will be pressurized with 0.8 MPa water pressure to simulate confinement by backfill. Thermal stresses will be applied in the pillar by the use of electric heaters to reach the spalling conditions. To quantify the degree of damage during the experiment, an Acoustic Emission (AE) system will be used and strain measurements will be installed. FRACOD is a two dimensional BEM/DDM code for fracturing analysis in rock material. Here it has been used to model the rock mass response during the planned sequences of excavation-confinement-heating. The models predict the stress and displacement fields, fracture initiation and propagation, coalescence and the final failure of the rock mass. The presences of pre-existing fractures, which may have significant influence on the pillar behaviour, have also been considered in the modelling. This report summarises the modelling work using FRACOD to simulate the various experimental stages

  7. Selected elements of rock burst state assessment in case studies from the Silesian hard coal mines

    Institute of Scientific and Technical Information of China (English)

    KABIESZ Józef; MAKóWKA Janusz

    2009-01-01

    Exploitation of coal seams in the Upper Silesian Coal Basin is conducted in complex and difficult conditions. These difficulties are connected with the occurrence of many natural mining hazards and limitations resulting from the existing in this area surface infrastructure. One of the most important problems of Polish mining is the rock burst hazard and reliable evaluation of its condition. During long-years' mining practice in Poland a comprehensive system of evaluation and control of this hazard was de-veloped. In the paper the main aspects of rock burst hazard state evaluation will be presented, comprising: 1) rock mass inclination for rock bursts, I.e., rock strength properties investigation, comprehensive parametric evaluation of rock mass inclination for rock bursts, prognosis of seismic events induced by mining operations, methods of computer-aided modelling of stress and rock mass deformation parameters distribution, strategic rock mass classification under rock burst degrees; 2) immediate seismic and rock burst hazard state evaluation, I.e., low diameter test drilling method, seismologic and seismoacoustic method, comprehensive method of rock burst hazard state evaluation, non-standard methods of evaluation; 3) legal aspects of rock burst hazard state evaluation. Selected elements of the hazard state evaluation system are illustrated with specific practical examples of their applica-tion.

  8. Test with different stress measurement methods in two orthogonal bore holes in Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Janson, Thomas; Stigsson, Martin [Golder Associates AB, Stockholm (Sweden)

    2002-12-01

    Within the scope of work, to provide the necessary rock mechanics support for the site investigations, SKB has studied some available pieces of equipment for in situ stress measurements in deep boreholes. A project with the objective to compare three different pieces of equipment for in situ stress measurements under similar conditions has been carried out. The main objective for the project is to compare the three different pieces of equipment for in situ stress measurements and find a strategy for SKB's Site Investigations to determine the state of stress in the rock mass. Two units of equipment use the overcoring method while the third uses the hydraulic fracturing method. The overcoring was performed by AECL, using Deep Door stopper Gauge System (DDGS), and SwedPower, using their triaxial strain measuring instrument (Borre Probe). MeSy Geo Systeme GmbH performed the hydraulic fracturing. The DDGS system is a new method to SKB while the experience of the SwedPower overcoring and the hydraulic fracturing methods are long. The tests were performed in the same orthogonal boreholes at Aespoe Hard Rock Laboratory (HRL), Oskarshamn, Sweden. The measured results have been verified against known conditions at the Aespoe HRL. The results from the three in situ stress measurement methods rose more questions than answers. Which illustrate the complexity to determine the in situ stresses in a rock mass. To understand the difference in results and answer the questions, it was necessary to do deeper investigations such as laboratory tests and theoretical calculations such as geological structure model, analysis of the influence of a nearby fracture, P-wave measurements, uniaxial tests on small cores from the HQ-3 core, theoretical and numerical analyses of the hole bottom (theoretical strains, stress concentrations and microcracking), auditing of DDGS measurements results and assumptions in the DDGS analyse and microscopy investigations on the cores. The following

  9. Hydrogeophysics and remote sensing for the design of hydrogeological conceptual models in hard rocks - Sardón catchment (Spain)

    Science.gov (United States)

    Francés, Alain P.; Lubczynski, Maciek W.; Roy, Jean; Santos, Fernando A. M.; Mahmoudzadeh Ardekani, Mohammad R.

    2014-11-01

    Hard rock aquifers are highly heterogeneous and hydrogeologically complex. To contribute to the design of hydrogeological conceptual models of hard rock aquifers, we propose a multi-techniques methodology based on a downward approach that combines remote sensing (RS), non-invasive hydrogeophysics and hydrogeological field data acquisition. The proposed methodology is particularly suitable for data scarce areas. It was applied in the pilot research area of Sardón catchment (80 km2) located west of Salamanca (Spain). The area was selected because of hard-rock hydrogeology, semi-arid climate and scarcity of groundwater resources. The proposed methodology consisted of three main steps. First, we detected the main hydrogeological features at the catchment scale by processing: (i) a high resolution digital terrain model to map lineaments and to outline fault zones; and (ii) high-resolution, multispectral satellite QuickBird and WorldView-2 images to map the outcropping granite. Second, we characterized at the local scale the hydrogeological features identified at step one with: i) ground penetrating radar (GPR) to assess groundwater table depth complementing the available monitoring network data; ii) 2D electric resistivity tomography (ERT) and frequency domain electromagnetic (FDEM) to retrieve the hydrostratigraphy along selected survey transects; iii) magnetic resonance soundings (MRS) to retrieve the hydrostratigraphy and aquifer parameters at the selected survey sites. In the third step, we drilled 5 boreholes (25 to 48 m deep) and performed slug tests to verify the hydrogeophysical interpretation and to calibrate the MRS parameters. Finally, we compiled and integrated all acquired data to define the geometry and parameters of the Sardón aquifer at the catchment scale. In line with a general conceptual model of hard rock aquifers, we identified two main hydrostratigraphic layers: a saprolite layer and a fissured layer. Both layers were intersected and drained by

  10. Analysis of groundwater-level response to rainfall and estimation of annual recharge in fractured hard rock aquifers, NW Ireland

    Science.gov (United States)

    Cai, Zuansi; Ofterdinger, Ulrich

    2016-04-01

    Despite fractured hard rock aquifers underlying over 65% of Ireland, knowledge of key processes controlling groundwater recharge in these bedrock systems is inadequately constrained. In this study, we examined 19 groundwater-level hydrographs from two Irish hillslope sites underlain by hard rock aquifers. Water-level time-series in clustered monitoring wells completed at the subsoil, soil/bedrock interface, shallow and deep bedrocks were continuously monitored hourly over two hydrological years. Correlation methods were applied to investigate groundwater-level response to rainfall, as well as its seasonal variations. The results reveal that the direct groundwater recharge to the shallow and deep bedrocks on hillslope is very limited. Water-level variations within these geological units are likely dominated by slow flow rock matrix storage. The rapid responses to rainfall (⩽2 h) with little seasonal variations were observed to the monitoring wells installed at the subsoil and soil/bedrock interface, as well as those in the shallow or deep bedrocks at the base of the hillslope. This suggests that the direct recharge takes place within these units. An automated time-series procedure using the water-table fluctuation method was developed to estimate groundwater recharge from the water-level and rainfall data. Results show the annual recharge rates of 42-197 mm/yr in the subsoil and soil/bedrock interface, which represent 4-19% of the annual rainfall. Statistical analysis of the relationship between the rainfall intensity and water-table rise reveal that the low rainfall intensity group (⩽1 mm/h) has greater impact on the groundwater recharge rate than other groups (>1 mm/h). This study shows that the combination of the time-series analysis and the water-table fluctuation method could be an useful approach to investigate groundwater recharge in fractured hard rock aquifers in Ireland.

  11. A comparison of the effects of hard rock and easy listening on the frequency of observed inappropriate behaviors: control of environmental antecedents in a large public area.

    Science.gov (United States)

    Harris, C S; Bradley, R J; Titus, S K

    1992-01-01

    Observation of clients at a state mental health hospital by direct care staff indicated that they appeared to act in more inappropriate ways when "hard rock" or "rap" music was played in an open courtyard than when "easy listening" or "country" music was played. A study was conducted to compare the inappropriate behavior of clients when hard rock and rap music were played (21 days), followed by easy listening and country and western music (21 days). This comparison was followed by a reversal phase in which hard rock and rap music were again played (18 days). The behaviors of the clients were observed and recorded via a controlled methodology. The results demonstrated that more inappropriate behavior was observed under conditions in which hard rock and rap music were played than when easy listening and country western music were played. The implications of these findings are discussed. PMID:10118493

  12. Influence of confining stress on fracture characteristics and cutting efficiency of TBM cutters conducted on soft and hard rock

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-shuo; CAO Ping; LIU Jie; JIANG Zhe

    2015-01-01

    Combined with numerical simulation, the influence of confining stress on cutting process, fracture conditions and cutting efficiencies of soft and hard rock has been conducted on the triaxial testing machine (TRW-3000) designed and manufactured in Central South University (China). Results are obtained by performing analysis on the fracture scopes of cement and granite plates, the characteristics of cutting force in cutting processes and the cutting efficiency. Firstly, the increase of latitude fracture scope and the decrease of longitude fracture scope are both more notable in the tests conducted on cement plates subjected to the increasing confining stresses; secondly, the increase tendency of peak penetration forces obtained from tests conducted on granite plates is more obvious, however, the increase tendencies of average penetration forces achieved from cement and granite plates are close to each other; thirdly, the cutting efficiency could be improved by increasing the spacing between cutters when the confining stress which acts on soft and hard rock increases in a certain degree, and the cutting efficiency of soft rock is more sensitive to the varying confining stresses.

  13. Couple analyzing the acoustic emission characters from hard composite rock fracture

    Institute of Scientific and Technical Information of China (English)

    Xingping Lai; Linhai Wang; Meifeng Cai

    2004-01-01

    Rock mass is fractured media. Its fracture is a nonlinear process. The accumulation of acoustic emission (AE) is closely related to the degree of damage. The dynamics problem is simply described based on the non-equilibrium statistical theory of crack evolvement, trying to use the hybrid analysis of the statistical theory and scan electron microscopy (SEM), the characters of AE sig nals from rock damage in a mined-out area is synthetically analyzed and evaluated. These provide an evidence to reverse deduce and accurately infer the position of rock fracture for dynamical hazard control.

  14. Finite element calculation and model test for studying rock pressure manifestation in face during water infusion of hard roof

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Y.; Chen, H. (Beijing Research Institute of Coal Mining (China))

    1990-03-01

    Using finite element method and experimental models, the author studies the characteristics of rock pressure manifestation in working face before and after water infusion of hard roof, and under different water-infusion conditions. Comparative analysis shows that water infusion plasticizes the roof rockmass and changes the stress distribution, deformation and displacement of roof, so that the peaks of tensile and compression stresses are transferred to the hanging roof over the goaf. This facilitates the fracture and caving of roof in succession and reduces the dynamic load on the support, force transmission coefficient, and the intensity of periodic weighting. Theoretically, high pressure water infusion is an effective technical approach for controlling hard roof. 19 figs., 8 tabs.

  15. Stability of High Slope Interbedded Strata with Low Dip Angle Constituted by Soft and Hard Rock Mass

    Institute of Scientific and Technical Information of China (English)

    邓荣贵; 周德培; 张倬元

    2002-01-01

    Slopes consisting of interbedded strata of soft and hard rock mass, such as purplish red mudstone and grey-brown arkosic sandstone of Jurassic age, are very common in Sichuan basin of China. The mudstone is soft while the sandstone is hard and contains many opening or closing joints with a high dip angle. Some are nearly parallel and the others are nearly decussated with the trend of the slopes. Many natural slopes are in deformation or sliding because of those reasons. The stability of cutting slopes and supporting method to be taken for their stability in civil engineering are important. In this paper, the stability and deformation of the slopes are studied. The methods of analysis and support design principle are analyzed also. Finally, the method put forward is applied to study Fengdian high cutting slope in Sichuan section of the express way from Chengdu to Shanghai. The results indicate that the method is effective.

  16. Efficiency increase of hard rock destruction with the use of eccentric pulses

    Science.gov (United States)

    Pushmin, P.; Romanov, G.

    2015-11-01

    The increase of efficiency of expendable well-drilling directly depends on the mechanism of rock destruction. The depth of hole coverage should be at the maximum possible value and equal along the whole contact area. The design features of performing rock- destruction tool in rotary drilling prevent the cutters, located on different distance from rotation axis, from working with equal intensity. The application of the shock pulses to a boring tool increases the mechanical drilling speed and sinking per revolution. One of the techniques for the efficiency increase is the application of impactor machines. On the other hand, the high values of mechanical drilling speed require the high values of impact energy which results in high power inputs energy consumption. The use of eccentric impact loading instead of central one can provide the enhancement of rock destruction efficiency, lower the power inputs, and decrease the risk of borehole deviation.

  17. Comparison of Acoustic Energy Meter (AEM) and Schmidt hammer 'R' for rapid assessment of rock surface hardness: a preliminary assessment from southeast Queensland, Australia

    Science.gov (United States)

    Brook, Martin; Winkler, Stefan

    2015-04-01

    This research focuses on one of the key challenges in geomorphology - quantifying rock surface hardness via in situ measurements, to provide information on rock physical properties. This has been a focus in recent years with the rapid emergence of studies that center on surface and near surface weathering impacts, and rates of material loss. Indeed, a key element to understanding how weathering and erosion processes combine to influence rock surface (and landscape) evolution is the measurement and monitoring of rock surface hardness. We provide results from a preliminary assessment of the applicability of the Acoustic Energy Meter (AEM) to subaerial rock surface hardness, in comparison with an N-Type Schmidt hammer. The AEM apparatus consists of a geophone which is in contact with the rock surface and some electronics. The AEM is held normal to the surface to be tested and the surface is struck with a small hammer (typically 0.75 kg), with the AEM quantifying the decay time of seismically-induced oscillations within the top c. 1-2 m of the rock mass. Previous work using an AEM has focused on measuring roof stability and delamination in South African underground coal, gold and platinum mines, where long AEM reverberation times correlated well with weak rock mass and dense microfracturing. However, the technique has rarely been applied to the assessment of rock surfaces in a subaerial setting. We applied the technique to a range of lithologies at five sites in southeast Queensland in the Brisbane area, each an exposure of phyllite, granite, mudstone, argillite or volcanic tuff. The aims were: (1) quantifying the response of different rock masses to the AEM technique; and (2) assessing the applicability of the AEM as a rapid in situ measure of rock hardness by comparing results with Schmidt hammer 'R' values from the same exposures. Results showed that the AEM is useful in discriminating rock hardness across rocks with different lithological properties. Second, an

  18. CSM/OCRD hard rock test facility at the CSM experimental mine, Idaho Springs, Colorado

    International Nuclear Information System (INIS)

    This report is the first in a series describing research conducted by the Colorado School of Mines (CSM) for the Office of Crystalline Repository Development (OCRD) to determine the extent of blast damage in rock surrounding an underground opening. A special room, called the CSM/OCRD room, was excavated for the purpose of assessing blast damage in the rock around the room. Even though this mine is not proposed as a nuclear waste repository site, the instrumentation and methods of blast damage assessment developed in this project are applicable to proposed repository sites. This report describes the room, and summarizes the overall experimental program. 4 references, 2 figures

  19. Hydrogeological and geophysical study for deeper groundwater resource in quartzitic hard rock ridge region from 2D resistivity data

    Indian Academy of Sciences (India)

    Dewashish Kumar; V Ananda Rao; V S Sarma

    2014-04-01

    Electrical resistivity method is a versatile and economical technique for groundwater prospecting in different geological settings due to wide spectrum of resistivity compared to other geophysical parameters. Exploration and exploitation of groundwater, a vital and precious resource, is a challenging task in hard rock, which exhibits inherent heterogeneity. In the present study, two-dimensional Electrical Resistivity Tomography (2D-ERT) technique using two different arrays, viz., pole–dipole and pole–pole, were deployed to look into high signal strength data in a tectonically disturbed hard rock ridge region for groundwater. Four selected sites were investigated. 2D subsurface resistivity tomography data were collected using Syscal Pro Switch-10 channel system and covered a 2 km long profile in a tough terrain. The hydrogeological interpretation based on resistivity models reveal the water horizons trap within the clayey sand and weathered/fractured quartzite formations. Aquifer resistivity lies between ∼3–35 and 100–200 m. The results of the resistivity models decipher potential aquifer lying between 40 and 88 m depth, nevertheless, it corroborates with the static water level measurements in the area of study. The advantage of using pole–pole in conjunction with the pole–dipole array is well appreciated and proved worth which gives clear insight of the aquifer extent, variability and their dimension from shallow to deeper strata from the hydrogeological perspective in the present geological context.

  20. Utilization of hard rock dust with red clay to produce roof tiles

    Directory of Open Access Journals (Sweden)

    Mst. Shanjida Sultana

    2015-03-01

    Full Text Available Utilization of rock dust to produce roof tiles and its effects on properties of tiles, mixed with red clay collected from Naogaon district of Bangladesh were investigated. After proper characterization of the raw materials, tiles were prepared with different percentages of rock dust (10-50% mixed with clay sintered from 850-1100 °C temperature. Rock dust has been found good for using as fluxing material after XRF study. The samples were tested for different properties such as water absorption, porosity, mechanical strength, linear shrinkage, and bulk density. The strength values have exceeded the minimum standard requirement for roof tiles with low water absorption in most samples. The results obtained made it possible to conclude about the possibility of producing roof tiles incorporating up to 40% of rock dust having better properties (lower water absorption 6.5%, strength value 31.97 MPa fired at 900 °C. Therefore these dust acts as a fluxing agent and reducing the sinteringtemperature of the clay material.

  1. Hard rock excavation at the CSM/OCRD test site using Swedish blast design techniques

    International Nuclear Information System (INIS)

    This report is the third in a series describing research conducted by the Colorado School of Mines for the Office of Crystalline Repository Development (OCRD) to determine the extent of blast damage in rock surrounding an underground opening. A special room, called the CSM/OCRD room, was excavated at the CSM experimental mine for the purpose of assessing blast damage in the rock around the room. Even though this mine is not proposed as a nuclear waste repository site, the instrumentation and methods of blast damage assessment developed in this project are applicable to proposed repository sites. This report describes the application of Swedish blasting technology for the excavation of the test room. The design of the blasting patterns including the selection of explosives, hole sizes and location, explosive loading densities, and delay intervals is based upon the theories of Langefors and Kihlstrom in combination with methods used at the Swedish Detonic Research Foundation for minimizing unwanted rock damage. The practical application of the design procedures to seven rounds and the achieved results is discussed

  2. Seagrass on the rocks: Posidonia oceanica settled on shallow-water hard substrata withstands wave stress beyond predictions

    Science.gov (United States)

    Montefalcone, Monica; Vacchi, Matteo; Carbone, Cristina; Cabella, Roberto; Schiaffino, Chiara Francesca; Elter, Franco Marco; Morri, Carla; Bianchi, Carlo Nike; Ferrari, Marco

    2016-10-01

    A multidisciplinary approach was applied to investigate the role of abiotic constraints in the settlement of Posidonia oceanica on shallow rocks in two coastal areas of the Ligurian Sea (Italy, NW Mediterranean). Meadows developed very shallow upper limits, at 1.5 m depth in both areas, and with a distinctive morphology of stripes growing on rocky outcrops orthogonal to the coastline. Application of a predictive model to indicate the reference condition zone for the meadow upper limit, already validated on meadows developing on soft-bottoms, was not adequate for these rocky substrata as the meadow upper limits were found shallower than model predictions (>5 m depth). Geological and geomorphological characteristics of the rocky shores were analysed through geomechanic and petrographic analyses (i.e. thin sections, SEM analyses, rock hardness tests) whilst the shape and the features of the meadows (i.e. shoot density and maximum leaf length) were assessed through scuba diving surveys. Among the different lithotypes occurring at the sites in the alternating and interbedded outcrops, P. oceanica was passively selected (i.e. due to the seedlings survival and settlement there) on the strongest (i.e. less erodible) lithotypes, whilst the comparatively weaker and more erodible rocks remained unvegetated and covered by a layer of soft-sediments. P. oceanica, settling on specific rocky substrata with favourable lithological and geomechanical characteristics, is able to establish outside the theoretical reference zone predicted by the model for soft sediments due to greater attachment strength and possible resistance to hydrodynamic forces. Combining biological, ecological, mineralogical, geological and geomorphological approaches was effective for explaining the primary role of substratum nature in the spatial variability of seagrass meadows, with geomechanical and lithological characteristics of the rocks being equally important abiotic factors than sedimentological

  3. Smaller Footprint Drilling System for Deep and Hard Rock Environments; Feasibility of Ultra-High-Speed Diamond Drilling

    Energy Technology Data Exchange (ETDEWEB)

    TerraTek, A Schlumberger Company

    2008-12-31

    The two phase program addresses long-term developments in deep well and hard rock drilling. TerraTek believes that significant improvements in drilling deep hard rock will be obtained by applying ultra-high rotational speeds (greater than 10,000 rpm). The work includes a feasibility of concept research effort aimed at development that will ultimately result in the ability to reliably drill 'faster and deeper' possibly with smaller, more mobile rigs. The principle focus is on demonstration testing of diamond bits rotating at speeds in excess of 10,000 rpm to achieve high rate of penetration (ROP) rock cutting with substantially lower inputs of energy and loads. The significance of the 'ultra-high rotary speed drilling system' is the ability to drill into rock at very low weights on bit and possibly lower energy levels. The drilling and coring industry today does not practice this technology. The highest rotary speed systems in oil field and mining drilling and coring today run less than 10,000 rpm - usually well below 5,000 rpm. This document provides the progress through two phases of the program entitled 'Smaller Footprint Drilling System for Deep and Hard Rock Environments: Feasibility of Ultra-High-Speed Diamond Drilling' for the period starting 30 June 2003 and concluding 31 March 2009. The accomplishments of Phases 1 and 2 are summarized as follows: (1) TerraTek reviewed applicable literature and documentation and convened a project kick-off meeting with Industry Advisors in attendance (see Black and Judzis); (2) TerraTek designed and planned Phase I bench scale experiments (See Black and Judzis). Improvements were made to the loading mechanism and the rotational speed monitoring instrumentation. New drill bit designs were developed to provided a more consistent product with consistent performance. A test matrix for the final core bit testing program was completed; (3) TerraTek concluded small-scale cutting performance tests; (4

  4. Groundwater-quality data in the Santa Cruz, San Gabriel, and Peninsular Ranges Hard Rock Aquifers study unit, 2011-2012: results from the California GAMA program

    Science.gov (United States)

    Davis, Tracy; Shelton, Jennifer L.

    2014-01-01

    Groundwater quality in the 2,400-square-mile Santa Cruz, San Gabriel, and Peninsular Ranges Hard Rock Aquifers (Hard Rock) study unit was investigated by the U.S. Geological Survey (USGS) from March 2011 through March 2012, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA-PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The Hard Rock study unit was the 35th study unit to be sampled as part of the GAMA-PBP.

  5. Groundwater Quality Assessment in hard rock terrain of Rasipuram Taluk, Namakkal District

    Directory of Open Access Journals (Sweden)

    K.Ramesh,

    2016-02-01

    Full Text Available Groundwater is of most important to rural development in many countries of the world. Over exploitation of groundwater has become a major challenge not only to the present civilization and also for the future generations. The main focus of this study is to assess the suitability of groundwater quality for drinking and irrigation purposes in vicinity of Rasipuram block in Tamil Nadu. Groundwater samples from 15 locations were collected from different wells during January 2015 and analyzed for different physico-chemical parameters. The usefulness of these parameters in predicting groundwater quality characteristics were discussed. The quality of groundwater in the study area is fresh to brackish water, moderately hard to very hard in nature. The piper plot shows that the most of the groundwater samples fall in the field of Na+ -Cland mixed Ca++ -Na+ -Cltype. Water quality index rating was carried out to quantify overall groundwater quality status of the area. The WQI for these samples ranges from 37.34 to 650. Hence majority of the water samples are poor to very poor in water quality. The area in general is characterized by hard water, hence is not suitable for drinking purpose. The samples plotted in the piper and USSL diagram were used to understand the chemical characteristic of groundwater for irrigation purposes. However, the values of SAR, Na% and RSC indicate that groundwater is suitable for irrigation purposes. Overall water quality of the study area was found satisfactory for drinking purpose except in few locations and suitable for irrigation purpose. Hence the local government needs to initiate remedial measures.

  6. Epistemic uncertainty and limitations of the κ0 model for near-surface attenuation at hard rock sites

    Science.gov (United States)

    Edwards, Benjamin; Ktenidou, Olga-Joan; Cotton, Fabrice; Abrahamson, Norman; Van Houtte, Chris; Fäh, Donat

    2015-09-01

    The determination of near-surface attenuation for hard rock sites is an important issue in a wide range of seismological applications, particularly seismic hazard analysis. In this article we choose six hard to very-hard rock sites (Vs30 1030-3000 m s-1) and apply a range of analysis methods to measure the observed attenuation at distance based on a simple exponential decay model with whole-path attenuation operator κr. The κr values are subsequently decoupled from path attenuation (Q) so as to obtain estimates of near-surface attenuation (κ0). Five methods are employed to measure κr which can be split into two groups: broad-band methods and high-frequency methods. Each of the applied methods has advantages and disadvantages, which are explored and discussed through the comparison of results from common data sets. In our first step we examine the variability of the individual measured κr values. Some variation between methods is expected due to simplifications of source, path, and site effects. However, we find that significant differences arise between attenuation measured on individual recordings, depending on the method employed or the modelling decisions made during a particular approach. Some of the differences can be explained through site amplification effects: although usually weak at rock sites, amplification may still lead to bias of the measured κr due to the chosen fitting frequency bandwidth, which often varies between methods. At some sites the observed high-frequency spectral shape was clearly different to the typical κr attenuation model, with curved or bi-linear rather than linear decay at high frequencies. In addition to amplification effects this could be related to frequency-dependent attenuation effects [e.g. Q( f )]: since the κr model is implicitly frequency independent, κr will in this case be dependent on the selected analysis bandwidth. In our second step, using the whole-path κr data sets from the five approaches, we investigate

  7. Epistemic Uncertainty and Limitations of the Kappa0 model for Near-surface Attenuation at Hard Rock Sites

    Science.gov (United States)

    Edwards, Benjamin

    2016-04-01

    The determination of near-surface attenuation for hard rock sites is an important issue in a wide range of seismological applications, particularly seismic hazard analysis. In this article we choose six hard to very-hard rock sites (Vs30 1030 to 3000 m/s) and apply a range of analysis methods to measure the observed attenuation at distance based on a simple exponential decay model with whole-path attenuation operator κ. The κ values are subsequently decoupled from path attenuation (Q) so as to obtain estimates of near-surface attenuation (κ0). Five methods are employed to measure κ which can be split into two groups: broadband methods and high-frequency methods. Each of the applied methods has advantages and disadvantages, which are explored and discussed through the comparison of results from common datasets. In our first step we examine the variability of the individual measured κ values. Some variation between methods is expected due to simplifications of source, path, and site effects. However, we find that significant differences arise between attenuation measured on individual recordings, depending on the method employed or the modelling decisions made during a particular approach. Some of the differences can be explained through site amplification effects: although usually weak at rock sites, amplification may still lead to bias of the measured κ due to the chosen fitting frequency bandwidth, which often varies between methods. At some sites the observed high-frequency spectral shape was clearly different to the typical κ attenuation model, with curved or bi-linear rather than linear decay at high frequencies. In addition to amplification effects this could be related to frequency-dependent attenuation effects (e.g., Q(f)): since the κ model is implicitly frequency independent, κ will in this case be dependent on the selected analysis bandwidth. In our second step, using the whole-path κ datasets from the five approaches, we investigate the

  8. In situ heating experiments in hard rock: their objectives and design

    International Nuclear Information System (INIS)

    Of the many alternatives that are being considered for the disposal of nuclear wastes, deep underground burial is favored. The wealth of experience concerning the design and construction of underground excavations does not include the unique effects of heating excavations by radioactive decay, nor the issue of long-term isolation. The effects of heating are important in establishing the feasibility of this method of disposal and are essential for the design of an underground repository. Near-field phenomena around individual canisters can be studied by full-scale experiments, using electrical heaters. The thermal diffusivity of rock is so low that information concerning the interaction between full-scale heaters and of the effects of heating a large volume of rock cannot be measured in full-scale experiments lasting less than a few decades. To overcome this difficulty, a time-scaled heating experiment has been developed in which a reduction in linear scale is accompanied by an acceleration of the time scale to the second power. In this experiment, the linear scale is about a third, so that the time scale is about ten fold

  9. Assessment of groundwater quality for drinking and irrigation use in shallow hard rock aquifer of Pudunagaram, Palakkad District Kerala

    Science.gov (United States)

    Satish Kumar, V.; Amarender, B.; Dhakate, Ratnakar; Sankaran, S.; Raj Kumar, K.

    2016-06-01

    Groundwater samples were collected for pre-monsoon and post-monsoon seasons based on the variation in the geomorphological, geological, and hydrogeological factors for assessment of groundwater quality for drinking and irrigation use in a shallow hard rock aquifer of Pudunagaram area, Palakkad district, Kerala. The samples were analyzed for various physico-chemical parameters and major ion chemistry. Based on analytical results, Gibbs diagram and Wilcox plots were plotted and groundwater quality has been distinguished for drinking and irrigation use. Gibbs diagram shows that the samples are rock dominance and controlling the mechanism for groundwater chemistry in the study area, while Wilcox plot suggest that most of the samples are within the permissible limit of drinking and irrigation use. Further, the suitability of water for irrigation was determined by analyzing sodium adsorption ratio, residual sodium carbonate, sodium percent (%Na), Kelly's ratio, residual sodium carbonate, soluble sodium percentage, permeability index, and water quality index. It has been concluded that, the water from the study area is good for drinking and irrigation use, apart few samples which are exceeding the limits due to anthropogenic activities and those samples were indisposed for irrigation.

  10. Heat-energy storage through semi-opened circulation into low-permeability hard-rock aquifers

    Science.gov (United States)

    Pettenati, Marie; Bour, Olivier; Ausseur, Jean-Yves; de Dreuzy, Jean-Raynald; de la Bernardie, Jérôme; Chatton, Eliot; Lesueur, Hervé; Bethencourt, Lorine; Mougin, Bruno; Aquilina, Luc; Koch, Florian; Dewandel, Benoit; Boisson, Alexandre; Mosser, Jean-François; Pauwels, Hélène

    2016-04-01

    In low-permeability environments, the solutions of heat storage are still limited to the capacities of geothermal borehole heat exchangers. The ANR Stock-en-Socle project explores the possibilities of periodic storage of sensitive heat1 in low-permeability environments that would offer much better performance than that of borehole heat exchangers, especially in terms of unit capacity. This project examines the storage possibilities of using semi-open water circulation in typically a Standing Column Well (SCW), using the strong heterogeneity of hard-rock aquifers in targeting the least favorable areas for water resources. To solve the main scientific issues, which include evaluating the minimum level of permeability required around a well as well as its evolution through time (increase and decrease) due to water-rock interaction processes, the study is based on an experimental program of fieldwork and modelling for studying the thermal, hydraulic and geochemical processes involved. This includes tracer and water-circulation tests by injecting hot water in different wells located in distinct hard-rock settings (i.e. granite and schist) in Brittany, Ploemeur (H+ observatory network) and Naizin. A numerical modelling approach allows studying the effects of permeability structures on the storage and heat-recovery capacities, whereas the modelling of reactive transfers will provide an understanding of how permeability evolves under the influence of dissolution and precipitation. Based on the obtained results, technical solutions will be studied for constructing a well of the SCW type in a low-permeability environment. This work will be completed by a technical and economic feasibility study leading to an investment and operations model. This study aims to describe the suitability of SCW storage for shallow geothermal energy. In order to reach these objectives, Stock-en-Socle is constructed around a public/private partnership between two public research organizations, G

  11. Choosing between rocks, hard places and a lot more. The economic interface

    International Nuclear Information System (INIS)

    decisions: for deciding whether or not to explore or develop, for choosing between exploration prospects ('rocks') in a licensing round, for choosing between basins or countries ('places') in which one wants to explore and produce, and for choosing between development concepts, recovery mechanisms, plateau rates, ... (and a lot more), in field development planning. Due to the largely unpredictable nature of the subsurface and the future oil price, the concepts of 'risk' (=possibility of a financial loss or an unachieved objective) and unfortunately, to a lesser extent 'grisk' (possibility of a financial gain in excess of the objective) are quite central in the oil business. Illustrations of 'risk' and 'grisk' will be presented. 24 refs

  12. Statistical patterns of geochemistry in crystalline rock and effect of sorption kinetics on radionuclide migration

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Shulan; Woerman, A. [Uppsala Univ. (Sweden). Dept. of Earth Sciences

    1998-09-01

    The overall objective of the current project is to develop a quantitative understanding of the effects of spatial variability in physical and geochemical properties of the rock on the migration of radionuclides along a single fracture in crystalline rock. The strategy is first to deduce the basic geostatistics of the main model parameters by means of detailed laboratory (batch) experiments on a large number of rock samples taken from Swedish crystalline basement. The results are then analysed by geostatistical methods and used for stochastic interpretations of a series of laboratory migration experiments to be conducted in a later phase of the project. In an earlier phase of the project, a new mathematical model was developed as a basis for the interpretation of experimental results and the generalisation to performance assessment analyses. The model describes migration of radionuclides along a two-dimensional fracture and includes the transversal diffusion into the rock matrix and surface. To be able to discriminate between the effects of parameter heterogeneity and potential effects of kinetics, a model description has also been developed for first-order sorption kinetics. The main model parameters are represented as spatially random. This report contains results from the batch tests and the geostatistical analysis and the progress of the model formulation for transport of radionuclides. Geostatistics of the main parameters was experimentally determined for two rock types, Aespoe diorite, and Smaaland granite. Drill cores were collected at the Aespoe Hard Rock Laboratory and sawn into a large number of slabs. The porosity, the effective diffusivity and the adsorption characteristics were determined using various experimental methods on the individual pieces. Semi-variograms show that both porosity and effective diffusivity are correlated over a separation distance of 30 to 40 cm. The coefficients of variation of the porosity of rock samples with a size of 20x20

  13. Influence of intermediate principal stress on failure mechanism of hard rock with a pre-existing circular opening

    Institute of Scientific and Technical Information of China (English)

    张社荣; 孙博; 王超; 严磊

    2014-01-01

    Based on particle flow theory, the influences of the magnitude and direction of the intermediate principal stress on failure mechanism of hard rock with a pre-existing circular opening were studied by carrying out true triaxial tests on siltstone specimen. It is shown that peak strength of siltstone specimen increases firstly and subsequently decreases with the increase of the intermediate principal stress. And its turning point is related to the minimum principal stress and the direction of the intermediate principal stress. Failure characteristic (brittleness or ductility) of siltstone is determined by the minimum principal stress and the difference between the intermediate and minimum principal stress. The intermediate principal stress has a significant effect on the types and distributions of microcracks. The failure modes of the specimen are determined by the magnitude and direction of the intermediate principal stress, and related to weakening effect of the opening and inhibition effect of confining pressure in essence:when weakening effect of the opening is greater than inhibition effect of confining pressure, the failure surface is parallel to the x axis (such as σ2=σ3=0 MPa);conversely, the failure surface is parallel to the z axis (such asσ2=20 MPa,σ3=0 MPa).

  14. Site investigations: Strategy for rock mechanics site descriptive model

    International Nuclear Information System (INIS)

    As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate

  15. Site investigations: Strategy for rock mechanics site descriptive model

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Johan [JA Streamflow AB, Aelvsjoe (Sweden); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hudson, John [Rock Engineering Consultants, Welwyn Garden City (United Kingdom)

    2002-05-01

    As a part of the planning work for the Site Investigations, SKB has developed a Rock Mechanics Site Descriptive Modelling Strategy. Similar strategies are being developed for other disciplines. The objective of the strategy is that it should guide the practical implementation of evaluating site specific data during the Site Investigations. It is also understood that further development may be needed. This methodology enables the crystalline rock mass to be characterised in terms of the quality at different sites, for considering rock engineering constructability, and for providing the input to numerical models and performance assessment calculations. The model describes the initial stresses and the distribution of deformation and strength properties of the intact rock, of fractures and fracture zones, and of the rock mass. The rock mass mechanical properties are estimated by empirical relations and by numerical simulations. The methodology is based on estimation of mechanical properties using both empirical and heroretical/numerical approaches; and estimation of in situ rock stress using judgement and numerical modelling, including the influence of fracture zones. These approaches are initially used separately, and then combined to produce the required characterisation estimates. The methodology was evaluated with a Test Case at the Aespoe Hard Rock Laboratory in Sweden. The quality control aspects are an important feature of the methodology: these include Protocols to ensure the structure and coherence of the procedures used, regular meetings to enhance communication, feedback from internal and external reviewing, plus the recording of an audit trail of the development steps and decisions made. The strategy will be reviewed and, if required, updated as appropriate.

  16. Modeling of the Influence of the Swedish Äspö Hard Rock Laboratory (HRL) on Groundwater Flow

    Science.gov (United States)

    Gylling, B.; Hartley, L.; Rhen, I.; Selroos, J.

    2008-12-01

    Three-dimensional, regional, numerical models of groundwater flow and solute transport in fractured crystalline rock are used for two sites in Sweden that are considered for geological disposal of spent nuclear fuel. As a part of the site descriptive modeling for one of the sites, Laxemar, a number of simulations have been carried out to investigate if the Äspö Hard Rock Laboratory (HRL), an approximately 450 m deep tunnel below the island of Äspö located outside the Laxemar area, has an impact on the groundwater flow situation at Äspö and Laxemar. In the reference case, a specified head boundary condition was set on the top surface. For this study, two simulations were performed for each set of hydraulic properties and boundary conditions considered: one with the Äspö HRL present and water abstracted according to the inflow rates measured in the tunnel weirs; and a simulation under undisturbed conditions. In both simulations, the calculations start at 1960 using appropriate models of palaeo-hydrogeology without any disturbance for the initial condition and then the models are run until 2006 with a one year time-step. The cases were compared in terms of modeled drawdown, and changes to the Darcy velocity and hydro-geochemistry. Sensitivities of the results were considered in relation to the top surface boundary condition including a maximum infiltration of 165 mm/year or 80 m/year, and varying the hydraulic contact between the sea and the bedrock beneath. A number of comparisons with field data can be made to assess which of the variants is considered to best reflect site conditions and to possibly inform future developments of the site descriptive model. Drawdown measurements are available for several percussion drilled boreholes. Data are also available for salinity of the water collected in the weirs within the tunnel. Essentially, this can be used as a long-term interference test with the Äspö HRL as the sink and the percussion drilled boreholes as

  17. Surface-groundwater interactions in hard rocks in Sardon Catchment of western Spain: An integrated modeling approach

    Science.gov (United States)

    Hassan, S. M. Tanvir; Lubczynski, Maciek W.; Niswonger, Richard G.; Su, Zhongbo

    2014-09-01

    The structural and hydrological complexity of hard rock systems (HRSs) affects dynamics of surface-groundwater interactions. These complexities are not well described or understood by hydrogeologists because simplified analyses typically are used to study HRSs. A transient, integrated hydrologic model (IHM) GSFLOW (Groundwater and Surface water FLOW) was calibrated and post-audited using 18 years of daily groundwater head and stream discharge data to evaluate the surface-groundwater interactions in semi-arid, ∼80 km2 granitic Sardon hilly catchment in Spain characterized by shallow water table conditions, relatively low storage, dense drainage networks and frequent, high intensity rainfall. The following hydrological observations for the Sardon Catchment, and more generally for HRSs were made: (i) significant bi-directional vertical flows occur between surface water and groundwater throughout the HRSs; (ii) relatively large groundwater recharge represents 16% of precipitation (P, 562 mm.y-1) and large groundwater exfiltration (∼11% of P) results in short groundwater flow paths due to a dense network of streams, low permeability and hilly topographic relief; deep, long groundwater flow paths constitute a smaller component of the water budget (∼1% of P); quite high groundwater evapotranspiration (∼5% of P and ∼7% of total evapotranspiration); low permeability and shallow soils are the main reasons for relatively large components of Hortonian flow and interflow (15% and 11% of P, respectively); (iii) the majority of drainage from the catchment leaves as surface water; (iv) declining 18 years trend (4.44 mm.y-1) of groundwater storage; and (v) large spatio-temporal variability of water fluxes. This IHM study of HRSs provides greater understanding of these relatively unknown hydrologic systems that are widespread throughout the world and are important for water resources in many regions.

  18. Surface-groundwater interactions in hard rocks in Sardon Catchment of western Spain: an integrated modeling approach

    Science.gov (United States)

    Hassan, S.M. Tanvir; Lubczynski, Maciek W.; Niswonger, Richard G.; Zhongbo, Su

    2014-01-01

    The structural and hydrological complexity of hard rock systems (HRSs) affects dynamics of surface–groundwater interactions. These complexities are not well described or understood by hydrogeologists because simplified analyses typically are used to study HRSs. A transient, integrated hydrologic model (IHM) GSFLOW (Groundwater and Surface water FLOW) was calibrated and post-audited using 18 years of daily groundwater head and stream discharge data to evaluate the surface–groundwater interactions in semi-arid, ∼80 km2 granitic Sardon hilly catchment in Spain characterized by shallow water table conditions, relatively low storage, dense drainage networks and frequent, high intensity rainfall. The following hydrological observations for the Sardon Catchment, and more generally for HRSs were made: (i) significant bi-directional vertical flows occur between surface water and groundwater throughout the HRSs; (ii) relatively large groundwater recharge represents 16% of precipitation (P, 562 mm.y−1) and large groundwater exfiltration (∼11% of P) results in short groundwater flow paths due to a dense network of streams, low permeability and hilly topographic relief; deep, long groundwater flow paths constitute a smaller component of the water budget (∼1% of P); quite high groundwater evapotranspiration (∼5% of P and ∼7% of total evapotranspiration); low permeability and shallow soils are the main reasons for relatively large components of Hortonian flow and interflow (15% and 11% of P, respectively); (iii) the majority of drainage from the catchment leaves as surface water; (iv) declining 18 years trend (4.44 mm.y−1) of groundwater storage; and (v) large spatio-temporal variability of water fluxes. This IHM study of HRSs provides greater understanding of these relatively unknown hydrologic systems that are widespread throughout the world and are important for water resources in many regions.

  19. Assessing and modelling hard rock aquifer recharge based on complementary methodologies : a case study in the Gabbros of Beja Aquifer System, South Portugal

    OpenAIRE

    Paralta, Eduardo; Oliveira, M.

    2005-01-01

    The "Gabbros of Beja" Aquifer System extends for approximately 350 km2 and is one of the most important reservoirs of groundwater in the context of hard rocks aquifers of South Portugal (Alentejo Region). The average annual rainfall in the area is about 500 to 600 mm. Groundwater resources are used for public supply over 3 councils and irrigation. During drought cycles consumption increases and pumping rates decrease with correspondent management difficulties and conflicts between private ...

  20. Cutting system arrangement method of hard rock boring machine%硬岩掘进机破碎机构布置方法

    Institute of Scientific and Technical Information of China (English)

    毛君; 谢春雪; 梁晗; 黄华

    2013-01-01

      Hard rock roadheader is the key equipment in laneway constructions. In view of the traditional point-attack picks sever loss while breaking rocks, this paper put forward a shock and rolling breaking method which utilizes impact mechanism and a rolling mechanism to break rocks. This study analyzed the duration, the reliability and the driving efficiency on the cutter of the hard rock tunnel boring machine, and optimized the relations between the hard rock crushers using multi-disciplinary optimization method. In addition, this paper researched on factors that influence the layout of crushers which include global coordinating optimization as main factor, coordinating the optimization of parameters, the impact parameter, cutting force, cutting parameters and rock properties matching. The results of study show that the arrangement of the hard rock crusher was feasible, and it is optimal in energy consumption, tool wearing, driving efficiency and overall performance.%  针对传统镐齿破碎岩石的损耗严重,提出一种冲击滚压破碎方式。其结构采用冲击机构和滚压机构配合破碎岩石,考虑影响硬岩掘进机刀具的寿命、可靠性、掘进效率因素,采用多学科优化方法构建硬岩掘进机破碎机构布置关系,并以全局协调优化为主导,总体协调优化参数,对破碎机构的布置进行冲击参数、刀具受力、切削参数、围岩属性的匹配研究。研究结果表明:该硬岩掘进机破碎机构布置方法可行,降低了硬岩掘进机能量消耗、刀具的磨损,提高了掘进效率,使整机性能达到最优。

  1. Characterisation, design and execution of two grouting fans at 450 m level, Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Emmelin, Ann [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Eriksson, Magnus [Royal Inst. of Technology, Stockholm (Sweden); Fransson, Aasa [Chalmers Univ. of Technology, Goeteborg (Sweden)

    2004-09-01

    During June 2003 a grouting field experiment was carried out at Aespoe HRL, in connection with the construction of a tunnel (TASQ) for the Aespoe Pillar Stability Experiment (APSE). The tunnel is situated in connection to the elevator shaft landing at 450 m depth and runs in direction N/E. The grouting was carried out as part of the ordinary construction work, but was accompanied by extra investigations and analyses during operations and an active adaptation of a basic grouting design to the encountered conditions. The main objectives of this set-up were to Investigate what can be achieved with best available technology, material and knowledge under the current conditions, i.e. a relatively tight crystalline rock mass at great depth; Collect data and evaluate theories resulting from previous research projects on characterisation and predictions on grout spread; Collect data to further develop those above mentioned theories; Contribute to the achievement of good conditions at the experimental site for the pillar stability experiments. The characterization method is based on analyses of stepwise investigations consisting of investigations in an initially drilled core-drill hole followed by probe and grouting boreholes with pressure-build-up tests and measuring of inflow during drilling, all aiming at identifying the singular fractures that are to be sealed. The decision about grouting design is based on the successively up-dated rock description from the characterization and iterative selection and testing of grouting design and grout in a numeric model, resulting in an expected grout spread and sealing effect. Based on investigations and analysis of results from investigations of a core-drilled hole at the site, a basic design was set up, together with conditions for application. Probe boreholes covering the first anticipated fan gave substantially larger inflows than expected, and subsequently the design was changed. A first round was drilled and grouted, sealing

  2. Characterisation, design and execution of two grouting fans at 450 m level, Aespoe HRL

    International Nuclear Information System (INIS)

    During June 2003 a grouting field experiment was carried out at Aespoe HRL, in connection with the construction of a tunnel (TASQ) for the Aespoe Pillar Stability Experiment (APSE). The tunnel is situated in connection to the elevator shaft landing at 450 m depth and runs in direction N/E. The grouting was carried out as part of the ordinary construction work, but was accompanied by extra investigations and analyses during operations and an active adaptation of a basic grouting design to the encountered conditions. The main objectives of this set-up were to Investigate what can be achieved with best available technology, material and knowledge under the current conditions, i.e. a relatively tight crystalline rock mass at great depth; Collect data and evaluate theories resulting from previous research projects on characterisation and predictions on grout spread; Collect data to further develop those above mentioned theories; Contribute to the achievement of good conditions at the experimental site for the pillar stability experiments. The characterization method is based on analyses of stepwise investigations consisting of investigations in an initially drilled core-drill hole followed by probe and grouting boreholes with pressure-build-up tests and measuring of inflow during drilling, all aiming at identifying the singular fractures that are to be sealed. The decision about grouting design is based on the successively up-dated rock description from the characterization and iterative selection and testing of grouting design and grout in a numeric model, resulting in an expected grout spread and sealing effect. Based on investigations and analysis of results from investigations of a core-drilled hole at the site, a basic design was set up, together with conditions for application. Probe boreholes covering the first anticipated fan gave substantially larger inflows than expected, and subsequently the design was changed. A first round was drilled and grouted, sealing

  3. Review: Natural tracers in fractured hard-rock aquifers in the Austrian part of the Eastern Alps—previous approaches and future perspectives for hydrogeology in mountain regions

    Science.gov (United States)

    Hilberg, Sylke

    2016-08-01

    Extensive in-depth research is required for the implementation of natural tracer approaches to hydrogeological investigation to be feasible in mountainous regions. This review considers the application of hydrochemical and biotic parameters in mountain regions over the past few decades with particular reference to the Austrian Alps, as an example for alpine-type mountain belts. A brief introduction to Austria's hydrogeological arrangement is given to show the significance of fractured hard-rock aquifers for hydrogeological science as well as for water supply purposes. A literature search showed that research concerning fractured hard-rock aquifers in Austria is clearly underrepresented to date, especially when taking the abundance of this aquifer type and the significance of this topic into consideration. The application of abiotic natural tracers (hydrochemical and isotope parameters) is discussed generally and by means of examples from the Austrian Alps. The potential of biotic tracers (microbiota and meiofauna) is elucidated. It is shown that the meiofauna approach to investigating fractured aquifers has not yet been applied in the reviewed region, nor worldwide. Two examples of new approaches in mountainous fractured aquifers are introduced: (1) use of CO2 partial pressure and calcite saturation of spring water to reconstruct catchments and flow dynamics (abiotic approach), and, (2) consideration of hard-rock aquifers as habitats to reconstruct aquifer conditions (biotic approach).

  4. Examination of the Excavation Damaged Zone in the TASS tunnel, Aespoe HRL

    International Nuclear Information System (INIS)

    The question of an existing continuous Excavation Damage Zone (EDZ) is very important for SKB. Is it possible to use drilling and blasting in the planned repository for spent nuclear fuel? Could fractures from blasting form a continuous EDZ? In order to increase the understanding of the EDZ and the possibility of an existing continuous EDZ along the deposition tunnel, SKB decided to examine the fracturing in a selected area of the TASS tunnel and to create a 3D model of the fractures in the investigated area. It was of special interest to study the transition zones between the blast rounds to examine if the EDZ from the bottom charges could form a continuous EDZ from one round to another. The TASS-tunnel is situated at the 450-m level in the Aespoe Hard Rock Laboratory. The tunnel, with a cross-section area of 20 m2, was planned to be 90 m long. In a subproject called Excavation the purpose was to test different plans for drilling, charging and initiation in order to give recommendations on how the final repository of spent fuel should be excavated. The test methodology used in this investigation comprised the following steps: selecting test area, drilling and wire sawing of blocks, surveying the blocks, removal and transportation of the blocks to the surface, cutting the blocks into slabs, fracture identification with penetrants, positioning and photographing the slabs, digitizing and 3D modelling of the fractures. The test area for EDZ consisted of an 8 m long and 1.5 m high section in excavation sequence no 4. The selected section covered the end of round 9, the entire round 10 and the start of round 11. In the contour and the helpers small diameter charges for smooth blasting were used (decoupled charges). These charges also have a relatively low detonation velocity (VOD) and this, together with the decoupling, gives short fracture lengths i.e. a small EDZ. The contour holes and the helpers were initiated with electronic detonators to achieve a simultaneous

  5. Simulations of pressure and salinity fields at Aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Loefman, J. [VTT Energy, Espoo (Finland)

    1997-04-01

    The primary objective of this study was to examine whether the geochemical field data from Aespoe could be interpreted and understood by means of numerical simulations for flow and transport. A site-specific simulation model for groundwater flow and salt transport was developed on the basis of the field investigations. Both steady-state and transient simulations of flow and transport were performed. In the transient simulations, land uplift and the effect of diffusion into/from the matrix blocks with stagnant water were taken into account. The computational results were evaluated on the basis of the experimental values for the pressure and salt concentration.

  6. A contribution to open pit hard coal mine waste rock management : comparing sidehill fill with layered dumping

    OpenAIRE

    Ahmad, Shakeel

    2013-01-01

    Coal mining is an important economic activity as it covers the energy demands, generates export revenues and creates employment opportunities. Mining can, however, impact the local environment. Different mining operations produce several types of waste materials and one of the major wastes produced by open-pit mines is waste rock, which is dumped at waste rock dumps. The waste rock dumps can impact the environment in several ways. For instance, in Vietnam open-pit mines have disturbed the bea...

  7. The fate of nitrogen and sulfur in hard-rock aquifers as shown by sulfate-isotope tracing

    Energy Technology Data Exchange (ETDEWEB)

    Pauwels, Helene, E-mail: h.pauwels@brgm.fr [BRGM, Water Division, BP 36009, 45060 Orleans Cedex 2 (France); Ayraud-Vergnaud, Virginie [BRGM, Water Division, BP 36009, 45060 Orleans Cedex 2 (France)] [CAREN-Geosciences, UMR 6118, Universite Rennes 1-CNRS, Rennes (France); Aquilina, Luc [CAREN-Geosciences, UMR 6118, Universite Rennes 1-CNRS, Rennes (France); Molenat, Jerome [CAREN-UMR INRA-Agrocampus Sol Agronomie Spatialisation, Rennes (France)] [IRD-Laboratoire d' etude des Interactions Sol-Agrosystemes-Hydrosystemes, UMR INRA-IRD-Supagro, Montpellier (France)

    2010-01-15

    Stable SO{sub 4} isotopes ({delta}{sup 34}S{sub -SO4} and {delta}{sup 18}O{sub -SO4}), and more occasionally {delta}{sup 15}N{sub -NO3} were studied in groundwater from seven hard-rock aquifer catchments. The sites are located in Brittany (France) and all are characterized by intensive agricultural activity. The purpose of the study was to investigate the potential use of these isotopes for highlighting the fate of both SO{sub 4} and NO{sub 3} in the different aquifer compartments. Nitrate-contaminated groundwater occurs in the regolith; {delta}{sup 34}S fingerprints the origin of SO{sub 4}, such as atmospheric deposition and fertilizers, and {delta}{sup 18}O{sub -SO4} provides evidence of the cycling of S within soil. The correlation between the {delta}{sup 18}O{sub -SO4} of sulfates and the {delta}{sup 15}N{sub -NO3} of nitrates suggests that S and N were both cycled in soil before being leached to groundwater. Autotrophic and heterotrophic denitrification was noted in fissured aquifers and in wetlands, respectively, the two processes being distinguished on the basis of stable SO{sub 4} isotopes. During autotrophic denitrification, both {delta}{sup 34}S{sub -SO4} and {delta}{sup 18}O{sub -SO4} decrease due to the oxidation of pyrite and the incorporation of O from the NO{sub 3} molecule in the newly formed SO{sub 4}. Within wetlands, fractionation occurs of O isotopes on SO{sub 4} in favour of lighter isotopes, probably through reductive assimilation processes. Fractionation of S isotopes is negligible as the redox conditions are not sufficiently reductive for dissimilatory reduction. {delta}{sup 34}S{sub -SO4} and {delta}{sup 18}O{sub -SO4} data fingerprint the presence of a NO{sub 3}-free brackish groundwater in the deepest parts of the aquifer. Through mixing with present-day denitrified groundwater, this brackish groundwater can contribute to significantly increase the salinity of pumped water from the fissured aquifer.

  8. Examination of the Excavation Damaged Zone in the TASS tunnel, Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Mats (Swebrec, Luleaa Univ. of Technology, Luleaa (Sweden)); Markstroem, Ingemar; Pettersson, Anders; Straeng, Malin (Golder Associates, Uppsala (Sweden))

    2009-10-15

    The question of an existing continuous Excavation Damage Zone (EDZ) is very important for SKB. Is it possible to use drilling and blasting in the planned repository for spent nuclear fuel? Could fractures from blasting form a continuous EDZ? In order to increase the understanding of the EDZ and the possibility of an existing continuous EDZ along the deposition tunnel, SKB decided to examine the fracturing in a selected area of the TASS tunnel and to create a 3D model of the fractures in the investigated area. It was of special interest to study the transition zones between the blast rounds to examine if the EDZ from the bottom charges could form a continuous EDZ from one round to another. The TASS-tunnel is situated at the 450-m level in the Aespoe Hard Rock Laboratory. The tunnel, with a cross-section area of 20 m2, was planned to be 90 m long. In a subproject called Excavation the purpose was to test different plans for drilling, charging and initiation in order to give recommendations on how the final repository of spent fuel should be excavated. The test methodology used in this investigation comprised the following steps: selecting test area, drilling and wire sawing of blocks, surveying the blocks, removal and transportation of the blocks to the surface, cutting the blocks into slabs, fracture identification with penetrants, positioning and photographing the slabs, digitizing and 3D modelling of the fractures. The test area for EDZ consisted of an 8 m long and 1.5 m high section in excavation sequence no 4. The selected section covered the end of round 9, the entire round 10 and the start of round 11. In the contour and the helpers small diameter charges for smooth blasting were used (decoupled charges). These charges also have a relatively low detonation velocity (VOD) and this, together with the decoupling, gives short fracture lengths i.e. a small EDZ. The contour holes and the helpers were initiated with electronic detonators to achieve a simultaneous

  9. Groundwater targeting in a hard-rock terrain using fracture-pattern modeling, Niva River basin, Andhra Pradesh, India

    Science.gov (United States)

    Srinivasa Rao, Y.; Reddy, T. V. K.; Nayudu, P. T.

    2000-09-01

    In hard-rock terrain, due to the lack of primary porosity in the bedrock, joints, fault zones, and weathered zones are the sources for groundwater occurrence and movement. To study the groundwater potential in the hard-rock terrain and drought-prone area in the Niva River basin, southern Andhra Pradesh state, India, Landsat 5 photographic data were used to prepare an integrated hydrogeomorphology map. Larsson's integrated deformation model was applied to identify the various fracture systems, to pinpoint those younger tensile fracture sets that are the main groundwater reservoirs, and to understand the importance of fracture density in groundwater prospecting. N35°-55°E fractures were identified as tensile and N35°-55°W fractures as both tensile and shear in the study area. Apparently, these fractures are the youngest open fractures. Wherever N35°-55°E and N35°-55°W fracture densities are high, weathered-zone thickness is greater, water-table fluctuations are small, and well yields are high. Groundwater-potential zones were delineated and classified as very good, good to very good, moderate to good, and poor. Résumé. Dans les roches de socle, l'absence de porosité primaire dans la roche fait que les fractures, les zones de faille et les zones d'altération sont les sites où l'eau souterraine est présente et s'écoule. Pour étudier le potentiel en eau souterraine dans la région de socle sujette à la sécheresse du bassin de la rivière Niva (sud de l'État d'Andhra Pradesh, Inde), des données photographiques de Landsat 5 ont été utilisées pour préparer une carte hydro-géomorphologique. Le modèle intégré de déformation de Larssons a été mis en œuvre pour identifier les différents systèmes de fractures, pour mettre l'accent sur les ensembles de fractures en extension les plus jeunes qui constituent les principaux réservoirs d'eau souterraine, et pour comprendre l'importance de la densité de fractures pour la prospection de l

  10. Groundwater targeting in a hard-rock terrain using fracture-pattern modeling, Niva River basin, Andhra Pradesh, India

    Science.gov (United States)

    Srinivasa Rao, Y.; Reddy, T. V. K.; Nayudu, P. T.

    2000-09-01

    In hard-rock terrain, due to the lack of primary porosity in the bedrock, joints, fault zones, and weathered zones are the sources for groundwater occurrence and movement. To study the groundwater potential in the hard-rock terrain and drought-prone area in the Niva River basin, southern Andhra Pradesh state, India, Landsat 5 photographic data were used to prepare an integrated hydrogeomorphology map. Larsson's integrated deformation model was applied to identify the various fracture systems, to pinpoint those younger tensile fracture sets that are the main groundwater reservoirs, and to understand the importance of fracture density in groundwater prospecting. N35°-55°E fractures were identified as tensile and N35°-55°W fractures as both tensile and shear in the study area. Apparently, these fractures are the youngest open fractures. Wherever N35°-55°E and N35°-55°W fracture densities are high, weathered-zone thickness is greater, water-table fluctuations are small, and well yields are high. Groundwater-potential zones were delineated and classified as very good, good to very good, moderate to good, and poor. Résumé. Dans les roches de socle, l'absence de porosité primaire dans la roche fait que les fractures, les zones de faille et les zones d'altération sont les sites où l'eau souterraine est présente et s'écoule. Pour étudier le potentiel en eau souterraine dans la région de socle sujette à la sécheresse du bassin de la rivière Niva (sud de l'État d'Andhra Pradesh, Inde), des données photographiques de Landsat 5 ont été utilisées pour préparer une carte hydro-géomorphologique. Le modèle intégré de déformation de Larssons a été mis en œuvre pour identifier les différents systèmes de fractures, pour mettre l'accent sur les ensembles de fractures en extension les plus jeunes qui constituent les principaux réservoirs d'eau souterraine, et pour comprendre l'importance de la densité de fractures pour la prospection de l

  11. Characterization and evaluation of sites for deep geological disposal of radioactive waste in fractured rocks. Proceedings

    International Nuclear Information System (INIS)

    The third Aespoe International Seminar was organised by SKB to assess the state of the art in characterisation and evaluation of sites for deep geological disposal of radioactive waste in fractured rocks. Site characterisation and evaluation are important elements for determining the site suitability and long-term safety of a geological repository for radioactive waste disposal. Characterisation work also provides vital information for the design of the underground facility and the engineered barrier system that will contain the waste. The aim of the seminar was to provide a comprehensive assessment of the current know-how on this topic based on world-wide experience from more than 20 years of characterisation and evaluation work. The seminar, which was held at the Aespoe Hard Rock Laboratory was attended by 72 scientists from 10 different countries. The program was divided into four sessions of which two were run in parallel. A total of 38 oral and 5 poster presentations were given at the seminar. The presentations gave a comprehensive summary of recently completed and current work on site characterisation, modelling and application in performance assessments. The results presented at the seminar generally show that significant progress has been made in this field during the last decade. New characterisation techniques have become available, strategies for site investigations have developed further, and model concepts and codes have reached new levels of refinement. Data obtained from site characterisation have also successfully been applied in several site specific performance assessments. The seminar clearly showed that there is a solid scientific basis for assessing the suitability of sites for actual repositories based on currently available site characterisation technology and modelling capabilities. Separate abstracts have been prepared for 38 of the presentations

  12. Characterization and evaluation of sites for deep geological disposal of radioactive waste in fractured rocks. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    The third Aespoe International Seminar was organised by SKB to assess the state of the art in characterisation and evaluation of sites for deep geological disposal of radioactive waste in fractured rocks. Site characterisation and evaluation are important elements for determining the site suitability and long-term safety of a geological repository for radioactive waste disposal. Characterisation work also provides vital information for the design of the underground facility and the engineered barrier system that will contain the waste. The aim of the seminar was to provide a comprehensive assessment of the current know-how on this topic based on world-wide experience from more than 20 years of characterisation and evaluation work. The seminar, which was held at the Aespoe Hard Rock Laboratory was attended by 72 scientists from 10 different countries. The program was divided into four sessions of which two were run in parallel. A total of 38 oral and 5 poster presentations were given at the seminar. The presentations gave a comprehensive summary of recently completed and current work on site characterisation, modelling and application in performance assessments. The results presented at the seminar generally show that significant progress has been made in this field during the last decade. New characterisation techniques have become available, strategies for site investigations have developed further, and model concepts and codes have reached new levels of refinement. Data obtained from site characterisation have also successfully been applied in several site specific performance assessments. The seminar clearly showed that there is a solid scientific basis for assessing the suitability of sites for actual repositories based on currently available site characterisation technology and modelling capabilities. Separate abstracts have been prepared for 38 of the presentations

  13. Long term test of buffer material at the Aespoe HRL, LOT project. Final report on the A0 test parcel

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Olsson, Siv; Sanden, Torbjoern; Faelth, Billy (Clay Technology AB, Lund (Sweden)); Jansson, Mats; Eriksen, Trygve E.; Svaerdstroem, Kjell (KTH Royal Inst. of Technology, Stockholm (Sweden)); Rosborg, Bo (Studsvik AB, Nykoeping (Sweden); Rosborg Consulting, Nykoeping (Sweden)); Muurinen, Arto (VTT, Espoo (Finland))

    2011-02-15

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, could be expected to produce minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory are focused on identifying and quantifying any mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks to a total diameter of 30 cm as well as temperature, total pressure, water pressure and humidity sensors. In each test parcel, an electrical heater placed inside the copper tube is used to simulate the heat generation from the decaying spent fuel. Three test parcels (S1 to S3) have been exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and three parcels (A1 to A3) to adverse conditions (maximum temperature below approx140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (> 5 years) and long term tests (> 10 years). The present report concerns an additional short term test, thereby the designation A0, which was exposed to adverse conditions for approximately 1.5 years. Cu-coupons, 134Cs and 57Co tracers and specific chemical agents were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at the test site and the bentonite material was sampled for specified analyses. The main aspects of the various tests and analyses

  14. Long term test of buffer material at the Aespoe HRL, LOT project. Final report on the A0 test parcel

    International Nuclear Information System (INIS)

    In the Swedish repository concept for nuclear waste (KBS-3 concept), the spent nuclear fuel will be stored in copper canisters surrounded by compacted bentonite. The decaying power of the fuel will increase the temperature in the repository which, in combination with the uptake of ground-water, could be expected to produce minor mineralogical changes in the bentonite. The ongoing LOT test series at the Aespoe Hard Rock Laboratory are focused on identifying and quantifying any mineralogical alterations in the bentonite exposed to typical repository-like conditions. Further, buffer-related processes concerning copper corrosion, cation transport, and bacterial survival/activity are studied. In total, the LOT project includes seven test parcels, which contain a central Cu-tube surrounded by cylindrical bentonite blocks to a total diameter of 30 cm as well as temperature, total pressure, water pressure and humidity sensors. In each test parcel, an electrical heater placed inside the copper tube is used to simulate the heat generation from the decaying spent fuel. Three test parcels (S1 to S3) have been exposed to standard KBS-3 conditions (maximum temperature below 100 deg C) and three parcels (A1 to A3) to adverse conditions (maximum temperature below ∼140 deg C). Both the standard and the adverse test series include short term tests (1 to 2 years), medium term tests (> 5 years) and long term tests (> 10 years). The present report concerns an additional short term test, thereby the designation A0, which was exposed to adverse conditions for approximately 1.5 years. Cu-coupons, 134Cs and 57Co tracers and specific chemical agents were placed in the bentonite at defined positions. After field exposure, the entire test parcel was released from the rock by overlapping percussion drilling and wire sawing. The parcel was lifted and divided at the test site and the bentonite material was sampled for specified analyses. The main aspects of the various tests and analyses may

  15. Investigating the impact of global climatic and landuse changes on groundwater resources in hard rock areas of South India

    Science.gov (United States)

    Ferrant, S.; Perrin, J.; Marechal, J.; Dewandel, B.; Aulong, S.; Ahmed, S.

    2010-12-01

    In most parts of India, and particularly in South India, groundwater levels are hazardously declining, while agricultural groundwater use is increasing. The current issue is to address the probable evolution of water table levels in relation with climate and agricultural changes. The aim of the SHIVA-ANR project (http://www.shiva-anr.org) is to provide some indicators of the water availability at the village scale to evaluate the vulnerability of farmers facing global changes. This study focuses on a particularly water stressed semi-arid area of South India characterized by hard rock geology with naturally low recharge capacity and limited surface water availability. The study catchment is located in the agricultural area of the Kudaliar river watershed (980km^2) located 50 km north of Hyderabad, India. It is composed of about 120 villages. Socio economic surveys have been carried out at the village scale to evaluate the present socio-economic situation of farmers. It also provides more details on various cultural and irrigation practices at this scale. The landuse has been evaluated by remote sensing with two satellite images, one after monsoon (October 2009), and the other during dry season (March 2010). Groundwater-irrigated rice paddies represent about 10% of the area, whereas rainfed crop (corn and cotton) represent about 45%. Numerous small tanks (reservoir) situated on the river network define a water harvesting system of 2% of the catchment area which captures surface runoff during monsoon. No discharges data are available at the outlet, as the river is dry most of the year. A hydro-geological survey has been carried out to provide a map of aquifer thickness and the general state of the groundwater level before and after monsoon. The Soil Water Assessment Tool model (SWAT) has been calibrated to assess the water budget of the agricultural catchment under present conditions. Soil parameters calibration is made first on seasonal groundwater recharge for

  16. Combining hydrologic and geologic data to determine recharge areas in hard rocks, an example from the Eastern Alps, Austria

    Science.gov (United States)

    Staunig, R.; Winkler, G.; Birk, S.; Poltnig, W.

    2009-04-01

    Tectonic structures as faults and/or fault zones and slope tectonics take a great influence on water flow in hard rocks. They may represent hydraulic barriers or conduits, or a combination of both. Accurate predictions of water flow is often a critical aspect e.g. in tunnel design, the long-term stability of dams, and especially for determining recharge areas of springs as related to water quality protection. The discharge rates in respect to the topographic divided areas of springs (catchments) provide the understanding of the drainage directions of complex hydrogeologic systems. To determine the recharge areas (areas surrounded by groundwater-divides) the structural geologic data analysing the tectonics and the slope tectonics have also to be considered. With a conceptual approach hydrologic and structural geologic data were combined to determine recharge areas of springs draining a carbonatic fractured aquifer. The investigation area belongs to the Sattnitz-Conglomerate-Plateau extending in the north of and parallel to the Karawanken mountain range as a tableland in the south of the Klagenfurter Basin. The investigation area is the western part of the Sattnitz-Conglomerate-plateau built up by carbonatic conglomerates with a thickness up to 200 m and an extent of approximately 6 km². The conglomerates are of pliocene age and are composed of coarse grained, mainly carbonatic components cemented with a carbonatic matrix. The plateau is completely underlayed by a premesozoic crystalline basement and grained miocene silt and clay sediments containing coal layers as a permanent aquicludefine. The area has no streams and drains mainly to the west and north over several springs. The major springs were equipped with data loggers measuring continuously discharge, electric conductivity and temperature over several years. The major spring, its discharge rangs between approximately 25 l/s to more than 400 l/s, is situated in the northwest of the investigation area and

  17. SITE-94. Far-field rock mechanics modelling for nuclear waste disposal

    International Nuclear Information System (INIS)

    The objectives of the far-field rock mechanics study were to investigate the mechanical influence of thermal loading and glaciation on the stability and safety of a hypothetical repository. The Aespoe Hard Rock Laboratory test site was used as a target site for regional and local geology, in situ stress data and material properties. The study treated the rock mass as an assembly of discrete blocks defined by a number of major faults and fracture zones. Two computational models with 15 and 23 major faults and fracture zones were constructed and studied. Thermal loading due to waste emplacement and mechanical loading from a hypothetical glaciation/deglaciation cycle was applied in order to examine the global behaviour of the rock mass under such loading conditions. The problem was treated as a three-dimensional one, simulated by using the three-d distinct element method code 3DEC. From the numerical results, it was found that a maximum temperature of 48 deg C would be reached 200 years after the emplacement of the waste canisters. The average increase of maximum principal stress due to thermal loading is 9.5 MPa horizontally and 20.2 MPa vertically due to glaciation. The maximum shear displacement induced by thermal loading is 25 mm and 81.9 mm by glaciation. 15 refs

  18. Proceedings of the fifth international groundwater conference on the assessment and management of groundwater resources in hard rock systems with special reference to basaltic terrain

    International Nuclear Information System (INIS)

    Groundwater resources in hard rock regions with limited renewable potential have to be managed judiciously to ensure adequate supplies of dependable quantity and quality. It is a natural resource with economic, strategic and environmental value, which is under stress both due to changing climatic and anthropogenic factors. Therefore the management strategies need to be aimed at sustenance of this limited resource. In India, and also elsewhere in the world major parts of the semi-arid regions are characterized by hard rocks and it is of vital importance to understand the nature of the aquifer systems and its current stress conditions. Though the achievements through scientific development in exploration and exploitation are commendable, it has adversely affected the hard rock aquifer system, both in terms of quantity and quality; which is of major concern today. In order to reverse the situation, better management strategy of groundwater resources needs to be devised for prevention of further degradation of quality and meeting out the future demand of quantity. This necessitates: understanding the flow mechanism, evaluating the potential and evolving optimal utilization schemes, and assessing and monitoring quality in the changing scenario of anthropogenically induced agricultural, urban, industrial and climatic change. The groundwater flow mechanism through fractures in hard rocks is yet to be fully understood in terms of fracture geometry and its relation to groundwater flow. The characterization of flow geometry in basaltic aquifer is yet to be fully explored. Groundwater pollution due to anthropogenic factors is very slow process with long-term impacts on carbon cycle and global climatic change on one hand and quality on the other. It is generally recognized that the prevention of groundwater pollution is cheaper than its remedial measures in the long run. Furthermore, because of the nature of groundwater flow and the complexity and management uncertainty of

  19. Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the theoretical approach

    Energy Technology Data Exchange (ETDEWEB)

    Staub, Isabelle; Fredriksson, Anders; Outters, Nils [Golder Associates AB, Uppsala (Sweden)

    2002-05-01

    deal with spatial variability and data uncertainties of the modelling results, and in order to minimise the number of numerical models to run, Monte Carlo simulations are used. The methodology was tested in Sweden on a limited set of data coming from the Aespoe Hard Rock Laboratory. The mechanical properties of the rock mass were determined in two scales, (I) in a 550 m block in which 'ordinary rock units' and 'deformation zone units' are identified,and (II) in a box located at depth from -380 to -500 m,and divided in 30x30x30 m cubes.

  20. 硬脆岩石的微观颗粒模型及其卸荷岩爆效应研究%A MICRO PARTICLE MODEL FOR HARD BRITTLE ROCK AND THE EFFECT OF UNLOADING ROCK BURST

    Institute of Scientific and Technical Information of China (English)

    马春驰; 李天斌; 陈国庆; 陈子全

    2015-01-01

    A bonding particle model for hard brittle rock has been established to simulate the effect of rock burst. To make the microscopic model reflecting properties of hardness and brittleness,the following steps were used. Firstly,the microstructure of simulated rock samples was measured with the X-ray diffraction testing for granite rock. Secondly,the mechanical properties of the rock samples were analyzed, supported with the evaluation indicators of hardness and brittleness(indicators were determined in terms of the energy and stress-strain characteristics). Finally,a visual framework of the bonding particle model(depending on the tendency and magnitude limitation of the existed microstructure,the parameters of particles and bonds) representing the properties of hardness and brittleness was established. The model and the particle flow code(PFC3D) were used to simulate the triaxial unloading test and to analyze the effect of rock burst. The fractures are found to be mainly tensile in the unloading tests with the low and high confining pressures. Bigger proportion of tensile fractures and larger stress dropping(more brittle) occurs under the high confining pressure than under the low confining pressure. The kinetic energy of particles under the low confining pressure develops uniformly in the whole fracturing process of simulated sample,and the rock burst is a continuous type. However,the kinetic energy of particles under the high confining pressure developed non-uniformly,and the rock burst occurred suddenly and explosively.%为准确反映硬脆岩石的力学特性并对其卸荷岩爆效应进行合理模拟,从微观层面建立了硬脆岩石的力学模型。首先依据花岗岩岩样的衍射测试确定了模拟岩样的微观结构,其次从能量发展和应力–应变2个角度确定了硬脆特性的评价指标,借助评价指标进行岩样的颗粒效应分析和力学性能调控,进而构建了一种反映岩石硬脆特性的微观颗粒模

  1. Rock stress orientation measurements using induced thermal spalling in slim boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Hakami, Eva [Geosigma AB, Uppsala (Sweden)

    2011-05-15

    In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

  2. Choosing between a rock and a hard place: Camouflage in the round-tailed horned lizard Phrynosoma modestum

    Institute of Scientific and Technical Information of China (English)

    William E.COOPER; Wade C.SHERBROOKE

    2012-01-01

    The round-tailed horned lizard Phrynosoma modestum is cryptically colored and resembles a small stone when it draws legs close to its body and elevates its back.We investigated effectiveness of camouflage in P.modestum and its dependence on stones by placing a lizard in one of two microhabitats (uniform sand or sand with surface rocks approximately the same size as lizards).An observer who knew which microhabitat contained the lizard was asked to locate the lizard visually.Latency to detection was longer and probability of no detection within 60 s was higher for lizards on rock background than on bare sand.In arenas where lizards could choose to occupy rock or bare sand,much higher proportions selected rocky backgrounds throughout the day;at night all lizards slept among stones.A unique posture gives P.modestum a rounded appearance similar to many natural stones.Lizards occasionally adopted the posture,but none did so in response to a nearby experimenter.Stimuli that elicit the posture are unknown.That P.modestum is better camouflaged among rocks than on bare sand and prefers to occupy rocky areas suggests that special resemblance to rocks (masquerade) enhances camouflage attributable to coloration and immobility.

  3. P-wave velocity changes in freezing hard low-porosity rocks: a laboratory-based time-average model

    Directory of Open Access Journals (Sweden)

    D. Draebing

    2012-10-01

    Full Text Available P-wave refraction seismics is a key method in permafrost research but its applicability to low-porosity rocks, which constitute alpine rock walls, has been denied in prior studies. These studies explain p-wave velocity changes in freezing rocks exclusively due to changing velocities of pore infill, i.e. water, air and ice. In existing models, no significant velocity increase is expected for low-porosity bedrock. We postulate, that mixing laws apply for high-porosity rocks, but freezing in confined space in low-porosity bedrock also alters physical rock matrix properties. In the laboratory, we measured p-wave velocities of 22 decimetre-large low-porosity (< 10% metamorphic, magmatic and sedimentary rock samples from permafrost sites with a natural texture (> 100 micro-fissures from 25 °C to −15 °C in 0.3 °C increments close to the freezing point. When freezing, p-wave velocity increases by 11–166% perpendicular to cleavage/bedding and equivalent to a matrix velocity increase from 11–200% coincident to an anisotropy decrease in most samples. The expansion of rigid bedrock upon freezing is restricted and ice pressure will increase matrix velocity and decrease anisotropy while changing velocities of the pore infill are insignificant. Here, we present a modified Timur's two-phase-equation implementing changes in matrix velocity dependent on lithology and demonstrate the general applicability of refraction seismics to differentiate frozen and unfrozen low-porosity bedrock.

  4. Real Time Grouting Control Method. Development and application using Aespoe HRL data

    International Nuclear Information System (INIS)

    The spread of grout is governed by a number of complex relations. The desired results, such as grout penetration and sealing of fractures, cannot be directly measured during the grouting process. This means that the issue of how or when the injection of grout should be stopped cannot be answered by simple rules of thumb. This is also the background to the great variety of empirical rules used in the grouting sector worldwide. The research during recent years has given a better understanding of the water-bearing structures of the rock mass as well as analytical solutions. In this report the methodology has been further studied and a method for design and control of rock grouting has been proposed. The concept of what we call the 'Real Time Grouting Control Method' is to calculate the grout penetration and control grouting in real time by applying the development of the theories for grout spread. Our intention is to combine our method with a computerized logging tool to acquire an active tool in order to be able to govern the grout spread in real time during the grouting operation. The objectives of this report are: to further develop the theory concerning the relationship between grout penetration and grouting time to describe the real course of grouting, to establish the concept of 'Real Time Grouting Control Method' for design and control for rock grouting based on the developed theory, and to verify the concept by using the field data from the grouting experiment at the 450 m level in the Aespoe HRL. In this report, the approximations and analysis of dimensionality have been checked and further developments of the theory with respect to varying grouting pressure, time-dependent grout properties, changing grout mixes, and changing the flow dimension of the fracture have been carried out. The concept of 'Real Time Grouting Control Method' has been described in order to calculate the grout penetration and to control grouting in real time by applying developed

  5. Accurate 3D point cloud comparison and volumetric change analysis of Terrestrial Laser Scan data in a hard rock coastal cliff environment

    Science.gov (United States)

    Earlie, C. S.; Masselink, G.; Russell, P.; Shail, R.; Kingston, K.

    2013-12-01

    Our understanding of the evolution of hard rock coastlines is limited due to the episodic nature and ';slow' rate at which changes occur. High-resolution surveying techniques, such as Terrestrial Laser Scanning (TLS), have just begun to be adopted as a method of obtaining detailed point cloud data to monitor topographical changes over short periods of time (weeks to months). However, the difficulties involved in comparing consecutive point cloud data sets in a complex three-dimensional plane, such as occlusion due to surface roughness and positioning of data capture point as a result of a consistently changing environment (a beach profile), mean that comparing data sets can lead to errors in the region of 10 - 20 cm. Meshing techniques are often used for point cloud data analysis for simple surfaces, but in surfaces such as rocky cliff faces, this technique has been found to be ineffective. Recession rates of hard rock coastlines in the UK are typically determined using aerial photography or airborne LiDAR data, yet the detail of the important changes occurring to the cliff face and toe are missed using such techniques. In this study we apply an algorithm (M3C2 - Multiscale Model to Model Cloud Comparison), initially developed for analysing fluvial morphological change, that directly compares point to point cloud data using surface normals that are consistent with surface roughness and measure the change that occurs along the normal direction (Lague et al., 2013). The surfaces changes are analysed using a set of user defined scales based on surface roughness and registration error. Once the correct parameters are defined, the volumetric cliff face changes are calculated by integrating the mean distance between the point clouds. The analysis has been undertaken at two hard rock sites identified for their active erosion located on the UK's south west peninsular at Porthleven in south west Cornwall and Godrevy in north Cornwall. Alongside TLS point cloud data, in

  6. Integrating gamma log and conventional electrical logs to improve identification of fracture zones in hard rocks for hydrofracturing: a case study from Ghana

    Science.gov (United States)

    Amartey, E. O.; Akiti, T. T.; Armah, T.; Osae, S.; Agyekum, W. A.

    2016-07-01

    Hydrofracturing of low-yielding boreholes in hard rocks is a widely used technique in Africa for improvement of yield, thus making them qualified for installation of a hand-pump for domestic water supply. However, the success rate of the hydrofracturing campaigns seems not to be that high as generally claimed by contractors. One reason amongst others might be that the selection of zones for hydrofracturing in the individual borehole is based on pre-hydrofracturing investigation using conventional electrical logs only. Thereby, the zones selected are the occurring resistivity minima interpreted as weak zones with some fracturing. However, resistivity minima can also be caused solely by lithological reasons, which then in most cases could have been seen on a gamma log as corresponding increased gamma radiation. The advantages of using gamma logging in combination with conventional electrical logging technique for prediction of fractured zones in basement rocks is illustrated by investigations of three low-yielding boreholes located in different geological environments in crystalline basement rocks in Ghana.

  7. A new method to improve operating performance for underground hard rock mining - with new scheduling, controlling and forecastingtechniques

    OpenAIRE

    Song, Zhen

    2015-01-01

    In underground mining, there are missing links among mine planning, mining machines and mineral processing. They have significantly affected the overall performance of the entire mining process. There have been quite few studies aiming to improve the mining process of underground mines. In underground mines, mobile mining equipment is mostly scheduled instinctively, without theoretical support for these decisions. Furthermore, in case of unexpected events, it is hard for miners to rapidly fin...

  8. Utilizing partial least square and support vector machine for TBM penetration rate prediction in hard rock conditions

    Institute of Scientific and Technical Information of China (English)

    高栗; 李夕兵

    2015-01-01

    Rate of penetration (ROP) of a tunnel boring machine (TBM) in a rock environment is generally a key parameter for the successful accomplishment of a tunneling project. The objectives of this work are to compare the accuracy of prediction models employing partial least squares (PLS) regression and support vector machine (SVM) regression technique for modeling the penetration rate of TBM. To develop the proposed models, the database that is composed of intact rock properties including uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), and peak slope index (PSI), and also rock mass properties including distance between planes of weakness (DPW) and the alpha angle (α) are input as dependent variables and the measured ROP is chosen as an independent variable. Two hundred sets of data are collected from Queens Water Tunnel and Karaj−Tehran water transfer tunnel TBM project. The accuracy of the prediction models is measured by the coefficient of determination (R2) and root mean squares error (RMSE) between predicted and observed yield employing 10-fold cross-validation schemes. The R2 and RMSE of prediction are 0.8183 and 0.1807 for SVMR method, and 0.9999 and 0.0011 for PLS method, respectively. Comparison between the values of statistical parameters reveals the superiority of the PLSR model over SVMR one.

  9. Use of the {sup 14}C-PMMA and He-gas methods to characterise excavation disturbance in crystalline rock

    Energy Technology Data Exchange (ETDEWEB)

    Autio, J.; Kirkkomaeki, T. [Saanio and Riekkola Oy, Helsinki (Finland); Siitari-Kauppi, M. [University of Helsinki (Finland). Lab. of Radiochemistry; Timonen, J.; Laajalahti, M.; Aaltonen, T.; Maaranen, J. [University of Jyvaeskylae (Finland). Dept. of Physics

    1999-04-01

    Characterisation of the excavation disturbance caused by boring of experimental full-scale deposition holes in the Research Tunnel at Olkiluoto was carried out successfully by using two novel methods; the {sup 14}C-PMMA and He-gas methods, which were modified and applied for the first time in this type of study. The experience obtained implies that the techniques are feasible and can be used to study similar types of rock excavation disturbance such as that caused by boring with mini discs, a technique which will be used in the underground Hard Rock Laboratory at Aespoe during late 1998 and early 1999. Both of the measurement methods have been in continuous use and the work has included development of both the measuring and interpretation techniques. Use of the {sup 14}C-PMMA method is suggested for studies of rock structure and the spatial distribution of porosity. The {sup 14}C-PMMA method also provides quantitative information about nanometer-range porosity which is beyond the scope of most standard methods of microscopic investigation. The use of He-gas methods are proposed for determining the diffusion coefficient, permeability and complementary porosity of rock samples taken from the disturbed zone. (orig.) 23 refs.

  10. On the use of borehole radar measurements for 3D assessment of structures in rock volumes

    Energy Technology Data Exchange (ETDEWEB)

    Tiren, S.A. [GEOSIGMA AB, Uppsala (Sweden)

    1998-09-01

    Construction of a three-dimensional model of an area, for example a site for radioactive waste disposal, requires subsurface extrapolation of surface data and interpolation of subsurface and surface data. Such structural interpretation is based on local information in the perspective of the regional structural setting of the site. The SKB borehole radar, which can detect structures within a radius of 15 to 25 m around the borehole, is one of the most important sources of geometrical information from boreholes. Directional borehole radar measurements produce information on the angle ({alpha}) at which a feature intersects the borehole and the location (azimuth) relative to the borehole. Although the azimuthal information is important for the subsequent interpretation, the critical parameter that determines whether the feature is detected by the radar appears to be the {alpha}-angle. In this paper, the performance of the radar tool concerning {alpha}-angles is studied. The reason for undertaking the study was that predicted low angle intersections between boreholes and structures were not identified. This suggests that the relationship between the sampled population and the target population needs to be investigated. The analysed data sets comprise 307 reflectors from the Romuvaara site in Finland and 307 reflectors from the cored boreholes in the Hard Rock Laboratory at Aespoe. In the Aespoe bedrock, the shape of the frequency histogram displaying the {alpha}-angles is very consistent throughout the area. A brief comparison of amplitudes and reflectivity shows that the shape of the frequency histogram is tool-dependent rather than depending on the physical properties of the zones. The potential of the borehole radar to detect structures intersecting the borehole at very high angles is low due to the transmitter-receiver configuration of the tool. In the Aespoe radar data, the range of the borehole radar appears to be narrower than expected, with very few radar

  11. A CUSP CATASTROPHE, PRECURSORS PATTERN ANDEVOLUTION PROCESS OF ROCKBUST OF COAL PILLARUNDER A HARD ROCK SUBJECT TO ELASTIC SUPPORT

    Institute of Scientific and Technical Information of China (English)

    徐曾和; 徐小荷

    1996-01-01

    The rockburst of the coal pillar under a thick hard roof stratum is modelled as the instability failure problem of coal pillars under strata subject to elastic support. The instability mechanism of rockburst is studied by applying cusp catastrophic theory. The effects of the stiffness ratio of the system and loads imposed on the system on the rockburst are explicated.The factors affecting rockbursts are discussed. Based on them, the "evolution process, the forewarning regularity and forewarning sings of rockbursts are studied. It is indicated that the subsidence velocity of roof stratum, which increases quickly and tends to infinity, is the forewarning measurable signs of the rockbursts of coal pillar.

  12. Assessment of groundwater potential based on aquifer properties of hard rock terrain in the Chittar-Uppodai watershed, Tamil Nadu, India

    Science.gov (United States)

    Kumar, T. Jeyavel Raja; Balasubramanian, A.; Kumar, R. S.; Dushiyanthan, C.; Thiruneelakandan, B.; Suresh, R.; Karthikeyan, K.; Davidraju, D.

    2016-06-01

    Aquifer performance was tested in 24 locations to assess the groundwater potential of the hard rock terrain in the Chittar-Uppodai watershed of the Tambaraparani River basin. Geologically, the area consists of biotite gneiss, charnockite, and quartzite. The aquifer characteristics, such as transmissivity ( T), the storage coefficient, specific capacity, optimum yield, and the recovery rate were calculated. The drawdown transmissivity was determined using Jacob's straight-line method, while the recovery transmissivity was determined by the Theis method. The drawdown transmissivity was low in the western areas, particularly at Kadayanallur, and was higher in the other areas. The recovery transmissivity was high in the western area, and, with the exception of Gangaikondan, was low at other locations. The assessment indicates that there is groundwater potential in the western part of the study area because of favorable results for recovery drawdown, aquifer thickness, and specific capacity.

  13. Study of regional temperature and thermohydrological effects of an underground repository for nuclear wastes in hard rock

    International Nuclear Information System (INIS)

    Heat released by the radioactive decay of nuclear wastes in an underground repository causes a long-term thermal disturbance in the surrounding rock mass. The nature of this disturbance for a planar repository 3000 m in diameter at a depth of 500 m below surface is investigated for various waste forms. The effects of changes in the density and viscosity of groundwater caused by the temperature changes on the flow through a simple model of a vertical fracture connected to a horizontal fracture in a rock mass are evaluated. It is concluded that different waste forms and time periods before burial have significant effects on the thermal disturbance and that buoyant groundwater flow is a function of both the vertical and horizontal fracture transmissivities, as well as the changes in temperature. Loaded initially with a power density of 10 W/m2 of spent fuel assemblies 10 years after discharge from a reactor, the maximum increase in temperature of the repository in granite is about 500C and the epicentral thermal gradient about 700C/km. 30 figures, 4 tables

  14. SITE-94. Development of a geological and a structural model of Aespoe, southeastern Sweden

    International Nuclear Information System (INIS)

    The objective of the present study is to construct three-dimensional geological and structural models to be used within the SKI SITE-94 project as a base for modelling hydrogeological, hydrochemical, and rock mechanical bedrock conditions, mass transport and layout of a hypothetical repository. The basic input data in the SITE-94 geological and structural models are restricted to geological and structural readings and geophysical measurements made prior to building the Hard Rock Laboratory. 114 refs, 82 figs, 28 tabs

  15. Contamination of fluoride in groundwater and its effect on human health: a case study in hard rock aquifers of Siddipet, Telangana State, India

    Science.gov (United States)

    Narsimha, A.; Sudarshan, V.

    2016-06-01

    Hydrogeochemical investigation has been carried out in the granitic terrain of Siddipet area, Medak district, Telangana State, India with an aim to understand the distribution of fluoride in the groundwater and to understand the relationship of fluoride with other major ions, and also to identify the high fluoride-bearing groundwater zones. 104 groundwater samples were analyzed in the study area for fluoride and other major ions like calcium, magnesium, chloride, carbonate, bicarbonate, sodium, potassium, sulfate, and nitrate in addition to pH and electrical conductivity. The studies revealed that the concentration of fluoride in groundwater is ranging from 0.2 to 2.2 mg L-1 with a mean of 1.1 mg L-1. Nearly 22 % of groundwater has more than the permissible limit of fluoride (1.5 mg L-1), which is responsible for the endemic dental fluorosis in the area concerned. Geochemical classification of groundwater shows that Na-HCO3, Ca-Cl, and Ca-HCO3-Na are the dominant hydrochemical facies. Gibbs diagram shows rock-water interaction dominance and evaporation dominance, which are responsible for the change in the quality of water in the hard rock aquifer of the study area. The groundwater in villages and its environs are affected by fluoride contamination, and consequently majority of the population living in these villages suffer from dental fluorosis. Hence, they are advised to consume drinking water which has less than 1.5 mg L-1 fluoride to avoid further fluorosis risks.

  16. Evaluation of regional fracture properties for groundwater development using hydrolithostructural domain approach in variably fractured hard rocks of Purulia district, West Bengal, India

    Indian Academy of Sciences (India)

    Tapas Acharya; Rajesh Prasad; S Chakrabarti

    2014-04-01

    Estimation of geohydrologic properties of fractured aquifers in hard crystalline and/or metamorphosed country rocks is a challenge due to the complex nature of secondary porosity that is caused by differential fracturing. Hydrologic potentiality of such aquifers may be assessed if the geological controls governing the spatial distribution of these fracture systems are computed using a software-based model. As an exemplar, the Precambrian metamorphics exposed in and around the Balarampur town of Purulia district, West Bengal (India) were studied to find out the spatial pattern and consistency of such fracture systems. Surfer and Statistica softwares were used to characterize these rock masses in terms of hydrological, structural and lithological domains. The technique is based on the use of hydraulically significant fracture properties to generate representative modal and coefficient of variance () of fracture datasets of each domain. The is interpreted to obtain the spatial variability of hydraulically significant fracture properties that, in turn, define and identify the corresponding hydrolithostructural domains. The groundwater flow estimated from such a technique is verified with the routine hydrological studies to validate the procedure. It is suggested that the hydrolithostructural domain approach is a useful alternative for evaluation of fracture properties and aquifer potentiality, and development of a regional groundwater model thereof.

  17. Establishment of earth tides effect on water level fluctuations in an unconfined hard rock aquifer using spectral analysis

    CERN Document Server

    Maréchal, Jean-Christophe; Ahmed, Shakeel; Lachassagne, Patrick

    2010-01-01

    Short-interval water level measurements using automatic water level recorder in a deep well in an unconfined crystalline rock aquifer at the campus of NGRI, near Hyderabad shows a cyclic fluctuation in the water levels. The observed values clearly show the principal trend due to rainfall recharge. Spectral analysis was carried out to evaluate correlation of the cyclic fluctuation to the synthetic earth tides as well as groundwater withdrawal time series in the surrounding. It was found that these fluctuations have considerably high correlation with earth tides whereas groundwater pumping does not show any significant correlation with water table fluctuations. It is concluded that earth tides cause the fluctuation in the water table. These fluctuations were hitherto unobserved during manual observations made over larger time intervals. It indicates that the unconfined aquifer is characterised by a low porosity.

  18. A physical basis for Ms-yield scaling in hard rock and implications for late-time damage of the source medium

    Science.gov (United States)

    Patton, Howard J.

    2016-07-01

    Surface wave magnitude Ms for a compilation of 72 nuclear tests detonated in hard rock media for which yields and burial depths have been reported in the literature is shown to scale with yield W as a + b × log[W], where a = 2.50 ± 0.08 and b = 0.80 ± 0.05. While the exponent b is consistent with an Ms scaling model for fully coupled, normal containment-depth explosions, the intercept a is offset 0.45 magnitude units lower than the model. The cause of offset is important to understand in terms of the explosion source. Hard rock explosions conducted in extensional and compressional stress regimes show similar offsets, an indication that the tectonic setting in which an explosion occurs plays no role causing the offset. The scaling model accounts for the effects of source medium material properties on the generation of 20-s period Rayleigh wave amplitudes. Aided by thorough characterizations of the explosion and tectonic release sources, an extensive analysis of the 1963 October 26 Shoal nuclear test detonated in granite 27 miles southeast of Fallon NV shows that the offset is consistent with the predictions of a material damage source model related to non-linear stress wave interactions with the free surface. This source emits Rayleigh waves with polarity opposite to waves emitted by the explosion. The Shoal results were extended to analyse surface waves from the 1962 February 15 Hardhat nuclear test, the 1988 September 14 Soviet Joint Verification Experiment, and the anomalous 1979 August 18 northeast Balapan explosion which exhibits opposite polarity, azimuth-independent source component U1 compared to an explosion. Modelling these tests shows that Rayleigh wave amplitudes generated by the damage source are nearly as large as or larger than amplitudes from the explosion. As such, destructive interference can be drastic, introducing metastable conditions due to the sensitivity of reduced amplitudes to Rayleigh wave initial phase angles of the explosion and

  19. Exploitation of high-yields in hard-rock aquifers: downscaling methodology combining GIS and multicriteria analysis to delineate field prospecting zones.

    Science.gov (United States)

    Lachassagne, P; Wyns, R; Bérard, P; Bruel, T; Chéry, L; Coutand, T; Desprats, J F; Le Strat, P

    2001-01-01

    Based on research work in the Truyère River catchment of the Massif Central (Lozère Department, France), a methodology has been developed for delineating favorable prospecting zones of a few square kilometers within basement areas of several hundred, if not thousand, square kilometers for the purpose of sitting high-yield water wells. The methodology adopts a functional approach to hard-rock aquifers using a conceptual model of the aquifer structure and of the functioning of the main aquifer compartments: the alterites (weathered and decayed rock), the underlying weathered-fissured zone, and the fractured bedrock. It involves an economically feasible method of mapping the thickness and spatial distribution of the alterites and the weathered-fissured zone, on which the long-term exploitation of the water resource chiefly depends. This method is used for the first time in hydrogeology. The potential ground water resources were mapped by GIS multicriteria analysis using parameters characterizing the structure and functioning of the aquifer, i.e., lithology and hydrogeological properties of the substratum, nature and thickness of the alterites and weathered-fissured zone, depth of the water table, slope, fracture networks and present-day tectonic stresses, and forecasted ground water quality. The methodology involves a coherent process of downscaling that, through applying methods that are increasingly precise but also increasingly costly, enables the selection of sites with diminishing surface areas as the work advances. The resulting documents are used for ground water exploration, although they can also be applied to the broader domain of land-use management. PMID:11447857

  20. SITE-94. Discrete-feature modelling of the Aespoe Site: 3. Predictions of hydrogeological parameters for performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Geier, J.E. [Golder Associates AB, Uppsala (Sweden)

    1996-12-01

    A 3-dimensional, discrete-feature hydrological model is developed. The model integrates structural and hydrologic data for the Aespoe site, on scales ranging from semi regional fracture zones to individual fractures in the vicinity of the nuclear waste canisters. Predicted parameters for the near field include fracture spacing, fracture aperture, and Darcy velocity at each of forty canister deposition holes. Parameters for the far field include discharge location, Darcy velocity, effective longitudinal dispersion coefficient and head gradient, flow porosity, and flow wetted surface, for each canister source that discharges to the biosphere. Results are presented in the form of statistical summaries for a total of 42 calculation cases, which treat a set of 25 model variants in various combinations. The variants for the SITE-94 Reference Case model address conceptual and parametric uncertainty related to the site-scale hydrogeologic model and its properties, the fracture network within the repository, effective semi regional boundary conditions for the model, and the disturbed-rock zone around the repository tunnels and shafts. Two calculation cases simulate hydrologic conditions that are predicted to occur during future glacial episodes. 30 refs.

  1. SITE-94. Discrete-feature modelling of the Aespoe Site: 3. Predictions of hydrogeological parameters for performance assessment

    International Nuclear Information System (INIS)

    A 3-dimensional, discrete-feature hydrological model is developed. The model integrates structural and hydrologic data for the Aespoe site, on scales ranging from semi regional fracture zones to individual fractures in the vicinity of the nuclear waste canisters. Predicted parameters for the near field include fracture spacing, fracture aperture, and Darcy velocity at each of forty canister deposition holes. Parameters for the far field include discharge location, Darcy velocity, effective longitudinal dispersion coefficient and head gradient, flow porosity, and flow wetted surface, for each canister source that discharges to the biosphere. Results are presented in the form of statistical summaries for a total of 42 calculation cases, which treat a set of 25 model variants in various combinations. The variants for the SITE-94 Reference Case model address conceptual and parametric uncertainty related to the site-scale hydrogeologic model and its properties, the fracture network within the repository, effective semi regional boundary conditions for the model, and the disturbed-rock zone around the repository tunnels and shafts. Two calculation cases simulate hydrologic conditions that are predicted to occur during future glacial episodes. 30 refs

  2. Theoretical study of rock mass investigation efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Holmen, Johan G.; Outters, Nils [Golder Associates, Uppsala (Sweden)

    2002-05-01

    The study concerns a mathematical modelling of a fractured rock mass and its investigations by use of theoretical boreholes and rock surfaces, with the purpose of analysing the efficiency (precision) of such investigations and determine the amount of investigations necessary to obtain reliable estimations of the structural-geological parameters of the studied rock mass. The study is not about estimating suitable sample sizes to be used in site investigations.The purpose of the study is to analyse the amount of information necessary for deriving estimates of the geological parameters studied, within defined confidence intervals and confidence level In other words, how the confidence in models of the rock mass (considering a selected number of parameters) will change with amount of information collected form boreholes and surfaces. The study is limited to a selected number of geometrical structural-geological parameters: Fracture orientation: mean direction and dispersion (Fisher Kappa and SRI). Different measures of fracture density (P10, P21 and P32). Fracture trace-length and strike distributions as seen on horizontal windows. A numerical Discrete Fracture Network (DFN) was used for representation of a fractured rock mass. The DFN-model was primarily based on the properties of an actual fracture network investigated at the Aespoe Hard Rock Laboratory. The rock mass studied (DFN-model) contained three different fracture sets with different orientations and fracture densities. The rock unit studied was statistically homogeneous. The study includes a limited sensitivity analysis of the properties of the DFN-model. The study is a theoretical and computer-based comparison between samples of fracture properties of a theoretical rock unit and the known true properties of the same unit. The samples are derived from numerically generated boreholes and surfaces that intersect the DFN-network. Two different boreholes are analysed; a vertical borehole and a borehole that is

  3. Groundwater potentiality mapping of hard-rock terrain in arid regions using geospatial modelling: example from Wadi Feiran basin, South Sinai, Egypt

    Science.gov (United States)

    Arnous, Mohamed O.

    2016-04-01

    Identifying a good site for groundwater exploitation in hard-rock terrains is a challenging task. In Sinai, Egypt, groundwater is the only source of water for local inhabitants. Interpretation of satellite data for delineation of lithological units and weathered zones, and for mapping of lineament density and their trends, provides a valuable aid for the location of groundwater promising areas. Complex deformational histories of the wide range of lithological formations add to the difficulty. Groundwater prospect mapping is a systematic approach that considers the major controlling factors which influence the aquifer and quality of groundwater. The presented study aims to delineate, identify, model and map groundwater potential zones in arid South Sinai using remote sensing data and a geographic information system (GIS) to prepare various hydromorphogeological thematic maps such as maps of slope, drainage density, lithology, landforms, structural lineaments, rainfall intensity and plan curvature. The controlling-factor thematic maps are each allocated a fixed score and weight, computed by using a linear equation approach. Furthermore, each weighted thematic map is statistically computed to yield a groundwater potential zone map of the study area. The groundwater potential zones thus obtained were divided into five categories (very poor, poor, moderate, good and very good) and were validated using the relation between the zone and the spatial distribution of productive wells and of previous geophysical investigations from a literature review. The results show the groundwater potential zones in the study area, and create awareness for better planning and management of groundwater resources.

  4. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 1. Executive summary. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-05-01

    Potomac Electric Power Company (PEPCO) and Acres American Incorporated (AAI) have carried out a preliminary design study of water-compensated Compressed Air Energy Storage (CAES) and Underground Pumped Hydroelectric (UPH) plants for siting in geological conditions suitable for hard rock excavations. The work was carried out over a period of three years and was sponsored by the US Department of Energy (DOE), the Electric Power Research Institute (EPRI) and PEPCO. The study was divided into five primary tasks as follows: establishment of design criteria and analysis of impact on power system; selection of site and establishment of site characteristics; formulation of design approaches; assessment of environmental and safety aspects; and preparation of preliminary design of plant. The salient aspects considered and the conclusions reached during the consideration of the five primary tasks for both CAES and UPH are presented in this Executive Summary, which forms Volume 1 of the series of reports prepared during the study. The investigations and analyses carried out, together with the results and conclusions reached, are described in detail in Volumes 2 through 13 and ten appendices.

  5. Groundwater potentiality mapping of hard-rock terrain in arid regions using geospatial modelling: example from Wadi Feiran basin, South Sinai, Egypt

    Science.gov (United States)

    Arnous, Mohamed O.

    2016-09-01

    Identifying a good site for groundwater exploitation in hard-rock terrains is a challenging task. In Sinai, Egypt, groundwater is the only source of water for local inhabitants. Interpretation of satellite data for delineation of lithological units and weathered zones, and for mapping of lineament density and their trends, provides a valuable aid for the location of groundwater promising areas. Complex deformational histories of the wide range of lithological formations add to the difficulty. Groundwater prospect mapping is a systematic approach that considers the major controlling factors which influence the aquifer and quality of groundwater. The presented study aims to delineate, identify, model and map groundwater potential zones in arid South Sinai using remote sensing data and a geographic information system (GIS) to prepare various hydromorphogeological thematic maps such as maps of slope, drainage density, lithology, landforms, structural lineaments, rainfall intensity and plan curvature. The controlling-factor thematic maps are each allocated a fixed score and weight, computed by using a linear equation approach. Furthermore, each weighted thematic map is statistically computed to yield a groundwater potential zone map of the study area. The groundwater potential zones thus obtained were divided into five categories (very poor, poor, moderate, good and very good) and were validated using the relation between the zone and the spatial distribution of productive wells and of previous geophysical investigations from a literature review. The results show the groundwater potential zones in the study area, and create awareness for better planning and management of groundwater resources.

  6. DRILLING OF HARD ROCKS USING PULSED POWER TECHNOLOGY%利用脉冲功率技术对岩石进行钻孔

    Institute of Scientific and Technical Information of China (English)

    白峰; 邱毓昌

    2001-01-01

    本文介绍一种脉冲功率技术在工业中的最新应用—在坚硬的岩石上钻孔。这种方法不同于以往对岩石进行加工的方法,其基本原理是由于液体和固体介质的动态击穿场强不同,当一高能量短脉冲施加于液体-固体界面时,固体介质表面比液体更容易发生击穿。这种方法单脉冲最大刻蚀量可以达到183cm3。%This article introduces the latest application of pulsed powertechnology in industry—drilling of hard rocks. It is different from the previous process method, the principle of which is based on the difference of dynamic breakdown-field strength in liquid and solid material. When a liquid-solid interface is applied with high-power short-pulse, the surface of solid material is broken down more easily than liquid. The maximal cutting amount can reach 183 cm3 by the new method.

  7. Effects of glacial/post-glacial weathering compared with hydrothermal alteration - implications for matrix diffusion. Results from drillcore studies in porphyritic quartz monzodiorite from Aespoe SE Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Landstroem, Ove [Studsvik Eco and Safety AB, Nykoeping (Sweden); Tullborg, Eva-Lena [Terralogica AB, Graabo (Sweden); Eriksson, Gunda; Sandell, Yvonne [Studsvik Nuclear AB, Nykoeping (Sweden)

    2001-08-01

    The effects of hydrothermal + subsequent low temperature alteration and glacial/post-glacial weathering have been studied in two cores of quartz monzodiorite. One core (YA 1192) was drilled into the hydrothermally altered wall rock of a water-conducting fracture exposed at 170 m depth in the access tunnel to the Aespoe Hard Rock Laboratory. The other one (Bas 1) was drilled from an outcrop with a glacially polished surface, 1 km north of the YA 1192 site. Both drill cores were sectioned into mm-thick slices perpendicular to the core axis. The fracture filling of the YA 1192 core, the weathered surface of the BAS 1 core and the different slices were analysed for major and trace elements and isotopes of U and Th. The altered zone of the YA 1192 core extends to approx. 2.5 cm from the fracture surface. The alteration (mainly plagioclase {yields} albite + sericite + epidote) has resulted in a higher porosity and formation of sorbing secondary minerals (e.g. sericite), favouring matrix diffusion. Increased Br concentrations in the altered zone are indicative of saline water in pores and micro fractures i.e. the presence of a diffusion medium. 234U/238U activity ratios > 1 and increased Cs in the altered zone are then interpreted as diffusion of U and Cs from fracture groundwater and subsequent sorption. The U migration is geologically recent (< 1 Ma). The 2.5 cm altered zone (corresponding to the zone of active matrix diffusion) significantly exceeds the visible red staining zone (0.5 cm) caused by hematite/FeOOH micrograins, emphasizing the need of microscopy to identify zones of alteration. The conspicuous weathering at the BAS 1 site is confined to a narrow rim of the bedrock surface (approx. 0.2-0.5 cm thick). Mass balance calculations for this rim (based on immobility of K) indicate that mechanical erosion has dominated over chemical dissolution processes (is roughly 10 times greater). The chemical weathering has affected mainly plagioclase and chlorite resulting

  8. Effects of glacial/post-glacial weathering compared with hydrothermal alteration - implications for matrix diffusion. Results from drillcore studies in porphyritic quartz monzodiorite from Aespoe SE Sweden

    International Nuclear Information System (INIS)

    The effects of hydrothermal + subsequent low temperature alteration and glacial/post-glacial weathering have been studied in two cores of quartz monzodiorite. One core (YA 1192) was drilled into the hydrothermally altered wall rock of a water-conducting fracture exposed at 170 m depth in the access tunnel to the Aespoe Hard Rock Laboratory. The other one (Bas 1) was drilled from an outcrop with a glacially polished surface, 1 km north of the YA 1192 site. Both drill cores were sectioned into mm-thick slices perpendicular to the core axis. The fracture filling of the YA 1192 core, the weathered surface of the BAS 1 core and the different slices were analysed for major and trace elements and isotopes of U and Th. The altered zone of the YA 1192 core extends to approx. 2.5 cm from the fracture surface. The alteration (mainly plagioclase → albite + sericite + epidote) has resulted in a higher porosity and formation of sorbing secondary minerals (e.g. sericite), favouring matrix diffusion. Increased Br concentrations in the altered zone are indicative of saline water in pores and micro fractures i.e. the presence of a diffusion medium. 234U/238U activity ratios > 1 and increased Cs in the altered zone are then interpreted as diffusion of U and Cs from fracture groundwater and subsequent sorption. The U migration is geologically recent (< 1 Ma). The 2.5 cm altered zone (corresponding to the zone of active matrix diffusion) significantly exceeds the visible red staining zone (0.5 cm) caused by hematite/FeOOH micrograins, emphasizing the need of microscopy to identify zones of alteration. The conspicuous weathering at the BAS 1 site is confined to a narrow rim of the bedrock surface (approx. 0.2-0.5 cm thick). Mass balance calculations for this rim (based on immobility of K) indicate that mechanical erosion has dominated over chemical dissolution processes (is roughly 10 times greater). The chemical weathering has affected mainly plagioclase and chlorite resulting in

  9. Palaeohydrological implications in the Baltic area and its relation to the groundwater at Aespoe, south-eastern Sweden - A literature study

    International Nuclear Information System (INIS)

    A literature study of different groundwaters in the circum Baltic region is presented in this work. The study is mainly focused on the isotopic signatures observed in different groundwaters in Sweden and Finland. Several saline groundwaters in the Baltic region at depth of 150 to 500m depth show stable (δD, δ13C, δ18O) and radiogenic (δ87Sr) isotope assembly which is suggestive of a marine origin. However, a discrepancy is sometimes observed between the stable as well as radiogenic isotopes of the intermediate groundwater, which suggest a mixture of fossil marine water and a post-glacial runoff of melt water. In order to explain this phenomenon, the initial setting in δ18O may have been depleted due to large input of high latitude marine water or cold melt waters. A solution to the contradiction between the strontium (δ87Sr) and stable isotope (δD, δ13C, δ18O) signatures of the groundwater and of the calcite fracture fillings at Aespoe and other places is attained, if it is assumed that the strontium in Baltic Sea water has undergone a significant decrease in δ87Sr since the last glaciation. A scenario can be constructed to suggest that the Baltic Sea during the initial stage of the Litorina sea (8000 to 5000 Y B.P.) contained strontium with much larger δ87Sr values. Another explanation for the positive δ87Sr values may be due to water/rock interaction between the groundwater and the abundant fracture clay minerals, which are observed at Aespoe. Typically most of the saline groundwaters occur both in Sweden and Finland below the highest marine shore line during the Holocene. Almost all inland groundwaters show a totally different pattern which is typically non marine, meteoric in origin. This study also summarises the stable isotope (δ13C,δ18O) geochemistry dependence of the important global and regional environmental changes which may have influenced of the palaeohydrology as well as groundwater formation and in the Baltic region and especially at

  10. Conceptual and analytical modeling of fracture zone aquifers in hard rock. Implications of pumping tests in the Pohjukansalo well field, east-central Finland

    International Nuclear Information System (INIS)

    the approximate cone of depression around pumping wells and, subsequently, the extent of protection areas. In many developing countries, knowledge of water level fluctuations is insufficient and long-term pumping tests are not economically feasible. Sustainable well yield must be estimated by extrapolating short-term tests. Fractional flow dimension models commonly simulate responses to pumping in hard rocks and, therefore, can improve the present groundwater management methods. Conductive fracture zones generally control the 3-dimensional flow paths in fractured rocks and, subsequently, affect the spatial variations of groundwater composition. Studies of groundwater quality should probably take into account to what extent the sampled bored well represents groundwater in the hydrogeologically favorable parts of the bedrock. (orig.)

  11. Palaeohydrological implications in the Baltic area and its relation to the groundwater at Aespoe, south-eastern Sweden - A literature study

    Energy Technology Data Exchange (ETDEWEB)

    Wallin, B. [Geokema AB, Lidingoe (Sweden)

    1995-03-01

    A literature study of different groundwaters in the circum Baltic region is presented in this work. The study is mainly focused on the isotopic signatures observed in different groundwaters in Sweden and Finland. Several saline groundwaters in the Baltic region at depth of 150 to 500m depth show stable ({delta}D, {delta}{sup 13}C, {delta}{sup 18}O) and radiogenic ({delta}{sup 87}Sr) isotope assembly which is suggestive of a marine origin. However, a discrepancy is sometimes observed between the stable as well as radiogenic isotopes of the intermediate groundwater, which suggest a mixture of fossil marine water and a post-glacial runoff of melt water. In order to explain this phenomenon, the initial setting in {delta}{sup 18}O may have been depleted due to large input of high latitude marine water or cold melt waters. A solution to the contradiction between the strontium ({delta}{sup 87}Sr) and stable isotope ({delta}D, {delta}{sup 13}C, {delta}{sup 18}O) signatures of the groundwater and of the calcite fracture fillings at Aespoe and other places is attained, if it is assumed that the strontium in Baltic Sea water has undergone a significant decrease in {delta}{sup 87}Sr since the last glaciation. A scenario can be constructed to suggest that the Baltic Sea during the initial stage of the Litorina sea (8000 to 5000 Y B.P.) contained strontium with much larger {delta}{sup 87}Sr values. Another explanation for the positive {delta}{sup 87}Sr values may be due to water/rock interaction between the groundwater and the abundant fracture clay minerals, which are observed at Aespoe. Typically most of the saline groundwaters occur both in Sweden and Finland below the highest marine shore line during the Holocene. Almost all inland groundwaters show a totally different pattern which is typically non marine, meteoric in origin. (Abstract Truncated)

  12. Characterising and modelling the excavation damaged zone (EDZ) in crystalline rock in the context of radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, J.A.; Backstrom, A.; Rutqvist, J.; Jing, L.; Backers, T.; Chijimatsu, M.; Christiansson, R.; Feng, X.-T.; Kobayashi, A.; Koyama, T.; Lee, H.-S.; Neretnieks, I.; Pan, P.Z.; Rinne, M.; Shen, B.-T.

    2008-10-01

    This paper describes current knowledge about the nature of and potential for thermo-hydro-mechanical-chemical modelling of the Excavation Damaged Zone (EDZ) around the excavations for an underground radioactive waste repository. In the first part of the paper, the disturbances associated with excavation are explained, together with reviews of Workshops that have been held on the subject. In the second part of the paper, the results of a DECOVALEX research programme on modelling the EDZ are presented. Four research teams used four different models to simulate the complete stress-strain curve for Avro granite from the Swedish Aespoe Hard Rock Laboratory. Subsequent research extended the work to computer simulation of the evolution of the repository using a 'wall block model' and a 'near-field model'. This included assessing the evolution of stress, failure and permeability and time dependent effects during repository evolution. As discussed, all the computer models are well suited to sensitivity studies for evaluating the influence of their respective supporting parameters on the complete stress-strain curve for rock and for modelling the EDZ.

  13. Hard Roof Control of Extended Working Face with Shallow Depth and Rock Burst Hazard%浅埋冲击危险性加长工作面坚硬顶板控制研究

    Institute of Scientific and Technical Information of China (English)

    张书敬

    2016-01-01

    In order to control the hard roof of extend working face with rock burst hazard effectively, based on support pressure moni-toring, microseism monitoring, numerical simulation and composite index evaluation, filed test of rock pressure of extend working face with hard roof, numerical calculation of treatment scope in roof that overhead the pillar and evaluation of working face rock burst hazard were carried out, then practiced in filed. The research results showed that extend working face experienced the following characters, which included the middle rock burst hazard, hard roof moved violently, stress change and regional deformation of roadway and so on. In ’ single face square’ zone, strata energy of hard roof released concentration, roadway deformation largely, high stress concen-tration appeared in coal pillar, then the treatment scope of hard roof in different zone was confirmed, advanced presplit blasting in deep was practiced in filed, the problem of hard roof and rock burst hazard were controlled effectively.%为实现冲击危险性加长工作面坚硬顶板的有效控制,采用支架压力监测、微震监测、数值模拟和综合指数评价的方法,开展加长工作面坚硬顶板条件矿压显现规律现场实测、煤柱上方顶板处理范围的数值计算以及工作面冲击地压危险评价,并进行了现场实践。研究表明,加长工作面具有中等冲击危险,坚硬顶板活动剧烈程度、应力变化、巷道变形具有区域性,在“单面见方”等区域,坚硬顶板岩层能量集中释放,巷道变形量大,煤柱应力集中程度高,确定了不同区域坚硬顶板处理范围,开展了超前深孔预裂爆破的现场实践,使坚硬顶板问题与冲击地压危险得到有效地控制。

  14. Groundwater-quality data in the Bear Valley and Selected Hard Rock Areas study unit, 2010: Results from the California GAMA Program

    Science.gov (United States)

    Mathany, Timothy M.; Belitz, Kenneth

    2013-01-01

    Groundwater quality in the 112-square-mile Bear Valley and Selected Hard Rock Areas (BEAR) study unit was investigated by the U.S. Geological Survey (USGS) from April to August 2010, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA-PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The BEAR study unit was the thirty-first study unit to be sampled as part of the GAMA-PBP. The GAMA Bear Valley and Selected Hard Rock Areas study was designed to provide a spatially unbiased assessment of untreated-groundwater quality in the primary aquifer system and to facilitate statistically consistent comparisons of untreated groundwater quality throughout California. The primary aquifer system is defined as the zones corresponding to the perforation intervals of wells listed in the California Department of Public Health (CDPH) database for the BEAR study unit. Groundwater quality in the primary aquifer system may differ from the quality in the shallow or deep water-bearing zones; shallow groundwater may be more vulnerable to surficial contamination. In the BEAR study unit, groundwater samples were collected from two study areas (Bear Valley and Selected Hard Rock Areas) in San Bernardino County. Of the 38 sampling sites, 27 were selected by using a spatially distributed, randomized grid-based method to provide statistical representation of the primary aquifer system in the study unit (grid sites), and the remaining 11 sites were selected to aid in the understanding of the potential groundwater-quality issues associated with septic tank use and with ski areas in the study unit (understanding sites). The groundwater samples were analyzed for organic constituents (volatile organic compounds [VOCs], pesticides and

  15. Microbial O{sub 2} consumption in the Aespoe tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Kotelnikova, S.; Pedersen, Karsten [Goeteborg Univ. (Sweden). Dept. of Cell and Molecular Biology, Microbiology

    1998-04-01

    The report presents data on microbial O{sub 2} reduction activities by microorganisms obtained with different techniques: Winkler method, gas chromatography, most probable numbering, enrichment technique, inhibitor analysis and radiotracer measurements. The samples were collected from boreholes and open funnel ponds at Aespoe in 1996-1998. The evaluation of the microbial activities in open ponds predicts the future microbial activities after the O{sub 2} intrusion around the future repository. The metabolic potential of the microbial population inhabiting groundwater was evaluated on the basis of electron donors available and microbial 16S rRNA gene diversity. The contribution of different microbial groups to the O{sub 2} reduction was elucidated using specific inhibitors selectively affecting different microbial groups. Our experiments show that microbial O{sub 2} reduction occurs in deep groundwater. Carbon dioxide was produced concurrently with O{sub 2} reduction confirming the biogenic nature of the reduction. The populations developed O{sub 2} reduction rates and capacity depending on the initial concentration of dissolved O{sub 2} reduction. Rates of O{sub 2} reduction ranged from 0.32 to 4.5 {mu}M/day. Depending on temperature and the type of groundwater the approximate time needed for consumption of 500 {mu}M of dissolved O{sub 2} ranged from 0.31 to 3.99 years. After approximately a 2 weeks period the microbial population in vitro was able to consume O{sub 2} both at 30 deg C and 60 deg C. At 16 deg C no delay in O{sub 2} consumption was observed. Our results demonstrated that methanotrophs survive in deep groundwater and that they were induced by O{sub 2}. Some bacteria use Hg or CH{sub 4} as electron donor instead of organic matter, which means that microbial O{sub 2} reduction will occur also in deep groundwaters where the availability of organic carbon is limited. Specific CH{sub 4} oxidation rates ranged between 3.00 and 220 nM CH{sub 4} per litre per

  16. Microbial O2 consumption in the Aespoe tunnel

    International Nuclear Information System (INIS)

    The report presents data on microbial O2 reduction activities by microorganisms obtained with different techniques: Winkler method, gas chromatography, most probable numbering, enrichment technique, inhibitor analysis and radiotracer measurements. The samples were collected from boreholes and open funnel ponds at Aespoe in 1996-1998. The evaluation of the microbial activities in open ponds predicts the future microbial activities after the O2 intrusion around the future repository. The metabolic potential of the microbial population inhabiting groundwater was evaluated on the basis of electron donors available and microbial 16S rRNA gene diversity. The contribution of different microbial groups to the O2 reduction was elucidated using specific inhibitors selectively affecting different microbial groups. Our experiments show that microbial O2 reduction occurs in deep groundwater. Carbon dioxide was produced concurrently with O2 reduction confirming the biogenic nature of the reduction. The populations developed O2 reduction rates and capacity depending on the initial concentration of dissolved O2 reduction. Rates of O2 reduction ranged from 0.32 to 4.5 μM/day. Depending on temperature and the type of groundwater the approximate time needed for consumption of 500 μM of dissolved O2 ranged from 0.31 to 3.99 years. After approximately a 2 weeks period the microbial population in vitro was able to consume O2 both at 30 deg C and 60 deg C. At 16 deg C no delay in O2 consumption was observed. Our results demonstrated that methanotrophs survive in deep groundwater and that they were induced by O2. Some bacteria use Hg or CH4 as electron donor instead of organic matter, which means that microbial O2 reduction will occur also in deep groundwaters where the availability of organic carbon is limited. Specific CH4 oxidation rates ranged between 3.00 and 220 nM CH4 per litre per day. Comparison of the total O2 reducing activities by gas chromatography and radiotracer tests

  17. Challenges in planning and performing the retrieval of the prototype repository at Aespoe HRL- Project management's reflections and practical experiences from field work

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Since 2001 the Prototype Repository at Aespoe Hard Rock Laboratory has been carried out as a large-scale experimental installation of the KBS-3 Swedish/Finnish concept for final disposal of spent nuclear fuel. The overall objective of the trial 'Prototype Repository' is to test and demonstrate the integrated function of sub-components in a final repository under realistic full-scale conditions. Data from the experiment shall also be compared to results from modelling based on site conditions. Opening of the outer section for the Prototype Repository was recognized as substantial operation. No trial of this size has been made earlier with regard to removal of buffer and backfilling. Experience was available only from retrieval of the buffer in Canister Retrieval Test at Aespoe HRL where samples of the buffer were taken, down to the mid-height of the canister. It was expected that sampling of the buffer in the deposition holes of the Prototype Repository would be very difficult, especially deep down in the holes. No significant experience regarding the breaching of such a concrete plug or removing backfill was available. The lack of experience together with the size of the project made extensive planning essential before the opening and removal could begin. It was decided that SKB (Sweden) and Posiva Oy (Finland) should run the project in a co-operation, where SKB is responsible for managing the project. In addition, a wide international interest was observed and accordingly waste management organisations were invited by SKB and Posiva to be a party to the Retrieval of the Prototype Repository. Six individual project agreements were signed with Andra (France), NUMO (Japan), NDA (United Kingdom), NAGRA (Switzerland), BMWi (Germany) and NWMO (Canada). The planning of the Retrieval of the Prototype Repository (section II) started at the beginning of 2010. The planning phase was successful meaning that the breaching of

  18. High spatial variability of nitrate in the hard rock aquifer of an irrigated catchment: Implications for water resource assessment and vulnerability

    Science.gov (United States)

    Buvaneshwari, Sriramulu; Riotte, Jean; Ruiz, Laurent; Sekhar, Muddu; Mohan Kumar, Mandalagiri S.; Sharma, Amit Kumar; Duprey, Jean Louis; Audry, Stephane; Praveen, Yerabham; Hemanth, Moger; Durand, Patrick; Braun, Jean Jacques

    2016-04-01

    groundwater gradient was high, NO3 concentrations were low to moderate, suggesting that significant lateral flow prevented NO3 enrichment; iii) Finally, low NO3 concentrations were also found in situations where gradient was small but groundwater was shallow and hence reserve was large: these zones are potentially vulnerable to intensification of pumping and fertilizer application. Subsequent decline in groundwater level would then lead to rapid degradation of groundwater quality. We propose that the groundwater level and gradient mapping could be used in hard rock aquifers to delineate zones affected or vulnerable to intensification of irrigated agriculture. Wells located in low gradient zones are suitable for assessing the impacts of local agricultural systems. To the contrary, wells located in zones with high gradient (well mixed) are more representative of the average groundwater quality of the catchment, and hence should be used in priority for regional mapping of groundwater quality.

  19. My Pet Rock

    Science.gov (United States)

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  20. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Hard material technologies were surveyed to establish the hard electronic technology which offers superior characteristics under hard operational or environmental conditions as compared with conventional Si devices. The following technologies were separately surveyed: (1) The device and integration technologies of wide gap hard semiconductors such as SiC, diamond and nitride, (2) The technology of hard semiconductor devices for vacuum micro- electronics technology, and (3) The technology of hard new material devices for oxides. The formation technology of oxide thin films made remarkable progress after discovery of oxide superconductor materials, resulting in development of an atomic layer growth method and mist deposition method. This leading research is expected to solve such issues difficult to be easily realized by current Si technology as high-power, high-frequency and low-loss devices in power electronics, high temperature-proof and radiation-proof devices in ultimate electronics, and high-speed and dense- integrated devices in information electronics. 432 refs., 136 figs., 15 tabs.

  1. 硬岩巷道中深孔爆破掘进复楔形掏槽试验研究%Duplex Wedge Cutting on Mid-depth Borehole Tunneling Blasting in Hard rock

    Institute of Scientific and Technical Information of China (English)

    余永强; 王超; 褚怀保; 吴帅峰

    2013-01-01

    In order to improve the advancing speed of hard-rock tunnel blasting,three kinds of duplex wedge cutting schemes were designed and analyzed,including two levels digging,adding auxiliary cutting hole and reinforcing center hole charge.Based on problems in deep hard rock tunnel boring,the blasting theory,empirical formulas and site situation were taken into account.Suitable cutting method,blast hole depth and the main cutting hole parameters were introduced.Results show that the reinforced charge of center hole in duplex wedge cutting improved the effect of cutting blasting in hard rock and offer reference to other similar works.%为提高硬岩巷道爆破掘进速度,在分析其中所存在问题的基础上,根据爆破理论与经验公式计算,结合试验工作面的具体情况,介绍了硬岩巷道条件下合理掏槽方式、炮孔深度以及掏槽孔布置参数的选取;设计并现场试验了二级、加辅助掏槽孔、加装药中心孔三种复楔形掏槽爆破方案;比较分析了各种掏槽方案的爆破效果及有关技术问题.结果表明:采用加装药中心孔的复楔形掏槽方案,对硬岩掏槽爆破效果改善明显.

  2. Hard electronics; Hard electronics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    In the fields of power conversion devices and broadcasting/communication amplifiers, high power, high frequency and low losses are desirable. Further, for electronic elements in aerospace/aeronautical/geothermal surveys, etc., heat resistance to 500degC is required. Devices which respond to such hard specifications are called hard electronic devices. However, with Si which is at the core of the present electronics, the specifications cannot fully be fulfilled because of the restrictions arising from physical values. Accordingly, taking up new device materials/structures necessary to construct hard electronics, technologies to develop these to a level of IC were examined and studied. They are a technology to make devices/IC of new semiconductors such as SiC, diamond, etc. which can handle higher temperature, higher power and higher frequency than Si and also is possible of reducing losses, a technology to make devices of hard semiconducter materials such as a vacuum microelectronics technology using ultra-micro/high-luminance electronic emitter using negative electron affinity which diamond, etc. have, a technology to make devices of oxides which have various electric properties, etc. 321 refs., 194 figs., 8 tabs.

  3. Evaluation of modelling of the TRUE-1 radially converging tests with sorbing tracers. The Aespoe task force on modelling of groundwater flow and transport of solutes. Tasks 4E and 4F

    Energy Technology Data Exchange (ETDEWEB)

    Elert, M.; Svensson, Haakan [Kemakta Konsult AB, Stockholm (Sweden)

    2001-05-01

    The Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes is a forum for the international organisations supporting the Aespoe HRL Project. The purpose of the Task Force is to interact in the area of conceptual and numerical modelling of groundwater flow and solute transport in fractured rock. Task 4 of the Aespoe Modelling Task Force consists of modelling exercises in support of the TRUE-1 tracer tests. In this report, the modelling work performed within Tasks 4E and 4F is evaluated, which comprised predictive modelling of the tracer tests (STT-1, STT-1b and STT-2) performed within the TRUE-1 project using sorbing and non-sorbing tracers. The tests were made between packed off boreholes penetrating a water-conducting geological feature with a simple structure (Feature A). Nine modelling teams representing eight organisations have performed predictive modelling of the tracer tests using different modelling approaches and models. The modelling groups were initially given data from the site characterisation, data from preliminary tracer tests performed with non-sorbing tracers and data on the experimental set-up of the sorbing tracer tests. Based on this information, model predictions were made of drawdown, tracer mass recovery and tracer breakthrough. For the predictions of the STT-1b and STT-2 tests results from previous tracer tests with sorbing tracer were also available. The predictions of the sorbing tracer breakthrough in the initial tracer test (STT-1) generally underestimated the breakthrough time, suggesting the need to include additional processes and evaluate the application of the laboratory data. As a result of model calibration and modification the predictions were considerably improved for the latter tracer tests (STT-1b and STT-2). Task 4E and 4F have proved to be very valuable in increasing the understanding of non-sorbing tracer transport in fractured rock. There is a general consensus on the major processes responsible for

  4. Immobilization of uranium and neptunium by microorganisms in subsurface crystalline rock environments

    International Nuclear Information System (INIS)

    In crystalline rock, the dominant transport medium for radionuclides is groundwater flowing through subsurface fractures. Since groundwater is containing microorganisms, fracture surfaces support biological growth of microbial communities, the so-called bio-films. The microbial diversity of these bio-films depends on the microbial consortia and the chemical composition of the fracture water. Subsurface bio-films have a significant effect on the adsorption capacity of host rock formations by forming a barrier between the rock surface and the groundwater. They can significantly affect subsurface biogeochemical interactions, leading to the immobilization and adsorption of radionuclides. Microbial studies were performed to evaluate the relevance of microbial processes for the immobilization of radionuclides in a deep crystalline repository for high-level radioactive waste. Studies were performed in Olkiluoto, in the rock characterization facility ONKALO in Finland, and in the Aespoe Hard Rock Laboratory (HRL) in Sweden. Massive 5-10-mm thick bio-films were observed in both sites attached to tunnel walls where groundwater was seeping from bedrock fractures. In experiments the effect of uranium on bio-films was studied on site in the ONKALO tunnel by adding UO2(ClO4)2 with a final U-concentration of 1.0x10-5 M to the fracture water in a self-constructed flow cell by using detached bio-film samples. bio-film specimens collected for transmission electron microscopy studies indicated that uranium in the bio-film was immobilized intracellularly in microorganisms as needle-shaped uranyl phosphate minerals, similar to meta-Autunite (Ca[UO2]2[PO4]2.10-12H2O). In contrast, thermodynamic calculation of the theoretical predominant fields of uranium species and time-resolved laser fluorescence spectroscopy showed that the formation of aqueous uranium carbonate species Ca2UO2(CO3)3 and Mg2UO2(CO3)3 was predicted due to the high concentration of carbonate in the groundwater. At the

  5. Properties of waterproof sprayed concrete tunnel linings: A study of EVA-based sprayed membranes for waterproofing of rail and road tunnels in hard rock and cold climate

    OpenAIRE

    Holter, Karl Gunnar

    2015-01-01

    Investigate the long term effects of exposure of the SCL lining to higher ground water pressure, particularly the exposure of the membrane to pressurized water at cracks Investigate the effects of slow deformations and slow thermal fluctuations in order to complement the finding from short-term accelerated testing the mechanical performance parameters Investigate the longitudinal thermal profile of selected tunnels, combined with thermal monitoring in the lining and rock mass in...

  6. Hard rock drilling: from conventional technologies to the potential use of laser; Perfuracao em rochas duras: das tecnologias convencionais ate o potencial uso do laser

    Energy Technology Data Exchange (ETDEWEB)

    Amaro, Renato; Lomba, Rosana Fatima Teixieira [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil); Perez, Maria Angelica Acosta; Valente, Luiz Carlos Guedes; Braga, Arthur Martins Barbosa [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)

    2012-07-01

    One of the biggest challenges in the drilling of the carbonate rocks of the Pre-salt is to overcome the low penetration rates that have been obtained in the drilling of the reservoir rock in the vertical and directional wells. To overcome this challenge, a great effort is being developed in several lines of research, both in developing new concepts in drill bits and in the selection of a drilling system that together with appropriate type of bit provide an expected improvement in performance. To achieve these results, procedures are being prioritized and drilling systems with lower vibration levels are being used, since this phenomenon of vibration reduces the performance of penetration rate also affecting the lifetime of the equipment and consequently causes a reduction in reliability of all system and raises the cost per meter of drilling. Thus, new drill bit technology and new drilling systems are under development and, among these technologies we can distinguish those that promote improvements in conventional technologies and innovative technologies frankly which uses new mechanisms to cut or weaken the rock. This paper presents an overview of the conventional technology of drilling systems and drill bits, and provides information about the researches that have been developed with the use of innovative technologies which is presented as highly promising, among these innovative technologies, laser drilling and the drilling itself assisted by laser. In this process the laser beam has the main function to weaken the rock improving the rate of penetration. This paper presents a summary of studies and analyzes which are underway to investigate the potential of laser technology, also presents some results of laboratory tests already carried out. The drilling fluid in which the laser will have to pass through in the future applications is analyzed on the approach of their physicochemical properties. Thus, a better understanding of the interaction with the drilling

  7. 基于改进RBF神经网络的硬岩岩体变形模量预测%Prediction of deformation modulus of hard rock mass based on improved RBF neural network mode

    Institute of Scientific and Technical Information of China (English)

    赵渊; 王亮清; 周鹏

    2015-01-01

    岩体变形模量确定方法有室内外试验法、数值分析法、反分析法、岩体分类法等。上述方法均存在很大缺陷,而神经网络法的日益完善使通过建模预测岩体参数成为可能。以溪洛渡水电站的88组数据为基础,考虑岩石质量指标RQD、RMD、Vp等因素,建立了基于模式搜索法的改进RBF神经网络模型,并用该模型预测岩体变形模量。为了验证模型的准确性,将西藏如美水电站岩体的17组数据代入,将其预测结果与BP神经网络模型结果及原位数据作对比。结果表明,改进RBF模型更适于硬岩岩体变形模量的预测。%The deformation modulus of rock mass can be determined by in-situ and indoor test, numerical analysis, back a-nalysis and rock mass classification methods etc. These methods have limitations, but the improvement of the artificial neural net-work ( ANN) method makes it possible to predict the rock mass deformation modulus accurately. On the basis of 88 sets of test data of Xiluoda Hydropower Station and by consideration of several rock quality index such as RQD, RMD and Vp, an improved RBF ( Radial Basis Function) neural network model is established to predict the deformation modulus of rock mass, in which, the pattern search method is used to solve the optimal SPREAD value. For verifying the correctness of the model, 17 sets of data of Rumei Hydropower Station, Tibet, were put into the model and the results were compared with the measured data and the results obtained by BP neural network respectively. It is concluded that the improved RBF neural network model is more suitable for the prediction of deformation modulus of hard rock mass.

  8. Hard rock excavation at the CSM/OCRD test site using crater theory and current United States controlled smooth wall blasting practices, June 1982

    International Nuclear Information System (INIS)

    This report is the fourth in a series describing experiments conducted by the Colorado School of Mines for the Office of Crystalline Repository Development (OCRD) to determine the extent of blast damage in rock surrounding an underground opening. The report describes the application of tunnel design procedures based upon crater theory and current United States controlled smooth wall blasting practices for the excavation of the CSM/OCRD test room in the Colorado School of Mines, Experimental Mine (Edgar Mine) in Idaho Springs, Colorado. Ten blast rounds were used to excavate the test room. The first seven rounds were designed with Swedish Techniques, and described in the third report in this series, and the design of rounds eight through ten used crater theory. Crater theory is described in this document along with its application to the CSM/OCRD Room excavation. Calculation for spacing, burden, number and type of holes, explosives placement, and overall powder factor are discussed. A series of single charge cratering test shots, designed to evaluate some of the input data for the blast designs, are discussed. The input data include: Strain Energy Factor E, a dimensionless factor which varies according to the explosive and rock type; Critical Depth, N, the charge depth at which the explosive begins to fracture rock at the free face; Optimum Depth Ratio Δ0, which is a ratio between Optimum Charge Depth, d0, and Critical Charge Depth, d/sub c/; and charge Weight, W. A non-linear least squared regression method to best fit the general bell-shape curve of the crater results is discussed. Both scaled weight and scaled volume criteria are reported in the analysis of results. 10 references, 17 figures, 16 tables

  9. SITE-94. Discrete-feature modelling of the Aespoe site: 4. Source data and detailed analysis procedures

    Energy Technology Data Exchange (ETDEWEB)

    Geier, J.E. [Golder Associates AB, Uppsala (Sweden)

    1996-12-01

    Specific procedures and source data are described for the construction and application of discrete-feature hydrological models for the vicinity of Aespoe. Documentation is given for all major phases of the work, including: Statistical analyses to develop and validate discrete-fracture network models, Preliminary evaluation, construction, and calibration of the site-scale model based on the SITE-94 structural model of Aespoe, Simulation of multiple realizations of the integrated model, and variations, to predict groundwater flow, and Evaluation of near-field and far-field parameters for performance assessment calculations. Procedures are documented in terms of the computer batch files and executable scripts that were used to perform the main steps in these analyses, to provide for traceability of results that are used in the SITE-94 performance assessment calculations. 43 refs.

  10. 上软下硬岩质地层浅埋大跨隧道松动压力计算%Calculation method of relaxation pressure of shallow large span tunnel in up-soft/low-hard rock stratum

    Institute of Scientific and Technical Information of China (English)

    王志伟; 乔春生; 宋超业

    2014-01-01

    In accordance with the problems of existing methods for surrounding rock pressure of shallow large-span tunnel in up-soft/low-hard rock stratum, by using DEM (distinct element method) and orthogonal array testing method, the law and sensibilities of the failure mechanism of loose zone and the thickness of overlying weak rock stratum and the joint occurrence influencing on shape and scope of the loose zone are analyzed. In sequence, the sensibilities of factors are as follows in the magnitude order: thickness of overlying weak rock stratum, tunnel depth, angle and distance of continuous inclined joint, distance of horizontal joints in weak rock stratum. Through comparative analysis two failure modes of arch collapse and caving collapse are obtained;the boundary curves are analyzed and fit with linear and non-linear models by using the software ORIGIN, the test results show their boundary curves are power function curve and parabola curve. In accordance with caving collapse loose zone, new formulae for the length of earth surface crack and the soil strip width above the vault are formulated by using the liner least squares method. The errors of the empirical formulae are analyzed. According to the stress transfer principle, a differential trapezoid geotechnical strip is chosen as research object, the formula of surrounding rock pressure of loose zone which considering the joint occurrence and thickness of overlying weak rock stratum is deduced. Case studies show that the results of proposed method are smaller than the results of the existing representative methods.%针对现有方法在上软下硬岩质地层中浅埋大跨隧道松动压力计算方面存在的问题,通过离散元数值模拟和正交试验,分析了围岩的松动破坏机制、风化层厚度和岩体中节理分布状态对隧道松动区形状和范围的影响规律及敏感性。结果表明:影响松动区的主要因素依次为风化层厚度、隧道埋深、贯通倾斜节理的

  11. Evaluation of modelling of the TRUE-1 radially converging and dipole tests with conservative tracers. The Aespoe task force on modelling of groundwater flow and transport of solutes. Tasks 4C and 4D

    Energy Technology Data Exchange (ETDEWEB)

    Elert, M. [Kemakta Konsult AB, Stockholm (Sweden)

    1999-05-01

    The `Aespoe task force on modelling of groundwater flow and transport of solutes` is a forum for the international organisations supporting the Aespoe HRL Project. The purpose of the Task Force is to interact in the area of conceptual and numerical modelling of groundwater flow and solute transport in fractured rock. Task 4 of the Aespoe Modelling Task Force consists of modelling exercises in support of the TRUE-1 tracer tests. In this report, the modelling work performed within Tasks 4C and 4D is evaluated, which comprised predictive modelling of the radially converging tracer tests and dipole tracer tests performed within the TRUE-1 tests using non-sorbing tracers. The tests were performed between packed off boreholes penetrating a water-conducting geological feature with a simple structure (Feature A). These tests are to a great extent preparatory steps for the subsequent tests with sorbing radioactive tracers. In Tasks 4E and 4F of the Aespoe Modelling Task Force predictive modelling of the sorbing tracer tests is performed. Eight modelling teams representing seven organisations have performed predictive modelling using different modelling approaches and models. The modelling groups were initially given data from the site characterisation and data on the experimental set-up of the tracer tests. Based on this information model predictions were performed of drawdown, tracer mass recovery and tracer breakthrough. The performed predictions shows that the concept of Feature A as a singular well-connected feature with limited connectivity to its surroundings is quite adequate for predictions of drawdown in boreholes and conservative tracer breakthrough. Reasonable estimates were obtained using relatively simple models. However, more elaborate models with calibration or conditioning of transmissivities and transport apertures are required for more accurate predictions. The general flow and transport processes are well understood, but the methodology to derive the

  12. Hard coatings

    OpenAIRE

    Dan, J.; Boving, H.; Hintermann, H.

    1993-01-01

    Hard, wear resistant and low friction coatings are presently produced on a world-wide basis, by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, CVD and PVD. Some of the most advanced processes, especially those dedicated to thin film depositions, basically belong to CVD or PVD technologies, and will be looked at in more detail. The hard coatings mainly consist of oxides, nitrides, carbides, borides or carbon. Over the years, many process...

  13. Between a Rock and a Hard Place

    DEFF Research Database (Denmark)

    Thorsen, Mira Skadegård; Horst, Christian

    2016-01-01

    the following: 1) Complex, shared underlying knowledge of discrimination which encompasses systematized stratifications of difference. 2) “A knowing the inside/being the outside position” which, for some individuals, may contribute to challenges in regard to navigations within discriminatory contexts....

  14. Regional groundwater flow in hard rocks

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco, Fernando A.L., E-mail: fpacheco@utad.pt

    2015-02-15

    The territory of continental Portugal has a geologic history marked by the Hercynian orogeny, and to the north of this country the Hercynian large-scale tectonic structures are typically represented by long and deep NW–SE trending ductile shear zones and NNE–SSW trending fragile faults. These structures are elements of mineral and thermal water circuits that discharge as springs in more than one hundred locations. The purpose of this study is to investigate if these structures are also used by shallower non-mineral groundwater, integrated in a large-scale regional flow system. Using an original combination of water balance and recession flow models, it was possible to calculate catchment turnover times based solely on groundwater discharge rates and recession flow parameters. These times were then used to classify a group of 46 watersheds as closed or open basins, and among the later class to identify source and sink basins, based on innovative interpretations of relationships between turnover time and catchment area. By definition, source basins transfer groundwater to sink basins and altogether form a regional flow system. Using a Geographic Information System, it could be demonstrated the spatial association of open basins to the Hercynian ductile and fragile tectonic structures and hence to classify the basins as discharge cells of a regional flow system. Most of the studied watersheds are sub-basins of the Douro River basin, one of the largest regional catchments in the Iberian Peninsula, being located in its mouth area. Because the largest part of open basins is sink, which by definition tends to dominate in the mouth area of regional catchments, it is proposed as an extension of the studied area conceptual boundaries towards the Douro River basin headwaters, where the corresponding sources could be searched for. - Highlights: • Introduce a method to distinguish open from closed groundwater basins • Identify structural elements of a regional flow system in northern Portugal • Propose the Douro River basin as the regional watershed • Combine topographic, hydrologic and geologic data in a GIS.

  15. The Aespoe redox investigations in block scale. Project summary and implications for repository performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Banwart, S. [ed.] [Bradford Univ. (United Kingdom). Dept. of Civil Engineering

    1995-11-01

    During construction and operation of a deep repository for high level waste, the groundwater environment will be open to oxidizing surface conditions and surface water inflow. Construction of the access tunnel to the Hard Rock Laboratory intersected a vertical fracture zone at a depth of 70 m. Changes in the groundwater chemistry were then monitored for a period of three years. Mass balances for conservative and reactive natural tracers provided a basis for a site model of the fracture zone. Groundwater dilution was the dominant process affecting the geochemistry of the site. There was associated Na-Ca ion-exchange. There is evidence for extensive lateral flow between recharge areas and the discharge point in the access tunnel. There was a significant transport of young organic carbon from the surface to the discharge borehole during recharge. Proposed microbial processes during lateral flow include anaerobic respiration coupled to reduction of iron hydroxide, methanogenesis, precipitation of calcite and secondary ferrous minerals. There is strong evidence to rule out sulfate reduction. Sulfate increased dramatically, possibly by desorption from fracture minerals. Fracture performance is affected by the extensive groundwater dilution and by the microbial processes that occur. Dilution affects aqueous speciation, radionuclide solubility and sorption, and the stability and mobility of colloids. Aerobic respiration provides an effective sink for oxygen. Maintaining anoxia favors low solubility for Tc, Np, Pu and U. Reductive dissolution of iron hydroxide will release sorbed radionuclides, while formation of biogenic Fe(II) minerals can provide an effective reducing migration barrier to radionuclides and to future intrusion of oxygen from the surface. 26 refs, 13 figs, 10 tabs.

  16. Groundwater flow dynamics of weathered hard-rock aquifers under climate-change conditions: an illustrative example of numerical modeling through the equivalent porous media approach in the north-western Pyrenees (France)

    Science.gov (United States)

    Jaunat, J.; Dupuy, A.; Huneau, F.; Celle-Jeanton, H.; Le Coustumer, P.

    2016-09-01

    A numerical groundwater model of the weathered crystalline aquifer of Ursuya (a major water source for the north-western Pyrenees region, south-western France) has been computed based on monitoring of hydrological, hydrodynamic and meteorological parameters over 3 years. The equivalent porous media model was used to simulate groundwater flow in the different layers of the weathered profile: from surface to depth, the weathered layer (5 · 10-8 ≤ K ≤ 5 · 10-7 m s-1), the transition layer (7 · 10-8 ≤ K ≤ 1 · 10-5 m s-1, the highest values being along major discontinuities), two fissured layers (3.5 · 10-8 ≤ K ≤ 5 · 10-4 m s-1, depending on weathering profile conditions and on the existence of active fractures), and the hard-rock basement simulated with a negligible hydraulic conductivity ( K = 1 10 -9 ). Hydrodynamic properties of these five calculation layers demonstrate both the impact of the weathering degree and of the discontinuities on the groundwater flow. The great agreement between simulated and observed hydraulic conditions allowed for validation of the methodology and its proposed use for application on analogous aquifers. With the aim of long-term management of this strategic aquifer, the model was then used to evaluate the impact of climate change on the groundwater resource. The simulations performed according to the most pessimistic climatic scenario until 2050 show a low sensitivity of the aquifer. The decreasing trend of the natural discharge is estimated at about -360 m3 y-1 for recharge decreasing at about -5.6 mm y-1 (0.8 % of annual recharge).

  17. Hard and Heavy Music: Can It Make a Difference in the Young Cancer Patients' Life?

    OpenAIRE

    Fereshteh Ahmadi

    2009-01-01

    The aim of the present article is to discuss the role hard and heavy music plays in coping with cancer. Here, hard and heavy music refers to genres such as heavy metal, hard rock, hard rap, punk rock and aggressive pop music.

  18. Hard and Heavy Music: Can It Make a Difference in the Young Cancer Patients' Life?

    Directory of Open Access Journals (Sweden)

    Fereshteh Ahmadi

    2009-07-01

    Full Text Available The aim of the present article is to discuss the role hard and heavy music plays in coping with cancer. Here, hard and heavy music refers to genres such as heavy metal, hard rock, hard rap, punk rock and aggressive pop music.

  19. Strategy for a Rock Mechanics Site Descriptive Model. Development and testing of the empirical approach

    Energy Technology Data Exchange (ETDEWEB)

    Roeshoff, Kennert; Lanaro, Flavio [Berg Bygg Konsult AB, Stockholm (Sweden); Lanru Jing [Royal Inst. of Techn., Stockholm (Sweden). Div. of Engineering Geology

    2002-05-01

    This report presents the results of one part of a wide project for the determination of a methodology for the determination of the rock mechanics properties of the rock mass for the so-called Aespoe Test Case. The Project consists of three major parts: the empirical part dealing with the characterisation of the rock mass by applying empirical methods, a part determining the rock mechanics properties of the rock mass through numerical modelling, and a third part carrying out numerical modelling for the determination of the stress state at Aespoe. All Project's parts were performed based on a limited amount of data about the geology and mechanical tests on samples selected from the Aespoe Database. This Report only considers the empirical approach. The purpose of the project is the development of a descriptive rock mechanics model for SKBs rock mass investigations for a final repository site. The empirical characterisation of the rock mass provides correlations with some of the rock mechanics properties of the rock mass such as the deformation modulus, the friction angle and cohesion for a certain stress interval and the uniaxial compressive strength. For the characterisation of the rock mass, several empirical methods were analysed and reviewed. Among those methods, some were chosen because robust, applicable and widespread in modern rock mechanics. Major weight was given to the well-known Tunnel Quality Index (Q) and Rock Mass Rating (RMR) but also the Rock Mass Index (RMi), the Geological Strength Index (GSI) and Ramamurthy's Criterion were applied for comparison with the two classical methods. The process of: i) sorting the geometrical/geological/rock mechanics data, ii) identifying homogeneous rock volumes, iii) determining the input parameters for the empirical ratings for rock mass characterisation; iv) evaluating the mechanical properties by using empirical relations with the rock mass ratings; was considered. By comparing the methodologies involved

  20. Soft rocks in Argentina

    Institute of Scientific and Technical Information of China (English)

    Giambastiani; Mauricio

    2014-01-01

    Soft rocks are a still fairly unexplored chapter in rock mechanics. Within this category are the clastic sedimentary rocks and pyroclastic volcanic rocks, of low to moderate lithification (consolidation, cemen-tation, new formed minerals), chemical sedimentary rocks and metamorphic rocks formed by minerals with Mohs hardness less than 3.5, such as limestone, gypsum, halite, sylvite, between the first and phyllites, graphitic schist, chloritic shale, talc, etc., among the latter. They also include any type of rock that suffered alteration processes (hydrothermal or weathering). In Argentina the study of low-strength rocks has not received much attention despite having extensive outcrops in the Andes and great impact in the design criteria. Correlation between geomechanical properties (UCS, deformability) to physical index (porosity, density, etc.) has shown promising results to be better studied. There are many studies and engineering projects in Argentina in soft rock geological environments, some cited in the text (Chihuído dam, N. Kirchner dam, J. Cepernic Dam, etc.) and others such as International Tunnel in the Province of Mendoza (Corredor Bioceánico), which will require the valuable contribution from rock mechanics. The lack of consistency between some of the physical and mechanical parameters explored from studies in the country may be due to an insufficient amount of information and/or non-standardization of criteria for testing materials. It is understood that more and better academic and professional efforts in improv-ing techniques will result in benefits to the better understanding of the geomechanics of weak rocks.

  1. Holocene sediment accumulation in the Aespoe area. A study of a sediment core

    International Nuclear Information System (INIS)

    A sediment core was collected in 1993 in the archipelago above the tunnel between the Aespoe Island and Simpevarp nuclear power plant. The sediment sequence consists of four types of accumulations: brownish clay, bluish clay, sand mixed with gravel and gyttja. The sequence was studied according to its content of siliceous microfossils (mainly diatoms), mineral magnetic characteristics, clay mineralogy and it was dated by the AMS technique on bulk sediment samples. According to the diatom content, both types of clay were probably deposited during the brackish water Yoldia Sea stage. The clay is relatively uniform, except an abrupt increase in the mineral magnetic parameters HIRM and S-ratio at around 810 cm depth, which probably is the result from a change in the material source. The clay mineralogy, with enhanced chlorite values, indicates a relatively uniform material. A major change occurs at the transition from the bluish to brownish clay, where all magnetic concentrations drop dramatically as the result from a major shift in material source and/or sedimentation environment. The thin layer of sand and gravel is indicative of a major hiatus in the stratigraphy. Mineral magnetic concentrations increase slightly as the result from mixing with single domain ground surface generated particles. Based on a Yoldia Sea age for the underlying clay and deposition in the Litorina Sea 3000 years BP for the superimposed gyttja, it is suggested that the length of the hiatus is about 7000 years. It is not until the studied site became protected enough by rising land areas, that organic rich gyttja started to accumulate.It is likely that this scenario was established when sea level was situated at around 10 m above present day. Since then it seems, as determined from the mineral magnetic graphs, that the sedimentary conditions have been relatively uniform. More pronounced fluctuations in mineral magnetic concentrations (especially ARM/SIRM ratios)in the upper 2 m of the core

  2. Holocene sediment accumulation in the Aespoe area. A study of a sediment core

    Energy Technology Data Exchange (ETDEWEB)

    Risberg, Jan [Stockholm Univ. (Sweden). Dept. of Quaternary Research

    2002-12-01

    A sediment core was collected in 1993 in the archipelago above the tunnel between the Aespoe Island and Simpevarp nuclear power plant. The sediment sequence consists of four types of accumulations: brownish clay, bluish clay, sand mixed with gravel and gyttja. The sequence was studied according to its content of siliceous microfossils (mainly diatoms), mineral magnetic characteristics, clay mineralogy and it was dated by the AMS technique on bulk sediment samples. According to the diatom content, both types of clay were probably deposited during the brackish water Yoldia Sea stage. The clay is relatively uniform, except an abrupt increase in the mineral magnetic parameters HIRM and S-ratio at around 810 cm depth, which probably is the result from a change in the material source. The clay mineralogy, with enhanced chlorite values, indicates a relatively uniform material. A major change occurs at the transition from the bluish to brownish clay, where all magnetic concentrations drop dramatically as the result from a major shift in material source and/or sedimentation environment. The thin layer of sand and gravel is indicative of a major hiatus in the stratigraphy. Mineral magnetic concentrations increase slightly as the result from mixing with single domain ground surface generated particles. Based on a Yoldia Sea age for the underlying clay and deposition in the Litorina Sea 3000 years BP for the superimposed gyttja, it is suggested that the length of the hiatus is about 7000 years. It is not until the studied site became protected enough by rising land areas, that organic rich gyttja started to accumulate.It is likely that this scenario was established when sea level was situated at around 10 m above present day. Since then it seems, as determined from the mineral magnetic graphs, that the sedimentary conditions have been relatively uniform. More pronounced fluctuations in mineral magnetic concentrations (especially ARM/SIRM ratios)in the upper 2 m of the core

  3. Aespoe Task Force on modelling of groundwater flow and transport of solutes. Review of Tasks 6D, 6E, 6F and 6F2

    Energy Technology Data Exchange (ETDEWEB)

    Hodgkinson, David (Quintessa, Henley-on-Thames (GB))

    2007-09-15

    This report forms part of an independent review of the specifications, execution and results of Task 6 of the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, which is seeking to provide a bridge between site characterization and performance assessment approaches to modelling solute transport in fractured rock. The objectives of Task 6 are: To assess simplifications used in Performance Assessment (PA) models. To determine how, and to what extent, experimental tracer and flow experiments can constrain the range of parameters used in PA models. To support the design of Site Characterisation (SC) programmes to ensure that the results have optimal value for performance assessment calculations. To improve the understanding of site-specific flow and transport behaviour at different scales using site characterisation models. The present report is concerned with Tasks 6D, 6E, 6F and 6F2. It follows on from two previous reviews of Tasks 6A, 6B and 6B2, and Task 6C. In Task 6D the transport of tracers through a fracture network is modelled using the conditions of the C2 TRUE-Block Scale tracer test, based on the synthetic structural model developed in Task 6C. Task 6E extends the Task 6D transport calculations to a reference set of PA time scales and boundary conditions. Task 6F consists of a series of 'benchmark' studies on single features from the Task 6C hydrostructural model in order to improve the understanding of differences between the participating models. Task 6F2 utilises models set up for Tasks 6E and 6F to perform additional sensitivity studies with the aim of increasing the understanding of how models behave, the reason for differences in modelling results, and the sensitivity of models to various assumptions and parameter values. Eight modelling teams representing five organisations participated in this exercise using Discrete Fracture Network (DFN), continuum and channel network concepts implemented in a range of different

  4. Standard hardness conversion tables for metals relationship among brinell hardness, vickers hardness, rockwell hardness, superficial hardness, knoop hardness, and scleroscope hardness

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 Conversion Table 1 presents data in the Rockwell C hardness range on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, Knoop hardness, and Scleroscope hardness of non-austenitic steels including carbon, alloy, and tool steels in the as-forged, annealed, normalized, and quenched and tempered conditions provided that they are homogeneous. 1.2 Conversion Table 2 presents data in the Rockwell B hardness range on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, Knoop hardness, and Scleroscope hardness of non-austenitic steels including carbon, alloy, and tool steels in the as-forged, annealed, normalized, and quenched and tempered conditions provided that they are homogeneous. 1.3 Conversion Table 3 presents data on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, and Knoop hardness of nickel and high-nickel alloys (nickel content o...

  5. Hard coatings

    International Nuclear Information System (INIS)

    Hard, wear resistant and low friction coatings are presently produced on a world-wide basis, by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, CVD and PVD. Some of the most advanced processes, especially those dedicated to thin film depositions, basically belong to CVD or PVD technologies, and will be looked at in more detail. The hard coatings mainly consist of oxides, nitrides, carbides, borides or carbon. Over the years, many processes have been developed which are variations and/or combinations of the basic CVD and PVD methods. The main difference between these two families of deposition techniques is that the CVD is an elevated temperature process (≥ 700 C), while the PVD on the contrary, is rather a low temperature process (≤ 500 C); this of course influences the choice of substrates and properties of the coating/substrate systems. Fundamental aspects of the vapor phase deposition techniques and some of their influences on coating properties will be discussed, as well as the very important interactions between deposit and substrate: diffusions, internal stress, etc. Advantages and limitations of CVD and PVD respectively will briefly be reviewed and examples of applications of the layers will be given. Parallel to the development and permanent updating of surface modification technologies, an effort was made to create novel characterisation methods. A close look will be given to the coating adherence control by means of the scratch test, at the coating hardness measurement by means of nanoindentation, at the coating wear resistance by means of a pin-on-disc tribometer, and at the surface quality evaluation by Atomic Force Microscopy (AFM). Finally, main important trends will be highlighted. (orig.)

  6. Recorded corrosion rates on copper electrodes in the Prototype Repository at the Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Rosborg, Bo [Rosborg Consulting, Nykoeping (Sweden)

    2013-04-15

    Real-time corrosion monitoring by means of electrochemical methods has been applied in an effort to measure corrosion rates of pure copper in the Prototype Repository at the Aspo Hard Rock Laboratory. Copper electrodes were installed in bentonite blocks on top of the electrically heated copper canisters in two deposition holes (dh). Three nominally identical cylindrical copper electrodes were installed in dh 1 and another three in dh 5 a few days before the heat was turned on to the canisters in September 2001 and in May 2003 respectively. The temperature of the copper electrodes has been around 30 deg C in dh 1 and somewhat below 35 deg C in dh 5. Real-time corrosion monitoring for both electrode setups was first applied in January 2004, and then periodically in 2005, 2006, 2008, and most recently in the end of 2010 just before work to open the outer section of the Prototype Repository was started. The recorded corrosion rates fall below 1.3 {mu}m/year (using a default value of n=2 in the software to convert the corrosion current density to a penetration rate by means of Faraday's law, and with no correction applied for the used measuring frequency of 0.01 Hz; also disregarding highly scattered data obtained for the copper electrodes in dh 1 during 2010). While the recorded rates on the electrodes in dh 5 first increased from about 0.2 {mu}m/year in 2004 up to a maximum of 1.3 {mu}m/year a year later (the drainage of the inner and outer sections was temporary closed in the end of 2004), and then gradually decreased to 0.7 {mu}m/year in the end of 2010, the recorded rates on the electrodes in dh 1 show a quite different picture. The recorded rates fall in the range 0.4-0.7 {mu}m/year and do not reflect any obvious decrease. However, it is anticipated that a similar time dependence as observed for the electrodes in dh 5 could have been present early on in the exposure; the electrodes were installed in 2001 but the first measurements were performed in 2004. Also

  7. Research present situation and analysis on classification of rock drillability

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhi-hong; MA Qin-yong

    2001-01-01

    Rock drillability reflects the drill bit fragments rock hardly or easily. At present, rock drillability classification indexes have rock single-axle compressive strength, point load intensity,fracture stress during chiseling, drill speed, chiseling specific work, acoustic parameter, cutting magnitude, and so on. Every index reflects rock drillability but isn't overall. It is feasible that using many indexes of fuzzy mathematics method etc. to evaluate rock drillability.

  8. Analysis on influence of surface load to stress-strain characteristics of pipeline buried in hard rock region%地表载荷对硬岩区埋地管道应力应变影响分析∗

    Institute of Scientific and Technical Information of China (English)

    韩传军; 张瀚; 张杰; 李琦

    2015-01-01

    In order to study the influence of surface load on mechanical performance of pipeline buried in hard rock region, a pipeline-soil coupling 3D numerical model was built. The influences by magnitude of surface load, action area, inner pressure, radius-thickness ratio of pipeline and elasticity modulus of backfill soil on stress distribution, plastic strain and ovality of the pipeline were analyzed. The results showed that under the action of surface load, the high stress zone, which is oval, appears on the upside of the pipeline. With the increasing of surface load and force area, the high stress zone enlarges gradually, and the stress concentration appears on the left and right sides of the cross section in the pipeline. With the increasing of elasticity modulus of backfill soil, thickness and inner pressure of pipeline, the high stress zone shrinks, and the maximum equivalent stress decreases. The plastic strain zone appears on the upside of pipeline firstly, and it increases with the increasing of surface load and action length, but decreases with the increasing of elasticity modulus of backfill soil and thickness of pipeline. The plastic strain and plastic zone of pipeline decrease with the increasing of inner pressure when the inner pressure ranges from 0 to 4 MPa. The ovality of pipeline decreases with the increasing of elasticity modulus of backfill soil, thickness and in ner pressure of pipeline, but increases when the surface load increases.%为研究地表载荷对硬岩区埋地管道力学性能的影响,建立了管-土耦合三维数值模型,分析了地表载荷大小、作用面积、管道压力、管道径厚比及回填土弹性模量对管道应力分布、塑性应变、椭圆度的影响。结果表明:地表压载作用下,高应力区首先出现在管道顶部且呈椭圆形;随着地表载荷及其作用面积的增大,管道高应力区逐渐扩大,管道截面左右两侧也出现应力集中;随着回填土弹性模量

  9. KREEP Rocks

    Institute of Scientific and Technical Information of China (English)

    邹永廖; 徐琳; 欧阳自远

    2004-01-01

    KREEP rocks with high contents of K, REE and P were first recognized in Apollo-12 samples, and it was confirmed later that there were KREEP rock fragments in all of the Apollo samples, particularly in Apollo-12 and-14 samples. The KREEP rocks distributed on the lunar surface are the very important objects of study on the evolution of the moon, as well as to evaluate the utilization prospect of REE in KREEP rocks. Based on previous studies and lunar exploration data, the authors analyzed the chemical and mineral characteristics of KREEP rocks, the abundance of Th on the lunar surface materials, the correlation between Th and REE of KREEP rocks in abundance, studied the distribution regions of KREEP rocks on the lunar surface, and further evaluated the utilization prospect of REE in KREEP rocks.

  10. Rock Stars

    Institute of Scientific and Technical Information of China (English)

    张国平

    2000-01-01

    Around the world young people are spending unbelievable sums of money to listen to rock music. Forbes Magazine reports that at least fifty rock stars have incomes between two million and six million dollars per year.

  11. Rock Finding

    Science.gov (United States)

    Rommel-Esham, Katie; Constable, Susan D.

    2006-01-01

    In this article, the authors discuss a literature-based activity that helps students discover the importance of making detailed observations. In an inspiring children's classic book, "Everybody Needs a Rock" by Byrd Baylor (1974), the author invites readers to go "rock finding," laying out 10 rules for finding a "perfect" rock. In this way, the…

  12. Groundwater degassing in fractured rock: Modelling and data comparison

    Energy Technology Data Exchange (ETDEWEB)

    Jarsjoe, J.; Destouni, G. [Royal Inst. of Tech., Stockholm (Sweden). Water Resources Engineering

    1998-11-01

    Dissolved gas may be released from deep groundwater in the vicinity of open boreholes and drifts, where the water pressures are relatively low. Degassing of groundwater may influence observations of hydraulic conditions made in drifts, interpretation of experiments performed close to drifts, and buffer mass and backfill performance, particularly during emplacement and repository closure. Under certain conditions, considerable fracture inflow and transmissivity reductions have been observed during degassing experiments in the field and in the laboratory; such reductions affect the outcome and interpretation of both hydraulic and tracer tests. We develop models for the estimation of the resulting degree of fracture gas saturation and the associated transmissivity reduction due to groundwater degassing in fractured rock. Derived expressions for bubble trapping probability show that fracture aperture variability and correlation length influence the conditions for capillary bubble trapping and gas accumulation. The laboratory observations of bubble trapping in an Aespoe fracture replica are consistent with the prediction of a relatively high probability of bubble trapping in this fracture. The prediction was based on the measured aperture distribution of the Aespoe fracture and the applied hydraulic gradient. Results also show that the conceptualisation of gas and water occupancy in a fracture greatly influences model predictions of gas saturation and relative transmissivity. Images from laboratory degassing experiments indicate that tight apertures are completely filled with water, whereas both gas and water exist in wider apertures under degassing conditions; implementation of this relation in our model resulted in the best agreement between predictions and laboratory observations. Model predictions for conditions similar to those prevailing in field for single fractures at great depths indicate that degassing effects in boreholes should generally be small, unless the

  13. REINFORCING MECHANISM AND SIMULATING METHOD FOR REINFORCING EFFECTS OF SYSTEMICALLY GROUTED BOLTS IN DEEP-BURIED HARD ROCK TUNNELS%深埋硬岩隧洞系统砂浆锚杆的加固机制与加固效果模拟方法

    Institute of Scientific and Technical Information of China (English)

    吴文平; 冯夏庭; 张传庆; 邱士利; 李占海

    2012-01-01

    Systematically grouted bolts, as the main support structure of deep-buried hard rock tunnels, compose the bolt-rock composite structure with surrounding rocks. which reinforces the mechanical property of surrounding rocks. Based on the Mohr-Coulomb(M-C) criterion, the stress condition and the strength of the composite structure meeting the M-C criterion were derived under high-stress conditions. Combining with the rock mass deterioration model(RDM) of brittle rock, an approach to determine the mechanical parameters of the composite structure was presented. The difference of mechanical parameters between two different composite structures of bolt-elastic surrounding rock and bolt-yielding surrounding rock was taken into account. In this approach, the mechanical parameters of the bolt-yielding surrounding rock composite structure were associated with present equivalent plastic strain of surrounding rocks. A numerical method, which could model the reinforcing effect of normally grouted bolts laid out systematically during excavating and supporting stages, was proposed. It is identified that this method has an advantage over other methods in modeling the effect of supporting time on surrounding rock stability. Finally, the method was applied to evaluate the stability of surrounding rocks, and related references were provided for design and construction of the diversion tunnel #2 of Jinping Ⅱ hydropower station.%系统布置的砂浆锚杆是深埋硬岩隧洞主要支护结构,锚杆与围岩组成锚杆-围岩复合结构体,使围岩的力学特性得到改善.基于岩体的莫尔-库仑(M-C)屈服准则,推导锚杆-围岩复合结构体满足M-C准则的应力条件.结合岩体劣化本构模型,提出确定锚杆-围岩复合结构体力学参数的方法.锚杆与弹性围岩和屈服围岩组成的锚杆-围岩复合结构体的力学参数确定方法不同,锚杆与屈服围岩组成的锚杆-围岩复合结构体的力学参数与围岩当前状态的等

  14. Intra-terrestrial Biosorption of Radionuclides and Analogous Trace Elements. Microbial Interference with the 'Water/Rock Interface'

    International Nuclear Information System (INIS)

    The Swedish nuclear fuel management company (SKB) has instigated final site investigations for a deep subsurface high level nuclear waste (HLW) repository in granitic rock. This facility will be situated 500 meters below ground level and will isolate the HLW from the environment using an engineered multi-barrier system with a supposed design life of 105 to 106 years. As microbial life is ubiquitous in intra-terrestrial environments, assessing the subsurface geochemical and geomicrobial influences is critical for predicting the safety and longevity of HLW storage. In the possible event of repository failure, the transport of radionuclides through water conducting rock fractures is the predominant concern but radionuclide migration can be retarded by abiotic and biotic sorption processes. In this study biofilms were grown under in situ pressures and conditions using groundwater sourced from boreholes 296 m to 450m below sea level at the Aespoe hard rock laboratory (IM) in Sweden. Purpose built biofilm reactors were installed and left to develop microbial communities for up to one year. The community genera were then analysed genetically along with the population characteristics. Scintillation, NaI Y-detection, ICP-MS and autoradiography were used to investigate the ability of these biofilms to absorb trace metals from fracture fluids and synthetic groundwater containing Co, Pm, Np, Am, Th, U and Mo. The concentrations of PGE (platinum group elements) and REE (rare earth elements) were also measured by ICP-MS for experiments conducted in aerobic conditions. Results indicate that aerobic biofilms grown in near neutral pH conditions, with low pressure (1 bar) and oxygen (<1.5 mg/l; Eh <190 mV), can rapidly attenuate metals to over 1000-fold higher than the levels within the groundwater. In anaerobic conditions biofilms in 1.5 % salt and near neutral pH tend to favour the adsorption of the 3+ valence state (Am, Pm) over other radionuclides such as Co, Th, Np, U and Mo

  15. Water exchange estimates derived from forcing for the hydraulically coupled basins surrounding Aespoe island and adjacent coastal water

    International Nuclear Information System (INIS)

    A numerical model study based on representative physical forcing data (statistically averaged from approximately 10 years) has been performed of the Aespoe area, subdivided into five separate basins, interconnected by four straits and connected to the Baltic coast through three straits. The water exchange of the shallow Borholmsfjaerden, with comparatively small section areas of its straits, is dominated by the sea level variations while the baroclinic exchange components (estuarine and intermediary circulation) also contribute. The average transit retention time (averaged over the basin volume for a full year cycle) is found to be a little over 40 days for exogenous water (i.e. coastal water and freshwater combined); this measure of the water exchange is comparable to the combined average of an ensemble consisting of 157 similarly analyzed basins distributed along the Swedish east and west coasts. The exchange mechanisms and model assumptions are discussed. The consequences for the retention times by short- and long-term variations of the forcing is also analyzed. The standard deviation (SD) of the retention time during an average year (intra-annual variation) is greater than the SD between years (interannual variation) for all basins except Borholmsfjaerden for which these two measures are in parity. The range of the retention times that results from an extreme combination of forcing factor variation between years is found to be greater the farther a particular basin is located from the coast, measured as the minimal number of separating straits. The results of an earlier investigation are also reviewed

  16. The rock resources of the Northern Emirates

    OpenAIRE

    Mitchell, Clive; Styles, Michael

    2011-01-01

    The Rock Resources of the Northern Emirates The United Arab Emirates (UAE) has vast resources of limestone and hard rock in the northern Emirates. These are currently exploited by quarrying companies to produce construction aggregate and raw material for the manufacture of cement, with a small amount being used to produce rock wool, dimension stone and mineral filler. The demand by industry for higher value mineral products that could be produced from these resources is mostly met by impor...

  17. THM-issues in repository rock. Thermal, mechanical, thermo-mechanical and hydro-mechanical evolution of the rock at the Forsmark and Laxemar sites

    Energy Technology Data Exchange (ETDEWEB)

    Hoekmark, Harald; Loennqvist, Margareta; Faelth, Billy (Clay Technology AB, Lund (Sweden))

    2010-05-15

    even in the hottest ones. To account for uncertainties in the thermal calculations, the layout is established with a margin of about 5 deg C to the 100 deg C limit. It is demonstrated here that the spatial variability of rock heat transport properties means that there is considerable robustness in the design approach. An underestimate of the uncertainty margin by a few degrees appears to impact on very few canisters, even under the conservative assumption that all deposition holes are completely dry. Spalling after excavation of a deposition hole excavation is not likely unless the major horizontal stress is aligned off the orientation of the tunnel axis by the largest angle given within the uncertainty range of the Forsmark in situ stress model. In case it happens, the spalling will be limited to the top 1 m of the deposition hole for the most likely Forsmark major stress magnitude and to the top 3 m for the upper bound stress magnitude. Thermally-induced spalling is almost certain to occur after some time of heating, i.e. also for the most favourable conditions regarding stress orientation and magnitude. However, for the most favourable conditions the spalling will occur late and be limited to the top 5 m of the deposition hole. All spalling risk estimates are based on the assumption that the spalling strength varies between 52% and 62% of the uniaxial compressive strength of the intact rock, as suggested by field experiments performed in the Aespoe Hard Rock Laboratory. It is also assumed that the deposition holes are completely dry, i.e. without any swelling pressure to support and stabilize the walls. These assumptions are all claimed to be conservative. The stress path for rock in the walls of KBS-3 deposition holes will be different from corresponding stress paths in the field experiments and a small support pressure, possibly sufficient to limit the extent of the spalling, will be found also in dry deposition holes. Transmissivity effects on rock fractures are

  18. Mechanism of Rock Burst Occurrence in Specially Thick Coal Seam with Rock Parting

    Science.gov (United States)

    Wang, Jian-chao; Jiang, Fu-xing; Meng, Xiang-jun; Wang, Xu-you; Zhu, Si-tao; Feng, Yu

    2016-05-01

    Specially thick coal seam with complex construction, such as rock parting and alternative soft and hard coal, is called specially thick coal seam with rock parting (STCSRP), which easily leads to rock burst during mining. Based on the stress distribution of rock parting zone, this study investigated the mechanism, engineering discriminant conditions, prevention methods, and risk evaluation method of rock burst occurrence in STCSRP through setting up a mechanical model. The main conclusions of this study are as follows. (1) When the mining face moves closer to the rock parting zone, the original non-uniform stress of the rock parting zone and the advancing stress of the mining face are combined to intensify gradually the shearing action of coal near the mining face. When the shearing action reaches a certain degree, rock burst easily occurs near the mining face. (2) Rock burst occurrence in STCSRP is positively associated with mining depth, advancing stress concentration factor of the mining face, thickness of rock parting, bursting liability of coal, thickness ratio of rock parting to coal seam, and difference of elastic modulus between rock parting and coal, whereas negatively associated with shear strength. (3) Technologies of large-diameter drilling, coal seam water injection, and deep hole blasting can reduce advancing stress concentration factor, thickness of rock parting, and difference of elastic modulus between rock parting and coal to lower the risk of rock burst in STCSRP. (4) The research result was applied to evaluate and control the risk of rock burst occurrence in STCSRP.

  19. 高应力硬岩卸荷岩爆的劈裂判据及因素敏感性分析%Splitting criterion of unloading rock burst for high-stress hard rock and its sensitivity analysis of factors

    Institute of Scientific and Technical Information of China (English)

    张晓君

    2013-01-01

    针对现有岩爆研究的不足,基于突变理论建立了围岩卸荷岩爆的劈裂突变模型,得到了考虑卸荷影响的劈裂岩爆必要条件和充分条件并在此基础上进行了因素敏感性分析.研究表明,开挖卸荷致拉明显降低了突变特征值及岩爆发生的门槛,使岩爆发生的可能性大为增加,而且当拉应力σx=πσt/4时,必要条件就成为充分条件;卸荷后一段时间围岩发生变形,达到发生岩爆至少所需的卸荷细观拉应力,形成标准或滞后岩爆模式;竖向应力达到一定值,围岩卸荷瞬间其突变特征值△≤0,形成瞬时岩爆模式;岩爆劈裂要满足一定的临空面尺寸要求,随竖向应力的增大这种要求明显减弱;发生岩爆时岩爆区释放的能量△E,σx,△对竖向应力的敏感性很强,△对σ3极为敏感.%In this paper, aiming at the existing defects of rock burst study, a splitting catastrophe model of unloading rock burst of surrounding rock was established based on the mutation theory, and the necessary and sufficient conditions of splitting rock burst were obtained while considering the unloading influence, then the sensitivity of influence factors was further analyzed. The results show that the mutation characteristic value and critical condition of rock burst were reduced obviously by excavation unloading, and the occurrence possibility of rock burst increases greatly, when the tensile stress meets the condition of σχ=πσt/4, the necessary conditions will become the sufficient conditions. Meanwhile, the surrounding rock will be displaced after a period of unloading, the standard or delayed rock burst will occur when the unloading microscopic tensile stress reaches the needed condition to induce rock burst, while the instant rock burst occur will occur when the vertical stress reaches to a certain value and the mutation characteristic value of surrounding rock during unloading moment meets the condition of △≤0. In

  20. Differentiation and analysis on rock breaking characteristics of TBM disc cutter at different rock temperatures

    Institute of Scientific and Technical Information of China (English)

    谭青; 张桂菊; 夏毅敏; 李建芳

    2015-01-01

    In order to study rock breaking characteristics of tunnel boring machine (TBM) disc cutter at different rock temperatures, thermodynamic rock breaking mathematical model of TBM disc cutter was established on the basis of rock temperature change by using particle flow code theory and the influence law of interaction mechanism between disc cutter and rock was also numerically simulated. Furthermore, by using the linear cutting experiment platform, rock breaking process of TBM disc cutter at different rock temperatures was well verified by the experiments. Finally, rock breaking characteristics of TBM disc cutter were differentiated and analyzed from microscale perspective. The results indicate the follows. 1) When rock temperature increases, the mechanical properties of rock such as hardness, and strength, were greatly reduced, simultaneously the microcracks rapidly grow with the cracks number increasing, which leads to rock breaking load decreasing and improves rock breaking efficiency for TBM disc cutter. 2) The higher the rock temperature, the lower the rock internal stress. The stress distribution rules coincide with the Buzin Neske stress circle rules: the maximum stress value is below the cutting edge region and then gradually decreases radiant around; stress distribution is symmetrical and the total stress of rock becomes smaller. 3) The higher the rock temperature is, the more the numbers of micro, tensile and shear cracks produced are by rock as well as the easier the rock intrusion, along with shear failure mode mainly showing. 4) With rock temperature increasing, the resistance intrusive coefficients of rock and intrusion power decrease obviously, so the specific energy consumption that TBM disc cutter achieves leaping broken also decreases subsequently. 5) The acoustic emission frequency remarkably increases along with the temperature increasing, which improves the rock breaking efficiency.

  1. Water exchange estimates derived from forcing for the hydraulically coupled basins surrounding Aespoe island and adjacent coastal water

    Energy Technology Data Exchange (ETDEWEB)

    Engqvist, A. [A and I Engqvist Konsult HB, Vaxholm (Sweden)

    1997-08-01

    A numerical model study based on representative physical forcing data (statistically averaged from approximately 10 years) has been performed of the Aespoe area, subdivided into five separate basins, interconnected by four straits and connected to the Baltic coast through three straits. The water exchange of the shallow Borholmsfjaerden, with comparatively small section areas of its straits, is dominated by the sea level variations while the baroclinic exchange components (estuarine and intermediary circulation) also contribute. The average transit retention time (averaged over the basin volume for a full year cycle) is found to be a little over 40 days for exogenous water (i.e. coastal water and freshwater combined); this measure of the water exchange is comparable to the combined average of an ensemble consisting of 157 similarly analyzed basins distributed along the Swedish east and west coasts. The exchange mechanisms and model assumptions are discussed. The consequences for the retention times by short- and long-term variations of the forcing is also analyzed. The standard deviation (SD) of the retention time during an average year (intra-annual variation) is greater than the SD between years (interannual variation) for all basins except Borholmsfjaerden for which these two measures are in parity. The range of the retention times that results from an extreme combination of forcing factor variation between years is found to be greater the farther a particular basin is located from the coast, measured as the minimal number of separating straits. The results of an earlier investigation are also reviewed 24 refs, 12 figs, 13 tabs

  2. DECOVALEX III/BENCHPAR PROJECTS. Evaluation of the Impact of Thermal-Hydro-Mechanical Couplings in Bentonite and Near-Field Rock Barriers on a Nuclear Waste Repository in a Sparsely Fractured Hard Rock. Report of BMT1C/WP2

    Energy Technology Data Exchange (ETDEWEB)

    Jing, L. [Royal Inst. of Technology, Stockholm (Sweden). Engineering Geology; Nguyen, T.S. [Canadian Nuclear Safety Commission, Ottawa, ON (Canada)] (eds.)

    2005-02-15

    This report presents the works performed for the third, also the last, phase (BMT1C) of BMT1 of the DECOVALEX III project for the period of 1999-2002. The works of BMT1 is divided into three phases: BMT1A, BMT1B and BMT1C. The BMT1A concerns with calibration of the computer codes with a reference Thermal (T), Hydrological (H) and Mechanical (M) experiment at Kamaishi Mine, Japan. The objective is to validate the numerical approaches, computer codes and material models, so that the teams simulating tools are at a comparable level of maturity and sophistication. The BMT1B uses the calibrated codes to perform scoping calculations, considering varying degrees of THM coupling and varying permeability values of the surrounding rock for a reference generic repository design without fractures. The aim is to identify the coupling mechanisms of importance for construction, performance and safety of the repository. BMT1C concerns with scoping calculations with different coupling combinations for the case where a horizontal fracture intersects the deposition hole and a vertical fracture zone divides two adjacent deposition tunnel/hole system. A hydrostatic condition is applied along the vertical fracture as a hydraulic boundary condition. In addition, the SKI/KTH team performed an additional calculation case of a highly fractured rock mass with two orthogonal sets of fractures with a spacing of 0.5 m. The chosen measures for evaluating the long term safety and performance of the repository are the maximal temperature created by the thermal loading from the emplaced wastes, the time for resaturation of the buffer, the maximal swelling stress developed in the buffer, the structural integrity of the rock mass and the permeability evolution in the rock mass. The analyses fro BMT1C were conducted by four research teams: SKI/KTH (Sweden), CNSC (Canada), IRSN/CEA(France) and JNC (Japan), using FEM approach with different computer codes. From the results, it is clear that the

  3. Wear of hard materials by hard particles

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey A.

    2003-10-01

    Hard materials, such as WC-Co, boron carbide, titanium diboride and composite carbide made up of Mo2C and WC, have been tested in abrasion and erosion conditions. These hard materials showed negligible wear in abrasion against SiC particles and erosion using Al2O3 particles. The WC-Co materials have the highest wear rate of these hard materials and a very different material removal mechanism. Wear mechanisms for these materials were different for each material with the overall wear rate controlled by binder composition and content and material grain size.

  4. Rock Paintings.

    Science.gov (United States)

    Jones, Julienne Edwards

    1998-01-01

    Discusses the integration of art and academics in a fifth-grade instructional unit on Native American culture. Describes how students studied Native American pictographs, designed their own pictographs, made their own tools, and created rock paintings of their pictographs using these tools. Provides a list of references on Native American…

  5. Intellektuaalne rock

    Index Scriptorium Estoniae

    2007-01-01

    Briti laulja-helilooja ja näitleja Toyah Willcox ning Bill Rieflin ansamblist R.E.M. ja Pat Mastelotto King Krimsonist esinevad koos ansamblitega The Humans ja Tuner 25. okt. Tallinnas Rock Cafés ja 27. okt Tartu Jaani kirikus

  6. Effect of surfactant on surface hardness of dental stone and investment casts produced from polyvinyl siloxane duplicating materials.

    Science.gov (United States)

    Al-Johani, Attalah; Clark, Robert K F; Juszczyk, Andrzej S; Radford, David R

    2008-06-01

    Polyvinylsiloxane duplicating materials are typically treated with a topical surfactant before pouring dental models, but the use of topical surfactants in the dental laboratory may affect the surface hardness of the resultant models. The effect of two different topical surfactants on surface hardness of two dental stones (FujiRock and Dentstone) and one phosphate bonded investment material (Croform WB) produced from polyvinyl siloxane (PVS) dental laboratory duplicating moulds was investigated. Topical surfactants affected the surface hardness of FujiRock, Dentstone and Croform WB investment material. Surface hardness of FujiRock increased with Wax-Mate surfactant. However, surface hardness of Croform WB investment material decreased with both topical surfactants.

  7. Rock mass response during high pressure grouting

    OpenAIRE

    Gothäll, Rikard

    2006-01-01

    The sealing of hard jointed rock by grouting involves several complicated mechanical systems. The result is a complex coupled system of hydro- logical and mechanical precesses. In order to determine the higher order effects of the resulting system the fracture deformations must be assessed. This requires a model that mimics the mechanical behaviour of not only fractures under normal load but also the entire rock mass system. This model indicates that there are two dominant regimes involved; a...

  8. 大同矿区"三硬"煤层巷道煤壁整体推出型冲击地压发生机理的研究%Research on the rock burst mechanism of coal tunnel wall being pushing out overall in Datong coal mining area′s "three hard" coal roadway

    Institute of Scientific and Technical Information of China (English)

    王旭宏; 康立勋; 杨双锁

    2009-01-01

    建立了大同矿区"三硬"煤层巷道煤壁整体推出型冲击地压的数学力学模型,研究了整体推出型冲击地压发生的力学机理.认为在煤层与顶板已经离层的条件下,发生煤体整体移动所需的垂直应力的值很小,易发生煤体被挤出、整体向外移动的现象.%By establishing the mathematical model about the rock burst type of coal wall overall being pushed out in "three hard" coal roadway of Datong Coal Mining Area, the writer studied the mechanism of this type. Under the condition of having separated the seam and roof, the occurrence of coal as a whole to be moved and of having the vertical stress is very small, because it′s possible to happen that the coal is vulnerably squeezed out and moved outward as a whole.

  9. Rock stresses (Grimsel rock laboratory)

    International Nuclear Information System (INIS)

    On the research and development project 'Rock Stress Measurements' the BGR has developed and tested several test devices and methods at GTS for use in boreholes at a depth of 200 m and has carried out rock mechanical and engineering geological investigations for the evaluation and interpretation of the stress measurements. The first time a computer for data processing was installed in the borehole together with the BGR-probe. Laboratory tests on hollow cylinders were made to study the stress-deformation behavior. To validate and to interprete the measurement results some test methods were modelled using the finite-element method. The dilatometer-tests yielded high values of Young's modulus, whereas laboratory tests showed lower values with a distinct deformation anisotropy. Stress measurements with the BGR-probe yielded horizontal stresses being higher than the theoretical overburden pressure and vertical stresses which agree well with the theoretical overburden pressure. These results are comparable to the results of the hydraulic fracturing tests, whereas stresses obtained with CSIR-triaxial cells are generally lower. The detailed geological mapping of the borehole indicated relationships between stress and geology. With regard to borehole depth different zones of rock structure joint frequency, joint orientation, and orientation of microfissures as well as stress magnitude, stress direction, and degree of deformation anisotropy could be distinguished. (orig./HP)

  10. Redox zone II. Coupled modeling of groundwater flow, solute transport, chemical reactions and microbial processes in the Aespoe island

    International Nuclear Information System (INIS)

    The Redox Zone Experiment was carried out at the Aespoe HRL in order to study the redox behaviour and the hydrochemistry of an isolated vertical fracture zone disturbed by the excavation of an access tunnel. Overall results and interpretation of the Redox Zone Project were reported by Banwart et al. Later, Banwart presented a summary of the hydrochemistry of the Redox Zone Experiment. Coupled groundwater flow and reactive transport models of this experiment were carried out by Molinero who proposed a revised conceptual model for the hydrogeology of the Redox Zone Experiment which could explain simultaneously measured drawdown and salinity data. The numerical model was found useful to understand the natural system. Several conclusions were drawn about the redox conditions of recharge waters, cation exchange capacity of the fracture zone and the role of mineral phases such as pyrite, calcite, hematite and goethite. This model could reproduce the measured trends of dissolved species, except for bicarbonate and sulphate which are affected by microbially-mediated processes. In order to explore the role of microbial processes, a coupled numerical model has been constructed which accounts for water flow, reactive transport and microbial processes. The results of this model is presented in this report. This model accounts for groundwater flow and reactive transport in a manner similar to that of Molinero and extends the preliminary microbial model of Zhang by accounting for microbially-driven organic matter fermentation and organic matter oxidation. This updated microbial model considers simultaneously the fermentation of particulate organic matter by yeast and the oxidation of dissolved organic matter, a product of fermentation. Dissolved organic matter is produced by yeast and serves also as a substrate for iron-reducing bacteria. Model results reproduce the observed increase in bicarbonate and sulfaphe concentration, thus adding additional evidence for the possibility

  11. Redox zone II. Coupled modeling of groundwater flow, solute transport, chemical reactions and microbial processes in the Aespoe island

    Energy Technology Data Exchange (ETDEWEB)

    Samper, Javier; Molinero, Jorge; Changbing Yang; Guoxiang Zhang [Univ. Da Coruna (Spain)

    2003-12-01

    The Redox Zone Experiment was carried out at the Aespoe HRL in order to study the redox behaviour and the hydrochemistry of an isolated vertical fracture zone disturbed by the excavation of an access tunnel. Overall results and interpretation of the Redox Zone Project were reported by Banwart et al. Later, Banwart presented a summary of the hydrochemistry of the Redox Zone Experiment. Coupled groundwater flow and reactive transport models of this experiment were carried out by Molinero who proposed a revised conceptual model for the hydrogeology of the Redox Zone Experiment which could explain simultaneously measured drawdown and salinity data. The numerical model was found useful to understand the natural system. Several conclusions were drawn about the redox conditions of recharge waters, cation exchange capacity of the fracture zone and the role of mineral phases such as pyrite, calcite, hematite and goethite. This model could reproduce the measured trends of dissolved species, except for bicarbonate and sulphate which are affected by microbially-mediated processes. In order to explore the role of microbial processes, a coupled numerical model has been constructed which accounts for water flow, reactive transport and microbial processes. The results of this model is presented in this report. This model accounts for groundwater flow and reactive transport in a manner similar to that of Molinero and extends the preliminary microbial model of Zhang by accounting for microbially-driven organic matter fermentation and organic matter oxidation. This updated microbial model considers simultaneously the fermentation of particulate organic matter by yeast and the oxidation of dissolved organic matter, a product of fermentation. Dissolved organic matter is produced by yeast and serves also as a substrate for iron-reducing bacteria. Model results reproduce the observed increase in bicarbonate and sulfaphe concentration, thus adding additional evidence for the possibility

  12. Studies on the chemical conditions and microstructure in package 1 of alternative buffer materials project (ABM) in aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Muurinen, A. (VTT Technical research Centre of Finland, Espoo (Finland))

    2010-02-15

    The chemical and microstructural properties of MX-80, Asha and Deponit bentonites and of Friedland Clay in package 1 of the ABM project in Aespoe HRL were studied after over two years of experiment. The concentration distribution of chloride and sulphate in different clays as a function of distance from the heater and in the reference bentonites, not used in the experiment, were determined. The concentration distributions of chloride were quite even. In Friedland clay and Asha the chloride concentrations in the clay decreased during the experiment while in MX-80 and Deponit the concentrations increased. Sulphate accumulated towards the hot end in the samples where the initial content of sulphate was high (Friedland Clay, MX-80, Deponit), while in Asha, where the initial sulphate concentration was low, such an accumulation did not occur. The cation exchange capacity in different clays was determined at different distances from the heater using the complex of copper(II) ion with trietylenetetramine [Cu(trien)]2+ as the index cation. The CEC of MX-80 and Deponit increased slightly close to the heater. In Asha there was some indication about the decrease of CEC close to the heater while in Friedland Clay there was small decreasing trend towards the heater and the CEC was generally slightly higher than in the reference sample. The pH measurements in the clays were performed with IrOx electrodes at a distance of 8 cm from the heater. The pH values were for Friedland Clay 6.5 - 6.6, for MX-80 6.6 - 6.8, for Asha 6.9 - 7.0 and for Deponit 6.6 - 6.9. The Eh measurements were performed with Pt and Au electrodes placed in the clays at 8 cm from the heater. The final values obtained after five months of measurement with Au and Pt electrodes were for Friedland Clay 17 mV and -231 mV, for MX-80 22 mV and -48 mV, for Asha 104 mV and 40 mV and for Deponit 76 mV and 75 mV, respectively. The water content and bulk density were measured at different distances from the heater; the dry

  13. Studies on the chemical conditions and microstructure in the reference bentonites of alternative buffer materials project (ABM) in Aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Muurinen, A. (VTT Technical Research Centre of Finland, Espoo (Finland))

    2009-06-15

    The chemical and microstructural properties of some bentonites used in the ABM project in Aespoe HRL were studied in laboratory experiments. The aim was to obtain information about the materials before they were used in the field experiment and to test the research methods that will be used when the packages of the field experiment are retrieved. The bentonites of interest were MX-80, Deponit CAN, Asha 505 and Friedland Clay. The pH values in the compacted samples prepared from the clay powders and deionized water were about 8 for MX-80, 7 for Deponit and Asha, and 6.5 for Friedland clay. The Eh values in the compacted MX-80, Asha and Deponit samples varied between 100 mV and -100 mV, and in the Friedland clay from 0 mV to 200 mV. The total porosity, chloride porosity and the microstructure were studied in compacted samples prepared from MX-80, Deponit, Asha and Friedland Clay and equilibrated through filter plates with 0.1 M NaCl solution for 12.5 months in aerobic conditions. The dry densities of the samples were approximately 0.7, 1.0, 1.25 and 1.55 g/cm3. XRD and SAXS (Small Angle X-ray Scattering) were used to study the microstructure of the MX-80 and Deponit bentonites. It was obvious that the chloride porosity was lower than the water porosity in all the clays, which indicates the exclusion of anions caused by the negatively charged surfaces. In the XRD measurements on MX-80, Asha and Deponit, the measured basal spaces represented by the diffraction peaks were smaller than the theoretical one assuming a homogenous microstructure. This indicates that there was a substantial amount of water also in the pores, which were not seen by XRD. The SAXS data modelling which considered single discs and stacks of discs proposed that a large fraction of the clay should be considered as single platelets. The fraction of the single discs decreased with the increasing density of the sample. The number of layers in the stacks varied from 4 to 8. By combining the information

  14. Comprehensive hard materials

    CERN Document Server

    2014-01-01

    Comprehensive Hard Materials deals with the production, uses and properties of the carbides, nitrides and borides of these metals and those of titanium, as well as tools of ceramics, the superhard boron nitrides and diamond and related compounds. Articles include the technologies of powder production (including their precursor materials), milling, granulation, cold and hot compaction, sintering, hot isostatic pressing, hot-pressing, injection moulding, as well as on the coating technologies for refractory metals, hard metals and hard materials. The characterization, testing, quality assurance and applications are also covered. Comprehensive Hard Materials provides meaningful insights on materials at the leading edge of technology. It aids continued research and development of these materials and as such it is a critical information resource to academics and industry professionals facing the technological challenges of the future. Hard materials operate at the leading edge of technology, and continued res...

  15. Effect of coatings on hardness of commercial marbles

    Science.gov (United States)

    Zedef, Veysel

    2016-04-01

    In this study, three type of marble and one granite were chosen to understand if the coating is effective on hardness of the commercial rocks. To understand the hardness of the rock, Schmidt hammer tests were undertaken. The used device allowed us uniaxial compressive strength (UCS) as well as Schmidt rebound (R). The coated samples have clearly high R and UCS values when compared to uncoated samples. The Elazig visne, the well-known marble of Turkey, have 35.6 R and 44.2 MPa UCS values of coated samples. On the other hand, uncoated surface of the same marble have 30.5 R and 35.4 MPa UCS.

  16. A Rock Mechanics and Coupled Hydro mechanical Analysis of Geological Repository of High Level Nuclear Waste in Fractured Rocks

    International Nuclear Information System (INIS)

    This paper introduces a few case studies on fractured hard rock based on geological data from Sweden, Korea is one of a few countries where crystalline rock is the most promising rock formation as a candidate site of geological repository of high level nuclear waste. Despite the progress made in the area of rock mechanics and coupled hydro mechanics, extensive site specific study on multiple candidate sites is essential in order to choose the optimal site. For many countries concerned about the safe isolation of nuclear wastes from the biosphere, disposal in a deep geological formation is considered an attractive option. In geological repository, thermal loading continuously disturbs the repository system in addition to disturbances a recent development in rock mechanics and coupled hydro mechanical study using DFN(Discrete Fracture Network) - DEM(Discrete Element Method) approach mainly applied in hard, crystalline rock containing numerous fracture which are main sources of deformation and groundwater flow

  17. Determination of relationships between thermal conductivity and material properties of rocks

    Institute of Scientific and Technical Information of China (English)

    Kazim G(o)rgülü

    2004-01-01

    Energy transfer between the adjacent parts of rocks in underground mines is widely influenced by the thermal conductivity of rocks. The relationships between the thermal conductivity and some material properties of rocks such as the uniaxial compressive strength, unit mass, tensile strength, cohesion, Young's modulus, point load strength, Schmidt rebound hardness, Shore scleroscope hardness and toughness strength were investigated. The statistical analysis of the data obtained in laboratory tests shows that the thermal conductivity increases with increasing the uniaxial compressive strength, unit mass, tensile strength, cohesion, Young's modulus, point load strength, Schmidt rebound hardness and Shore scleroscope hardness, and decreases with increasing the toughness strength.

  18. Hardness and excitation energy

    Indian Academy of Sciences (India)

    Á Nagy

    2005-09-01

    The concept of the ensemble Kohn-Sham hardness is introduced. It is shown that the first excitation energy can be given by the Kohn-Sham hardness (i.e. the energy difference of the ground-state lowest unoccupied and highest occupied levels) plus an extra term coming from the partial derivative of the ensemble exchange-correlation energy with respect to the weighting factor in the limit → 0. It is proposed that the first excitation energy can be used as a reactivity index instead of the hardness.

  19. Water - rock interaction in different rock environments

    International Nuclear Information System (INIS)

    The study assesses the groundwater geochemistry and geological environment of 44 study sites for radioactive waste disposal. Initially, the study sites were divided by rock type into 5 groups: (1) acid - intermediate rocks, (2) mafic - ultramafic rocks, (3) gabbros, amphibolites and gneisses that contain calc-silicate (skarn) rocks, (4) carbonates and (5) sandstones. Separate assessments are made of acid - intermediate plutonic rocks and of a subgroup that comprises migmatites, granite and mica gneiss. These all belong to the group of acid - intermediate rocks. Within the mafic -ultramafic rock group, a subgroup that comprises mafic - ultramafic plutonic rocks, serpentinites, mafic - ultramafic volcanic rocks and volcanic - sedimentary schists is also evaluated separately. Bedrock groundwaters are classified by their concentration of total dissolved solids as fresh, brackish, saline, strongly saline and brine-class groundwaters. (75 refs., 24 figs., 3 tabs.)

  20. Automated sliding susceptibility mapping of rock slopes

    Directory of Open Access Journals (Sweden)

    A. Günther

    2004-01-01

    Full Text Available We present a suite of extensions for ARCVIEW GIS™ (ESRI that allows to map the spatial distribution of first-order mechanical slope-properties in hard rock terrain, e.g. for large slope areas like water reservoir slopes. Besides digital elevation data, this expert-system includes regional continuous grid-based data on geological structures that might act as potential sliding or cutoff planes for rockslides. The system allows rapid automated mapping of geometrical and kinematical slope properties in hard rock, providing the basis for spatially distributed deterministic sliding-susceptibility evaluations on a pixel base. Changing hydrostatic slope conditions and rock mechanical parameters can be implemented and used for simple predictive static stability calculations. Application is demonstrated for a study area in the Harz Mts., Germany.

  1. Radioactive waste - Between a rock and a hard place

    International Nuclear Information System (INIS)

    Full text: Throughout the world, plans for repositories face difficulties. The search for sites has found difficulties in France, Sweden, Switzerland and most recently in the UK. This is despite massive public relations exercises and, in the case of the UK and Switzerland, broad-based local support for the project. Tom Cur-tin will present a view on the lessons to be learnt from the Nirex project and give some pointers on the sociology and politics involved in the disposal of radioactive waste. This paper will review the sociology and politics of radioactive waste disposal. Lessons Learnt: It is not just a scientific process: The fundamental lesson learrit from the Nirex experience so far is that the process is not merely scientific; The project has to succeed politically: To concentrate on the technical aspects of siting without considering the political aspect equates to building castles in the air; Any form of imposition leads to rejection: The prevailing feeling among some politicians was that the project was unfairly imposed; One player cannot support the whole edifice: One company cannot carry on its shoulder the entire weight of the project; Third parties must support the project: Another fundamental criterion of the political process is the active involvement of third parties. Summary: The developer cannot do all the work alone - a number of players are needed. Total control - for example, a timetable - is not possible as local communities must have power. Openness and transparency at all stages are essential and finally, and most importantly, politics comes before science, emotion before rational thought. Finally, delays are a part of long-lived projects. The objective is to manage them, not to be defeated by them

  2. Structural Discrimination – Between a Rock and a Hard Place

    DEFF Research Database (Denmark)

    Skadegaard Thorsen, Mira

    This article examines challenges that arise when discrimination is expressed in communication across perceived differences (inter-cultural communication). More specifically, it looks at how visible minority Danes navigate in regard to structural discrimination (implicit and underlying forms...... of discrimination) imbricated in seemingly neutral everyday communication. It argues that structural discrimination is discursive and constitutive and is expressed in language as well as communicated in the form of naturalizations and embodiments of discrimination. It suggests that structural discrimination is so...

  3. Construction experiences from underground works at Oskarshamn. Compilation report

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Anders (Vattenfall Power Consultant AB, Stockholm (SE)); Christiansson, Rolf (Swedish Nuclear Fuel and Waste Management Co., Stockholm (SE))

    2007-12-15

    The main objective with this report is to compile experiences from the underground works carried out at Oskarshamn, primarily construction experiences from the tunnelling of the cooling water tunnels of the Oskarshamn nuclear power units 1,2 and 3, from the underground excavations of Clab 1 and 2 (Central Interim Storage Facility for Spent Nuclear Fuel), and Aespoe Hard Rock Laboratory. In addition, an account is given of the operational experience of Clab 1 and 2 and of the Aespoe HRL on primarily scaling and rock support solutions. This report, as being a compilation report, is in its substance based on earlier published material as presented in the list of references. Approximately 8,000 m of tunnels including three major rock caverns with a total volume of about 550,000 m3 have been excavated. The excavation works of the various tunnels and rock caverns were carried out during the period of 1966-2000. In addition, minor excavation works were carried out at the Aespoe HRL in 2003. The depth location of the underground structures varies from near surface down to 450 m. As an overall conclusion it may be said that the rock mass conditions in the area are well suited for underground construction. This conclusion is supported by the experiences from the rock excavation works in the Simpevarp and Aespoe area. These works have shown that no major problems occurred during the excavation works; nor have any stability or other rock engineering problems of significance been identified after the commissioning of the Oskarshamn nuclear power units O1, O2 and O3, BFA, Clab 1 and 2, and Aespoe Hard Rock Laboratory. The underground structures of these facilities were built according to plan, and since than been operated as planned. Thus, the quality of the rock mass within the construction area is such that it lends itself to excavation of large rock caverns with a minimum of rock support

  4. Hard probes 2006 Asilomar

    CERN Multimedia

    2006-01-01

    "The second international conference on hard and electromagnetic probes of high-energy nuclear collisions was held June 9 to 16, 2006 at the Asilomar Conference grounds in Pacific Grove, California" (photo and 1/2 page)

  5. Hard coal; Steinkohle

    Energy Technology Data Exchange (ETDEWEB)

    Loo, Kai van de; Sitte, Andreas-Peter [Gesamtverband Steinkohle e.V., Herne (Germany)

    2013-04-01

    The year 2012 benefited from a growth of the consumption of hard coal at the national level as well as at the international level. Worldwide, the hard coal still is the number one energy source for power generation. This leads to an increasing demand for power plant coal. In this year, the conversion of hard coal into electricity also increases in this year. In contrast to this, the demand for coking coal as well as for coke of the steel industry is still declining depending on the market conditions. The enhanced utilization of coal for the domestic power generation is due to the reduction of the nuclear power from a relatively bad year for wind power as well as reduced import prices and low CO{sub 2} prices. Both justify a significant price advantage for coal in comparison to the utilisation of natural gas in power plants. This was mainly due to the price erosion of the inexpensive US coal which partly was replaced by the expansion of shale gas on the domestic market. As a result of this, the inexpensive US coal looked for an outlet for sales in Europe. The domestic hard coal has continued the process of adaptation and phase-out as scheduled. Two further hard coal mines were decommissioned in the year 2012. RAG Aktiengesellschaft (Herne, Federal Republic of Germany) running the hard coal mining in this country begins with the preparations for the activities after the time of mining.

  6. Grouting methodology in crystalline rock

    International Nuclear Information System (INIS)

    For this paper, an initial literature review was conducted to investigate the potential applications of grouting technology for geological disposal of high level radioactive waste (hereafter called geological disposal), and the potential grouting material for each application. The results show the necessity of using suspension grout, such as cement-based grout, during excavation work, especially deep underground. Next, the method to achieve highly effective seals in crystalline rock with cement grout is studied. To enhance the sealing quality, cement grout should penetrate into very fine fractures, e.g. less than 100 μm aperture. In the case of suspension grout, clogging with grout at the openings of rock fractures, especially fine fractures, tends to occur, which results in poor grout penetration. A laboratory experiment was conducted to investigate the clogging phenomenon; the results suggest that high injection pressures could be effective to prevent clogging. Finally, focusing on pre-excavation grouting for horizontal tunnels in crystalline rock, the effective grout hole patterns for achieving high quality sealing was studied. A series of theoretical calculations for water inflow and cost studies were conducted. The results indicate that a dense arrangement of grout holes in a relatively narrow area around a tunnel section, as practised in the Nordic countries, is favorable in hard crystalline rock. (author)

  7. CERN Rocks

    CERN Multimedia

    2004-01-01

    The 15th CERN Hardronic Festival took place on 17 July on the terrace of Rest 3 (Prévessin). Over 1000 people, from CERN and other International Organizations, came to enjoy the warm summer night, and to watch the best of the World's High Energy music. Jazz, rock, pop, country, metal, blues, funk and punk blasted out from 9 bands from the CERN Musiclub and Jazz club, alternating on two stages in a non-stop show.  The night reached its hottest point when The Canettes Blues Band got everybody dancing to sixties R&B tunes (pictured). Meanwhile, the bars and food vans were working at full capacity, under the expert management of the CERN Softball club, who were at the same time running a Softball tournament in the adjacent "Higgs Field". The Hardronic Festival is the main yearly CERN music event, and it is organized with the support of the Staff Association and the CERN Administration.

  8. Hardness of metallic crystals

    Indian Academy of Sciences (India)

    Wuhui Li; Fengzhang Ren; Juanhua Su; Zhanhong Ma; Ke Cao; Baohong Tian

    2011-07-01

    This paper presents a new formula for calculating the hardness of metallic crystals, resulted from the research on the critical grain size with stable dislocations. The formula is = 6 /[(1 – )], where is the hardness, the coefficient, the shear modulus, the Poisson’s ratio, a function of the radius of an atom () and the electron density at the atom interface (). The formula will not only be used to testify the critical grain size with stable dislocations, but also play an important role in the understanding of mechanical properties of nanocrystalline metals.

  9. Hard exclusive QCD processes

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, W.

    2007-01-15

    Hard exclusive processes in high energy electron proton scattering offer the opportunity to get access to a new generation of parton distributions, the so-called generalized parton distributions (GPDs). This functions provide more detailed informations about the structure of the nucleon than the usual PDFs obtained from DIS. In this work we present a detailed analysis of exclusive processes, especially of hard exclusive meson production. We investigated the influence of exclusive produced mesons on the semi-inclusive production of mesons at fixed target experiments like HERMES. Further we give a detailed analysis of higher order corrections (NLO) for the exclusive production of mesons in a very broad range of kinematics. (orig.)

  10. Hard-hat day

    CERN Multimedia

    2003-01-01

    CERN will be organizing a special information day on Friday, 27th June, designed to promote the wearing of hard hats and ensure that they are worn correctly. A new prevention campaign will also be launched.The event will take place in the hall of the Main Building from 11.30 a.m. to 2.00 p.m., when you will be able to come and try on various models of hard hat, including some of the very latest innovative designs, ask questions and pass on any comments and suggestions.

  11. Budgeting in Hard Times.

    Science.gov (United States)

    Parrino, Frank M.

    2003-01-01

    Interviews with school board members and administrators produced a list of suggestions for balancing a budget in hard times. Among these are changing calendars and schedules to reduce heating and cooling costs; sharing personnel; rescheduling some extracurricular activities; and forming cooperative agreements with other districts. (MLF)

  12. Rock et Cinéma

    OpenAIRE

    Bart, Christian Le; Didelot, Jérôme; Eizykman, Claudine; Gorin, François; Grünberg, Serge; Jousse, Thierry; Juiller, Laurent; Le Guern, Philippe; Leveratto, Jean-Marc; Neyrat, Cyril; ribac, françois; Siclier, Sylvain

    2006-01-01

    This special issue of Volume ! is dedicated to the relationships between rock music and cinema. It was published during the second edition of the Paris-Cinéma Festival. Its articles analyze the use of rock 'n' roll in various films: Phantom of Paradise by Brian De Palma, Exploding Plastic Inevitable by Andy Warhol with The Velvet Underground's music, A Hard Day's Night by Richard Lester, David Lynch movies, as well as Frank Zappa, Aphex Twin and "kinok". Ce hors-série de Volume ! est consa­c...

  13. Experimental study on the physical and chemical properties of the deep hard brittle shale

    OpenAIRE

    Jian Xiong; Xiangjun Liu; Lixi Liang; Yi Ding; Meng Lei

    2016-01-01

    In the hard brittle shale formation, rock composition, physical and chemical properties, mechanics property before and after interacting with fluid have direct relation with borehole problems, such as borehole wall collapse, mud loss, hole shrinkage. To achieve hard brittle shale micro-structure, physical–chemical properties and mechanics property, energy-dispersive X-ray diffraction (XRD), cation exchange capacity experiment and hardness test are conducted. The result of laboratory experimen...

  14. Energy analysis for damage and catastrophic failure of rocks

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The development history and current state of studies on the characteristics and mechanisms of deformation and failure of rock materials were briefly reviewed from the viewpoint of energy.The main scope and the achievable objectives of the energy-based research system were expatiated.It was validated by experiments that the damage process of rocks can be well described by the rock damage evolution equation established based on energy dissipation.It was found from the uniaxial compression and biaxial compression tests that only a small proportion of the total input energy in hard rocks is dissipated before peak load and a large proportion in soft rocks is dissipated before peak load.For both hard and soft rocks,the energy dissipated after peak load accounts for a greater proportion.More energy would be required for rock failure under equal biaxial compression than under unequal biaxial compression.The total absorbed energy is different for rock failure under high-rate loading and low-rate loading.More fragmented failure pattern usually corresponds to higher energy absorption.The mesoscopic analysis on the damage and failure of bedded salt rocks showed that the energy dissipation is prominent and the total absorbed energy for rock failure is low when cracks propagate in the weak mud interlayer while it is contrary when cracks propagate in the salt rock.The energy accumulation,transfer,dissipation and release during the failure process of tunnel with impending failure under disturbance were analyzed theoretically based on the elastoplastic mechanics theory.Furthermore,the spatial distribution of energy dissipation and energy release of fractured rocks under unloading was simulated numerically.It was demonstrated that energy is likely to be released from the weakest surface under compression,which triggers the global failure of rocks.

  15. Rock shape, restitution coefficients and rockfall trajectory modelling

    Science.gov (United States)

    Glover, James; Christen, Marc; Bühler, Yves; Bartelt, Perry

    2014-05-01

    Restitution coefficients are used in rockfall trajectory modelling to describe the ratio between incident and rebound velocities during ground impact. They are central to the problem of rockfall hazard analysis as they link rock mass characteristics to terrain properties. Using laboratory experiments as a guide, we first show that restitution coefficients exhibit a wide range of scatter, although the material properties of the rock and ground are constant. This leads us to the conclusion that restitution coefficients are poor descriptors of rock-ground interaction. The primary problem is that "apparent" restitution coefficients are applied at the rock's centre-of-mass and do not account for rock shape. An accurate description of the rock-ground interaction requires the contact forces to be applied at the rock surface with consideration of the momentary rock position and spin. This leads to a variety of rock motions including bouncing, sliding, skipping and rolling. Depending on the impact configuration a wide range of motions is possible. This explains the large scatter of apparent restitution coefficients. We present a rockfall model based on newly developed hard-contact algorithms which includes the effects of rock shape and therefore is able to reproduce the results of different impact configurations. We simulate the laboratory experiments to show that it is possible to reproduce run-out and dispersion of different rock shapes using parameters obtained from independent tests. Although this is a step forward in rockfall trajectory modelling, the problem of parametersing real terrain remains.

  16. Interaction of clay and concrete plugs - Plugging of 5 m deep hole KA1621G01 at Aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Drawrite AB, Lund (Sweden); Luleaa Technical Univ., Luleaa (Sweden); Ramqvist, Gunnar [Eltekno AB, Figeholm (Sweden)

    2011-11-15

    Sealing of deep boreholes in repository rock is planned to be made by installing dense smectite clay plugs where the rock is low-permeable and casting concrete where the holes intersect water-bearing fracture zones. Such zones have to be stabilized before sealing starts because fragments of rock can otherwise fall off and make it difficult to bring equipment for concrete casting and clay plug units down. These parts of the holes are filled with concrete and clay plugs are then inserted up to the nearest fracture zone where concrete is filled to the required level etc. The role of the concrete in the hole and in the closest part of the surrounding fracture zone is to provide stable parts that are sufficiently fine-porous to prevent clay particles from contacting clay plugs to migrate into the fractures and be lost by erosion. While the larger parts of long clay plugs are believed to stay largely intact chemically for hundreds of thousands of years, the parts adjacent to concrete plugs may undergo changes and so can the concrete plugs themselves. The objective of the presently reported project was to identify the detailed processes and quantify associated changes in physical properties by investigating samples of clay and concrete from a 2.5 m long plug of clay over which an equally long concrete plug had been cast and left to rest for 3 years. The outcome of the investigations was that significant chemically induced changes in mineralogy and physical performance had occurred within a few centimetres distance from the clay/concrete contact but that virtually no changes had taken place at larger distance. A comprehensive laboratory study including X-ray diffraction (XRD), X-ray fluorescence (XRF) and electron microscopy study (SEM and TEM) on the sample material was performed including also dual beam (combined ion and electron) microscopy. It was found that the clay had infiltrated the contacting concrete plug after filling of the borehole since clay was detected both

  17. The rock diet

    OpenAIRE

    Fordyce, Fiona; Johnson, Chris

    2002-01-01

    You may think there is little connection between rocks and our diet, indeed a serving of rocks may sound very unappetising! But rocks are a vital source of the essential elements and minerals we need to keep us healthy, such as calcium for healthy teeth and bones.

  18. Hard metal composition

    Science.gov (United States)

    Sheinberg, Haskell

    1986-01-01

    A composition of matter having a Rockwell A hardness of at least 85 is formed from a precursor mixture comprising between 3 and 10 weight percent boron carbide and the remainder a metal mixture comprising from 70 to 90 percent tungsten or molybdenum, with the remainder of the metal mixture comprising nickel and iron or a mixture thereof. The composition has a relatively low density of between 7 to 14 g/cc. The precursor is preferably hot pressed to yield a composition having greater than 100% of theoretical density.

  19. Hard exclusive pion leptoproduction

    CERN Document Server

    Kroll, Peter

    2016-01-01

    In this talk it is reported on an analysis of hard exclusive leptoproduction of pions within the handbag approach. It is argued that recent measurements of this process performed by HERMES and CLAS clearly indicate the occurrence of strong contributions from transversely polarized photons. Within the handbag approach such gamma*_T -> pi transitions are described by the transversity GPDs accompanied by twist-3 pion wave functions. It is shown that the handbag approach leads to results on cross sections and single-spin asymmetries in fair agreement with experiment. Predictions for other pseudoscalar meson channels are also briefly discussed.8 pages

  20. Rock History and Culture

    OpenAIRE

    Gonzalez, Éric

    2013-01-01

    Two ambitious works written by French-speaking scholars tackle rock music as a research object, from different but complementary perspectives. Both are a definite must-read for anyone interested in the contextualisation of rock music in western popular culture. In Une histoire musicale du rock (i.e. A Musical History of Rock), rock music is approached from the point of view of the people – musicians and industry – behind the music. Christophe Pirenne endeavours to examine that field from a m...

  1. T-H-M couplings in rock. Overview of results of importance to the SR-Can safety assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hoekmark, Harald; Faelth, Billy [Clay Technology AB, Lund (Sweden); Wallroth, Thomas [BERGAB, Goeteborg (Sweden)

    2006-09-15

    hydraulic significance of the Excavation Damaged Zone (EDZ) is assessed from experiences and observations made during different tunnelling projects at the Aespoe Hard Rock laboratory and from conclusions of topical overviews. Previously, the general view was that an EDZ would form an independent and fast pathway along the drift. This is recognized to be an oversimplification. Rather, the EDZ is more likely to be discontinuous. In addition, it will be possible to reduce the damage by applying improved drill and blast procedures. The impacts of heat generation and glacial load on the hydraulic conditions in the far-field are analyzed using results from large-scale DEC thermo-mechanical models and preliminary results from on-going simulations of the ice-crust-mantle interaction during the most recent glaciation. Spalling in the walls of deposition holes as a result of excavation is concluded to be unlikely at all sites, but almost certain to occur after a few years of heating in dry deposition holes where the bentonite buffer has not taken up sufficient amounts of water to establish any support pressure. There are many uncertainties. The most important one is probably that of the development of stresses and pore pressures at repository depth during a glacial cycle. The ice-crust-mantle interaction analyses used to calculate the stresses assumed in this report are based on an earth model that appears to be too simplistic for this particular purpose. New analyses, with more realistic earth models and with updated ice load data, are underway and will be used to revise the results given here. Also some of the stress-transmissivity relations are uncertain, in particular when it comes to estimating effects of deformations of large fractures. Other uncertainties, for instance in site data such as the magnitudes and orientations of in situ stresses and rock properties data, are large but not larger than corresponding differences between the different sites, and do not appear to be of

  2. EXPERIMENTAL STUDY OF ROCK BREAKING EFFECT OF STEEL PARTICLES

    Institute of Scientific and Technical Information of China (English)

    CUI Meng; ZHAI Ying-hu; JI Guo-dong

    2011-01-01

    Particle impact drilling is an efficient drilling technology for deep-well hard formation, With this technology, the rock is cut mainly by high-speed spherical particle impact under hydraulic action. In this article, the influence of jet flow factors, hydraulic factors and abrasive factors on rock breaking is studied through indoor experiments of impact by steel particles. The results indicate that the particle water jet has an optimal standoff distance and particle concentration; the rock breaking effect declines with the increase of the confining pressure and the decrease of the pump pressure and particle diameter. This study will provide some food of thought for the development of particle impact drilling technology.

  3. Hard photoproduction at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, M. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier / CNRS-IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France)

    2007-07-01

    In view of possible photoproduction studies in ultra-peripheral heavy-ion collisions at the LHC, we briefly review the present theoretical understanding of photons and hard photoproduction processes at HERA, discussing the production of jets, light and heavy hadrons, quarkonia, and prompt photons. We address in particular the extraction of the strong coupling constant from photon structure function and inclusive jet measurements, the infrared safety and computing time of jet definitions, the sensitivity of di-jet cross sections on the parton densities in the photon, factorization breaking in diffractive di-jet production, the treatment of the heavy-quark mass in charm production, the relevance of the color-octet mechanism for quarkonium production, and isolation criteria for prompt photons. (author)

  4. Experimental study of a new multifunctional device for rock fragmentation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Fu-jun(赵伏军); LI Xi-bing(李夕兵); FENG Tao(冯涛)

    2004-01-01

    A new multifunctional testing device for rock fragmentation was introduced, which can conduct many experiments such as single cutting under static load, crushing under impact load, thrusting under static load and cutting-impact test under the dynamic and static load. The results of granite and concrete's experiments with polycrystalline diamond compact (PDC) flat cutters and carbide alloy cutters under different loadings show that the device has good performance, and the characteristics of broken rock under the combined loads are similar to that under the single static pressure or impact crushing the rock, and the combined loads can increase the effect of rock fragmentation obviously. The experimental methods and effects have the important meaning for studying new drilling tool on hard rock fragmentation.

  5. Constitutive relationships for elastic deformation of clay rock: Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.H.; Rutqvist, J.; Birkholzer, J.T.

    2011-04-15

    Geological repositories have been considered a feasible option worldwide for storing high-level nuclear waste. Clay rock is one of the rock types under consideration for such purposes, because of its favorable features to prevent radionuclide transport from the repository. Coupled hydromechanical processes have an important impact on the performance of a clay repository, and establishing constitutive relationships for modeling such processes are essential. In this study, we propose several constitutive relationships for elastic deformation in indurated clay rocks based on three recently developed concepts. First, when applying Hooke's law in clay rocks, true strain (rock volume change divided by the current rock volume), rather than engineering strain (rock volume change divided by unstressed rock volume), should be used, except when the degree of deformation is very small. In the latter case, the two strains will be practically identical. Second, because of its inherent heterogeneity, clay rock can be divided into two parts, a hard part and a soft part, with the hard part subject to a relatively small degree of deformation compared with the soft part. Third, for swelling rock like clay, effective stress needs to be generalized to include an additional term resulting from the swelling process. To evaluate our theoretical development, we analyze uniaxial test data for core samples of Opalinus clay and laboratory measurements of single fractures within macro-cracked Callovo-Oxfordian argillite samples subject to both confinement and water reduced swelling. The results from this evaluation indicate that our constitutive relationships can adequately represent the data and explain the related observations.

  6. Hungry for Rocks

    Science.gov (United States)

    2004-01-01

    This image from the Mars Exploration Rover Spirit hazard identification camera shows the rover's perspective just before its first post-egress drive on Mars. On Sunday, the 15th martian day, or sol, of Spirit's journey, engineers drove Spirit approximately 3 meters (10 feet) toward its first rock target, a football-sized, mountain-shaped rock called Adirondack (not pictured). In the foreground of this image are 'Sashimi' and 'Sushi' - two rocks that scientists considered investigating first. Ultimately, these rocks were not chosen because their rough and dusty surfaces are ill-suited for grinding.

  7. Hard coal; Steinkohle

    Energy Technology Data Exchange (ETDEWEB)

    Loo, Kai van de; Sitte, Andreas-Peter [Gesamtverband Steinkohle e.V. (GVSt), Herne (Germany)

    2015-07-01

    International the coal market in 2014 was the first time in a long time in a period of stagnation. In Germany, the coal consumption decreased even significantly, mainly due to the decrease in power generation. Here the national energy transition has now been noticable affected negative for coal use. The political guidances can expect a further significant downward movement for the future. In the present phase-out process of the German hard coal industry with still three active mines there was in 2014 no decommissioning. But the next is at the end of 2015, and the plans for the time after mining have been continued. [German] International war der Markt fuer Steinkohle 2014 erstmals seit langem wieder von einer Stagnation gekennzeichnet. In Deutschland ging der Steinkohlenverbrauch sogar deutlich zurueck, vor allem wegen des Rueckgangs in der Stromerzeugung. Hier hat sich die nationale Energiewende nun spuerbar und fuer die Steinkohlennutzung negativ ausgewirkt. Die politischen Weichenstellungen lassen fuer die Zukunft eine weitere erhebliche Abwaertsbewegung erwarten. Bei dem im Auslaufprozess befindlichen deutschen Steinkohlenbergbau mit noch drei aktiven Bergwerken gab es 2014 keine Stilllegung. Doch die naechste steht zum Jahresende 2015 an, und die Planungen fuer die Zeit nach dem Bergbau sind fortgefuehrt worden.

  8. Specific Energy of Hard Coal Under Load

    Science.gov (United States)

    Bogusz, Anna; Bukowska, Mirosława

    2015-03-01

    The article presents results of experimental tests of energy parameters of hard coals under loading, collected from research sites located within five main geologic structures of Upper Silesian Coal Basin (GZW) - Main Trough, Main Anticline, Bytom Trough, Rybnik Trough and Chwałowice Trough. Coals from12 mines were analysed, starting with seams of group 200, through groups 400, 500, 600 and, finally, seams of group 700. Coal of each of the groups of seams underwent uniaxial compression stress of the energy parameters, in a servo-controlled testing machine MTS-810NEW, for the full range of strain of the tested coal samples. Based on the tests the dependence of different types of specific energy of longitudinal strain of coals on the value of uniaxial compression strength was determined. The dependence of the value of dissipated energy and kinetic energy of coals on the uniaxial compression strength was described with a linear function, both for coals which due to their age belong to various bed sand for various lithotypes of coal. An increase in the value of dissipated energy and in kinetic energy was observed, which was correlated with an increase in uniaxial compression strength of coal. The share of dissipated energy is dominant in the total energy of strain. Share of recoverable energy in the total energy of strain is small, independent of the compression strength of coals and is at most a few per cent high. In coals of low strength and dominant share of dissipated energy, share of recoverable energy is the biggest among the tested coals. It was shown that following an increase in compression strength the share of recoverable energy decreases, while the share of dissipated energy in the total energy increases. Further studies of specific energy of longitudinal strain of rocks in the full-range strain will be the next step inperfecting methodology of research into natural rock burst susceptibility of Carboniferous rock mass and changes in the susceptibility

  9. Comments on chevron bend specimen for determining fracture toughness of rock

    Institute of Scientific and Technical Information of China (English)

    孙宗颀; 陈枫; 徐纪成

    2001-01-01

    Based on a number of tests on different rocks, Suggested Methods for Determining the Fracture Toughness of Rock (SMs) was reviewed. The advantages of SMs are obvious, but some problems are also discovered. A serious one is that the nonlinear corrected fracture toughness of chevron bend specimens, KCCB, is less than the uncorrected one, KCB, for hard rock like granite, marble and others. The reason is discussed and the proposal is given.

  10. Measuring the Hardness of Minerals

    Science.gov (United States)

    Bushby, Jessica

    2005-01-01

    The author discusses Moh's hardness scale, a comparative scale for minerals, whereby the softest mineral (talc) is placed at 1 and the hardest mineral (diamond) is placed at 10, with all other minerals ordered in between, according to their hardness. Development history of the scale is outlined, as well as a description of how the scale is used…

  11. Why All the Hard Work?

    Institute of Scientific and Technical Information of China (English)

    VALERIE; SARTOR

    2011-01-01

    The stereotype of the hard working Chinese has been around for a long time in the West. As early a 1894, Arthur Smith, a missionary who spent 54 years in China, wrote book introducing the hard-working Chinese people to Americans. In his book Chinese Characteristics, Smith wrote about the dili

  12. Melting of polydisperse hard disks

    NARCIS (Netherlands)

    Pronk, S.; Frenkel, D.

    2004-01-01

    The melting of a polydisperse hard-disk system is investigated by Monte Carlo simulations in the semigrand canonical ensemble. This is done in the context of possible continuous melting by a dislocation-unbinding mechanism, as an extension of the two-dimensional hard-disk melting problem. We find th

  13. Space Weathering of Rocks

    Science.gov (United States)

    Noble, Sarah

    2011-01-01

    Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. On the Moon, rocks make up only a very small percentage of the exposed surface and areas where rocks are exposed, like central peaks, are often among the least space weathered regions we find in remote sensing data. However, our studies of weathered Ap 17 rocks 76015 and 76237 show that significant amounts of weathering products can build up on rock surfaces. Because rocks have much longer surface lifetimes than an individual soil grain, and thus record a longer history of exposure, we can study these products to gain a deeper perspective on the weathering process and better assess the relative impo!1ance of various weathering components on the Moon. In contrast to the lunar case, on small asteroids, like Itokowa, rocks make up a large fraction of the exposed surface. Results from the Hayabusa spacecraft at Itokowa suggest that while the low gravity does not allow for the development of a mature regolith, weathering patinas can and do develop on rock surfaces, in fact, the rocky surfaces were seen to be darker and appear spectrally more weathered than regions with finer materials. To explore how weathering of asteroidal rocks may differ from lunar, a set of ordinary chondrite meteorites (H, L, and LL) which have been subjected to artificial space weathering by nanopulse laser were examined by TEM. NpFe(sup 0) bearing glasses were ubiquitous in both the naturally-weathered lunar and the artificially-weathered meteorite samples.

  14. CRITERIA FOR ROCK ENGINEERING FAILURE

    Institute of Scientific and Technical Information of China (English)

    ZHUDeren; ZHANGYuzhuo

    1995-01-01

    A great number of underground rock projects are maintained in the rock mass which is subject to rock damage and failure development. In many cases, the rock. engineering is still under normal working conditions even though rock is already fails to some extent. This paper introduces two different concepts: rock failure and rock engineering failure. Rock failure is defined as a mechanical state under which an applicable characteristic is changed or lost.However, the rock engineering failure is an engineering state under which an applicable function is changed or lost. The failure of surrounding rocks is the major reason of rock engineering failure. The criterion of rock engineering failure depends on the limit of applicable functions. The rock engineering failure state possesses a corresponding point in rock failure state. In this paper, a description of rock engineering failure criterion is given by simply using a mechanical equation or expression. It is expected that the study of rock engineering failure criterion will be an optimal approach that combines research of rock mechanics with rock engineering problems.

  15. Rock kinoekraanil / Katrin Rajasaare

    Index Scriptorium Estoniae

    Rajasaare, Katrin

    2008-01-01

    7.-11. juulini kinos Sõprus toimuval filminädalal "Rock On Screen" ekraanile jõudvatest rockmuusikuid portreteerivatest filmidest "Lou Reed's Berlin", "The Future Is Unwritten: Joe Strummer", "Control: Joy Division", "Hurriganes", "Shlaager"

  16. Pop & rock / Berk Vaher

    Index Scriptorium Estoniae

    Vaher, Berk, 1975-

    2001-01-01

    Uute heliplaatide Redman "Malpractice", Brian Eno & Peter Schwalm "Popstars", Clawfinger "A Whole Lot of Nothing", Dario G "In Full Color", MLTR e. Michael Learns To Rock "Blue Night" lühitutvustused

  17. Making silica rock coatings in the lab: synthetic desert varnish

    Science.gov (United States)

    Perry, Randall S.; Kolb, Vera M.; Philip, Ajish I.; Lynne, Bridget Y.; McLoughlin, Nicola; Sephton, Mark; Wacey, David; Green, Owen R.

    2005-09-01

    Desert varnish and silica rock coatings have perplexed investigators since Humboldt and Darwin. They are found in arid regions and deserts on Earth but the mechanism of their formation remains challenging (see Perry et al. this volume). One method of researching this is to investigate natural coatings, but another way is to attempt to produce coatings in vitro. Sugars, amino acids, and silicic acid, as well as other organic and (bio)organic compounds add to the complexity of naturally forming rock coatings. In the lab we reduced the complexity of the natural components and produced hard, silica coatings on basaltic chips obtained from the Mojave Desert. Sodium silicate solution was poured over the rocks and continuously exposed to heat and/or UV light. Upon evaporation the solutions were replenished. Experiments were performed at various pH's. The micro-deposits formed were analyzed using optical, SEM-EDAX, and electron microprobe. The coatings formed are similar in hardness and composition to silica glazes found on basalts in Hawaii as well as natural desert varnish found in US southwest deserts. Thermodynamic mechanisms are presented showing the theoretical mechanisms for overcoming energy barriers that allow amorphous silica to condense into hard coatings. This is the first time synthetic silica glazes that resemble natural coatings in hardness and chemical composition have been successfully reproduced in the laboratory, and helps to support an inorganic mechanism of formation of desert varnish as well as manganese-deficient silica glazes.

  18. Relationship between the rock mass deformation and places of occurrence of seismological events

    Institute of Scientific and Technical Information of China (English)

    MAKOWKA Janusz; KABIESZ Jozef; DOU Lin-ming

    2009-01-01

    Static effort of rock mass very rarely causes of rock burst in polish coal mines. Rock bursts with source in the seismic tremor within the roof rock layers are prevailing. A seismic tremor is an effect of rupture or sliding in roof layers above the exploited panel in coal seam, sometime in a distance from actual exploitation. Sliding, as a rule occurs in fault zone and tremors in it are expected, but monolithic layer rupture is very hard to predict. In a past few years a practice of analyzing state of deformation in high energy seismic tremors zones has been employed. It let gathering experience thanks to witch determination of dangerous shape of reformatted roof is possible. In the paper some typical forms of roof rocks deformations leading to seismic tremor occurrence will be presented. In general these are various types of multidirectional rock layers bending. Real examples of seismic events and rock bursts will be shown.

  19. Thermal dimensioning of the deep repository. Influence of canister spacing, canister power, rock thermal properties and nearfield design on the maximum canister surface temperature

    Energy Technology Data Exchange (ETDEWEB)

    Hoekmark, Harald; Faelth, Billy [Clay Technology AB, Lund (Sweden)

    2003-12-01

    The report addresses the problem of the minimum spacing required between neighbouring canisters in the deep repository. That spacing is calculated for a number of assumptions regarding the conditions that govern the temperature in the nearfield and at the surfaces of the canisters. The spacing criterion is that the temperature at the canister surfaces must not exceed 100 deg C .The results are given in the form of nomographic charts, such that it is in principle possible to determine the spacing as soon as site data, i.e. the initial undisturbed rock temperature and the host rock heat transport properties, are available. Results of canister spacing calculations are given for the KBS-3V concept as well as for the KBS-3H concept. A combination of numerical and analytical methods is used for the KBS-3H calculations, while the KBS-3V calculations are purely analytical. Both methods are described in detail. Open gaps are assigned equivalent heat conductivities, calculated such that the conduction across the gaps will include also the heat transferred by radiation. The equivalent heat conductivities are based on the emissivities of the different gap surfaces. For the canister copper surface, the emissivity is determined by back-calculation of temperatures measured in the Prototype experiment at Aespoe HRL. The size of the different gaps and the emissivity values are of great importance for the results and will be investigated further in the future.

  20. Geoelectric investigations into sandstone moisture regimes: Implications for rock weathering and the deterioration of San Rock Art in the Golden Gate Reserve, South Africa

    Science.gov (United States)

    Mol, L.; Viles, H. A.

    2010-06-01

    The Clarens sandstone in the Golden Gate Reserve, South Africa, is the canvas for a collection of San (Bushmen) Rock Art, dating from Neolithic times until as recently as 150 years ago. This Rock Art is under threat from human interference but also, to a greater degree, from weathering processes on the rock surface. The dominant weathering processes occurring in the rock shelters which host the Rock Art are flaking and honeycombing. Two rock shelter sites in the Reserve have been investigated using electric resistivity tomography (ERT) and supportive methods for measuring surface moisture (Protimeter) and surface hardness (Equotip). These non-destructive techniques can be used in situ to assess the extent of weathering within a rock outcrop and are especially suited for investigations in sensitive areas such as Rock Art sites. Moisture movement has been mapped and related to the weathering processes observed on the surface. The aim of the study is to aid Rock Art conservation in the Golden Gate Reserve through a better understanding of the driving processes of surface weathering. The evidence shows that the extensive flaking and honeycombing found in the rock shelters is most likely caused by water pockets in the near-surface zone, which are replenished through internal moisture transport, driving the superficial weathering processes. These weathering processes pose a significant problem: Rock Art in the Golden Gate Reserve shows severe deterioration due to flaking. Conservation strategies should therefore take internal processes into account as much as their superficial expression.

  1. Aespoe HRL - Geoscientific evaluation 1997/3. Results from pre-investigation and detailed site characterization. Comparison of predictions and observations. Geology and mechanical stability

    International Nuclear Information System (INIS)

    Prior to excavation of the laboratory in 1990 predictions were made for the excavation phase. The predictions concern five key issues: Geology, groundwater flow, groundwater chemistry, transport of solutes, and mechanical stability. Comparisons between predictions and observations were made during excavation in order to verify the reliability of the pre-investigations. This report presents a comparison between the geological and mechanical stability predictions and observations and an evaluation of data and investigation methods used for the 700-2874 m section of the tunnel. The report is specially highlighting the following conclusions: It is possible to localize major fracture zones during the pre-investigation at shallow (<200 m) depths; A number of minor fracture zones striking NNW-NNE were predicted to be hydraulically important and penetrate the southern area. A number of narrow fracture zone indications - 0.1-1 m wide - striking WNW-NE were mapped in the tunnel and pre-grouted sections confirm hydraulic conductors; It has not been possible to confirm the gently dipping zone EW-5, which was predicted as 'possible', with data from the tunnel; Predictions of the amount of different rock types were generally reliable as regards the major rocks, but the prediction of the distribution in space were poor as regards the minor rock types; The prediction of rock stress orientation corresponds well to the outcome; The prediction of rock quality for the tunnel, while applying the RMR-system, shows good correspondence to the observations made in the tunnel

  2. Experimental study and stress analysis of rock bolt anchorage performance

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2014-10-01

    Full Text Available A new method was developed to apply pull-and-shear loads to the bolt specimen in order to evaluate the anchorage performance of the rebar bolt and the D-Bolt. In the tests, five displacing angles (0°, 20°, 40°, 60°, and 90°, two joint gaps (0 mm and 30 mm, and three kinds of host rock materials (weak concrete, strong concrete, and concrete-granite were considered, and stress–strain measurements were conducted. Results show that the ultimate loads of both the D-Bolt and the rebar bolt remained constant with any displacing angles. The ultimate displacement of the D-Bolt changed from 140 mm at the 0° displacing angle (pure pull to approximately 70 mm at a displacing angle greater than 40°. The displacement capacity of the D-Bolt is approximately 3.5 times that of the rebar bolt under pure pull and 50% higher than that of the rebar bolt under pure shear. The compressive stress exists at 50 mm from the bolt head, and the maximum bending moment value rises with the increasing displacing angle. The rebar bolt mobilises greater applied load than the D-Bolt when subjected to the maximum bending. The yielding length (at 0° of the D-Bolt is longer than that of the rebar bolt. The displacement capacity of the bolts increased with the joint gap. The bolt subjected to joint gap effect yields more quickly with greater bending moment and smaller applied load. The displacement capacities of the D-Bolt and the rebar bolt are greater in the weak host rock than that in the hard host rock. In pure shear condition, the ultimate load of the bolts slightly decreases in the hard rock. The yielding speed in the hard rock is higher than that in the weak rock.

  3. Experimental study and stress analysis of rock bolt anchorage performance

    Institute of Scientific and Technical Information of China (English)

    Yu Chen

    2014-01-01

    A new method was developed to apply pull-and-shear loads to the bolt specimen in order to evaluate the anchorage performance of the rebar bolt and the D-Bolt. In the tests, five displacing angles (0?, 20?, 40?, 60?, and 90?), two joint gaps (0 mm and 30 mm), and three kinds of host rock materials (weak concrete, strong concrete, and concrete-granite) were considered, and stressestrain measurements were con-ducted. Results show that the ultimate loads of both the D-Bolt and the rebar bolt remained constant with any displacing angles. The ultimate displacement of the D-Bolt changed from 140 mm at the 0? displacing angle (pure pull) to approximately 70 mm at a displacing angle greater than 40?. The displacement capacity of the D-Bolt is approximately 3.5 times that of the rebar bolt under pure pull and 50%higher than that of the rebar bolt under pure shear. The compressive stress exists at 50 mm from the bolt head, and the maximum bending moment value rises with the increasing displacing angle. The rebar bolt mobilises greater applied load than the D-Bolt when subjected to the maximum bending. The yielding length (at 0?) of the D-Bolt is longer than that of the rebar bolt. The displacement capacity of the bolts increased with the joint gap. The bolt subjected to joint gap effect yields more quickly with greater bending moment and smaller applied load. The displacement capacities of the D-Bolt and the rebar bolt are greater in the weak host rock than that in the hard host rock. In pure shear condition, the ultimate load of the bolts slightly decreases in the hard rock. The yielding speed in the hard rock is higher than that in the weak rock.

  4. Examination and validation of the content of SKB progress reports 25-92-19 and 25-94-13

    International Nuclear Information System (INIS)

    The grouting work that has been performed in the Aespoe Hard Rock Laboratory has been part of a research work called 'Passage of water bearing zones'. The grouting has therefore been carefully followed-up and analyzed from practical as well as theoretical points of view. The two reports have been examined and a validation made of the relevance of the theoretical discussions, planning and performance of the grouting work and the evaluation of attained results

  5. An Investigation on Load Bearing Capacities of Cement and Resin Grouted Rock Bolts Installed in Weak Rocks

    Science.gov (United States)

    Kalyoncu Erguler, Guzide; Abiddin Erguler, Zeynal

    2015-04-01

    Rock bolts have been considered one of indispensable support method to improve load bearing capacity of many underground engineering projects, and thus, various types of them have been developed until now for different purposes. Although mechanically anchored rock bolts can be successfully installed to prevent structurally controlled instabilities in hard rocks, in comparison with cement and resin grouted rock bolts, these types of anchors are not so effective in weak rocks characterized by relatively low mechanical properties. In order to investigate the applicability and to measure relative performance of cement and resin grouted rock bolts into weak and heavily jointed rock mass, a research program mainly consisting of pull-out tests was performed in a metal mine in Turkey. The rock materials excavated in this underground mining were described as basalt, tuff, ore dominated volcanic rocks and dacite. To achieve more representative results for rock materials found in this mining and openings excavated in varied dimensions, the pull-out tests were conducted on rock bolts used in many different locations where more convergences were measured and deformation dependent instability was expected to cause greater engineering problems. It is well known that the capacity of rock bolts depends on the length, diameter and density of the bolt pattern, and so considering the thickness of plastic zone in the studied openings, the length and diameter of rock bolts were taken as 2.4 m. and 25 mm., respectively. The spacing between rows changed between 70 and 180 cm. In this study, totally twenty five pull-out tests were performed to have a general understanding about axial load bearing capacity and support reaction curves of cement and resin grouted rock bolts. When pull load-displacement curves belongs to cement and resin grouted rock bolts were compared with each other, it was determined that cement grouted rock bolts carry more load ranging between 115.6 kN and 127.5 kN with

  6. NANOCOMPOSITE COATINGS WITH ENHANCED HARDNESS

    Institute of Scientific and Technical Information of China (English)

    J. Musil

    2005-01-01

    The article reviews the present state of the art in the magnetron sputtering of hart and superhard nanocomposite coatings. It is shown that there are (1) two groups of hard and superhard nanocomposites: (i) nc-MN/hard phase and (ii) nc-MN/soft phase, (2) three possible origins of the enhanced hardness: (i) dislocation-dominated plastic deformation, (ii) cohesive forces between atoms and (iii) nanostructure of materials, and (3) huge differences in the microstructure of single- and two-phase films. A main attention is devoted to the formation of nanocrystalline and/or X-ray amorphous films. Such films are created in a vicinity of transitions between (i)crystalline and amorphous phases, (ii) two crystalline phases of different chemical composition or (iii) two different preferred orientations of grains of the sane material from which the coating is composed. The existence of the last transition makes it possible to explain the enhanced hardness in single-phase films. The thermal stability and oxidation resistance of hard nanocomposite films is also shortly discussed.

  7. Simulation of microwave propagation and absorption in heterogeneous rocks

    International Nuclear Information System (INIS)

    Full text: A FDTD simulation study of the propagation of a microwave beam in a two-component model for hard rock with absorbing inclusions (discs) randomly distributed in a non-absorbing matrix is presented. Reflections at the discs/matrix interfaces and absorption in the discs lead to up to 20% diffuse scattering. Stripe-like patterns appear which are associated with coherent scattering. Conclusions for the microwave induced inhomogeneous heating and damage of rocks due to local thermal stresses are drawn and supported by preliminary experiments and thermo-mechanical FEM simulations. FEM results show stresses of the order of literature values for the component strengths. (author)

  8. Groundwater in granitic rocks

    International Nuclear Information System (INIS)

    A comparison of published chemical analyses of ground waters found in granitic rocks from a variety of locations shows that their compositions fall into two distinct classes. Ground waters from shallow wells and springs have a high bicarbonate/chloride ratio resulting from the neutralization of carbonic acid (dissolved CO2) by weathering reactions. The sodium, potassium, and silica released by weathering reactions drive the solutions away from equilibrium with the dominant minerals in the granites (i.e., quartz, muscovite, potassium feldspar, and albite). On the other hand, ground waters from deep wells and excavations are rich in chloride relative to bicarbonate. Their Na, K, H, and silica activities indicate that they are nearly equilibrated with the granite minerals suggesting a very long residence time in the host rock. These observations furnish the basis for a powerful tool to aid in selecting sites for radioactive waste disposal in granitic rocks. When water-bearing fractures are encountered in these rocks, a chemical analysis of the solutions contained within the fracture can determine whether the water came from the surface, i.e., is bicarbonate rich and not equilibrated, or whether it is some sort of connate water that has resided in the rock for a long period, i.e., chloride rich and equilibrated. This technique should allow immediate recognition of fracture systems in granitic radioactive waste repositories that would allow radionuclides to escape to the surface

  9. Hard-soft composite magnets

    Energy Technology Data Exchange (ETDEWEB)

    Ghidini, M. [Department of Physics, University of Parma and CNISM, V.le G.P. Usberti 7/A, 43100, Parma (Italy)]. E-mail: ghidini@fis.unipr.it; Asti, G. [Department of Physics, University of Parma and CNISM, V.le G.P. Usberti 7/A, 43100, Parma (Italy); Pellicelli, R. [Department of Physics, University of Parma and CNISM, V.le G.P. Usberti 7/A, 43100, Parma (Italy); Pernechele, C. [Department of Physics, University of Parma and CNISM, V.le G.P. Usberti 7/A, 43100, Parma (Italy); Solzi, M. [Department of Physics, University of Parma and CNISM, V.le G.P. Usberti 7/A, 43100, Parma (Italy)

    2007-09-15

    A thorough micromagnetic analysis of the exchange-spring problem is reported with special emphasis on multilayers constituted by hard-soft exchange-coupled phases. The developed one-dimensional micromagnetic model leads to a complete magnetic phase diagram in terms of layer thicknesses. Both perpendicular and parallel configurations are considered. The phase diagram provides information on the type of demagnetization processes and the critical fields at which nucleation and reversal take place, depending on the intrinsic properties of the chosen soft and hard materials. The model has been applied to a variety of hard magnetic phases (e.g., FePt, CoPt, SmCo and NdFeB), coupled to different soft materials (e.g., Fe, FeCo, FeRh or permalloy) both in the form of bilayers and multilayers. The most significant results will be highlighted.

  10. Hard Diffraction in Pythia 8

    CERN Document Server

    Rasmussen, Christine O

    2015-01-01

    We present an overview of the options for diffraction implemented in the general--purpose event generator Pythia 8. We review the existing model for low-- and high--mass soft diffraction and present a new model for hard diffraction in pp and ppbar collisions. Both models uses the Pomeron approach pioneered by Ingelman and Schlein, factorising the single diffractive cross section into a Pomeron flux and a Pomeron PDF. The model for hard diffraction is implemented as a part of the multiparton interactions framework, thereby introducing a dynamical rapidity gap survival probability that explicitly breaks factorisation.

  11. Hard Diffraction in Pythia 8

    CERN Document Server

    Rasmussen, Christine O

    2015-01-01

    We present an overview of the options for diffraction implemented in the general-purpose event generator Pythia 8. We review the existing model for soft diffraction and present a new model for hard diffraction. Both models use the Pomeron approach pioneered by Ingelman and Schlein, factorising the diffractive cross section into a Pomeron flux and a Pomeron PDF, with several choices for both implemented in Pythia 8. The model of hard diffraction is implemented as a part of the multiparton interactions (MPI) framework, thus introducing a dynamical gap survival probability that explicitly breaks factorisation.

  12. Hard diffraction in Pythia 8

    Science.gov (United States)

    Overgaard Rasmussen, Christine

    2016-07-01

    We present an overview of the options for diffraction implemented in the general-purpose event generator Pythia 8 [1]. We review the existing model for soft diffraction and present a new model for hard diffraction. Both models use the Pomeron approach pioneered by Ingelman and Schlein, factorising the diffractive cross section into a Pomeron flux and a Pomeron PDF, with several choices for both implemented in Pythia 8. The model of hard diffraction is implemented as a part of the multiparton interactions (MPI) framework, thus introducing a dynamical gap survival probability that explicitly breaks factorisation.

  13. Rock mechanics research awards

    Science.gov (United States)

    Wagner, John E.

    The U.S. National Committee for Rock Mechanics, at its June 1983 annual meeting, adopted three actions to enhance the competition and public awareness of its annual awards program for rock mechanics papers. It will issue a call for nominations of outstanding papers; it will request participating societies to announce the names of award winners and the titles of papers, and it will publish an abstract of the winning papers in the proceedings of the annual U.S. Rock Mechanics Symposium in the year following the awards.The competition is open to papers, by U.S residents or students in a U.S. school, published in an English language publication normally available in the United States. The following authors and papers are the 1983 award winners:

  14. Hard Diffraction at D{phi}

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Gilvan A. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Lab. de Cosmologia e Fisica Experimental de Altas Energias

    2000-07-01

    Full text follows: We review recent Hard Diffraction results from the D{phi} experiment at Fermilab, for the following processes: hard color singlet exchange, hard single diffraction, and hard double pomeron exchange. Measurements of rates, {eta}, E{sub T} and {radical}S dependencies are presented and comparisons made with predictions of several models. (author)

  15. 7 CFR 201.21 - Hard seed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seed. 201.21 Section 201.21 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.21 Hard seed. The label shall show the percentage of hard seed... percentage of hard seed shall not be included as part of the germination percentage....

  16. 7 CFR 201.57 - Hard seeds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seeds. 201.57 Section 201.57 Agriculture... REGULATIONS Germination Tests in the Administration of the Act § 201.57 Hard seeds. Seeds which remain hard at..., are to be counted as “hard seed.” If at the end of the germination period provided for legumes,...

  17. 7 CFR 201.30 - Hard seed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Hard seed. 201.30 Section 201.30 Agriculture... REGULATIONS Labeling Vegetable Seeds § 201.30 Hard seed. The label shall show the percentage of hard seed, if... percentage of hard seed shall not be included as part of the germination percentage....

  18. No Reprieve for Tasmanian Rock Art

    Directory of Open Access Journals (Sweden)

    Peter C. Sims

    2013-10-01

    Full Text Available The Australian State of Tasmania, at latitude 42 degrees south, became an island about 8,000 years ago when the sea rose to its present level, following the melting of polar and glacial ice that covered much of the land mass. After that time, the Tasmanian Aboriginal rock art developed independently of mainland Australia, with its form being basically linear with some naturalistic figures and a predominance of cupules. The petroglyphs with one lithophone site occur on various rock substrates varying in hardness from granite to sandstone. Many sites exist along the western coastline that borders the Southern Ocean where the landscape in some places has changed little since the arrival of Europeans in 1803. The significance of this Tasmanian Aboriginal cultural heritage along what is now known as the Tarkine Coast, named after an Aboriginal band that once inhabited this area, was recognised by the Australian Government in February 2013 when a 21,000 ha strip, 2 km wide, was inscribed on its National Heritage Register, being one of 98 special places listed in the country. However, politics and racism hamper its management. This paper is based on the results of 40 years of field recording of the Tasmanian Aboriginal rock art sites, many of which remain unpublished.

  19. Digital carbonate rock physics

    Science.gov (United States)

    Saenger, Erik H.; Vialle, Stephanie; Lebedev, Maxim; Uribe, David; Osorno, Maria; Duda, Mandy; Steeb, Holger

    2016-08-01

    Modern estimation of rock properties combines imaging with advanced numerical simulations, an approach known as digital rock physics (DRP). In this paper we suggest a specific segmentation procedure of X-ray micro-computed tomography data with two different resolutions in the µm range for two sets of carbonate rock samples. These carbonates were already characterized in detail in a previous laboratory study which we complement with nanoindentation experiments (for local elastic properties). In a first step a non-local mean filter is applied to the raw image data. We then apply different thresholds to identify pores and solid phases. Because of a non-neglectable amount of unresolved microporosity (micritic phase) we also define intermediate threshold values for distinct phases. Based on this segmentation we determine porosity-dependent values for effective P- and S-wave velocities as well as for the intrinsic permeability. For effective velocities we confirm an observed two-phase trend reported in another study using a different carbonate data set. As an upscaling approach we use this two-phase trend as an effective medium approach to estimate the porosity-dependent elastic properties of the micritic phase for the low-resolution images. The porosity measured in the laboratory is then used to predict the effective rock properties from the observed trends for a comparison with experimental data. The two-phase trend can be regarded as an upper bound for elastic properties; the use of the two-phase trend for low-resolution images led to a good estimate for a lower bound of effective elastic properties. Anisotropy is observed for some of the considered subvolumes, but seems to be insignificant for the analysed rocks at the DRP scale. Because of the complexity of carbonates we suggest using DRP as a complementary tool for rock characterization in addition to classical experimental methods.

  20. Rock engineering applications, 1991

    International Nuclear Information System (INIS)

    This book demonstrates how to apply the theories and principles of rock engineering to actual engineering and construction tasks. It features insights on geology for mining and tunnelling applications. It is practical resource that focuses on the latest technological innovation and examines up-to-date procedures used by engineers for coping with complex rock conditions. The authors also discuss question related to underground space, from design approaches to underground housing and storage. And they cover the monitoring of storage caverns for liquid and gaseous products or toxic and radioactive wastes

  1. Rock Hellsinki, Marketing Research

    OpenAIRE

    Todd, Roosa; Jalkanen, Katariina

    2013-01-01

    This paper is a qualitative research about rock and heavy metal music tourism in the capital city of Finland, Helsinki. As Helsinki can be considered the city of contrasts, the silent nature city mixed with urban activities, it is important to also use the potential of the loud rock and heavy metal music contrasting the silence. Finland is known abroad for bands such as HIM, Nightwish, Korpiklaani and Children of Bodom so it would make sense to utilize these in the tourism sector as well. The...

  2. Aespoe HRL - Geoscientific evaluation 1997/3. Results from pre-investigation and detailed site characterization. Comparison of predictions and observations. Geology and mechanical stability

    Energy Technology Data Exchange (ETDEWEB)

    Stanfors, R. [RS Consulting, Lund (Sweden); Olsson, Paer [Skanska AB Stockholm (Sweden); Stille, H. [Royal Inst. of Tech., Stockholm (Sweden)

    1997-05-01

    Prior to excavation of the laboratory in 1990 predictions were made for the excavation phase. The predictions concern five key issues: Geology, groundwater flow, groundwater chemistry, transport of solutes, and mechanical stability. Comparisons between predictions and observations were made during excavation in order to verify the reliability of the pre-investigations. This report presents a comparison between the geological and mechanical stability predictions and observations and an evaluation of data and investigation methods used for the 700-2874 m section of the tunnel. The report is specially highlighting the following conclusions: It is possible to localize major fracture zones during the pre-investigation at shallow (<200 m) depths; A number of minor fracture zones striking NNW-NNE were predicted to be hydraulically important and penetrate the southern area. A number of narrow fracture zone indications - 0.1-1 m wide - striking WNW-NE were mapped in the tunnel and pre-grouted sections confirm hydraulic conductors; It has not been possible to confirm the gently dipping zone EW-5, which was predicted as `possible`, with data from the tunnel; Predictions of the amount of different rock types were generally reliable as regards the major rocks, but the prediction of the distribution in space were poor as regards the minor rock types; The prediction of rock stress orientation corresponds well to the outcome; The prediction of rock quality for the tunnel, while applying the RMR-system, shows good correspondence to the observations made in the tunnel. 59 refs, 51 figs, 21 tabs.

  3. Kinetic theory of hard spheres

    NARCIS (Netherlands)

    Beijeren, H. van; Ernst, M.H.

    1979-01-01

    Kinetic equations for the hard-sphere system are derived by diagrammatic techniques. A linear equation is obtained for the one-particle-one particle equilibrium time correlation function and a nonlinear equation for the one-particle distribution function in nonequilibrium. Both equations are nonloca

  4. Stress in hard metal films

    NARCIS (Netherlands)

    Janssen, G.C.A.M.; Kamminga, J.D.

    2004-01-01

    In the absence of thermal stress, tensile stress in hard metal films is caused by grain boundary shrinkage and compressive stress is caused by ion peening. It is shown that the two contributions are additive. Moreover tensile stress generated at the grain boundaries does not relax by ion bombardment

  5. Rock 'n Roller Coaster

    DEFF Research Database (Denmark)

    Timmermans, Bram; Bekkers, Rudi; Bordoli, Luca

    between different types of exit, e.g. firm closure, merger and acquisition, firms leaving the industry, and firms that move abroad (Carroll and Hannan, 2000). However, it is surprising that hardly any of the long list of industry studies focus on the post exit knowledge diffusion, especially since...

  6. Boring and Sealing Rock with Directed Energy Millimeter-Waves

    Science.gov (United States)

    Woskov, P.; Einstein, H. H.; Oglesby, K.

    2015-12-01

    Millimeter-wave directed energy is being investigated to penetrate into deep crystalline basement rock formations to lower well costs and to melt rocks, metals, and other additives to seal wells for applications that include nuclear waste storage and geothermal energy. Laboratory tests have established that intense millimeter-wave (MMW) beams > 1 kW/cm2 can melt and/ or vaporize hard crystalline rocks. In principle this will make it possible to create open boreholes and a method to seal them with a glass/ceramic liner and plug formed from the original rock or with other materials. A 10 kW, 28 GHz commercial (CPI) gyrotron system with a launched beam diameter of about 32 mm was used to heat basalt, granite, limestone, and sandstone specimens to temperatures over 2500 °C to create melts and holes. A calibrated 137 GHz radiometer view, collinear with the heating beam, monitored real time peak rock temperature. A water load surrounding the rock test specimen primarily monitored unabsorbed power at 28 GHz. Power balance analysis of the laboratory observations shows that the temperature rise is limited by radiative heat loss, which would be expected to be trapped in a borehole. The analysis also indicates that the emissivity (absorption efficiency) in the radiated infrared range is lower than the emissivity at 28 GHz, giving the MMW frequency range an important advantage for rock melting. Strength tests on one granite type indicated that heating the rock initially weakens it, but with exposure to higher temperatures the resolidified black glassy product regains strength. Basalt was the easiest to melt and penetrate, if a melt leak path was provided, because of its low viscosity. Full beam holes up to about 50 mm diameter (diffraction increased beam size) were achieved through 30 mm thick basalt and granite specimens. Laboratory experiments to form a seal in an existing hole have also been carried out by melting rock and a simulated steel casing.

  7. Hard processes in hadronic interactions

    International Nuclear Information System (INIS)

    Quantum chromodynamics is today accepted as the fundamental theory of strong interactions, even though most hadronic collisions lead to final states for which quantitative QCD predictions are still lacking. It therefore seems worthwhile to take stock of where we stand today and to what extent the presently available data on hard processes in hadronic collisions can be accounted for in terms of QCD. This is one reason for this work. The second reason--and in fact its original trigger--is the search for the quark-gluon plasma in high energy nuclear collisions. The hard processes to be considered here are the production of prompt photons, Drell-Yan dileptons, open charm, quarkonium states, and hard jets. For each of these, the authors discuss the present theoretical understanding, compare the resulting predictions to available data, and then show what behavior it leads to at RHIC and LHC energies. All of these processes have the structure mentioned above: they contain a hard partonic interaction, calculable perturbatively, but also the non-perturbative parton distribution within a hadron. These parton distributions, however, can be studied theoretically in terms of counting rule arguments, and they can be checked independently by measurements of the parton structure functions in deep inelastic lepton-hadron scattering. The present volume is the work of Hard Probe Collaboration, a group of theorists who are interested in the problem and were willing to dedicate a considerable amount of their time to work on it. The necessary preparation, planning and coordination of the project were carried out in two workshops of two weeks' duration each, in February 1994 at CERN in Geneva and in July 1994 at LBL in Berkeley. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  8. Rocking and Rolling Rattlebacks

    Science.gov (United States)

    Cross, Rod

    2013-01-01

    A rattleback is a well-known physics toy that has a preferred direction of rotation. If it is spun about a vertical axis in the "wrong" direction, it will slow down, start rocking from end to end, and then spin in the opposite (i.e. preferred) direction. Many articles have been written about rattlebacks. Some are highly mathematical and…

  9. Umhlanga Rocks coastal defense

    NARCIS (Netherlands)

    De Jong, L.; De Jong, B.; Ivanova, M.; Gerritse, A.; Rietberg, D.; Dorrepaal, S.

    2014-01-01

    The eThekwini coastline is a vulnerable coastline subject to chronic erosion and damage due to sea level rise. In 2007 a severe storm caused major physical and economic damage along the coastline, proving the need for action. Umhlanga Rocks is a densely populated premium holiday destination on the e

  10. Rock solid energy solution

    International Nuclear Information System (INIS)

    Scientists believe naturally radioactive rocks below the earth's surface could provide an inexhaustible and environmentally friendly power source. And Australia could be a geological hotbed should the concept get off the ground. Despite the scale, the concept itself is simple. The Earth's reserves of heat in naturally radioactive rocks could provide an effectively inexhaustible and environmentally friendly source of power. No greenhouse gas emissions, little water usage and minimal pollution. Natural hot springs are already used to make power in some parts of the world, such as Iceland, but creating artificial hot springs by drilling deep into granite -the hardest of rocks - is a much more ambitious concept. One cubic kilometre of hot granite at 250 deg C has the stored energy equivalent of 40 million barrels of oil. In a nutshell, water is pumped into the hot zone - some 3km to 5km down in Australian conditions - and spreads through a 'reservoir' of hot, cracked rocks. Once superheated, it returns to the surface as steam through a separate production well to spin turbines and generate electricity. The water can then be recaptured and reused, with test sites around the world recovering up to around 90 per cent

  11. Slippery Rock University

    Science.gov (United States)

    Arnhold, Robert W.

    2008-01-01

    Slippery Rock University (SRU), located in western Pennsylvania, is one of 14 state-owned institutions of higher education in Pennsylvania. The university has a rich tradition of providing professional preparation programs in special education, therapeutic recreation, physical education, and physical therapy for individuals with disabilities.…

  12. A New Method for Determination of Joint Roughness Coefficient of Rock Joints

    Directory of Open Access Journals (Sweden)

    Shigui Du

    2015-01-01

    Full Text Available The joint roughness coefficient (JRC of rock joints has the characteristic of scale effect. JRC measured on small-size exposed rock joints should be evaluated by JRC scale effect in order to obtain the JRC of actual-scale rock joints, since field rock joints are hardly fully exposed or well saved. Based on the validity analysis of JRC scale effect, concepts of rate of JRC scale effect and effective length of JRC scale effect were proposed. Then, a graphic method for determination of the effective length of JRC scale effect was established. Study results show that the JRC of actual-scale rock joints can be obtained through a fractal model of JRC scale effect according to the statistically measured results of the JRC of small-size partial exposed rock joints and by the selection of fractal dimension of JRC scale effect and the determination of effective length of JRC scale effect.

  13. Application of a fuzzy analytical hierarchy process to the prediction of vibration during rock sawing

    Institute of Scientific and Technical Information of China (English)

    Mikaeil Reza; Ataei Mohammad; Yousefi Reza

    2011-01-01

    A new predictive model for evaluating the vibration of a sawing machine was developed using a new rock classification system.The predictors are machine parameters and a rock sawability index.The new rock classification system includes four major parameters of the rock:uniaxial compressive strength,abrasivity index,mean Moh's hardness,and Young's modulus.The FAHP approach was used when determining the weights of these parameters by six decision makers.Two groups of carbonate rocks were sawn using a fully-instrumented laboratory sawing rig at different feed rates and depths of cut.During the sawing trials system vibration was monitored as a measure of saw performance.Then,a new statistical model was obtained by multiple regression on the machining parameters and the rock sawability index.The model is very useful for the evaluation of the system vibration,and for selecting suitable machining parameters,from a limited set of mechanical properties.

  14. Site selection and exploration in other countries. German-Russian co-operation for developing a methodology for site investigation and selection in hard rock formations; Standortsuche und Standorterundung - Wie machen es die Anderen? Deutsch-russische Zusammenarbeit zur Entwicklung eines methodischen Ansatzes fuer die Standortsuche und Standortauswahl in Hartgesteinsformationen

    Energy Technology Data Exchange (ETDEWEB)

    Krone, J.; Jobmann, M. [DBE TECHNOLOGY GmbH (Germany); Gupalo, T. [VNIPI Promtechnologii (VNIPI PT) (Germany); Fahrenholz, C.; Brewitz, W.; Fein, E. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS) (Germany); Hammer, J. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR) (Germany)

    2003-07-01

    German and Russian scientists cooperate in two exemplary site selection programmes in the southern Ural mountains (Mayak) and central Sibiria (Nishnekans) in order to develop a methodological approach for detailed characterisation of ultimate storage sites in crystalline rock for high-activity, heat generating radioactive waste. Based on the results of earlier investigations, it will be shown how a programme for site analysis can be established on the basis of earlier site-specific safety analyses. Already in an early phase of site exploration, a selective combination of the development of a geological site model with ultimate storage planning and design and with a safety analysis will provide information on the actual extent of information required and enable appropriate site selection. (orig.) [German] An Hand von zwei Beispielen russischer Standortauswahlprogramme im Suedural (Mayak) und Zentralsibirien (Nishnekansker Granitoidmassiv) erarbeiten russische und deutsche Wissenschaftler gegenwaertig gemeinsam einen methodischen Ansatz fuer die detaillierte Standortcharakterisierung und -auswahl zur Endlagerung hochradioaktiver waermeerzeugender Abfaelle im Kristallingestein. Aufbauend auf Ergebnisse frueher Erkundungsstadien soll gezeigt werden, wie ein mittels standortspezifischer Sicherheitsanalysen begruendetes und auf daraus abgeleiteten ergaenzenden Erkundungsmassnahmen ausgerichtetes Programm zur weiteren Standorterkundung erarbeitet werden kann, um letztlich den Nachweis der Standorteignung fuehren zu koennen. Bereits in einer fruehen Phase der Standorterkundung fuehrt die zielgerichtete Verknuepfung der Earbeitung eines geologischen Standortmodells sowie der Endlageplanung und -auslegung mit der Durchfuehrung einer Sicherheitsanalyse zur Ermittung des realen Erkundungsbedarfs und zu einer begruendeten Standortauswahl. (orig.)

  15. Clay-based grout injection in crystalline rock

    International Nuclear Information System (INIS)

    In the sealing of an underground disposal facilities for the high-level radioactive waste, a concept of the clay grouting in the sealing of the underground facilities applied to the hard rock is summarized, based on the results of clay grouting experiments Japan Nuclear Cycle Development Institute (JNC) has performed. JNC performed the clay grouting experiments in-situ of the hard rock. In the experiments, clay grout slurry was injected to the fractures on the floor of the test tunnel and to the excavated damage zone around the key cut off the excavated damage zone along the tunnel. Through the results of these experiments, the injected grout slurry to the target excavated damage zone area improved the hydraulic conductivity of the target area using the injection boreholes opened from the wall of the tunnel. Regarding the adequate design of the clay grouting in the hard rock, information of the fracture characterization (scale and distribution), distribution of the excavated damage zone (hydraulic characteristics), selection of the clay material, injection technique, target area of the injection of the grout (position and region) and so on is required. (author)

  16. Superhard nanophase cutter materials for rock drilling applications

    Energy Technology Data Exchange (ETDEWEB)

    Voronov, O.; Tompa, G.; Sadangi, R.; Kear, B.; Wilson, C.; Yan, P.

    2000-06-23

    The Low Pressure-High Temperature (LPHT) System has been developed for sintering of nanophase cutter and anvil materials. Microstructured and nanostructured cutters were sintered and studied for rock drilling applications. The WC/Co anvils were sintered and used for development of High Pressure-High Temperature (HPHT) Systems. Binderless diamond and superhard nanophase cutter materials were manufactured with help of HPHT Systems. The diamond materials were studied for rock machining and drilling applications. Binderless Polycrystalline Diamonds (BPCD) have high thermal stability and can be used in geothermal drilling of hard rock formations. Nanophase Polycrystalline Diamonds (NPCD) are under study in precision machining of optical lenses. Triphasic Diamond/Carbide/Metal Composites (TDCC) will be commercialized in drilling and machining applications.

  17. Dome-shaped PDC cutters drill harder rock effectively

    International Nuclear Information System (INIS)

    This paper reports that rock mechanics and sonic travel time log data indicate that bits with convex-shaped polycrystalline diamond compact (PDC) cutters can drill harder rock formations than comparable bits with flat PDC cutters. The Dome-shaped cutters have drilled carbonate formations with sonic travel times as small as 50 μsec/ft, compared to the standard cutoff of 75 μsec/ft for flat PCD cutters. Recent field data from slim hole wells drilled in the Permian basin have shown successful applications of the 3/8-in. Dome cutter in the Grayburg dolomite with its sonic travel times as low as 50-55 μsec/ft and compressive strengths significantly greater than the standard operating range for PDC bit applications. These field data indicate that the Dome cutters can successfully drill hard rock. The convex cutter shape as good impact resistance, cuttings removal, heat dissipation, and wear resistance

  18. Development of a multivariate empirical model for predicting weak rock mass modulus

    Institute of Scientific and Technical Information of China (English)

    Kallu Raj R.; Keffeler Evan R.; Watters Robert J.; Agharazi Alireza

    2015-01-01

    Estimating weak rock mass modulus has historically proven difficult although this mechanical property is an important input to many types of geotechnical analyses. An empirical database of weak rock mass modulus with associated detailed geotechnical parameters was assembled from plate loading tests per-formed at underground mines in Nevada, the Bakhtiary Dam project, and Portugues Dam project. The database was used to assess the accuracy of published single-variate models and to develop a multivari-ate model for predicting in-situ weak rock mass modulus when limited geotechnical data are available. Only two of the published models were adequate for predicting modulus of weak rock masses over lim-ited ranges of alteration intensities, and none of the models provided good estimates of modulus over a range of geotechnical properties. In light of this shortcoming, a multivariate model was developed from the weak rock mass modulus dataset, and the new model is exponential in form and has the following independent variables:(1) average block size or joint spacing, (2) field estimated rock strength, (3) dis-continuity roughness, and (4) discontinuity infilling hardness. The multivariate model provided better estimates of modulus for both hard-blocky rock masses and intensely-altered rock masses.

  19. Joint Commission on rock properties

    Science.gov (United States)

    A joint commission on Rock Properties for Petroleum Engineers (RPPE) has been established by the International Society of Rock Mechanics and the Society of Petroleum Engineers to set up data banks on the properties of sedimentary rocks encountered during drilling. Computer-based data banks of complete rock properties will be organized for sandstones (GRESA), shales (ARSHA) and carbonates (CARCA). The commission hopes to access data sources from members of the commission, private companies and the public domain.

  20. Hard exclusive scattering in QCD

    CERN Document Server

    Gousset, T; Gousset, Thierry; Pire, Bernard

    1995-01-01

    We review the theory of hard exclusive scattering in Quantum Chromodynamics. After recalling the classical counting rules which describe the leading scale dependence of form factors and elastic reactions at fixed angle, the pedagogical example of the pion form factor is developped in some detail in order to show explicitely what factorization means in the QCD framework. The inclusion of transverse degrees of freedom leads to the discussion of Sudakov effects which are crucial for protecting the calculation from dangerous infrared regions. The picture generalizes to many hard reactions; a strategy to extract distribution amplitudes from future data is sketched. We discuss also the particular case of hadron-hadron collisions where the independent scattering mechanism dominates asymptotically and where a different factorization formula applies. We briefly present the concepts of color transparency and nuclear filtering and critically discuss the few present data on this subject.

  1. Production, performance and maintenance time observations in mixed soil-rock EPB drives

    OpenAIRE

    González Paez, Claudia; Arroyo Alvarez de Toledo, Marcos; Gens Solé, Antonio

    2015-01-01

    Mechanized excavation in soft rock has been extensively studied in the field of mining when machines such as roadheaders are used. During this time, Tunnel Boring Machines (TBMs) have been the ideal machines for working in hard rock and their application has a good empirical / theoretical basis, especially regarding the excavation efficiency. Both techniques enjoy having such broad empirical support that it lets us establish a good number of benchmarks both to guide the design of the cutti...

  2. Experimental study on the physical and chemical properties of the deep hard brittle shale

    Directory of Open Access Journals (Sweden)

    Jian Xiong

    2016-03-01

    Full Text Available In the hard brittle shale formation, rock composition, physical and chemical properties, mechanics property before and after interacting with fluid have direct relation with borehole problems, such as borehole wall collapse, mud loss, hole shrinkage. To achieve hard brittle shale micro-structure, physical–chemical properties and mechanics property, energy-dispersive X-ray diffraction (XRD, cation exchange capacity experiment and hardness test are conducted. The result of laboratory experiments indicates that, clay mineral and quartz is dominated in mineral composition. In clay mineral, illite and illite/semectite mixed layers are abundant and there is no sign of montmorillonite. Value of cation exchange capacity (CEC ranges from 102.5–330 mmol/kg and average value is 199.56 mmol/kg. High value of CEC and content of clay mineral means hard brittle shale has strong ability of hydration. The image of XRD shows well developed micro-cracks and pores, which make rock failure easily, especially when fluid invades rock inside. Shale sample soaked with anti-high temperature KCL drilling fluid on shorter immersing time has stronger strength, whereas shale sample soaked with plugging and film forming KCL drilling fluid on longer immersing time has stronger strength.

  3. Rock and mineral magnetism

    CERN Document Server

    O’Reilly, W

    1984-01-01

    The past two decades have witnessed a revolution in the earth sciences. The quantitative, instrument-based measurements and physical models of. geophysics, together with advances in technology, have radically transformed the way in which the Earth, and especially its crust, is described. The study of the magnetism of the rocks of the Earth's crust has played a major part in this transformation. Rocks, or more specifically their constituent magnetic minerals, can be regarded as a measuring instrument provided by nature, which can be employed in the service of the earth sciences. Thus magnetic minerals are a recording magnetometer; a goniometer or protractor, recording the directions of flows, fields and forces; a clock; a recording thermometer; a position recorder; astrain gauge; an instrument for geo­ logical surveying; a tracer in climatology and hydrology; a tool in petrology. No instrument is linear, or free from noise and systematic errors, and the performance of nature's instrument must be assessed and ...

  4. Uranium in alkaline rocks

    International Nuclear Information System (INIS)

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential

  5. Uranium in alkaline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

    1978-04-01

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential.

  6. Limados : Rock peruano

    OpenAIRE

    García Morete, Ramiro

    2013-01-01

    Incentivado por la corriente nuevaolera que llegaba de México, fue señalado por especialistas como pionero del punk. Aunque el plan, era tocar con lo que hubiera. Un recodo ínfimo de un período breve pero sorprendentemente poderoso, los 60 en un país que hizo del rock una expresión propia de su cultura.

  7. Deformations of fractured rock

    International Nuclear Information System (INIS)

    Results of the DBM and FEM analysis in this study indicate that a suitable rock mass for repository of radioactive waste should be moderately jointed (about 1 joint/m2) and surrounded by shear zones of the first order. This allowes for a gentle and flexible deformation under tectonic stresses and prevent the development of large cross-cutting failures in the repository area. (author)

  8. Rock pushing and sampling under rocks on Mars

    Science.gov (United States)

    Moore, H.J.; Liebes, S.; Crouch, D.S.; Clark, L.V.

    1978-01-01

    Viking Lander 2 acquired samples on Mars from beneath two rocks, where living organisms and organic molecules would be protected from ultraviolet radiation. Selection of rocks to be moved was based on scientific and engineering considerations, including rock size, rock shape, burial depth, and location in a sample field. Rock locations and topography were established using the computerized interactive video-stereophotogrammetric system and plotted on vertical profiles and in plan view. Sampler commands were developed and tested on Earth using a full-size lander and surface mock-up. The use of power by the sampler motor correlates with rock movements, which were by plowing, skidding, and rolling. Provenance of the samples was determined by measurements and interpretation of pictures and positions of the sampler arm. Analytical results demonstrate that the samples were, in fact, from beneath the rocks. Results from the Gas Chromatograph-Mass Spectrometer of the Molecular Analysis experiment and the Gas Exchange instrument of the Biology experiment indicate that more adsorbed(?) water occurs in samples under rocks than in samples exposed to the sun. This is consistent with terrestrial arid environments, where more moisture occurs in near-surface soil un- der rocks than in surrounding soil because the net heat flow is toward the soil beneath the rock and the rock cap inhibits evaporation. Inorganic analyses show that samples of soil from under the rocks have significantly less iron than soil exposed to the sun. The scientific significance of analyses of samples under the rocks is only partly evaluated, but some facts are clear. Detectable quantities of martian organic molecules were not found in the sample from under a rock by the Molecular Analysis experiment. The Biology experiments did not find definitive evidence for Earth-like living organisms in their sample. Significant amounts of adsorbed water may be present in the martian regolith. The response of the soil

  9. Exploring the relation between personality and the appreciation of rock music.

    Science.gov (United States)

    Robinson, T O; Weaver, J B; Zillmann, D

    1996-02-01

    Scores on five personality characteristics, extraversion, neuroticism, and psychoticism as well as reactive and proactive rebelliousness, and the appreciation of soft/nonrebellious and hard/rebellious rock-music videotapes were explored. After completing the personality tests, female and male undergraduates were exposed to rock-music videotapes and asked to rate various aspects of their enjoyment of each. Analysis indicated that psychoticism and reactive rebelliousness were associated with enjoyment in a parallel fashion. Specifically, respondents scoring high on psychoticism or high on reactive rebelliousness enjoyed hard/rebellious rock-music videotapes more than did their peers scoring low on psychoticism or low on reactive rebelliousness. The reverse was evident for the enjoyment of soft/nonrebellious rock-music videotapes. In contrast, scores on extraversion, neuroticism, and proactive rebelliousness were not associated with enjoyment. Gender differences emerged, however; women (n = 78) enjoyed soft/nonrebellious rock music more than did men (n = 60); and conversely, men enjoyed hard/rebellious rock music more than did women. PMID:8839317

  10. Rock index properties for geoengineering in the Paradox Basin

    International Nuclear Information System (INIS)

    Previous researchers have investigated the use of a number of rapid index tests that can be used on core samples, or in situ, to determine rock properties needed for geoengineering design, or to predict construction performance in these rock types. Selected research is reviewed, and the correlations of index tests with laboratory tests of rock properties found by the earlier investigators are discussed. The selection and testing of rock core samples from the Gibson Dome No. 1 borehole in Paradox Basin are described. The samples consist primarily of non-salt rock above salt cycle 6, but include some samples of anhydrite and salt cycle 6. The index tests included the point load test, Schmidt hammer rebound test, and abrasion hardness test. Statistical methods were used to analyze the correlations of index test data with laboratory test data of rock properties for the same core. Complete statistical results and computer-generated graphics are presented; these results are discussed in relation to the work of earlier investigations for index testing of similar rock types. Generally, fair to good correlations were obtained for predicting unconfined compressive strength and Young's modulus for sandstone and siltstone, while poorer correlations were found for limestone. This may be due to the large variability of limestone properties compared to the small number of samples. Overall, the use of index tests to assess rock properties at Paradox Basin appears to be practial for some conceptual and preliminary design needs, and the technique should prove useful at any salt repository site. However, it is likely that specific correlations should be demonstrated separately for each site, and the data base for establishing the correlations should probably include at least several hundred data points for each type

  11. Rock in Rio: forever young

    Directory of Open Access Journals (Sweden)

    Ricardo Ferreira Freitas

    2014-12-01

    Full Text Available The purpose of this article is to discuss the role of Rock in Rio: The Musical, as herald of megafestival Rock in Rio. Driven by the success that musicals have reached in Brazil, we believe that the design of this spectacle of music, dance and staging renews the brand of the rock festival, once it adds the force of young and healthy bodies to its concept. Moreover, the musical provides Rock in Rio with some distance from the controversal trilogy of sex, drugs and rock and roll, a strong mark of past festivals around the world. Thus, the musical expands the possibilities of growth for the brand.

  12. Why Are Drugs So Hard to Quit?

    Medline Plus

    Full Text Available ... Quitting drugs is hard because addiction is a brain disease. Your brain is like a control tower that sends out ... and choices. Addiction changes the signals in your brain and makes it hard to feel OK without ...

  13. Tribological characterization of selected hard coatings

    OpenAIRE

    Karlsson, Patrik

    2009-01-01

    Hard coatings are often used for protection of tool surfaces due to coating properties like low friction and high wear resistance. Even though many of the hard coatings have been tested for wear, it is important to try new wear test setups to fully understand tribological mechanisms and the potential of hard coatings. Few experiments have been performed with dual-coated systems where the sliding contact surfaces are coated with the same, or different, hard coating. The dual-coated system coul...

  14. Settlement behavior of coal mine waste in different surrounding rock conditions

    Institute of Scientific and Technical Information of China (English)

    MA Chun-de; LI Xi-bing; HU Bing-nan; CHEN Feng; XU Ji-cheng; LI Di-yuan

    2008-01-01

    In order to investigate the influence of complex conditions of in-situ surrounding rocks on the settlement behavior of nubbly coal mine waste subjected to high gravity pressure, four kinds of loading chambers made of different similar materials with different elastic moduli in experiments were used to simulate the deformation features of in-site rocks, including soft, moderate hardness, hard and extra-hard rocks. The results show that all the settlement-axial load (or axial strain-stress) curves obtained under four different surrounding rock conditions present power-exponential function feature. The final settlement of coal mine waste under the same axial load is closely related to the lumpiness gradations and the deformation behavior of chamber materials used to simulate behaviors of different in-situ surrounding rocks. In the same surrounding rock condition, the final settlement under the same maximum axial load decreases with the decrease of the proportion of larger gradation of coal mine waste. While for the same lumpiness gradation case, the settlement increases with the decrease of elastic modulus of simulated surrounding rocks and the lateral pressure induced by axial load increases with the increase of elastic modulus of loading chambers that are used to simulate different surrounding rocks. The test results also reveal that both the compaction curve and lateral pressure curve show a three-stage behavior, and the duration of each stage, which is closely related to gradations and the deformation feature of loading chamber materials, decreases with the increase of the proportion of the small size of coal mine waste and elastic modulus of the simulated rock materials.

  15. Rock bolts - Improved design and possibilities

    OpenAIRE

    Thomas-Lepine, Capucine

    2012-01-01

    SummaryRock Bolts, improved design and possibilitiesMaster thesis NTNU 2012Student : Capucine Thomas-LepineSupervisor : Leif LiaKey words : rock foundation, small concrete dam, rock mass classification, rock joints, shear strength of rock discontinuities, fully grouted passive rock bolts designMasters Thesis : “Rock bolts, improved design and possibilities” is a continuation from the Masters Thesis NTNU 2011 “Rock bolts in dams, expected capacity” by Lars Kristian Neby. In...

  16. 30 CFR 57.15002 - Hard hats.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hard hats. 57.15002 Section 57.15002 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Underground § 57.15002 Hard hats. All persons shall wear suitable hard hats when in or around a mine or...

  17. 30 CFR 56.15002 - Hard hats.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hard hats. 56.15002 Section 56.15002 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personal Protection § 56.15002 Hard hats. All persons shall wear suitable hard hats when in or around a mine or plant where falling...

  18. Research on inspection of stability of subsiding area in composite rock-mass roadway

    Institute of Scientific and Technical Information of China (English)

    来兴平

    2002-01-01

    The research concentrates mainly on the development of failure process in composite rock-mass through acoustic emission, convergence inspection, stress measurement, subside area measurement, level measurement in the process of stability and safety monitoring as well as inspecting of subside area in composite hard rock. In terms of the modern signal analysis technology, various aspects are discussed. The monitoring result and the stability of rock mass can be synthetically evaluated and inferred, and the location of acoustic origin according to the acoustic emission regularity can be successfully detected. Finally the key factors of the deformation can be inferred from in subside area.

  19. Hard Identity and Soft Identity

    Directory of Open Access Journals (Sweden)

    Hassan Rachik

    2006-04-01

    Full Text Available Often collective identities are classified depending on their contents and rarely depending on their forms. Differentiation between soft identity and hard identity is applied to diverse collective identities: religious, political, national, tribal ones, etc. This classification is made following the principal dimensions of collective identities: type of classification (univocal and exclusive or relative and contextual, the absence or presence of conflictsof loyalty, selective or totalitarian, objective or subjective conception, among others. The different characteristics analysed contribute to outlining an increasingly frequent type of identity: the authoritarian identity.

  20. Radiation Hardness Assurance (RHA) Guideline

    Science.gov (United States)

    Campola, Michael J.

    2016-01-01

    Radiation Hardness Assurance (RHA) consists of all activities undertaken to ensure that the electronics and materials of a space system perform to their design specifications after exposure to the mission space environment. The subset of interests for NEPP and the REAG, are EEE parts. It is important to register that all of these undertakings are in a feedback loop and require constant iteration and updating throughout the mission life. More detail can be found in the reference materials on applicable test data for usage on parts.

  1. Systematic hardness studies on lithium niobate crystals

    Indian Academy of Sciences (India)

    K G Subhadra; K Kishan Rao; D B Sirdeshmukh

    2000-04-01

    In view of discrepancies in the available information on the hardness of lithium niobate, a systematic study of the hardness has been carried out. Measurements have been made on two pure lithium niobate crystals with different growth origins, and a Fe-doped sample. The problem of load variation of hardness is examined in detail. The true hardness of LiNbO3 is found to be 630 ± 30 kg/mm2. The Fe-doped crystal has a larger hardness of 750 ± 50 kg/mm2.

  2. Sealing of fractured rock

    International Nuclear Information System (INIS)

    This paper consists of a presentation of the third phase of the Stripa Project. This phase was dedicated to fracture sealing. First of all it has been necessary to show that fine-grained grouts could effectively be injected in relatively fine cracks, and that the fluidity of bentonite could also be enhanced. The field tests comprised investigation of excavation-induced disturbance and attempts to seal disturbed rock, and, in separate tests, grouting of deposition holes and a natural fine-fracture zone. (TEC). 12 figs., 1 tab., 6 refs

  3. From stones to rocks

    Science.gov (United States)

    Mortier, Marie-Astrid; Jean-Leroux, Kathleen; Cirio, Raymond

    2013-04-01

    With the Aquila earthquake in 2009, earthquake prediction is more and more necessary nowadays, and people are waiting for even more accurate data. Earthquake accuracy has increased in recent times mainly thanks to the understanding of how oceanic expansion works and significant development of numerical seismic prediction models. Despite the improvements, the location and the magnitude can't be as accurate as citizen and authorities would like. The basis of anticipating earthquakes requires the understanding of: - The composition of the earth, - The structure of the earth, - The relations and movements between the different parts of the surface of the earth. In order to answer these questions, the Alps are an interesting field for students. This study combines natural curiosity about understanding the predictable part of natural hazard in geology and scientific skills on site: observing and drawing landscape, choosing and reading a representative core drilling, replacing the facts chronologically and considering the age, the length of time and the strength needed. This experience requires students to have an approach of time and space radically different than the one they can consider in a classroom. It also limits their imagination, in a positive way, because they realize that prediction is based on real data and some of former theories have become present paradigms thanks to geologists. On each location the analyzed data include landscape, core drilling and the relation established between them by students. The data is used by the students to understand the meaning, so that the history of the formation of the rocks tells by the rocks can be explained. Until this year, the CBGA's perspective regarding the study of the Alps ground allowed students to build the story of the creation and disappearance of the ocean, which was a concept required by French educational authorities. But not long ago, the authorities changed their scientific expectations. To meet the

  4. Rock mechanics data package

    International Nuclear Information System (INIS)

    This data package provides a summary of available laboratory and in situ stress field test results from site characterization investigations by the Basalt Waste Isolation Project Modeling and Analysis Group. The objective is to furnish rock mechanics information for use by Rockwell Hanford Operations and their subcontractors in performance assessment and engineering studies. This release includes Reference Repository Location (RRL) site specific laboratory and field test data from boreholes RRL-2, RRL-6, and RRL-14 as well as previous Hanford wide data available as of April, 1985. 25 refs., 9 figs., 16 tabs

  5. Hard Fault Analysis of Trivium

    CERN Document Server

    Yupu, Hu; Yiwei, Zhang

    2009-01-01

    Fault analysis is a powerful attack to stream ciphers. Up to now, the major idea of fault analysis is to simplify the cipher system by injecting some soft faults. We call it soft fault analysis. As a hardware-oriented stream cipher, Trivium is weak under soft fault analysis. In this paper we consider another type of fault analysis of stream cipher, which is to simplify the cipher system by injecting some hard faults. We call it hard fault analysis. We present the following results about such attack to Trivium. In Case 1 with the probability not smaller than 0.2396, the attacker can obtain 69 bits of 80-bits-key. In Case 2 with the probability not smaller than 0.2291, the attacker can obtain all of 80-bits-key. In Case 3 with the probability not smaller than 0.2291, the attacker can partially solve the key. In Case 4 with non-neglectable probability, the attacker can obtain a simplified cipher, with smaller number of state bits and slower non-linearization procedure. In Case 5 with non-neglectable probability,...

  6. Fossils, rocks, and time

    Science.gov (United States)

    Edwards, Lucy E.; Pojeta, John

    1999-01-01

    We study our Earth for many reasons: to find water to drink or oil to run our cars or coal to heat our homes, to know where to expect earthquakes or landslides or floods, and to try to understand our natural surroundings. Earth is constantly changing--nothing on its surface is truly permanent. Rocks that are now on top of a mountain may once have been at the bottom of the sea. Thus, to understand the world we live on, we must add the dimension of time. We must study Earth's history. When we talk about recorded history, time is measured in years, centuries, and tens of centuries. When we talk about Earth history, time is measured in millions and billions of years. Time is an everyday part of our lives. We keep track of time with a marvelous invention, the calendar, which is based on the movements of Earth in space. One spin of Earth on its axis is a day, and one trip around the Sun is a year. The modern calendar is a great achievement, developed over many thousands of years as theory and technology improved. People who study Earth's history also use a type of calendar, called the geologic time scale. It looks very different from the familiar calendar. In some ways, it is more like a book, and the rocks are its pages. Some of the pages are torn or missing, and the pages are not numbered, but geology gives us the tools to help us read this book.

  7. Rock Properties Model

    International Nuclear Information System (INIS)

    The purpose of this model report is to document the Rock Properties Model version 3.1 with regard to input data, model methods, assumptions, uncertainties and limitations of model results, and qualification status of the model. The report also documents the differences between the current and previous versions and validation of the model. The rock properties model provides mean matrix and lithophysae porosity, and the cross-correlated mean bulk density as direct input to the ''Saturated Zone Flow and Transport Model Abstraction'', MDL-NBS-HS-000021, REV 02 (BSC 2004 [DIRS 170042]). The constraints, caveats, and limitations associated with this model are discussed in Section 6.6 and 8.2. Model validation accomplished by corroboration with data not cited as direct input is discussed in Section 7. The revision of this model report was performed as part of activities being conducted under the ''Technical Work Plan for: The Integrated Site Model, Revision 05'' (BSC 2004 [DIRS 169635]). The purpose of this revision is to bring the report up to current procedural requirements and address the Regulatory Integration Team evaluation comments. The work plan describes the scope, objectives, tasks, methodology, and procedures for this process

  8. A smart rock

    Science.gov (United States)

    Pressel, Phil

    2014-12-01

    This project was to design and build a protective weapon for a group of associations that believed in aliens and UFO's. They collected enough contributions from societies and individuals to be able to sponsor and totally fund the design, fabrication and testing of this equipment. The location of this facility is classified. It also eventually was redesigned by the Quartus Engineering Company for use at a major amusement park as a "shoot at targets facility." The challenge of this project was to design a "smart rock," namely an infrared bullet (the size of a gallon can of paint) that could be shot from the ground to intercept a UFO or any incoming suspicious item heading towards the earth. Some of the challenges to design this weapon were to feed cryogenic helium at 5 degrees Kelvin from an inair environment through a unique rotary coupling and air-vacuum seal while spinning the bullet at 1500 rpm and maintain its dynamic stability (wobble) about its spin axis to less than 10 micro-radians (2 arc seconds) while it operated in a vacuum. Precision optics monitored the dynamic motion of the "smart rock."

  9. Rock Properties Model

    Energy Technology Data Exchange (ETDEWEB)

    C. Lum

    2004-09-16

    The purpose of this model report is to document the Rock Properties Model version 3.1 with regard to input data, model methods, assumptions, uncertainties and limitations of model results, and qualification status of the model. The report also documents the differences between the current and previous versions and validation of the model. The rock properties model provides mean matrix and lithophysae porosity, and the cross-correlated mean bulk density as direct input to the ''Saturated Zone Flow and Transport Model Abstraction'', MDL-NBS-HS-000021, REV 02 (BSC 2004 [DIRS 170042]). The constraints, caveats, and limitations associated with this model are discussed in Section 6.6 and 8.2. Model validation accomplished by corroboration with data not cited as direct input is discussed in Section 7. The revision of this model report was performed as part of activities being conducted under the ''Technical Work Plan for: The Integrated Site Model, Revision 05'' (BSC 2004 [DIRS 169635]). The purpose of this revision is to bring the report up to current procedural requirements and address the Regulatory Integration Team evaluation comments. The work plan describes the scope, objectives, tasks, methodology, and procedures for this process.

  10. Rock critics as 'Mouldy Modernists'

    Directory of Open Access Journals (Sweden)

    Becky Shepherd

    2011-09-01

    Full Text Available Contemporary rock criticism appears to be firmly tied to the past. The specialist music press valorise rock music of the 1960s and 1970s, and new emerging artists are championed for their ‘retro’ sounding music by journalists who compare the sound of these new artists with those included in the established ‘canon’ of rock music. This article examines the narrative tropes of authenticity and nostalgia that frame the retrospective focus of this contemporary rock writing, and most significantly, the maintenance of the rock canon within contemporary popular culture. The article concludes by suggesting that while contemporary rock criticism is predominately characterised by nostalgia, this nostalgia is not simply a passive romanticism of the past. Rather, this nostalgia fuels a process of active recontextualisation within contemporary popular culture.

  11. Cataclastic effects in rock salt laboratory and in situ measurements

    International Nuclear Information System (INIS)

    The aim of the research is the determination of eventual cataclastic effects in environmental rock salt of a heated part of a vertical deep test bore hole, a model for HLW disposal. Known cataclastic systems from hard rock mining and rock salt mines will form the starting point for the explanation of convergence of underground cavity walls. In rock salt, however, different elements seem to prevail: crystal plasticity and micro-cataclasis. The environmental measurements at the deep bore hole have to be carried out from a distance. To this end the acoustic micro-seismic method will be a suitable one. The appropriate equipment for micro-seismic cross hole measurement is designed, constructed and tested in the laboratory as well as underground. Acoustic velocity data form a crucial point. A micro-seismic acoustic P-wave model, adapted to the process of structural changes, is developed. P-wave velocity measurements in rock salt cubes in the laboratory are described. An underground cross hole measurement in the wall of a gallery with semi-circular section is treated and analysed. A conclusion was that, in this case, no macro-cataclasis (systematic large fractures) will be involved in the process of gallery convergence, but that the mechanism proved to be a combination of crystal plasticity and micro-cataclasis. The same mechanism might be expected to be present in the environmental rock salt of the HLW-disposal deep bore hole. As a result this environmental rock salt might be expected to be impermeable. A plan for the application of the developed equipment during the heating test on the ECN-deep-bore-hole is shown. A theory on ''disking'' or ''rim cracks'' is presented in an annex

  12. [Hearing disorders and rock music].

    Science.gov (United States)

    Lindhardt, Bjarne Orskov

    2008-12-15

    Only few studies have investigated the frequency of hearing disorders in rock musicians. Performing rock music is apparently associated with a hearing loss in a fraction of musicians. Tinnitus and hyperacusis are more common among rock musicians than among the background population. It seems as if some sort of resistance against further hearing loss is developed over time. The use of ear protection devices have not been studied systematically but appears to be associated with diminished hearing loss. PMID:19128557

  13. True Triaxial Strength and Failure Modes of Cubic Rock Specimens with Unloading the Minor Principal Stress

    Science.gov (United States)

    Li, Xibing; Du, Kun; Li, Diyuan

    2015-11-01

    True triaxial tests have been carried out on granite, sandstone and cement mortar using cubic specimens with the process of unloading the minor principal stress. The strengths and failure modes of the three rock materials are studied in the processes of unloading σ 3 and loading σ 1 by the newly developed true triaxial test system under different σ 2, aiming to study the mechanical responses of the rock in underground excavation at depth. It shows that the rock strength increases with the raising of the intermediate principal stress σ 2 when σ 3 is unloaded to zero. The true triaxial strength criterion by the power-law relationship can be used to fit the testing data. The "best-fitting" material parameters A and n ( A > 1.4 and n < 1.0) are almost located in the same range as expected by Al-Ajmi and Zimmerman (Int J Rock Mech Min Sci 563 42(3):431-439, 2005). It indicates that the end effect caused by the height-to-width ratio of the cubic specimens will not significantly affect the testing results under true triaxial tests. Both the strength and failure modes of cubic rock specimens under true triaxial unloading condition are affected by the intermediate principal stress. When σ 2 increases to a critical value for the strong and hard rocks (R4, R5 and R6), the rock failure mode may change from shear to slabbing. However, for medium strong and weak rocks (R3 and R2), even with a relatively high intermediate principal stress, they tend to fail in shear after a large amount of plastic deformation. The maximum extension strain criterion Stacey (Int J Rock Mech Min Sci Geomech Abstr 651 18(6):469-474, 1981) can be used to explain the change of failure mode from shear to slabbing for strong and hard rocks under true triaxial unloading test condition.

  14. -wave velocity test for assessment of geotechnical properties of some rock materials

    Indian Academy of Sciences (India)

    Saffet Yagiz

    2011-07-01

    -wave velocity test, a non-destructive and easy method to apply in both field and laboratory conditions, has increasingly been conducted to determine the geotechnical properties of rock materials. The aim of this study is to predict the rock properties including the uniaxial compressive strength, Schmidt hardness, modulus of elasticity, water absorption and effective porosity, slake durability index, saturated and dry density of rock using -wave velocity (p). For this purpose geotechnical properties of nine different rock types were determined in the laboratory and their mineralogical composition examined using thin section analysis. Utilizing the generated data, sets of empirical equations were developed between p and relevant quantified rock parameters. The validity of the obtained empirical equations was confirmed using statistical analysis. It is evident that rock texture and mineralogical compositions affect the geotechnical properties of rock materials. Therefore, the best relationship obtained between both E and UCS with p in the correlation coefficient of 0.92 and 0.95 in that order. It is concluded that p could be practically used for estimating the measured rock properties except dry and saturated density of rocks ( = 0.58 and 0.46 respectively).

  15. Electromagnetic emissions during rock blasting

    Science.gov (United States)

    O'Keefe, S. G.; Thiel, D. V.

    1991-05-01

    Radio emissions during quarry blasting have been recorded in the audio frequency band. Three distinct mechanisms are suggested to explain the observed results; rock fracture at the time of the explosion, charged rocks discharging on impact with the pit floor and micro-fracture of the remaining rock wall due to pressure adjustment of the bench behind the blast. The last mechanism was evident by a train of discrete impulses recorded for up to one minute after the blast. It is assumed that during this time the rock behind the blast was subjected to a significant change in pressure. This may be related to ELF observations during earthquakes.

  16. Hard-gapped holographic superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Pallab, E-mail: pallab@phas.ubc.c [Department of Physics and Astronomy University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); He Jianyang, E-mail: jyhe@phas.ubc.c [Department of Physics and Astronomy University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Mukherjee, Anindya, E-mail: anindya@phas.ubc.c [Department of Physics and Astronomy University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Shieh, H.-H., E-mail: shieh@phas.ubc.c [Department of Physics and Astronomy University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Perimeter Institute for Theoretical Physics, 31 Caroline Street North Waterloo, Ontario, N2L 2Y5 (Canada)

    2010-05-17

    In this work we discuss the zero temperature limit of a 'p-wave' holographic superconductor. The bulk description consists of a non-Abelian SU(2) gauge fields minimally coupled to gravity. We numerically construct the zero temperature solution which is the gravity dual of the superconducting ground state of the 'p-wave' holographic superconductors. The solution is a smooth soliton with zero horizon size and shows an emergent conformal symmetry in the IR. We found the expected superconducting behavior. Using the near horizon analysis we show that the system has a 'hard gap' for the relevant gauge field fluctuations. At zero temperature the real part of the conductivity is zero for an excitation frequency less than the gap frequency. This is in contrast with what has been observed in similar scalar-gravity-gauge systems (holographic superconductors). We also discuss the low but finite temperature behavior of our solution.

  17. Determining dynamical equations is hard

    CERN Document Server

    Cubitt, Toby S; Wolf, Michael M

    2010-01-01

    The behaviour of any physical system is governed by its underlying dynamical equations--the differential equations describing how the system evolves with time--and much of physics is ultimately concerned with discovering these dynamical equations and understanding their consequences. At the end of the day, any such dynamical law is identified by making measurements at different times, and computing the dynamical equation consistent with the acquired data. In this work, we show that, remarkably, this process is a provably computationally intractable problem (technically, it is NP-hard). That is, even for a moderately complex system, no matter how accurately we have specified the data, discovering its dynamical equations can take an infeasibly long time (unless P=NP). As such, we find a complexity-theoretic solution to both the quantum and the classical embedding problems; the classical version is a long-standing open problem, dating from 1937, which we finally lay to rest.

  18. Rock.XML - Towards a library of rock physics models

    Science.gov (United States)

    Jensen, Erling Hugo; Hauge, Ragnar; Ulvmoen, Marit; Johansen, Tor Arne; Drottning, Åsmund

    2016-08-01

    Rock physics modelling provides tools for correlating physical properties of rocks and their constituents to the geophysical observations we measure on a larger scale. Many different theoretical and empirical models exist, to cover the range of different types of rocks. However, upon reviewing these, we see that they are all built around a few main concepts. Based on this observation, we propose a format for digitally storing the specifications for rock physics models which we have named Rock.XML. It does not only contain data about the various constituents, but also the theories and how they are used to combine these building blocks to make a representative model for a particular rock. The format is based on the Extensible Markup Language XML, making it flexible enough to handle complex models as well as scalable towards extending it with new theories and models. This technology has great advantages as far as documenting and exchanging models in an unambiguous way between people and between software. Rock.XML can become a platform for creating a library of rock physics models; making them more accessible to everyone.

  19. Rock the Globe

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    Created in 2005, the Swiss rock band "Wind of Change" is now candidate for the Eurovision Song Contest 2011 with a new song " Night & Light " with the music video filmed at CERN.   With over 20 gigs under their belt and two albums already released, the five members of the band (Alex Büchi, vocals; Arthur Spierer, drums; David Gantner, bass; Romain Mage and Yannick Gaudy, guitar) continue to excite audiences. For their latest composition "Night & Light", the group filmed their music video in the Globe of Science and Innovation. Winning the Eurovision contest would be a springboard in their artistic career for these young musicians. The selection results will be available December 11, 2010.      

  20. Rock and soil rheology

    International Nuclear Information System (INIS)

    The aim of the Euromech Colloquium 196 devoted to Rock and Soil Rheology is to review some of the main results obtained in the last years in this field of research and also to formulate some of the major not yet solved problems which are now under consideration. Exchange of opinions and scientific discussions are quite helpful mainly in those areas where some approaches are controversial and the progress made is quite fast. That is especially true for the rheology of geomaterials, domain of great interest for mining and petroleum engineers, engineering geology, seismology, geophysics, civil engineering, nuclear and industrial waste storage, geothermal energy storage, caverns for sports, culture, telecommunications, storage of goods and foodstuffs (cold, hot and refrigerated storages), underground oil and natural gas reservoirs etc. Some of the last obtained results are mentioned in the present volume. (orig./HP)

  1. Geoelectrical Classification of Gypsum Rocks

    Science.gov (United States)

    Guinea, Ander; Playà, Elisabet; Rivero, Lluís; Himi, Mahjoub; Bosch, Ricard

    2010-12-01

    Gypsum rocks are widely exploited in the world as industrial minerals. The purity of the gypsum rocks (percentage in gypsum mineral in the whole rock) is a critical factor to evaluate the potential exploitability of a gypsum deposit. It is considered than purities higher than 80% in gypsum are required to be economically profitable. Gypsum deposits have been studied with geoelectrical methods; a direct relationship between the electrical resistivity values of the gypsum rocks and its lithological composition has been established, with the presence of lutites being the main controlling factor in the geoelectrical response of the deposit. This phenomenon has been quantified in the present study, by means of a combination of theoretical calculations, laboratory measurements and field data acquisition. Direct modelling has been performed; the data have been inverted to obtain the mean electrical resistivity of the models. The laboratory measurements have been obtained from artificial gypsum-clay mixture pills, and the electrical resistivity has been measured using a simple electrical circuit with direct current power supply. Finally, electrical resistivity tomography data have been acquired in different evaporite Tertiary basins located in North East Spain; the selected gypsum deposits have different gypsum compositions. The geoelectrical response of gypsum rocks has been determined by comparing the resistivity values obtained from theoretical models, laboratory tests and field examples. A geoelectrical classification of gypsum rocks defining three types of gypsum rocks has been elaborated: (a) Pure Gypsum Rocks (>75% of gypsum content), (b) Transitional Gypsum Rocks (75-55%), and (c) Lutites and Gypsum-rich Lutites (800 ohm.m, can be exploited as industrial rocks. The methodology used could be applied in other geoelectrical rock studies, given that this relationship between the resistive particles embedded within a conductive matrix depends on the connectivity of the

  2. Composition and method for cleaning hydrocarbon oil from hard surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Blezard, M.; Mcallister, W.H.

    1983-09-28

    Hydrocarbon oils are cleaned from hard, inorganic surfaces by the application of an aqueous solution, such as seawater, containing a mixture of alkoxylated alcohol, carboxylic acid, alkyl phenol, or nonionic phosphate ester, with an alkyl mono- or di-ethanolamide or an ethoxylated or polyethoxylated alkyl mono- or di-ethanolamide. The method is of particular value for cleaning drilling oil from rock cuttings in offshore drilling operations, such as cold North Sea installations. Specific examples are a C10 primary alcohol, which is ethoxylated with 5 moles of ethylene oxide, mixed with a coconut diethanolamide. Typically, the mixture is supplied as a concentrate which is dissolved in, or diluted with, water to provide the cleansing solution at the site of the rig. 21 claims.

  3. Rock and drugs: multiliteracies and an aesthetics of violence for teenagers in school

    Directory of Open Access Journals (Sweden)

    Vera Helena Gomes Wielewicki

    2014-08-01

    Full Text Available Current study discusses an approach of hard rock, in English, for high school students, from a multimodal perspective. The songs are analyzed in terms of their musicality and literariness and hard rock is considered a historically constituted complex cultural movement. The aesthetics of violence, present in the rock’n’roll scenario, specifically focused on the themes of drugs and alcohol abuse, is analyzed from the perspective of multiliteracies, for the development of teenagers’ critical education. The paper is theoretically based on theory by Lévy (2010, Kress (2000 and Kalantzis and Cope (2000 for multiliteracy concepts and on Walser (1993 for the criticism on the musical language. Songs by the USA rock bands Metallica and Guns N’Roses are discussed.

  4. A new approach to local hardness

    CERN Document Server

    Gal, T; De Proft, F; Torrent-Sucarrat, M

    2011-01-01

    The applicability of the local hardness as defined by the derivative of the chemical potential with respect to the electron density is undermined by an essential ambiguity arising from this definition. Further, the local quantity defined in this way does not integrate to the (global) hardness - in contrast with the local softness, which integrates to the softness. It has also been shown recently that with the conventional formulae, the largest values of local hardness do not necessarily correspond to the hardest regions of a molecule. Here, in an attempt to fix these drawbacks, we propose a new approach to define and evaluate the local hardness. We define a local chemical potential, utilizing the fact that the chemical potential emerges as the additive constant term in the number-conserving functional derivative of the energy density functional. Then, differentiation of this local chemical potential with respect to the number of electrons leads to a local hardness that integrates to the hardness, and possesse...

  5. Soft And Hard Skills of Social Worker

    OpenAIRE

    HANTOVÁ, Libuše

    2011-01-01

    The work deals with soft and hard skills relevant to the profession of social worker. The theoretical part at first evaluates and analyzes important soft and hard skills necessary for people working in the field of social work. Then these skills are compared. The practical part illustrates the use of soft and hard skills in practice by means of model scenes and deals with the preferences in three groups of people ? students of social work, social workers and people outside the sphere, namely ...

  6. Shock Waves in Dense Hard Disk Fluids

    OpenAIRE

    Sirmas, Nick; Tudorache, Marion; Barahona, Javier; Radulescu, Matei I.

    2011-01-01

    Media composed of colliding hard disks (2D) or hard spheres (3D) serve as good approximations for the collective hydrodynamic description of gases, liquids and granular media. In the present study, the compressible hydrodynamics and shock dynamics are studied for a two-dimensional hard-disk medium at both the continuum and discrete particle level descriptions. For the continuum description, closed form analytical expressions for the inviscid hydrodynamic description, shock Hugoniot, isentropi...

  7. Physical vs. Mathematical Models in Rock Mechanics

    Science.gov (United States)

    Morozov, I. B.; Deng, W.

    2013-12-01

    empirical time-dependent bulk modulus can be formally constructed, and yet the physical significance of this modulus is limited. The asymptotic (initial and final) levels of this modulus represent the adiabatic and isothermal elastic moduli of the material, whereas the transition between these levels is arbitrary and depends on the type of deformations and thermal insulation of the specimen. For the dynamic loading experiment 4), the stress-strain phase lag is proportional to the difference between the adiabatic and isothermal moduli, but this lag also depends on external factors such as the thermal relaxation time and frequency of the loading force. Overall, although the correspondence principle formally applies to a thermoelastic cylinder, it is not entirely due to the material, cannot be assumed a priori, should not replace the full physical solution, and can hardly be used to extrapolate the behavior of the rock to geologic spatial and time scales. Similar conclusions likely apply to spatial averaging of anelastic microstructures.

  8. Preparation and Properties of High Hardness and Oxidation Resisting Coating Using Electric Arc Spray

    Institute of Scientific and Technical Information of China (English)

    LIZhuo-xin; CUILi; WANGJiang-ping; TANGChun-tian

    2004-01-01

    A coating with high hardness, wear and oxidation resistance was prepared by electric arc spray. The hardness, bonding strength, abrasive wear and values of porosity and oxidation resistance of the coating were investigated. The microstructures and function of Cr3C2 of the coating were analyzed. The results showed surface Rockness Hardness HR30 reached 72.5 and average bond strength reached 49.1Mpa. Also porosity value was less than 2%. In addition, it was found from the comparison between the coating and 45CT coating that, oxidation resistance of the coating was less than that of 45CT, but the abrasive wear of the coating was obvious better than that of 45CT.

  9. Preparation and Properties of High Hardness and Oxidation Resisting Coating Using Electric Arc Spray

    Institute of Scientific and Technical Information of China (English)

    LI Zhuo-xin; CUI Li; WANG Jiang-ping; TANG Chun-tian

    2004-01-01

    A coating with high hardness, wear and oxidation resistance was prepared by electric arc spray. The hardness,bonding strength, abrasive wear and values of porosity and oxidation resistance of the coating were investigated. The microstructures and function of Cr3C2 of the coating were analyzed. The results showed surface Rockness Hardness HR30 reached 72.5 and average bond strength reached 49.1Mpa. Also porosity value was less than 2%. In addition, it was found from the comparison between the coating and 45CT coating that, oxidation resistance of the coating was less than that of 45CT, but the abrasive wear of the coating was obvious better than that of 45CT.

  10. Rock Segmentation through Edge Regrouping

    Science.gov (United States)

    Burl, Michael

    2008-01-01

    Rockster is an algorithm that automatically identifies the locations and boundaries of rocks imaged by the rover hazard cameras (hazcams), navigation cameras (navcams), or panoramic cameras (pancams). The software uses edge detection and edge regrouping to identify closed contours that separate the rocks from the background.

  11. Rock Art in Kurdistan Iran

    Directory of Open Access Journals (Sweden)

    Jamal Lahafian

    2013-12-01

    Full Text Available Kurdistan, with great potential and prehistoric resources, has numerous petroglyphs in different areas of the province. During the last 14 years of extensive field study, more than 30 sites of rock art have been identified and introduced by the author. In this article, we summarize these rock art areas in Iranian Kurdistan.

  12. Rock Art in Kurdistan Iran

    OpenAIRE

    Jamal Lahafian

    2013-01-01

    Kurdistan, with great potential and prehistoric resources, has numerous petroglyphs in different areas of the province. During the last 14 years of extensive field study, more than 30 sites of rock art have been identified and introduced by the author. In this article, we summarize these rock art areas in Iranian Kurdistan.

  13. Origin of beach-stranded tars from source rocks indigeneous to Seychelles

    Energy Technology Data Exchange (ETDEWEB)

    Plummer, P.S. [Seychelles National Oil Co., Mahe (South Africa)

    1996-03-01

    Tarballs have been found stranded as traction deposits on a beach on northwest Mahe Island, Seychelles, with every ebbing tide. Weekly collections from mid-1993 to mid-1994 gathered nearly 4750 samples of two types of tar: a dominant black malleable tar and a less common brownish-black hard tar. Both tars represent moderately degraded extracts of crude oils seemingly derived from mature source rocks dominated by a combination of oil-prone phytoplanktonic and algal organic matter over gas-prone land-plant organic matter. Source rock deposition occurred principally in paralic to open-marine environments. The presence of minor oleanane and bicadinane, and a general preponderance of diasteranes and tricyclic terpanes in the hard tar suggest derivation from a Late Cretaceous clastic source rock with possible carbonate interbeds. By contrast, no samples of the malleable tar contain oleanane or bicadinane, but all contain significant norhopane and tetracyclic terpanes, which, along with significant sulfur and low diasterane contents, indicate derivation from a carbonate source rock of perhaps pre-Late Cretaceous age. Additionally, maturity and limited geochemical data from proven and potential source rocks present in the offshore wells enable the malleable and hard tars to be equated with specific units in the Seychelles stratigraphy; the malleable tar is seemingly derived from a Middle Jurassic carbonate of Tethyan affinity and the hard tar possibly originated from either Campanian or Maastrichtian-Paleocene shales. These tars are thus concluded to be natural seepage products derived from source rocks indigenous to Seychelles, and their persistent beach stranding significantly reduces the risk of hydrocarbon exploration in this frontier province.

  14. Workshop on hydrology of crystalline basement rocks

    Energy Technology Data Exchange (ETDEWEB)

    Davis, S.N. (comp.)

    1981-08-01

    This workshop covered the following subjects: measurements in relatively shallow boreholes; measurement and interpretation of data from deep boreholes; hydrologic properties of crystalline rocks as interpreted by geophysics and field geology; rock mechanics related to hydrology of crystalline rocks; the possible contributions of modeling to the understanding of the hydrology of crystalline rocks; and geochemical interpretations of the hydrology of crystalline rocks. (MHR)

  15. Rock suitability classification RSC 2012

    Energy Technology Data Exchange (ETDEWEB)

    McEwen, T. (ed.) [McEwen Consulting, Leicester (United Kingdom); Kapyaho, A. [Geological Survey of Finland, Espoo (Finland); Hella, P. [Saanio and Riekkola, Helsinki (Finland); Aro, S.; Kosunen, P.; Mattila, J.; Pere, T.

    2012-12-15

    This report presents Posiva's Rock Suitability Classification (RSC) system, developed for locating suitable rock volumes for repository design and construction. The RSC system comprises both the revised rock suitability criteria and the procedure for the suitability classification during the construction of the repository. The aim of the classification is to avoid such features of the host rock that may be detrimental to the favourable conditions within the repository, either initially or in the long term. This report also discusses the implications of applying the RSC system for the fulfilment of the regulatory requirements concerning the host rock as a natural barrier and the site's overall suitability for hosting a final repository of spent nuclear fuel.

  16. Rock suitability classification RSC 2012

    International Nuclear Information System (INIS)

    This report presents Posiva's Rock Suitability Classification (RSC) system, developed for locating suitable rock volumes for repository design and construction. The RSC system comprises both the revised rock suitability criteria and the procedure for the suitability classification during the construction of the repository. The aim of the classification is to avoid such features of the host rock that may be detrimental to the favourable conditions within the repository, either initially or in the long term. This report also discusses the implications of applying the RSC system for the fulfilment of the regulatory requirements concerning the host rock as a natural barrier and the site's overall suitability for hosting a final repository of spent nuclear fuel

  17. Seismic properties of polyphase rocks

    Science.gov (United States)

    Wang, Qin

    2005-11-01

    Knowledge about the seismic properties of polyphase rocks is fundamental for interpreting seismic refraction and reflection data and for establishing lithospheric structure and composition models. This study aims to obtain more precise relationships between seismic properties of rocks and controlling factors (e.g., pressure, temperature, mineralogical and chemical compositions, microstructure of rocks), particularly for those rocks imprinted by ultrahigh-pressure (UHP) metamorphism. These relationships will be very helpful to extrapolate calculated and measured seismic properties of rocks to depths of interest and to engender interpretations relevant to petrological composition and tectonic process. An Internet Database of Rock Seismic Properties (DRSP) was set up and a Handbook of Seismic Properties of Minerals, Rocks and Ores was published. They comprise almost all data available in the literature during the past 4 decades and can serve as a convenient, comprehensive and concise information source on physical properties of rocks to the earth sciences and geotechnical communities. Statistical results of the DRSP reveal the dependence of seismic properties on density, porosity, humidity, and mineralogical and chemical compositions. Using 16 different averaging methods, we calculated P-wave velocities of 696 dry samples according to the volume fraction and elastic constants of each constituent mineral. Although only 22 common minerals were taken into account in the computation, the calculated P-wave velocities agree well with laboratory values measured at about 300 MPa, where most microcracks are closed and the mean Vp of a polymineralic rock is exclusively controlled by its modal composition. However, none of these mixture rules can simultaneously fit measured P-wave velocities for all lithologies or at all pressures. Therefore, more prudence is required in selecting an appropriate mixture rule for calculation of seismic velocities of different rock types.

  18. 30 CFR 77.1710-1 - Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distinctively colored hard hats or hard caps... Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively different in color from those worn by experienced miners shall be worn...

  19. 30 CFR 75.1720-1 - Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distinctively colored hard hats, or hard caps... STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1720-1 Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively different in...

  20. Research on Mechanism of Rock Burst Generation and Development for High Stress Rock Tunnels

    Institute of Scientific and Technical Information of China (English)

    高全臣; 赫建明; 王代华

    2001-01-01

    Through the investigation and analysis of high stress distribution in surrounding rock during the excavation of rock tunnels,the key factors to cause rock burst and the mechanism of rock burst generation and development are researched. The result shows that the scale and range of rock burst are related with elastic deformation energy storied in rock mass and the characteristics of unloading stress waves. The measures of preventing from rock burst for high stress rock tunnels are put forward.

  1. Hard disks with SCSI interface

    CERN Document Server

    Denisov, O Yu

    1999-01-01

    The testing of 20 models of hard SCSI-disks is carried out: the Fujitsu MAE3091LP; the IBM DDRS-39130, DGHS-318220, DNES-318350, DRHS-36V and DRVS-18V; the Quantum Atlas VI 18.2; the Viking 11 9.1; the Seagate ST118202LW, ST118273LW, ST118273W, ST318203LW, ST318275LW, ST34520W, ST39140LW and ST39173W; and the Western Digital WDE9100-0007, WDE9100-AV0016, WDE9100-AV0030 and WDE9180-0048. All tests ran under the Windows NT 4.0 workstation operating system with Service Pack 4, under video mode with 1024*768 pixel resolution, 32- bit colour depth and V-frequency equal to 85 Hz. The detailed description and characteristics of SCSI stores are presented. Test results (ZD Winstone 99 and ZD WinBench 99 tests) are given in both table and diagram (disk transfer rate) forms. (0 refs).

  2. Radiation Hardness of Trigger Electronics

    Science.gov (United States)

    Zawisza, Irene; Safonov, Alexei; Gilmore, Jason; Khotilovich, Vadim

    2011-10-01

    As the maximum intensity of particle accelerators increases, probing the most basic questions of the Universe, detectors and electronics must be designed to insure reliability in high-radiation environments. As the Large Hadron Collider (LHC) beam intensity is increased, it is necessary to upgrade the electronics in the Compact Muon Solenoid (CMS). To select interesting events, CMS utilizes fast electronics, which are installed in the experimental cavern. However, much higher post-upgrade levels of radiation in the cavern set tight requirements on the radiation hardness of the new electronics. Damaging effects of high and low energy radiation leads to disruption of digital circuits and accumulated degradation of silicon components. Quantifying the radiation exposure is required for the design of a radiation-tolerant system, but current simulation studies suffer from large uncertainties. We compare simulation predictions with measured performance in two different experimental studies, which evaluate component performance for pre and post irradiation determining the survivability of electronics in the harsh CMS environment. Funded by DOE and NSF-REU Program.

  3. Quantitative geophysics in permafrost rock walls and their explanatory power for geomechanics

    Science.gov (United States)

    Krautblatter, M.; Dräbing, D.; Funk, D.; Kemna, A.

    2012-12-01

    An increasing number of rock falls has been reported for permafrost-affected rockwalls in the last two decades. The anticipation of the hazard induced by permafrost rock slope failure requires monitoring of thermal and hydrological regimes and geomechanical properties inside the rock mass and quantitative geophysics could provide certain information on all of them. Electrical resistivity tomography (ERT) in frozen rock walls could become a key method for such investigations since freezing and sub-freezing temperature changes induce significant and recognizable changes in resistivity. Testing temperature-resistivity T-ρ relationships from a double-digit number of low-porosity sedimentary, metamorphic and igneous rocks from Alpine and Arctic permafrost rockwalls in the laboratory, we found evidence that exponential T-ρ paths developed by McGinnis et al. (1973) do not describe the resistivity behaviour of hard rocks undergoing freezing or melting correctly, as freezing occurs in confined space. We provide evidence that bilinear functions of unfrozen and frozen T-ρ paths offer a better approximation. Inferring reliable thermal state variables from ERT images requires a quantitative approach involving calibrated (T-ρ) relationships and an adequate resistance error description in the ERT inversion process, where the correct description of data errors and the right degree of data fitting are crucial issues. We also provide evidence that seismic refraction tomography is technically feasible to detect permafrost in low-porosity bedrock that constitutes steep rock walls. We have tested temperature - P-wave velocity functions of 22 decimeter-large metamorphic, magmatic and sedimentary low-porosity rock samples with a natural texture of numerous micro-fissures from alpine and arctic rock walls. The results show the significance of the ice-pressure-induced matrix velocity increase in low-porosity rocks while the velocity increase of the pore infill is negligible. Hence, the

  4. Characterizing and modelling 'ghost-rock' weathered limestones

    Science.gov (United States)

    Dubois, Caroline; Goderniaux, Pascal; Deceuster, John; Poulain, Angélique; Kaufmann, Olivier

    2016-04-01

    'Ghost-rock' karst aquifer has recently been highlighted. In this particular type of aquifer, the karst is not expressed as open conduits but consists in zones where the limestone is weathered. The in-situ weathering of limestone leaves a soft porous material called 'alterite'. The hydro-mechanical properties of this material differs significantly from those of the host rock: the weathering enhances the storage capacity and the conductivity of the rock. This type of weathered karst aquifer has never been studied from a hydrogeological point of view. In this study, we present the hydraulic characterization of such weathered zones. We also present a modelling approach derived from the common Equivalent Porous Medium (EPM) approach, but including the spatial distribution of hydrogeological properties through the weathered features, from the hard rock to the alterite, according to a weathering index. Unlike the Discrete Fracture Network (DFN) approaches, which enable to take into account a limited number of fractures, this new approach allows creating models including thousands of weathered features. As the properties of the alterite have to be considered at a centimeter scale, it is necessary to upscale these properties to carry out simulations over large areas. Therefore, an upscaling method was developed, taking into account the anisotropy of the weathered features. Synthetic models are built, upscaled and different hydrogeological simulations are run to validate the method. This methodology is finally tested on a real case study: the modelling of the dewatering drainage flow of an exploited quarry in a weathered karst aquifer in Belgium.

  5. Rock salt constitutive modeling

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, R.E.

    1980-03-18

    The Serata model is the best operational model available today because it incorporates: (1) a yield function to demarcate between viscoelastic and viscoplastic behavior of rock salt; (2) a pressure and temperature dependence for yield stresses; and (3) a standard linear solid, which can be readily extended into the non-linear regime, to represent creep behavior. Its only deficiencies appear to be the lack of secondary creep behavior (a free dashpot) and some unsettling arbitrariness about the Poisson's ratio (..nu.. ..-->.. 0.5) argument for viscoplasticity. The Sandia/WIPP model will have good primary and secondary creep capability, but lacks the viscoplastic behavior. In some cases, estimated inelastic strains may be underpredicted. If a creep acceleration mechanism associated with brine inclusions is observed, this model may require extensive revision. Most of the other models available (SAI, RE-SPEC, etc.) are only useful for short-term calculations, because they employ temporal power law (t/sup n/) primary creep representations. These models are unsatisfactory because they cannot represent dual mechanisms with differing characteristic times. An approach based upon combined creep and plasticity is recommended in order to remove the remaining deficiency in the Serata model. DOE/Sandia/WIPP should be encouraged to move aggressively in this regard.

  6. They will rock you!

    CERN Multimedia

    Anaïs Schaeffer

    2013-01-01

    On 30 September, CERN will be the venue for one of the most prestigious events of the year: the concert for the Bosons&More event, the Organization’s celebration of the remarkable performance of the LHC and all its technical systems, as well as the recent fundamental discoveries. Topping the bill will be the Orchestre de la Suisse Romande, the CERN Choir, the Zürcher Sing-Akademie and the Alan Parsons Live Project rock group, who have joined forces to create an unforgettable evening’s entertainment.   The Orchestre de la Suisse Romande, directed by Maestro Neeme Järvi, artistic and musical director of the OSR. (Image: Grégory Maillot). >>> From the Orchestre de la Suisse Romande… Henk Swinnen, General Manager of the Orchestre de la Suisse Romande (OSR), answers some questions for the CERN Bulletin, just a few days before the event. How did this project come about? When CERN invited us to take part in the B...

  7. Uranium series, volcanic rocks

    Science.gov (United States)

    Vazquez, Jorge A.

    2014-01-01

    Application of U-series dating to volcanic rocks provides unique and valuable information about the absolute timing of crystallization and differentiation of magmas prior to eruption. The 238U–230Th and 230Th-226Ra methods are the most commonly employed for dating the crystallization of mafic to silicic magmas that erupt at volcanoes. Dates derived from the U–Th and Ra–Th methods reflect crystallization because diffusion of these elements at magmatic temperatures is sluggish (Cherniak 2010) and diffusive re-equilibration is insignificant over the timescales (less than or equal to 10^5 years) typically associated with pre-eruptive storage of nearly all magma compositions (Cooper and Reid 2008). Other dating methods based on elements that diffuse rapidly at magmatic temperatures, such as the 40Ar/39Ar and (U–Th)/He methods, yield dates for the cooling of magma at the time of eruption. Disequilibrium of some short-lived daughters of the uranium series such as 210Po may be fractionated by saturation of a volatile phase and can be employed to date magmatic gas loss that is synchronous with volcanic eruption (e.g., Rubin et al. 1994).

  8. Analytical Modeling of Hard-Coating Cantilever Composite Plate considering the Material Nonlinearity of Hard Coating

    OpenAIRE

    Wei Sun; Ying Liu; Guangyu Du

    2015-01-01

    Due to the material nonlinearity of hard coating, the coated structure produces the nonlinear dynamical behaviors of variable stiffness and damping, which make the modeling of hard-coating composite structure become a challenging task. In this study, the polynomial was adopted to characterize this material nonlinearity and an analytical modeling method was developed for the hard-coating composite plate. Firstly, to relate the hard-coating material parameters obtained by test and the analytica...

  9. Research into basic rocks types

    International Nuclear Information System (INIS)

    Teollisuuden Voima Oy (TVO) has carried out research into basic rock types in Finland. The research programme has been implemented in parallel with the preliminary site investigations for radioactive waste disposal in 1991-1993. The program contained two main objectives: firstly, to study the properties of the basic rock types and compare those with the other rock types under the investigation; secondly, to carry out an inventory of rock formations consisting of basic rock types and suitable in question for final disposal. A study of environmental factors important to know regarding the final disposal was made of formations identified. In total 159 formations exceeding the size of 4 km2 were identified in the inventory. Of these formations 97 were intrusive igneous rock types and 62 originally extrusive volcanic rock types. Deposits consisting of ore minerals, industrial minerals or building stones related to these formations were studied. Environmental factors like natural resources, protected areas or potential for restrictions in land use were also studied

  10. Source rock potential in Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Raza, H.A. (Hydrocarbon Development Institute of Pakistan, Islamabad (Pakistan))

    1991-03-01

    Pakistan contains two sedimentary basins: Indus in the east and Balochistan in the west. The Indus basin has received sediments from precambrian until Recent, albeit with breaks. It has been producing hydrocarbons since 1914 from three main producing regions, namely, the Potwar, Sulaisman, and Kirthar. In the Potwar, oil has been discovered in Cambrian, Permian, Jurassic, and Tertiary rocks. Potential source rocks are identified in Infra-Cambrian, Permian, Paleocene, and Eocene successions, but Paleocene/Eocene Patala Formation seems to be the main source of most of the oil. In the Sulaiman, gas has been found in Cretaceous and Tertiary; condensate in Cretaceous rocks. Potential source rocks are indicated in Cretaceous, Paleocene, and Eocene successions. The Sembar Formation of Early Cretaceous age appears to be the source of gas. In the Kirthar, oil and gas have been discovered in Cretaceous and gas has been discovered in paleocene and Eocene rocks. Potential source rocks are identified in Kirthar and Ghazij formations of Eocene age in the western part. However, in the easter oil- and gas-producing Badin platform area, Union Texas has recognized the Sembar Formation of Early Cretaceous age as the only source of Cretaceous oil and gas. The Balochistan basin is part of an Early Tertiary arc-trench system. The basin is inadequately explored, and there is no oil or gas discovery so far. However, potential source rocks have been identified in Eocene, Oligocene, Miocene, and Pliocene successions based on geochemical analysis of surface samples. Mud volcanoes are present.

  11. NP-hardness of hypercube 2-segmentation

    OpenAIRE

    Feige, Uriel

    2014-01-01

    The hypercube 2-segmentation problem is a certain biclustering problem that was previously claimed to be NP-hard, but for which there does not appear to be a publicly available proof of NP-hardness. This manuscript provides such a proof.

  12. ERRATUM: Work smart, wear your hard hat

    CERN Multimedia

    2003-01-01

    An error appeared in the article «Work smart, wear your hard hat» published in Weekly Bulletin 27/2003, page 5. The impact which pierced a hole in the hard hat worn by Gerd Fetchenhauer was the equivalent of a box weighing 5 kg and not 50 kg.

  13. Appraisal of selected epidemiologic issues from studies of lung cancer among uranium and hard rock miners

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, G R; Sever, L E

    1982-04-01

    An extensive body of published information about lung cancer among uranium miners was reviewed and diverse information, useful in identifying important issues but not in resolving them was found. Measuring exposure and response; thresholds of exposure; latency or the period from first mining experience to death; effort to predict excess risk of death, using a model; effects of smoking and radon daughter exposure on the histology of lung tumors; and the interplay of factors on the overall risk of death were all examined. The general concept of thresholds; that is, an exposure level below which risk does not increase was considered. The conclusion is that it should be possible to detect and estimate an epidemiologic threshold when the cohorts have been followed to the death of all members. Issues concerning latency in the studies of uranium miners published to date were examined. It is believed that the induction-latent period for lung cancer among uranium miners may be: as little as 10 to more than 40 years; dependent on age at which exposure begins; exposure rate; and ethnicity or smoking habits. Although suggested as factual, their existence is uncertain. An effect due to the exposure rate may exist although it has not been factual, their existence is uncertain. An effect due to the exposure rate may exist although it has not been confirmed. The median induction-latent period appears to be in excess of the 15 years frequently cited for US uranium miner. A distinct pattern of shorter induction-latent periods with increasing age at first mining exposure is reported. The evidence for and against an unusual histologic pattern of lung cancers among uranium miners was examined. The ratio of epidermoid to small