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Sample records for excavation disturbed zone

  1. Detailed measurements of deformation in the excavation disturbed zone

    International Nuclear Information System (INIS)

    Thompson, P.M.; Martino, J.B.; Spinney, M.H.

    1993-01-01

    An excavation damage extensometer (EDEX) is described. It was designed to enable detailed small-scale deformation measurements to be made in the excavation disturbed zone (EDZ) around a tunnel opening in stressed rock. Its use in the Mine-by Experiment in unfractured granitic rock at the Underground Research Laboratory (Manitoba) is described. The results obtained from an array of eight EDEX installations are presented. These demonstrate how the EDEX can be used to provide data on the EDZ which is supplementary to that obtained by larger scale borehole extensometers and a acoustic emission/micro-seismic monitoring system. (4 figures, 5 references) (UK)

  2. Grimsel test site. Excavation disturbed zone experiment (EDZ)

    International Nuclear Information System (INIS)

    Frieg, B.; Blaser, P. C.; Adams, J.; Dollinger, H.; Kuhlmann, U.; Lanyon, G. W.

    2012-07-01

    The ‘Excavation Disturbed Zone (EDZ) Experiment’ was conducted at the Grimsel Test Site (GTS) in the framework of safety analysis of deep geological repositories for radioactive wastes. It concentrated on investigating the hydraulic regime of the near-field of drilled tunnel sections under fully saturated conditions, with the aim of contributing to the development of methods for measuring and modelling axial water flow along tunnels and caverns. The studies focused on the mechanical and hydraulic properties of the rock mass in the direct vicinity of the tunnel wall. The EDZ is defined as the zone around the tunnel where excavation has altered the rock properties. The selected test location was a tunnel section where mechanical stressing of the rock and some breakouts had been observed. In-situ stress measurements were performed in order to record the actual stress redistribution in the tunnel near-field induced by excavation of the tunnel. A small stress increase and microfissures could be identified in the tunnel near-field. The stress measurements and the results of the geological mapping formed the basis for the rock mechanical modelling of the EDZ. Two different models of the development and geometry of the EDZ were used: (a) the regional 3D stress field modelling indicated that the topography has a significant influence on the primary stress field; a good agreement between the measured and calculated stresses in the GTS was achieved by applying an additional far-field tectonic stress component; (b) with the local 2D numerical disturbed zone modelling of the tunnel section itself, stress redistributions, possible plastifications and joint behaviour were investigated; all displacements of the rock matrix and the shear displacements of the discontinuities seem to be the result of the tunnel excavation; maximum shear deformations of 2 - 5 mm occur at the tunnel wall. Prior to the hydraulic test phase, the test location was decoupled from the normal GTS tunnel

  3. Hydraulic tests for the Excavation Disturbed Zone in NATM drift of North Extension

    International Nuclear Information System (INIS)

    Matsuoka, Eiken

    1997-03-01

    Investigation for characterization of rock properties of the Excavation Disturbed Zone (EDZ) were carried out in NATM drift of North Extension in the Tono Mine. As a part of this investigation, hydraulic tests were performed by means of the hydraulic measuring instrument, which had been developed by PNC Tono Geoscience Center. The purpose of this tests is to characterize the change in hydraulic properties of the EDZ caused by drift excavation using machine (boom header). The hydraulic tests were performed in the burials MH-1,2,3, in which hydraulic tests had been performed before the drift excavation in 1994. The test results indicate that the measured values of pore water pressure have decreased after excavation of the drift. The values ranged from -0.037 kgf/cm 2 to 0.039 kgf/cm 2 . The measured hydraulic conductivities ranged from 2.2*10 -11 cm/s to 9.1*10 -11 cm/s for mud stone and from 2.8*10 -9 cm/s to 2.4*10 -7 cm/s for conglomerate. The measured hydraulic conductivities for mud stone are below the lower limit of the instrument, and the change in the hydraulic conductivities for conglomerate is little. The hydraulic conductivities for conglomerate and mad stone (reference values) are interpreted. The change in hydraulic conductivities measured before and after excavation of the drift is insignificant. (author)

  4. Hydraulic tests for the Excavation Disturbed Zone in deep rock mass

    International Nuclear Information System (INIS)

    Matsuoka, Eiken

    1998-03-01

    Investigation for characterization of rock properties of the Excavation Disturbed Zone (EDZ) were carried out in 250 m level drift of KAMAISHI Mine. As a part of this investigation, hydraulic tests in the two different sections which were excavated by normal and smooth blasting method respectively, were performed in the vicinity of a drift wall and floor. The test results are as follows, 1) The distribution of pore water pressure in two sections was different. 2) In this investigation, hydraulic test was performed at the different depth in the horizontal and vertical down hole. The variation of measured permeability with depth from the drift wall and floor showed different character. 3) The measured permeability in horizontal hole has no change with depth from drift wall, but in vertical down hole, the measured permeability in nearest part from the floor indicated the higher value compared to the permeability in deeper part. 4) In horizontal holes in two sections there was no difference of the measured permeabilities dependent on the excavation method. The higher permeability was obtained in the vertical hole in smooth blasting section compared to normal blasting section. (author)

  5. Zedex - an in-situ study of the importance of the excavation disturbed zone to repository performance

    International Nuclear Information System (INIS)

    Olsson, O.; Slimane K.B.; Davies, N.

    1995-01-01

    The excavation of shafts and tunnels in a waste repository will cause a disturbance to the surrounding rock mass with possible alterations to rock mass stability and hydraulic properties. The properties and extent of the disturbed zone must be considered in the design of a repository and in the assessment of its long-term safety. In addition, the data collected in drifts, which will be used for detailed characterization of the repository, will be affected by excavation effects. ANDRA, UK Nirex, and SKB have jointly set up the ZEDEX Project at the Aespoe Hard Rock Laboratory, Sweden, in order to improve understanding of the properties and extent the Excavation Disturbed Zone (EDZ). The main objective is to study the mechanical behavior of the EDZ with respect to its origin, character, magnitude of property change, extent, and its dependence of excavation method. The project will also provide a test of equipment and methodology for quantifying the EDZ. The ZEDEX Project includes tests of open-quote normal close-quote excavation by drill and blast, a smooth blasting procedure based on low shock explosives, and excavation by tunnel boring. The ZEDEX Project is still in progress and results have not been fully analyzed. The preliminary analysis of the results indicates that the measurable changes in properties induced by tunnel excavation are comparatively small

  6. Joint ANDRA/Nirex/SKB zone of excavation disturbance experiment (ZEDEX) at the Aspo hard rock laboratory

    International Nuclear Information System (INIS)

    Hooper, A.J.; Olsson, O.

    1995-01-01

    The excavation of access shafts and tunnels and of the disposal areas of a waste repository will cause a disturbance in the surrounding rock mass with possible alterations to rock mass stability and hydraulic properties. For a number of disposal concepts this disturbance may be important for the operational and/or post-closure safety of the repository. Furthermore the disturbance may extend over time as a consequence of processes such as stress relaxation. The sponsors of ZEDEX, namely ANDRA, Nirex and SKB, are interested in developing the ability to produce reliable models of the disturbed zone that will develop around large cross-section excavations in fractured hard rock masses that are initially water saturated. Various models have been developed to calculate the important characteristics of the disturbed zone in such rock masses as a function of parameters related to the rock mass quality and the geometric description of the excavation. ZEDEX was initiated in the Aspo Hard Rock Laboratory in April 1994 with drilling and instrumentation of boreholes running alongside the planned extension of the spiral access ramp and a planned parallel experimental tunnel. ZEDEX has been designed to generate information for alternative methods of excavation. The extension to the spiral ramp is to be made by tunnel boring whereas the parallel experimental tunnel will be excavated in part by ''normal'' basting and in part by smooth blasting. The objective is to build confidence in the modelling of the disturbed zone to support the selection of excavation methods for repository construction. (authors). 3 figs

  7. Assessment of rock mass characteristics and the excavation disturbed zone in the Lingxin Coal Mine beneath the Xitian river, China

    International Nuclear Information System (INIS)

    Xingping Lai

    2006-01-01

    Safe production and induced hazard prevention in coal mines mainly concern problems in the excavation disturbed zone (EDZ), but coal mining can also make a significant impact on the environment. Comprehensive techniques using a borehole TV viewer system, electrical logging, and monitoring of drilling fluid leakage offer the ability to identify changing geological conditions and the location of any nearby abandoned mining workings. The inner collapsed zone and the expanding height of the crack zone transmitting water plus their spatial distribution after excavating the superincumbent coal seam stratum are determined at no. L3414 workings, Lingxin Coal Mine beneath the Xitian river, China. An integrated system of GIS-based on a stochastic model, which has been developed for the prediction of dynamic subsidence coupling the time function and probabilistic integral method, is verified through practice at the Lingxin Coal Mine. This development has greatly expanded the ability of the mine operator to characterize previously inaccessible areas of the mine, providing a reliable basis for safe mining and prevention of induced-hazards to ensure high production mining underneath the river bed. (author)

  8. Hydraulic Features of the Excavation Disturbed Zone - Laboratory investigations of samples taken from the Q- and S-tunnels at Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Ericsson, Lars O.; Brinkhoff, Petra; Gustafson, Gunnar; Kvartsberg, Sara (Div. of GeoEngineering, Dept. of Civil and Environmental Engineering, Chalmers Univ. of Technology, Goeteborg (Sweden))

    2009-12-15

    The general aim of the project has been to contribute to the SKB safety and assessment analysis with realistic figures of hydraulic properties in an excavation disturbed zone. The project had the following more detailed objectives: - Develop a laboratory method to determine fracture transmissivity under water-saturated conditions. - Provide magnitudes for realistic values for fracture transmissivity in the disturbed or damaged zone due to excavation. - Map micro cracks radially from the tunnel wall. - Map the spread of matrix porosity radially from the tunnel wall. - Develop single-hole hydraulic testing methodology in tunnel wall for saturated conditions. - Integration of fracture geometries and transmissivity investigations for conceptual hydraulic modelling of the bedrock along a tunnel wall

  9. Overview of the excavation disturbance experiment at the Kamaishi mine

    International Nuclear Information System (INIS)

    Matsui, Hiroya; Sato, Toshinori; Sugihara, Kozo; Kikuchi, Tadashi

    1999-01-01

    Excavation of an underground drift disturbs the rock mass around the opening by each of the following processes: Fracturing in the vicinity of opening induced by the excavation work and stress concentration. Changes in the apertures of existing fractures due to stress redistribution. Changes in water pressure around the opening due to water inflow and chemical changes due to the increased oxygen supply to the rock and such phenomena as degassing of groundwater. All of these mechanical, hydrological, and chemical changes to the rock mass are termed excavation disturbance and the affected area is called the 'Excavation Disturbed Zone (EDZ)'. The portion of the EDZ in which the rock mass is fractured due to excavation is called the Excavation Damaged Zone'. This experiment is focused on the mechanical and hydrological property changes caused by excavation, the degree and extend of which is important for the design, excavation and support of underground openings. The relevance of the EDZ for the geological isolation of nuclear waste disposal may be summarized as: 1) Relevance to near-field performance assessment. The EDZ is of importance for near-field performance assessment, as the development of new fractures and the opening of existing fractures due to excavation may create preferential pathways for mass transport from the engineered barrier system to natural transmissive flowpaths. 2) Relevance to the design, excavation and sealing of a repository. The excavation method affects the properties and the extend of the excavation damaged zone. The shape and the scale of the underground opening, and whether the underground opening is backfilled after excavation, will affect the final stress state. It is important to understand the EDZ for the design, excavation and sealing of a repository. 3) Initial and boundary conditions of in situ experiments. Information about the EDZ is necessary for the design and interpretation of certain in situ experiments. (author)

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

    International Nuclear Information System (INIS)

    Jonsson, Martin; Baeckstroem, Ann; Quanhong Feng; Berglund, Johan; Johansson, Malin; Mas Ivars, Diego; Olsson, Mats

    2009-05-01

    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

  11. 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

  12. DECOVALEX-THMC Project. Task B. Understanding and characterizing the excavation disturbed zone (EDZ). Phase 2 Report

    International Nuclear Information System (INIS)

    Hudson, John A.; Lanru Jing; Antikainen, Juha; Backers, Tobias; Baeckstroem, Ann; Koyama, Tomofumi; Xiating Feng; Pengzhi Pan; Kobayashi, Akira; Rinne, Mikael; Baotang Shen

    2007-02-01

    The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report summarizes the work contributed to Phase 2 of Task B of the project, which took place during the period of March 2004 to May 2006. The Phase 2 work incorporated the use of a wide range of numerical models to simulate the failure of a number of intact rock core samples, from the APSE tunnel at Aespoe HRL, as tested in uniaxial compression and other loading conditions with the intention of establishing the common and code-specific features of the models. The core samples of the Aespoe diorite were treated with different initial mechanical and chemical conditions as dry samples, saturated with distilled water, formation water and saline water, with different durations of submersion, respectively, in order to observe the mechanical effects of saturation by different chemical fluids on the mechanical properties of the intact core

  13. DECOVALEX-THMC Project. Task B. Understanding and characterizing the excavation disturbed zone (EDZ). Phase 2 Report

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, John A. (ed.) [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)]|[Rock Engineering Consultants (United Kingdom); Lanru Jing (ed.) [Royal Institute of Technology, Stockholm (Sweden); Antikainen, Juha [Helsinki University of Technology, Helsinki (Finland); Backers, Tobias [GeoFrames GmbH, (Germany); Baeckstroem, Ann [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)]|[Bergbyggkonsult AB (Sweden); Koyama, Tomofumi [Swedish Nuclear Power Inspectorate, Stockholm (Sweden); Xiating Feng; Pengzhi Pan [Chinese Academy of Sciences (China); Kobayashi, Akira [Kyoto Univ. (Japan); Rinne, Mikael; Baotang Shen [Fracom Ltd. (Finland)

    2007-02-15

    The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. The project involves a large number of research teams supported by radioactive waste management agencies or governmental regulatory bodies in Canada, China, Finland, France, Germany, Japan, Sweden and USA, who conducted advanced studies and numerical modelling of coupled THMC processes under five tasks. This report summarizes the work contributed to Phase 2 of Task B of the project, which took place during the period of March 2004 to May 2006. The Phase 2 work incorporated the use of a wide range of numerical models to simulate the failure of a number of intact rock core samples, from the APSE tunnel at Aespoe HRL, as tested in uniaxial compression and other loading conditions with the intention of establishing the common and code-specific features of the models. The core samples of the Aespoe diorite were treated with different initial mechanical and chemical conditions as dry samples, saturated with distilled water, formation water and saline water, with different durations of submersion, respectively, in order to observe the mechanical effects of saturation by different chemical fluids on the mechanical properties of the intact core

  14. Excavation/Fill/Soil Disturbance, Self-Study #31419

    Energy Technology Data Exchange (ETDEWEB)

    Grogin, Phillip W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-02-06

    This course, Excavation/Fill/Soil Disturbance Self-Study (#31419), presents an overview of the hazards, controls, and requirements that affect safe excavations at Los Alamos National Laboratory (LANL). An overview of the LANL excavation/fill/soil disturbance permit (EXID permit) approval process is also presented, along with potholing requirements for planning and performing excavations at LANL.

  15. Review of SKB's ZEDEX Report - A study of the zone of excavation disturbance for blasted and bored tunnels - SKB ICR 96-03, Vol. 1-3

    International Nuclear Information System (INIS)

    Palmqvist, K.

    1997-11-01

    We have reviewed and evaluated the contents of the ZEDEX report. The review has been focussed on investigation methods, results and interpretations. The conclusions of the review are that the ZEDEX was successful in some aspects. However, the study has not met with the objective of understanding the excavation disturbed zone (EDZ). A lot of questions remain to be answered as regards the origin, character and extent of the EDZ. Investigation of the hydraulic properties of the EDZ was not included as a major aim in the ZEDEX study and only some supporting studies were conducted. We find it regrettable that priority was not given to these aspects, since improved knowledge in this field is considered important with respect to the performance and safety of the repository. The review has identified a number of shortages in the expected outcome and objectives set up for the ZEDEX experiment that more or less have influenced the results of the study. Several problems of interpretation were introduced directly as a result of the unsatisfactory performance of the drill and blast drift. It would have been valuable if cautious blasting had been applied. A number of recommendations for future studies are made

  16. Characterisation and monitoring of the Excavation Disturbed Zone (EDZ) in fractured gneisses of the Roselend underground laboratory: permeability measurements, transport property changes and related radon bursts

    Science.gov (United States)

    Wassermann, Jérôme; Sabroux, Jean-Christophe; Richon, Patrick; Pontreau, Sébastien; Guillon, Sophie; Pili, Eric

    2010-05-01

    pressure measurements between an obturated borehole and the tunnel is conducted to monitor the possible modifications of the transport properties of the EDZ due to hydraulical and/or mechanical sollicitations of the nearby Roselend reservoir lake. As radon level is controlled by emanation and transport path through the medium. The observed bursts of radon should be due to changes of the radon transport properties (Trique et al. 1999) of the EDZ. A correlation between the differential pressure variations and radon bursts is clearly observed. Radon bursts seem to be related to overpressure events that take place in the instrumented borehole. Which external sollicitations, hydraulical or mechanical, or both, induce such a behaviour? References Bossart, P., Meier, P. M., Moeri, A., Trick, T., and J.-C. Mayor (2002). Geological and hydraulic characterisation of the excavation disturbed zone in the Opalinus Clay of the Mont Terri Rock Laboratory, Engineering Geology, 66, 19-38. Dezayes, C., and T. Villemin (2002). Etat de la fracturation dans la galerie CEA de Roselend et analyse de la déformation cassante dans le massif du Méraillet, technical report, Lab. de Geodyn. de Chaisnes Alp., Univ. de Savoie, Savoie, France. Jakubick, A. T., and T. Franz (1993). Vacuum testing of the permeability of the excavation damaged zone, Rock Mech. Rock Engng., 26(2), 165-182. Patriarche, D., Pili, E., Adler, P. M., and J.-F. Thovert (2007). Stereological analysis of fractures in the Roselend tunnel and permeability determination, Water Resour. Res., 43, W09421. Richon, P., Perrier, F., Sabroux, J.-C., Trique, M., Ferry, C., Voisin, V., and E. Pili (2004). Spatial and time variations of radon-222 concentration in the atmosphere of a dead-end horizontal tunnel, J. Environ. Radioact., 78, 179-198. Richon, P., Perrier, F., Pili, E., and J.-C. Sabroux (2009). Detectability and significance of the 12hr barometric tide in radon-222 signal, dripwater flow rate, air temperature and carbon dioxide

  17. Determination of near field excavation disturbance in crystalline rock

    International Nuclear Information System (INIS)

    Koopmans, R.; Hughes, R.W.

    1986-01-01

    The computerized dilatometer system has rapidly and economically provided deformation moduli of low and high modulus rock, determined the extent of excavation disturbance surrounding an underground opening and located open fracture within a rock mass. Results from both test sites indicate that the moduli obtained were influenced by the in situ tangential stress field. It has been shown that the near field excavation disturbance is kept to a minimum through the use of careful excavation techniques such as the tunnel boring machine. In turn, the in situ tangential stress levels and deformation moduli are maximized while the corresponding permeability is minimized

  18. ZEDEX - A study of damage and disturbance from tunnel excavation by blasting and tunnel boring

    International Nuclear Information System (INIS)

    Emsley, S.; Olsson, Olle; Stenberg, L.; Alheid, H.J.; Falls, S.

    1997-12-01

    The objectives of the ZEDEX project were to understand the mechanical behaviour of the excavation disturbed zone (EDZ) with respect to its origin, character, magnitude of property change, extent and its dependence on excavation method. Excavation with normal smooth blasting, blasting with low shock explosives and tunnel boring were studied. The drifts are located at Aespoe at a depth of 420 m, the profiles are circular and 5 m in diameter. The results have shown that there is a damaged zone, close to the drift wall dominated by changes in rock properties which are irreversible, and that there is a disturbed zone beyond the damaged zone that is dominated by changes in stress state and mainly reversible. There is no distinct boundary between the two zones. The results from ZEDEX indicate that the role of the EDZ as a preferential pathway to radionuclide transport is limited to the damaged zone. The extent of the damaged zone can be limited through application of appropriate excavation methods. By limiting the extent of the damaged zone it should also be feasible to block pathways in the damaged zone by plugs placed at strategic locations

  19. ZEDEX - A study of damage and disturbance from tunnel excavation by blasting and tunnel boring

    Energy Technology Data Exchange (ETDEWEB)

    Emsley, S [Golder Associates, Maidenhead (United Kingdom); Olsson, Olle; Stenberg, L [Swedish Nuclear Fuel and Waste Co., Figeholm (Sweden); Alheid, H J [Federal Inst. for Geosciences and Natural Resources, Hannover (Germany); Falls, S [Queens Univ., Kingston, ON (Canada)

    1997-12-01

    The objectives of the ZEDEX project were to understand the mechanical behaviour of the excavation disturbed zone (EDZ) with respect to its origin, character, magnitude of property change, extent and its dependence on excavation method. Excavation with normal smooth blasting, blasting with low shock explosives and tunnel boring were studied. The drifts are located at Aespoe at a depth of 420 m, the profiles are circular and 5 m in diameter. The results have shown that there is a damaged zone, close to the drift wall dominated by changes in rock properties which are irreversible, and that there is a disturbed zone beyond the damaged zone that is dominated by changes in stress state and mainly reversible. There is no distinct boundary between the two zones. The results from ZEDEX indicate that the role of the EDZ as a preferential pathway to radionuclide transport is limited to the damaged zone. The extent of the damaged zone can be limited through application of appropriate excavation methods. By limiting the extent of the damaged zone it should also be feasible to block pathways in the damaged zone by plugs placed at strategic locations 68 refs, 92 figs, 31 tabs

  20. Review of SKB`s ZEDEX Report - A study of the zone of excavation disturbance for blasted and bored tunnels - SKB ICR 96-03, Vol. 1-3

    Energy Technology Data Exchange (ETDEWEB)

    Palmqvist, K [Berggeologiska Undersoekningar AB, Goeteborg (Sweden)

    1997-11-01

    We have reviewed and evaluated the contents of the ZEDEX report. The review has been focussed on investigation methods, results and interpretations. The conclusions of the review are that the ZEDEX was successful in some aspects. However, the study has not met with the objective of understanding the excavation disturbed zone (EDZ). A lot of questions remain to be answered as regards the origin, character and extent of the EDZ. Investigation of the hydraulic properties of the EDZ was not included as a major aim in the ZEDEX study and only some supporting studies were conducted. We find it regrettable that priority was not given to these aspects, since improved knowledge in this field is considered important with respect to the performance and safety of the repository. The review has identified a number of shortages in the expected outcome and objectives set up for the ZEDEX experiment that more or less have influenced the results of the study. Several problems of interpretation were introduced directly as a result of the unsatisfactory performance of the drill and blast drift. It would have been valuable if cautious blasting had been applied. A number of recommendations for future studies are made.

  1. Prediction of permeability changes in an excavation response zone

    International Nuclear Information System (INIS)

    Kinoshita, Naoto; Ishii, Takashi; Kuroda, Hidetaka; Tada, Hiroyuki

    1992-01-01

    In geologic disposal of radioactive wastes, stress changes due to cavern excavation may expand the existing fractures and create possible bypasses for groundwater. This paper proposes a simple method for predicting permeability changes in the excavation response zones. Numerical analyses using this method predict that the response zones created by cavern excavation would differ greatly in thickness and permeability depending on the depth of the cavern site and the initial in-situ stress, that when the cavern site is deeper, response zones would expand more and permeability would increases more, and that if the ratio of horizontal to vertical in-situ stress is small, extensive permeable zones at the crown and the bottom would occur, whereas if the ratio is large, extensive permeable zones would occur in the side walls. (orig.)

  2. Brine and Gas Flow Patterns Between Excavated Areas and Disturbed Rock Zone in the 1996 Performance Assessment for the Waste Isolation Pilot Plant for a Single Drilling Intrusion that Penetrates Repository and Castile Brine Reservoir

    International Nuclear Information System (INIS)

    Economy, Kathleen M.; Helton, Jon Craig; Vaughn, Palmer

    1999-01-01

    The Waste Isolation Pilot Plant (WIPP), which is located in southeastern New Mexico, is being developed for the geologic disposal of transuranic (TRU) waste by the U.S. Department of Energy (DOE). Waste disposal will take place in panels excavated in a bedded salt formation approximately 2000 ft (610 m) below the land surface. The BRAGFLO computer program which solves a system of nonlinear partial differential equations for two-phase flow, was used to investigate brine and gas flow patterns in the vicinity of the repository for the 1996 WIPP performance assessment (PA). The present study examines the implications of modeling assumptions used in conjunction with BRAGFLO in the 1996 WIPP PA that affect brine and gas flow patterns involving two waste regions in the repository (i.e., a single waste panel and the remaining nine waste panels), a disturbed rock zone (DRZ) that lies just above and below these two regions, and a borehole that penetrates the single waste panel and a brine pocket below this panel. The two waste regions are separated by a panel closure. The following insights were obtained from this study. First, the impediment to flow between the two waste regions provided by the panel closure model is reduced due to the permeable and areally extensive nature of the DRZ adopted in the 1996 WIPP PA, which results in the DRZ becoming an effective pathway for gas and brine movement around the panel closures and thus between the two waste regions. Brine and gas flow between the two waste regions via the DRZ causes pressures between the two to equilibrate rapidly, with the result that processes in the intruded waste panel are not isolated from the rest of the repository. Second, the connection between intruded and unintruded waste panels provided by the DRZ increases the time required for repository pressures to equilibrate with the overlying and/or underlying units subsequent to a drilling intrusion. Third, the large and areally extensive DRZ void volumes is a

  3. Brine and Gas Flow Patterns Between Excavated Areas and Disturbed Rock Zone in the 1996 Performance Assessment for the Waste Isolation Pilot Plant for a Single Drilling Intrusion that Penetrates Repository and Castile Brine Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    ECONOMY,KATHLEEN M.; HELTON,JON CRAIG; VAUGHN,PALMER

    1999-10-01

    The Waste Isolation Pilot Plant (WIPP), which is located in southeastern New Mexico, is being developed for the geologic disposal of transuranic (TRU) waste by the U.S. Department of Energy (DOE). Waste disposal will take place in panels excavated in a bedded salt formation approximately 2000 ft (610 m) below the land surface. The BRAGFLO computer program which solves a system of nonlinear partial differential equations for two-phase flow, was used to investigate brine and gas flow patterns in the vicinity of the repository for the 1996 WIPP performance assessment (PA). The present study examines the implications of modeling assumptions used in conjunction with BRAGFLO in the 1996 WIPP PA that affect brine and gas flow patterns involving two waste regions in the repository (i.e., a single waste panel and the remaining nine waste panels), a disturbed rock zone (DRZ) that lies just above and below these two regions, and a borehole that penetrates the single waste panel and a brine pocket below this panel. The two waste regions are separated by a panel closure. The following insights were obtained from this study. First, the impediment to flow between the two waste regions provided by the panel closure model is reduced due to the permeable and areally extensive nature of the DRZ adopted in the 1996 WIPP PA, which results in the DRZ becoming an effective pathway for gas and brine movement around the panel closures and thus between the two waste regions. Brine and gas flow between the two waste regions via the DRZ causes pressures between the two to equilibrate rapidly, with the result that processes in the intruded waste panel are not isolated from the rest of the repository. Second, the connection between intruded and unintruded waste panels provided by the DRZ increases the time required for repository pressures to equilibrate with the overlying and/or underlying units subsequent to a drilling intrusion. Third, the large and areally extensive DRZ void volumes is a

  4. Excavation damage and disturbance in crystalline rock - results from experiments and analyses

    International Nuclear Information System (INIS)

    Baeckblom, Goeran

    2008-11-01

    SKB plans to submit the application to site and construct the final repository for spent nuclear fuel in 2010. One important basis for the application is the results of the safety assessments, for which one particular dataset is the axial hydraulic properties along the underground openings used to calculate the transport resistance for radionuclide transport in the event that the canister is impaired. SKB initiated a project (Zuse) to be run over the period 2007-2009 to: - establish the current knowledge base on excavation damage and disturbance with particular focus on the axial hydraulic properties along the underground openings; - provide a basis for the requirements and compliance criteria for the excavation damaged and disturbed zone; - devise methods and instruments to infer or measure the excavation damage and disturbance at different times during the repository construction and operation before closure; - propose demonstration tests for which the methods are used in situ to qualify appropriate data for use in the safety reports. This report presents the results of the first stage of the Zuse project. Previous major experiments and studies in Canada, Finland, Japan, Sweden and Switzerland on spalling, excavation damage and disturbance was compiled and evaluated to provide the SR-Site report with a defendable database on the properties for the excavation damage and disturbance. In preparation for the SR-Site report, a number of sensitivity studies were conducted in which reasonable ranges of values for spalling and damage were selected in combination with an impaired backfill. The report here describes the construction of the repository in eleven steps and for each of these steps, the potential evolution of THMCB (Thermal, Mechanical, Hydraulic and Chemical/ Biological) processes are reviewed. In this work it was found that descriptions of the chemical and microbiological evolution connected with excavation damage and disturbance was lacking. The preliminary

  5. Self-healing of excavation-disturbed rocks in the near field of underground cavities - exemplary measurements in rock salt and interpretation of preliminary results

    International Nuclear Information System (INIS)

    Wieczorek, K.; Schwarzianeck, P.; Rothfuchs, T.

    2001-01-01

    Excavation disturbed zones develop in all kinds of rock as a consequence of the opening of cavities. Such zones are characterized by a change in hydraulic behaviour which can form a problem with regard to the sealing of waste disposal areas. Rocks showing a plastic behaviour, like rock salt, have the potential of healing when the stress state which was disturbed by excavation returns to an advantageous state. If healing can reliably be predicted, the excavation disturbed zone may not form a long-term safety issue in rock salt. Investigations of permeability and stress state around lined and open excavations have been performed in order to relate hydraulic behaviour to stress state. First results which are presented here are promising. (authors)

  6. Excavation damage and disturbance in crystalline rock - results from experiments and analyses

    Energy Technology Data Exchange (ETDEWEB)

    Baeckblom, Goeran (Conrox AB, Stockholm (Sweden))

    2008-11-15

    SKB plans to submit the application to site and construct the final repository for spent nuclear fuel in 2010. One important basis for the application is the results of the safety assessments, for which one particular dataset is the axial hydraulic properties along the underground openings used to calculate the transport resistance for radionuclide transport in the event that the canister is impaired. SKB initiated a project (Zuse) to be run over the period 2007-2009 to: - establish the current knowledge base on excavation damage and disturbance with particular focus on the axial hydraulic properties along the underground openings; - provide a basis for the requirements and compliance criteria for the excavation damaged and disturbed zone; - devise methods and instruments to infer or measure the excavation damage and disturbance at different times during the repository construction and operation before closure; - propose demonstration tests for which the methods are used in situ to qualify appropriate data for use in the safety reports. This report presents the results of the first stage of the Zuse project. Previous major experiments and studies in Canada, Finland, Japan, Sweden and Switzerland on spalling, excavation damage and disturbance was compiled and evaluated to provide the SR-Site report with a defendable database on the properties for the excavation damage and disturbance. In preparation for the SR-Site report, a number of sensitivity studies were conducted in which reasonable ranges of values for spalling and damage were selected in combination with an impaired backfill. The report here describes the construction of the repository in eleven steps and for each of these steps, the potential evolution of THMCB (Thermal, Mechanical, Hydraulic and Chemical/ Biological) processes are reviewed. In this work it was found that descriptions of the chemical and microbiological evolution connected with excavation damage and disturbance was lacking. The preliminary

  7. ROCK MASS DAMAGED ZONE CAUSED BY BLASTING DURING TUNNEL EXCAVATION

    Directory of Open Access Journals (Sweden)

    Hrvoje Antičević

    2012-07-01

    Full Text Available Design of underground spaces, including tunnels, and repositories for radioactive waste include the application of the same or similar technologies. Tunnel excavation by blasting inevitably results in the damage in the rock mass around the excavation profile. The damage in the rock mass immediately next to the tunnel profile emerges as the expanding of the existing cracks and the appearance of new cracks, i.e. as the change of the physical and-mechanical properties of the rock mass. Concerning the design of deep geological repositories, requirements in terms of damaged rock are the same or more rigorous than for the design of tunnel. The aforementioned research is directed towards determining the depth of damage zone caused by blasting. The depth of the damage zone is determined by measuring the changes of physical and-mechanical properties of the rock mass around the tunnel excavation profile. By this research the drilling and blasting parameters were correlated with the depth and size of the damage zone (the paper is published in Croatian.

  8. Acoustic emission and ultrasonic-velocity methods used to characterise the excavation disturbance associated with deep tunnels in hard rock

    Science.gov (United States)

    Falls, Stephen D.; Young, R. Paul

    1998-04-01

    Acoustic emission (AE) and ultrasonic-velocity monitoring studies have been undertaken at both the Atomic Energy of Canada Limited (AECL) Underground Research Laboratory (URL) and at the Swedish Nuclear Fuel Waste Management Company (SKB) Hard Rock Laboratory (HRL). At both locations the excavations were tunnels in granitic material at approximately 420 m depth. However, the stress regime was more severe at the URL Mine-by tunnel site than the HRL ZEDEX tunnel. Different parts of the ZEDEX tunnel were created using different excavation techniques. Using AE and ultrasonic techniques to study these tunnels we have been able to examine the nature of the excavation-disturbed zone around the tunnel, as well as examining the effects of different stress regimes and excavation techniques. Studies were undertaken both during and after the Mine-by tunnel excavation and during excavation in the ZEDEX tunnel. AE monitoring in the wall of the Mine-by tunnel during excavation showed that some activity occurred in the sidewall regions, but the spatial density of AE hypocentres increased toward the regions in the floor and roof of the tunnel where breakout notches formed. This sidewall activity was clustered primarily within 0.5 m of the tunnel wall. AE monitoring in the floor of the tunnel showed that small numbers of AE continued to occur in the notch region in the floor of the tunnel over 2 years after excavation was completed. This activity became more acute as the rock was heated, imposing thermally induced stresses on the volume. Ultrasonic-velocity studies both in the floor and the wall of the tunnel showed that the velocity is strongly anisotropic with the direction of slowest velocity orthogonal to the tunnel surface. The velocity increased with distance into the rock from the tunnel surface. In the floor, this effect was seen up to 2 m from the tunnel surface. Most of the change occurred within the first 0.5 m from the tunnel perimeter. At the lower-stress HRL, most of

  9. Geohydromechanical Processes in the Excavation Damaged Zone in Crystalline Rock, Rock Salt, and Indurated and Plastic Clays

    International Nuclear Information System (INIS)

    Tsang, Chin-Fu; Bernier, Frederic; Davies, Christophe

    2004-01-01

    The creation of an excavation disturbed zone or excavation damaged zone is expected around all man-made openings in geologic formations. Macro- and micro-fracturing, and in general a redistribution of in situ stresses and rearrangement of rock structures, will occur in this zone, resulting in drastic changes of permeability to flow, mainly through the fractures and cracks induced by excavation. Such an EDZ may have significant implications for the operation and long-term performance of an underground nuclear waste repository. Various issues of concern need to be evaluated, such as processes creating fractures in the excavation damaged zone, the degree of permeability increase, and the potential for sealing or healing (with permeability reduction) in the zone. In recent years, efforts along these lines have been made for a potential repository in four rock types-crystalline rock, salt, indurated clay, and plastic clay-and these efforts have involved field, laboratory, and theoretical studies. The present work involves a synthesis of the ideas and issues that emerged from presentations and discussions on EDZ in these four rock types at a CLUSTER Conference and Workshop held in Luxembourg in November, 2003. First, definitions of excavation disturbed and excavation damaged zones are proposed. Then, an approach is suggested for the synthesis and intercomparison of geohydromechanical processes in the EDZ for the four rock types (crystalline rock, salt, indurated clay, and plastic clay). Comparison tables of relevant processes, associated factors, and modeling and testing techniques are developed. A discussion of the general state-of-the-art and outstanding issues are also presented. A substantial bibliography of relevant papers on the subject is supplied at the end of the paper

  10. Use of the 14C-PMMA and He-gas methods to characterise excavation disturbance in crystalline rock

    International Nuclear Information System (INIS)

    Autio, J.; Kirkkomaeki, T.; Siitari-Kauppi, M.; Timonen, J.; Laajalahti, M.; Aaltonen, T.; Maaranen, J.

    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 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 14 C-PMMA method is suggested for studies of rock structure and the spatial distribution of porosity. The 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.)

  11. Characterization of the excavation disturbance caused by boring of the experimental full scale deposition holes in the Research Tunnel of Olkiluoto

    International Nuclear Information System (INIS)

    Autio, J.

    1997-09-01

    Three holes, the size of deposition holes, were bored in the Research Tunnel using a novel full-face boring technique. During the boring test, procedures were carried out in order to determine the effect of changes in operating parameters on the performance of the boring machine and the quality of the hole. Evaluation of the quality of the hole included studies of the geometry of the holes, measurements of surface roughness using a laser profilometer, rock mechanical determinations and study of excavation disturbances in the zone adjacent to the surface of the holes using two novel methods, the He-gas method and the 14 C-polymethylmethacrylate ( 14 C-PMMA) method. It was found that there is a distinct disturbed zone adjacent to the surface of the full scale deposition holes which can be divided into three different zones. The zones are as follows: a crushed zone penetrating to a depth of about 3 mm from the surface, a fractured zone extending to a depth of 6 - 10 mm from the crushed zone and a micro fractured zone extending to a depth of 15 - 31 mm from the fractured zone. The porosity of the rock in the disturbed zone measured using the 14 C-PMMA method was clearly greater than the porosity of undisturbed rock to a depth of about 11 mm. The values of permeability and effective diffusion coefficient in the disturbed zone measured in a direction perpendicular to the disturbed surface were found to be approximately one order of magnitude larger than those of undisturbed rock. The degree of disturbance was found to be greater where higher levels of thrust had been employed during the boring process. The results obtained also suggest that the disturbance caused by using 4- and 5-row cutters in the cutter head is more pronounced than the disturbance caused when using 5- and 6-row cutters

  12. Ultrasonic sounding and monitoring of the excavation damaged zone in a soft supported gallery

    International Nuclear Information System (INIS)

    Balland, Cyrille; Souley, Mountaka; Morel, Jacques

    2012-01-01

    Document available in extended abstract form only. Under high in situ stresses and high anisotropic stress ratios, the excavation of underground openings generally causes the creation of a disturbed (EdZ: Excavation disturbed Zone) and/or damaged (EDZ: Excavation Damaged Zone) zone, resulting from the initiation and growth of cracks and fractures and by a redistribution and rearrangement of the initial stresses. Due to the modifications of mechanical and hydro-mechanical properties in the EdZ/EDZ, the latter constitute a potential risk for the efficiency of the geologic and/or engineered barriers. To estimate the performance of a site of radioactive waste storage, it is essential to know the geometry, the extensions of the EdZ/EDZ, the density of cracks, their connectivity and the variations of permeability which can result from it. In particular, their extension depends on numerous factors among which the nature of the rock, the pre-existent fractures and their reactivation, the initial stress field (magnitudes and/or rate of anisotropy), the time, the geometry and the techniques of excavations etc.. In addition, the evolution of EdZ/EDZ properties in the medium term is little or poorly known, particularly under the influence of environmental conditions such as the re-confining by near field rock creep in contact with a rigid structural support or the evolution of hydric conditions (desaturation and re-saturation). Ultrasonic experimentation under the OHZ experiment has been implemented to characterize the EDZ extension and its evolution in time according to the structural support type (soft or rigid) and the environmental conditions present in the laboratory. This study consists of two experimental components: (1) the prior auscultation of the sole and face of the gallery by ultrasonic transmission tomography, (2) the monitoring the EDZ and the analysis of measurable changes in the propagation of ultrasonic waves in the medium term. Mechanical modelling of the

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

    International Nuclear Information System (INIS)

    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.

    2008-01-01

    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

  14. 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.

  15. Field observations and failure analysis of an excavation damaged zone in the Horonobe Underground Research Laboratory

    International Nuclear Information System (INIS)

    Aoyagi, Kazuhei; Ishii, Eiichi; Ishida, Tsuyoshi

    2017-01-01

    In the construction of a deep underground facility, the hydromechanical properties of the rock mass around an underground opening are changed significantly due to stress redistribution. This zone is called an excavation damaged zone (EDZ). In high-level radioactive waste disposal, EDZs can provide a shortcut for the escape of radionuclides to the surface environment. Therefore, it is important to develop a method for predicting the detailed characteristics of EDZs. For prediction of the EDZ in the Horonobe Underground Research Laboratory of Japan, we conducted borehole televiewer surveys, rock core analyses, and repeated hydraulic conductivity measurements. We observed that niche excavation resulted in the formation of extension fractures within 0.2 to 1.0 m into the niche wall, i.e., the extent of the EDZ is within 0.2 to 1.0 m into the niche wall. These results are largely consistent with the results of a finite element analysis implemented with the failure criteria considering failure mode. The hydraulic conductivity in the EDZ was increased by 3 to 5 orders of magnitude compared with the outer zone. The hydraulic conductivity in and around the EDZ has not changed significantly in the two years following excavation of the niche. These results show that short-term unloading due to excavation of the niche created a highly permeable EDZ. (author)

  16. Excavation damage zone tracer experiment in the floor of the room 415 test tunnel

    International Nuclear Information System (INIS)

    Frost, L.H.; Everitt, R.A.

    1997-03-01

    A 3.5-m-diameter test tunnel was constructed on the 420 Level of AECL's Underground Research Laboratory using a mechanical excavation technique. The orientation of the tunnel was chosen to maximize the stress ratio in the plane perpendicular to the tunnel axis in order to promote and study stress-induced excavation damage. The resulting excavation damage zone (EDZ) is characterized by a distinct breakout notch in both the floor and roof of the tunnel. In the floor of the tunnel, the main flow pathway within the EDZ is within a zone of intense grain-size fracturing (process zone) located at the tip of the breakout notch; virtually no flow occurs outside this region. A tracer experiment was performed within the EDZ in the floor of the tunnel to characterize the solute transport properties (permeability, transport porosity and dispersivity) within the process zone, as well as to develop and demonstrate methods for determining the transport properties within EDZs of underground tunnels. The experiment was performed as a constant head test by continuously injecting a constant concentration of iodide tracer into a region of the process zone, and by monitoring tracer breakthrough from the zone at a distance 1.5 m away. An equivalent-porous-media approach was taken in analysing fluid flow and solute transport through the process zone. Based on mass flux calculations, the hydraulic conductivity and transport porosity of the process zone are estimated to be 7.4 x 10 -7 m/s and 2.7 % respectively. Based on an analytic solution that represents tracer transport within the process zone as one-dimensional advective diffusive transport in a finite homogeneous porous medium, the longitudinal dispersivity and transport porosity of the zone are estimated to be 0.60 m and 3.3 % respectively. The transport porosity values estimated by both the mass flux and analytic calculations compare quite well. (author)

  17. Estimation of the Magnitude of Excavation Damaged Zone at KURT

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Won Jin; Kim, Jin Sub; Lee, Changsoo; Cho, Heui Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    In the EDZ, the permeability of the rock increases. The annular EDZ surrounding the tunnel may act as a continuous and high-permeable pathway for the groundwater flow, which accelerates the intrusion of groundwater into the repository and increases the release of radionuclide into the biosphere from the repository. Therefore an investigation on the magnitude of the EDZ has been important from the viewpoint of mechanical stability and radiological safety for a geological repository. In this study, two in-situ measurements were performed at the KURT (KAERI Underground Research Tunnel) to investigate the magnitude of the EDZ. The magnitude of EDZ was estimated to be 0.6 to 1.8 m from the tunnel wall on the basis of the deformation modulus, and the value of deformation modulus in the EDZ is about 40% of those in undisturbed zone. The magnitude of EDZ can be estimated to be about 2 m from the viewpoint of permeability, and the permeabilities in the EDZ seem to be increased at up to 2 orders of magnitude compared with those in the intact rock. The magnitude of EDZ estimated based on the permeability is larger than that from the Goodman jack test.

  18. Assessment of geomechanical properties, maximum depth and excavation damaged zone aspects - Expert report

    International Nuclear Information System (INIS)

    Amann, F.; Löw, S.; Perras, M.

    2015-11-01

    This comprehensive report published by the Swiss National Nuclear Safety Inspectorate ENSI discusses the expert report published on the need for the assessment of geomechanical properties and maximum depth of repositories for high, medium and low-activity nuclear wastes. Also, aspects concerning excavation damaged zones (EDZ) are considered. These are all criteria for the selection of sites as part of Phase 2 of the Swiss waste disposal project. Four questions are examined: are NAGRA’s documented basic considerations and calculations on Opalinus Clay comprehensive enough and correct, are the calculations on maximum depth correct, are the proposed storage perimeters correct with respect to depth and will NAGRA be able to take possible excavation damaged zones (EDZ) into account? Literature and references concerning the subject are quoted

  19. Hollow Cylinder Tests on Boom Clay: Modelling of Strain Localization in the Anisotropic Excavation Damaged Zone

    Science.gov (United States)

    François, Bertrand; Labiouse, Vincent; Dizier, Arnaud; Marinelli, Ferdinando; Charlier, Robert; Collin, Frédéric

    2014-01-01

    Boom Clay is extensively studied as a potential candidate to host underground nuclear waste disposal in Belgium. To guarantee the safety of such a disposal, the mechanical behaviour of the clay during gallery excavation must be properly predicted. In that purpose, a hollow cylinder experiment on Boom Clay has been designed to reproduce, in a small-scale test, the Excavation Damaged Zone (EDZ) as experienced during the excavation of a disposal gallery in the underground. In this article, the focus is made on the hydro-mechanical constitutive interpretation of the displacement (experimentally obtained by medium resolution X-ray tomography scanning). The coupled hydro-mechanical response of Boom Clay in this experiment is addressed through finite element computations with a constitutive model including strain hardening/softening, elastic and plastic cross-anisotropy and a regularization method for the modelling of strain localization processes. The obtained results evidence the directional dependency of the mechanical response of the clay. The softening behaviour induces transient strain localization processes, addressed through a hydro-mechanical second grade model. The shape of the obtained damaged zone is clearly affected by the anisotropy of the materials, evidencing an eye-shaped EDZ. The modelling results agree with experiments not only qualitatively (in terms of the shape of the induced damaged zone), but also quantitatively (for the obtained displacement in three particular radial directions).

  20. Effect of excavation method on rock mass displacement

    International Nuclear Information System (INIS)

    Sato, Toshinori; Kikuchi, Tadashi; Sugihara, Kozo

    1998-01-01

    Rock mass displacement measurements have been performed to understand rock mass behavior and its dependence on excavation method during drift excavation at the Tono mine. Rock mass displacements of 1.46 mm and 0.67 mm have been measured at one meter (0.33D: blasting, 0.42D: machine, D: width of drift) from the walls of drifts excavated by the drill and blasting method and machine, respectively. Numerical analysis of rock mass displacements with Finite Element Method has been performed assuming an excavation disturbed zone. Measured and analysed rock mass displacements are consistent with each other for the drift excavation by the drill and blasting method. The excavation disturbed zone was narrower for the drift excavated by machine than for the drift excavated by the drill and blasting method. (author)

  1. Characteristics of the excavation response zone as applied to shaft sealing

    International Nuclear Information System (INIS)

    Jakubick, A.T.; Klein, R.; Gray, M.N.; Keil, L.D.

    1989-01-01

    Effective sealing of an underground repository requires high quality seals. Clay-based backfills in combination with cement plugs are the possible candidates. An important component of the shaft sealing program is the development of techniques to predict and monitor the flow in the excavation response zone (ERZ) and at the seal-rock interface. The mechanical and hydraulic performance of the seal and backfill and the flow characteristics of the ERZ under in situ conditions will be tested in three experimental shafts to be excavated in the URL. The use of the vacuum permeability technique for characterization of the hydraulic properties and of the permeability distribution in the ERZ under various geomechanical conditions is discussed

  2. Time-dependent evolution of the excavation damaged zone in the argillaceous Tournemire site

    Energy Technology Data Exchange (ETDEWEB)

    Rejeb, A.; Cabrera, J. [Institut de Radioprotection et de Surete Nucleaire (IRSN/DEI/SARG), Lab. d' Etude Hydrodynamique et Geotechnique, 92 - Fontenay-aux-Roses (France)

    2006-07-01

    The experimental Tournemire site enables the assessment of the Excavation Damaged Zones (EDZ) around three structures excavated in argilites: the century-old tunnel, the ten year-old east and west galleries, and the three year-old main gallery. This paper discusses the main experimental results concerning the EDZ characterisation and their interpretation. EDZ fracture analyses from the galleries (cartography) and the radial boreholes (core analyses) allow for accurate structural characterisation of the EDZs. The tunnel has an EDZ with dense, homogeneous fracturing parallel to the wall, resembling onion skins. However, the new galleries do not have an EDZ similar to that of the tunnel. Unsaturated micro-cracks, mainly parallel to the bedding planes are observed on the non covered walls of each gallery. The extent of the EDZ does not seem to be affected by the age of the structure. It is approximately 20 % of the mean radius of the structure. Based on the modelling and experimental characterisation work completed, it is considered that the EDZ in this argillaceous Tournemire site is due to a deferred failure. At first time, when the wall of the structures are not covered the desaturation/re-saturation phenomena induced a tensile failure around the new galleries. During the time, these desaturation/re-saturation phenomena cause a gradual weakening of the material. The EDZ tunnel fractures are explained by this possible hydric damage and a decreasing mechanical strength with the time. These assumptions remain to be confirmed through coupled numerical modelling in unsaturated medium. (authors)

  3. Time-dependent evolution of the excavation damaged zone in the argillaceous Tournemire site

    International Nuclear Information System (INIS)

    Rejeb, A.; Cabrera, J.

    2006-01-01

    The experimental Tournemire site enables the assessment of the Excavation Damaged Zones (EDZ) around three structures excavated in argilites: the century-old tunnel, the ten year-old east and west galleries, and the three year-old main gallery. This paper discusses the main experimental results concerning the EDZ characterisation and their interpretation. EDZ fracture analyses from the galleries (cartography) and the radial boreholes (core analyses) allow for accurate structural characterisation of the EDZs. The tunnel has an EDZ with dense, homogeneous fracturing parallel to the wall, resembling onion skins. However, the new galleries do not have an EDZ similar to that of the tunnel. Unsaturated micro-cracks, mainly parallel to the bedding planes are observed on the non covered walls of each gallery. The extent of the EDZ does not seem to be affected by the age of the structure. It is approximately 20 % of the mean radius of the structure. Based on the modelling and experimental characterisation work completed, it is considered that the EDZ in this argillaceous Tournemire site is due to a deferred failure. At first time, when the wall of the structures are not covered the desaturation/re-saturation phenomena induced a tensile failure around the new galleries. During the time, these desaturation/re-saturation phenomena cause a gradual weakening of the material. The EDZ tunnel fractures are explained by this possible hydric damage and a decreasing mechanical strength with the time. These assumptions remain to be confirmed through coupled numerical modelling in unsaturated medium. (authors)

  4. Hydrogeochemical and microbiological effects on fractures in the Excavation Damaged Zone (EDZ)

    Energy Technology Data Exchange (ETDEWEB)

    Laaksoharju, Marcus (Geopoint AB, Sollentuna (Sweden)); Gimeno, Maria; Auque, Luis F.; Gomez, Javier B.; Acero, Patricia (Univ. of Zaragoza, Earth Science Dept., Zaragoza (Spain)); Pedersen, Karsten (Microbial Analytics, Moelnlycke (Sweden))

    2009-01-15

    Due to the disturbances associated with the excavation, construction and closure of the repository for storage of spent nuclear fuel, the saturation state of the groundwaters at repository depth with respect to several mineral phases may change and mineral precipitation/dissolution reactions may take place. In addition, changing groundwater conditions may facilitate microbial growth on fracture walls. These processes are of importance since they may influence the stability and safety of the Excavation Damaged Zone (EDZ) because precipitation and microbial growth may seal the hydraulically conductive fractures caused by the repository construction. Different processes expected to occur in the EDZ during the open repository conditions and after repository closure have been evaluated based on data from Forsmark, Laxemar and Aespoe. Geochemical modelling by using PHREEQC was applied to simulate the following cases: - increase of temperature to 50 deg C and 100 deg C to simulate the thermal effects from spent nuclear fuel; - open repository conditions simulating atmospheric conditions (equilibrium with atmospheric partial pressures of CO{sub 2}(g) and O{sub 2}(g)); - mixing with deep saline water simulating up-coning; - mixing with shallow infiltration waters simulating down-coning; - mixing with different proportions of cement dissolution porewater. The effect of variable temperatures (up to 100 deg C) on most of the above modelled processes has also been assessed. A preliminary estimation of the effect of mineral precipitation on the hydraulic conductivity of the EDZ has been carried out. For most of the modelling cases, the estimated decrease of the hydraulic conductivity in ten years is smaller than 2%. Microbial evaluation was used to identify the potential for microbial calcite and iron hydroxide formation during various repository conditions. The most important groundwater parameters for microorganisms, are pH and carbonate, ferrous iron, methane and the

  5. Hydrogeochemical and microbiological effects on fractures in the Excavation Damaged Zone (EDZ)

    International Nuclear Information System (INIS)

    Laaksoharju, Marcus; Gimeno, Maria; Auque, Luis F.; Gomez, Javier B.; Acero, Patricia; Pedersen, Karsten

    2009-01-01

    Due to the disturbances associated with the excavation, construction and closure of the repository for storage of spent nuclear fuel, the saturation state of the groundwaters at repository depth with respect to several mineral phases may change and mineral precipitation/dissolution reactions may take place. In addition, changing groundwater conditions may facilitate microbial growth on fracture walls. These processes are of importance since they may influence the stability and safety of the Excavation Damaged Zone (EDZ) because precipitation and microbial growth may seal the hydraulically conductive fractures caused by the repository construction. Different processes expected to occur in the EDZ during the open repository conditions and after repository closure have been evaluated based on data from Forsmark, Laxemar and Aespoe. Geochemical modelling by using PHREEQC was applied to simulate the following cases: - increase of temperature to 50 deg C and 100 deg C to simulate the thermal effects from spent nuclear fuel; - open repository conditions simulating atmospheric conditions (equilibrium with atmospheric partial pressures of CO 2 (g) and O 2 (g)); - mixing with deep saline water simulating up-coning; - mixing with shallow infiltration waters simulating down-coning; - mixing with different proportions of cement dissolution porewater. The effect of variable temperatures (up to 100 deg C) on most of the above modelled processes has also been assessed. A preliminary estimation of the effect of mineral precipitation on the hydraulic conductivity of the EDZ has been carried out. For most of the modelling cases, the estimated decrease of the hydraulic conductivity in ten years is smaller than 2%. Microbial evaluation was used to identify the potential for microbial calcite and iron hydroxide formation during various repository conditions. The most important groundwater parameters for microorganisms, are pH and carbonate, ferrous iron, methane and the dissolved

  6. WIPP air-intake shaft disturbed-rock zone study

    International Nuclear Information System (INIS)

    Dale, T.; Hurtado, L.D.

    1996-01-01

    The disturbed-rock zone surrounding the air-intake shaft at the Waste Isolation Pilot Plant (WIPP) site was investigated to determine the extent and the permeability of the disturbed-rock zone as a function of radial distance from the 6.1 m diameter shaft, at different elevations within the Salado. Gas- and brine-permeability tests were performed in the bedded halite of the Salado formation at two levels within the air-intake shaft. The gas- and brine-permeability test results demonstrated that the radial distance to an undisturbed formation permeability of 1 x 10 -21 m 2 was less than 3.0 m

  7. 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

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

    International Nuclear Information System (INIS)

    Olsson, Mats; Markstroem, Ingemar; Pettersson, Anders; Straeng, Malin

    2009-10-01

    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 m 2 , 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. Hydrogeologic characterization and evolution of the 'excavation damaged zone' by statistical analyses of pressure signals: application to galleries excavated at the clay-stone sites of Mont Terri (Ga98) and Tournemire (Ga03)

    International Nuclear Information System (INIS)

    Fatmi, H.; Ababou, R.; Matray, J.M.; Joly, C.

    2010-01-01

    Document available in extended abstract form only. This paper presents methods of statistical analysis and interpretation of hydrogeological signals in clayey formations, e.g., pore water pressure and atmospheric pressure. The purpose of these analyses is to characterize the hydraulic behaviour of this type of formation in the case of a deep repository of Mid- Level/High-Level and Long-lived radioactive wastes, and to study the evolution of the geologic formation and its EDZ (Excavation Damaged Zone) during the excavation of galleries. We focus on galleries Ga98 and Ga03 in the sites of Mont Terri (Jura, Switzerland) and Tournemire (France, Aveyron), through data collected in the BPP- 1 and PH2 boreholes, respectively. The Mont Terri site, crossing the Aalenian Opalinus clay-stone, is an underground laboratory managed by an international consortium, namely the Mont Terri project (Switzerland). The Tournemire site, crossing the Toarcian clay-stone, is an Underground Research facility managed by IRSN (France). We have analysed pore water and atmospheric pressure signals at these sites, sometimes in correlation with other data. The methods of analysis are based on the theory of stationary random signals (correlation functions, Fourier spectra, transfer functions, envelopes), and on multi-resolution wavelet analysis (adapted to nonstationary and evolutionary signals). These methods are also combined with filtering techniques, and they can be used for single signals as well as pairs of signals (cross-analyses). The objective of this work is to exploit pressure measurements in selected boreholes from the two compacted clay sites, in order to: - evaluate phenomena affecting the measurements (earth tides, barometric pressures..); - estimate hydraulic properties (specific storage..) of the clay-stones prior to excavation works and compare them with those estimated by pulse or slug tests on shorter time scales; - analyze the effects of drift excavation on pore pressures

  10. Improvement of the excavation damaged zone in saliferous formations. Phase II. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, C.; Simo Kuate, E.; Borstel, L. von; Engelhardt, H.J.

    2016-01-15

    In Germany, salt formations are considered to be suitable to host a deep geological repository for radioactive waste. However, local stress changes adjacent to man-made openings lead to the evolution of an excavation damaged zone (EDZ) during and after excavation. Such an EDZ can have a major impact on the operation of a radioactive waste repository since it represents a region where progressive failure occurs. This decreases the material strength and thus increases the permeability of the originally tight host rock. The objective of this investigation is determined by the need to develop a modeling strategy that can be applied to simulate the permeability increase due to mechanical deterioration of rock salt, in particular that occurring in the EDZ. The identification of material parameters is often conducted by back-calculation of laboratory experiments. However, standard laboratory tests, e.g. compression tests, are only applicable to provide information about the macroscopic deformation. For this purpose, further laboratory tests were conducted to derive material parameters used in the constitutive models. Combined acoustic emission and uniaxial compression tests as well as microstructural analyses were carried out to dissolve the macroscopic behavior micromechanically. The information obtained was then used for parameter identification utilizing optimization methods. The objective was to identify the best estimate of the micro-parameter values that can be applied to simulate the laboratory results performed. To make a qualitative comparison between the numerical analysis and the acoustic emission (AE) testing, the onset of failure at contacts was equated with events detected by AE testing. The onset of failure is identified at stress levels above 3 MPa. The number of tensile fractures increases continuously and the maximum is reached between 10 and 12 MPa axial stress. At the beginning of loading, tensile fractures appear more frequently than shear fractures

  11. Characterization of textural and hydric heterogeneities in argillaceous geo-materials using induced polarization method: application to the excavation damaged zone (EDZ) of the Tournemire experimental station

    International Nuclear Information System (INIS)

    Okay, Gonca

    2011-01-01

    This Ph-D thesis investigates the potential of clay rocks for deep geological disposal of radioactive waste. Underground excavations are responsible in their vicinity a region, where the clay-rock is damaged or disturbed. This region must to be characterized to ensure the safety of repositories. The extension of the excavation damaged zone (EDZ) and its evolution over time have been investigated thought electrical resistivity and induced polarization methods from three galleries belonging to the French Institute of Radioprotection and Nuclear Safety (IRSN)'s experimental underground research laboratory of Tournemire (Aveyron, France). Time domain induced polarisation indicates the presence of mineralization (e.g., especially pyrite) located in the structural discontinuities such as tectonic fractures (mm-cm), tectonic fault (m) and calcareous nodules (cm). Combined electrical resistivity and Induced Polarization methods show the possibility to delineate textural changes associated to desaturation of the clay-rock induced by the ventilation of galleries. The impact of the desaturation is particularly observed on the gallery's walls. In addition, Spectral Induced Polarization (SIP) tomography results can be used to discriminate the responses of the de-saturated zones from the fractured zones. We have performed laboratory experiments (in the range 1.4 mHz - 12 kHz) using saturated unconsolidated sand-clay mixtures. The results illustrate that the amplitude of polarization is strongly affected by the surface properties of these mixtures (e.g., cation exchange capacity, specific surface area) and by the volumetric clay content. However, the amplitude of polarization is independent of the concentration of electrolyte. The SIP response is also strongly sensitive to the mineralogy of the clays. (author)

  12. The role of the disturbed rock zone in radioactive waste repository safety and performance assessment. A topical discussion and international overview

    International Nuclear Information System (INIS)

    Winberg, A.

    1991-06-01

    A discussion was presented of the role and relative importance of the disturbed rock zone (DRZ) around the underground openings of a repository for nuclear waste in crystalline rock. The term disturbed rock zone was defined and possible criteria to be sued to distinguish if from undisturbed rock was suggested. The processes decisive for the hydraulic characteristics of the DRZ were discussed. With regard to the integral hydraulic characteristics of the DRZ, the effects of the excavation methodology, stress redistribution, thermal changes, chemical changes and backfill were discussed. A review of in-situ observations of the DRZ was provided. Model analysis where the DRZ has been explicitly or implicitly represented, either from a phenomenological and performance assessment aspect were reviewed. The implications of the disturbed rock zone for the safe performance of a nuclear waste repository were discussed. Conceptual models for the geometry of the DRZ and hydraulic conductivity distribution in the DRZ were suggested. (au) (82 refs.)

  13. Controlled drill ampersand blast excavation at AECL's Underground Research Laboratory

    International Nuclear Information System (INIS)

    Kuzyk, G.W.; Onagi, D.P.; Thompson, P.M.

    1996-01-01

    A controlled drill and blast method has been developed and used to excavate the Underground Research Laboratory, a geotechnical facility constructed by Atomic Energy of Canada Limited (AECL) in crystalline rock. It has been demonstrated that the method can effectively reduce the excavation disturbed zone (EDZ) and is suitable for the construction of a used fuel disposal vault in the plutonic rock of the Canadian Shield

  14. Characterization and monitoring of the excavation damaged zone in fractured gneisses of the Roselend tunnel, French Alps

    Science.gov (United States)

    Wassermann, J.; Sabroux, J. C.; Pontreau, S.; Bondiguel, S.; Guillon, S.; Richon, P.; Pili, E.

    2011-04-01

    The Roselend dead-end tunnel was excavated in the last fifties by blasting in the Méraillet crystalline rock mass located on the shore of an artificial reservoir lake in the French Alps. Successive emptying and filling of the reservoir lake induce mechanical deformation of the rock mass. Thus, this tunnel is an exceptional place to study the evolution of the damaged zone (due to the excavation, and named EDZ) under a periodic mechanical or hydraulic loading. From the perspective of radioactive waste isolation in deep geological strata, the EDZ transport properties, and their evolution with time, are of major importance. The purpose of this study is, on the one hand, to quantify the transport properties of the EDZ of the Roselend tunnel through permeability measurements and drill core observations; on the other hand, to monitor the response of the EDZ to external solicitations via borehole pressure measurements. The air permeability has been deduced from pneumatic tests performed along several boreholes. The permeability profiles and the observation of drill cores lead to an estimation of the extent of the EDZ, of about 1 m around the tunnel. The response of the EDZ to barometric pumping has been observed through borehole pressure monitoring. Time-lag and attenuation of the barometric signal that propagates into the EDZ have been measured at a metric scale. The identification of potential time-lag and attenuation variations needs further investigations, the long time series of borehole pressure monitoring shows pressure increase probably due to percolating water during successive snow cover and thawing periods as observed in the Roselend area during winter.

  15. Characterizing Excavation Damaged Zone and Stability of Pressurized Lined Rock Caverns for Underground Compressed Air Energy Storage

    Science.gov (United States)

    Kim, Hyung-Mok; Rutqvist, Jonny; Jeong, Ju-Hwan; Choi, Byung-Hee; Ryu, Dong-Woo; Song, Won-Kyong

    2013-09-01

    In this paper, we investigate the influence of the excavation damaged zone (EDZ) on the geomechanical performance of compressed air energy storage (CAES) in lined rock caverns. We conducted a detailed characterization of the EDZ in rock caverns that have been excavated for a Korean pilot test program on CAES in (concrete) lined rock caverns at shallow depth. The EDZ was characterized by measurements of P- and S-wave velocities and permeability across the EDZ and into undisturbed host rock. Moreover, we constructed an in situ concrete lining model and conducted permeability measurements in boreholes penetrating the concrete, through the EDZ and into the undisturbed host rock. Using the site-specific conditions and the results of the EDZ characterization, we carried out a model simulation to investigate the influence of the EDZ on the CAES performance, in particular related to geomechanical responses and stability. We used a modeling approach including coupled thermodynamic multiphase flow and geomechanics, which was proven to be useful in previous generic CAES studies. Our modeling results showed that the potential for inducing tensile fractures and air leakage through the concrete lining could be substantially reduced if the EDZ around the cavern could be minimized. Moreover, the results showed that the most favorable design for reducing the potential for tensile failure in the lining would be a relatively compliant concrete lining with a tight inner seal, and a relatively stiff (uncompliant) host rock with a minimized EDZ. Because EDZ compliance depends on its compressibility (or modulus) and thickness, care should be taken during drill and blast operations to minimize the damage to the cavern walls.

  16. Elemental analyses on porcelains of Tang and Song Dynasties excavated from Yongjinwan zone at Jinsha site

    Science.gov (United States)

    Xia, C. D.; Ge, L. J.; Liu, M. T.; Zhu, J. J.; An, Z.; Bai, B.

    2018-02-01

    The work presented here carried out elemental analyses on 60 porcelain shards of Tang and Song Dynasties, unearthed from Yongjinwan zone at Jinsha site, Sichuan, China, using a combination of PIXE and RBS methods. Six shards from Liulichang kiln site and 6 from Shifangtang kiln site were also analyzed as reference materials. The factor analyses for the elemental compositions in the bodies and glazes of the total 72 porcelain shards have been performed to explore their similarities and differences. Combining the results of factor analyses on elements in bodies and glazes and the classification by traditional archaeological criteria, the provenances for most of shards unearthed from Yongjinwan zone in Jinsha site could be determined. Majority of shards with a Qiong-kiln style were found as products of Liulichang kiln, this is consistent with Yongjinwan's geographical location and social environment, i.e., Yongjinwan was a suburban settlement nearest to Liulichang kiln in ancient times. Although both products of Liulichang kiln and Shifangtang kiln belonged to Qiong-kiln system and they shared a similar appearance such as red body and celadon glaze, there were distinct differences in chemical composition which could be unraveled by PIXE-RBS measurements and factor analysis. There were no apparent differences of chemical compositions for the same kinds of body and glaze between Tang and Song Dynasties, which may suggest that raw materials and production techniques for the same kinds of body and glaze continued between Tang and Song Dynasties. The chemical characteristics for each kind of body and glaze and the correlations between element composition and porcelain appearance were also obtained in this work.

  17. A method of modeling time-dependent rock damage surrounding underground excavations in multiphase groundwater flow

    International Nuclear Information System (INIS)

    Christian-Frear, T.; Freeze, G.

    1997-01-01

    Underground excavations produce damaged zones surrounding the excavations which have disturbed hydrologic and geomechanical properties. Prediction of fluid flow in these zones must consider both the mechanical and fluid flow processes. Presented here is a methodology which utilizes a mechanical model to predict damage and disturbed rock zone (DRZ) development around the excavation and then uses the predictions to develop time-dependent DRZ porosity relationships. These relationships are then used to adjust the porosity of the DRZ in the fluid flow model based upon the time and distance from the edge of the excavation. The application of this methodology is presented using a site-specific example from the Waste Isolation Pilot Plant, a US Department of Energy facility in bedded salts being evaluated for demonstration of the safe underground disposal of transuranic waste from US defense-related activities

  18. Proposed preliminary definition of the disturbed-zone boundary appropriate for a repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Langkopf, B.S.

    1987-12-01

    Some of the calculations that support the licensing of a repository for high-level radioactive waste will use the regulatory concept of a disturbed zone. The Nevada Nuclear Waste Storage Investigations (NNWSI) project must determine the location of the boundary of the disturbed zone for use in these calculations. This paper summarizes results of computer analyses and laboratory experiments and suggests a preliminary definition for the boundary of the disturbed zone for the unsaturated environment at Yucca Mountain. Although the intent of this paper is to define the boundary of the disturbed zone at the edge of significant changes in intrinsic hydrologic properties, there is no evidence of changes in intrinsic hydrologic properties that could significantly change the groundwater travel time from the repository to the water table. Such a result suggests that the disturbed zone at Yucca Mountain is of minimal extent. Because the analyses and experiments reviewed here indicate that there are a variety of changes near the waste package and because the results are subject to uncertainty, the preliminary suggestion for the extent of the disturbed zone is a value larger than the results themselves would suggest: the boundary is proposed to be a plane 10 m below the lower boundary of the waste packages. 88 refs., 12 figs., 5 tabs

  19. Characterization of the mechanical and hydraulic damage in the excavation damaged zone of MHM with gas permeability measurement

    International Nuclear Information System (INIS)

    Yang, D.

    2008-09-01

    On the feasibility evaluation of nuclear waste storage in deep formations, the essential issues are as follows: the stability of underground structures over the reversible period, the influence of cavity excavation on geomechanical properties of the wall rock and the variation of those properties during the different phases while storage realization. The work presented here covers the investigations on the variation of geomechanical properties of the approximately 500 m deep MHM in France (mudstone in the departments of Meuse/Haute-Marne), chosen as a potential medium for nuclear waste disposal by ANDRA. In order to measure the very low permeability of mudstone and to observe the dependency on saturation, a special test scheme on measurement of gas permeability has been developed. In the scheme, in situ referenced stresses have been chosen as the stresses acting on the solid matrix. The gas permeability has been determined with both analytical and numerical methods. To estimate the mechanical damage of storage induced by the excavation, laboratory tests on gas permeability have been conducted on samples recovered from different locations situated at different distances from the wall of the main access shaft of the MHM (from 0,1 m to 12,5 m). Results of gas permeability obtained under an isotropic stress of 11 MPa vary between 10 -21 and 10 -22 m 2 and do not show significant variations between damaged zones (near the wall) and intact zones (sample located 12 m from the wall). The observations in laboratory tests coincide with in situ damage characterizations. The variation of gas permeability under the cycle of loading and unloading is an order less than the initial value under the isotropic stress. Taking into account the precision of the testing system, this variation is not significant. The oviparous intact samples have been imposed different saturations by salt solutions (with a relative humidity from 25 % to 98 %) to form a cycle of de- and re-saturation. The

  20. Examining excavators

    Energy Technology Data Exchange (ETDEWEB)

    Bartos, K.; Behalek, L.; Burysek, P. (and others) [Prodeco (Czech Republic)

    2006-11-15

    The paper reports on how excavators are adapted to different applications, as illustrated by Prodeco's experience at supplying bucket wheel and bucket chain excavators in the Czech Republic and worldwide. The reconstruction of the cutting equipment of a bucket wheel excavator KU 800.20 located at Doly Bilina to prepare for digging hard overburden without using shaking blasting is described. 2 tabs., 4 photos.

  1. Final report of the rock sealing project - Identification of zones disturbed by blasting and stress release

    International Nuclear Information System (INIS)

    Boergesson, L.; Pusch, R.; Fredriksson, A.; Hoekmark, H.; Karnland, O.; Sanden, R.

    1992-01-01

    Tests 2 and 3 of the rock sealing project comprised determination of the hydraulic properties of the disturbed rock around tunnels and drifts and the possibilities of decreasing the hydraulic conductivity of the disturbed zones by an attempt to seal the very fine fractures that are causing the increased conductivity. This report deals with the hydraulic testing while the grouting procedures and their effect are described in volume 3. The BMT drift was used for the experiments which basically consisted of measuring the flow of water from an inner pressurized slot and borehole curtain to an outer curtain with zero water pressure (Macro Flow Test). The 12 m long drift was sealed from water inflow by a slurry that filled the entire drift. The slurry was pressurized by a large water filled bladder for eliminating leakage along and through the drift. The flow tests were primarily evaluated by finite element modeling in which the rock was considered an equivalent porous medium. Two possible rock models were developed that satisfied not only the flow and water pressure measurements during the macro flow test but also 3 different flow situations preceding the test. The models imply a shallow blast-disturbed zone with a strongly increased hydraulic conductivity, and a stress disturbed zone with a decreased radial hydraulic conductivity. The main difference between the models is the extension of the blast-damaged zone and the axial hydraulic conductivity of the stress disturbed zone. (au)

  2. Monitoring the Excavation Damaged Zone in Opalinus clay by three dimensional reconstruction of the electrical resistivity in the Mont Terri gallery G-04

    Science.gov (United States)

    Lesparre, N.; Adler, A.; Nicollin, F.; Gibert, D.; Nussbaum, C.

    2012-04-01

    The characteristics of opalinus clay have been studied in the last years for its capacity to retain radionuclide transport as a low permeable rock. This formation presents thereby suitable properties for hosting repository sites of radioactive waste. The Mont Terri underground rock laboratory (Switzerland) has been excavated in opalinus clay layer in order to develop experiences improving the knowledge on the physico-chemical properties of the rock. The study of electrical properties furnishes information on the rock structure, its anisotropy and the changes of these properties with time (Nicollin et al., 2010 ; Thovert et al., 2011). Here the three dimensional reconstruction of the electrical resistivity aims at monitoring the temporal evolution of the excavation damaged zone. Three rings of electrodes have been set-up around the gallery and voltage is measured between two electrodes while a current is injected between two others (Gibert et al., 2006). Measurements have been achieved from July 2004 until April 2008 before, during and after the excavation of the gallery 04. In this study we develop a computational approach to reconstruct three dimensional images of the resistivity in the vicinity of the electrodes. A finite element model is used to represent the complex geometry of the gallery. The measurements inferred from a given resistivity distribution are estimated using the software EIDORS (Adler and Lionheart, 2006), this constitutes the forward problem. The reconstruction of the media resistivity is then implemented by fitting the estimated to the measured data, via the resolution of an inverse problem. The parameters of this inverse problem are defined by mapping the forward problem elements into a coarser mesh. This allows to reduce drastically the number of unknowns and so increases the robustness of the inversion. The inversion is executed with the conjugate gradient method regularised by an analysis of the Jacobian singular values. The results show an

  3. A computational model of pile vertical vibration in saturated soil based on the radial disturbed zone of pile driving

    International Nuclear Information System (INIS)

    Li Qiang; Shi Qian; Wang Kuihua

    2010-01-01

    In this study, a simplified computational model of pile vertical vibration was developed. The model was based on the inhomogeneous radial disturbed zone of soil in the vicinity of a pile disturbed by pile driving. The model contained two regions: the disturbed zone, which was located in the immediate vicinity of the pile, and the undisturbed region, external to the disturbed zone. In the model, excess pore pressure in the disturbed zone caused by pile driving was assumed to follow a logarithmic distribution. The relationships of stress and strain in the disturbed zone were based on the principle of effective stress under plain strain conditions. The external zone was governed by the poroelastic theory proposed by Biot. With the use of a variable separation method, an analytical solution in the frequency domain was obtained. Furthermore, a semi-analytical solution was attained by employing a numerical convolution method. Numerical results from the frequency and time domain indicated that the equivalent radius of the disturbed zone and the ratio of excess pore pressure had a significant effect on pile dynamic response. However, actual interactions between pile and soil will be weaker due to the presence of the radial disturbed zone, which is caused by pile driving. Consequently, the ideal undisturbed model overestimates the interaction between pile and soil; however, the proposed model reflects the interaction of pile and soil better than the perfect contact model. Numerical results indicate that the model can account for the time effect of pile dynamic tests.

  4. Investigations for a change of an excavation damaged zone with time at the 250 m gallery in the Horonobe Underground Research Laboratory

    International Nuclear Information System (INIS)

    Aoyagi, Kazuhei; Tsusaka, Kimikazu; Kondo, Keiji; Inagaki, Daisuke; Kubota, Kenji; Tokiwa, Tetsuya

    2014-01-01

    The authors have been conducting seismic and resistivity tomography surveys in a gallery of the Horonobe Underground Research Laboratory in order to investigate an extent of an Excavation Damaged Zone (EDZ) along time. The objective of this paper is to discuss an influence of fracture distribution and water saturation of a rock mass on variations in seismic velocity and the value of apparent resistivity in an EDZ. Based on the result of seismic tomography survey, the extent of a layer which has low seismic velocity was about 1.0 m from the gallery wall after excavation of the tomography area. From the results of resistivity tomography survey, the value of apparent resistivity has not changed remarkably along time. To investigate a relationship between variations in seismic velocity and density of fracture in the survey area, the authors built a three dimensional fracture model around the tomography area. From the comparison of seismic velocity with density of fracture, seismic velocity decreased almost linearly as the density of fracture increased. Also, it was found that density of fracture in the layer of low seismic velocity could be estimated using a simple numeric model. >From this result, seismic tomography survey and investigation of density of fracture are suitable method for evaluation of an EDZ. (author)

  5. DECOVALEX-THMC Project. Task C. Excavation Damaged Zone (EDZ) in argillaceous rock at Tournemire site (France). Report of Task C1

    Energy Technology Data Exchange (ETDEWEB)

    Rejeb, A. (comp.) [Inst. of Radioprotection and Nuclear Safety (France); Stephansson, O. (comp.) [GeoForschungsZentrum-Potsdam (Germany); Millard, A. [CEA/IRSN (France); Ziefle, G.; Kohlmeier, M.; Massmann, J.; Zielke, W. [ISEB/BGR (Germany); Uehara, S.; Kobayashi, A.; Chijimatsu, M.; Fujita, T. [KU/JAEA (Japan)

    2007-02-15

    The DECOVALEX-THMC project is an ongoing international co-operative project that was stared in 2004 to support the development of mathematical models of coupled Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) processes in geological media for siting potential nuclear fuel waste repositories. The general objective is to characterise and evaluate the coupled THMC processes in the near field and far field of a geological repository and to assess their impact on performance assessment: - during the three phases of repository development: excavation phase, operation phase and post-closure phase; - for three different rocks types: crystalline, argillaceous and tuff; - with specific focus on the issues of: Excavation Damaged Zone (EDZ), permanent property changes of rock masses, and glaciation and permafrost phenomena. This report describes the results of Task C1 of the project devoted to Excavation Damage Zone (EDZ) in argillaceous rock at the Tournemire site in France. The task is to develop adequate numerical models for interpretation of observed damaged zones around three different openings excavated at different time at the Tournemire site. The research teams are asked to model the evolution of the EDZ with time and to compare the results with measurements performed at the site. Three research teams are participating in this task: - CEA (Commissariat of Atomic Energy, France) and the IRSN (Institute of Radioprotection and Nuclear safety, France) ; - ISEB (Institute of Fluid Mechanics and Computer Applications in Civil Engineering, University of Hanover, Germany) supported by the BGR (Federal Institute for Geosciences and Natural Resources, Germany); - KU (Department of Urban and Environmental Engineering, Kyoto University, Japan) supported by the JAEA (Japan Atomic Energy Agency, Japan). This report presents a description and definition of Task C including a geological description of the site, the geomechanical characterisation of the argillaceous

  6. A numerical study of the effects of a discrete fracture and an excavation damage zone on 129I transport through the geosphere

    International Nuclear Information System (INIS)

    Chan, T.; Scheier, N.W.; O'Connor, P.A.

    1997-10-01

    A numerical study has been conducted to investigate the effects of a discrete fracture and an excavation damage zone (EDZ) on groundwater mediated transport of I2 9 from a hypothetical nuclear fuel waste disposal vault through saturated, sparsely fractured plutonic rock to the biosphere. The reference disposal system simulated in the present work is based on the median value case of the postclosure assessment case study presented by AECL to support the Environmental Impact Statement (EIS) submitted to the Canadian Environmental Assessment Agency (CEAA). In particular, the reference geosphere is based mainly on hydrogeological characteristics at the site of AECL's Underground Research Laboratory in the Whiteshell Research Area, southeastern Manitoba. Several features not explicitly simulated in the EIS postclosure assessment case study are investigated in this study. These include the hypothetical possibility of a discrete fracture or a narrow fracture zone existing in the rock in the immediate vicinity of the disposal vault. This hypothetical fracture is modeled as a discrete fracture that connects or almost connects the vault to nearby fracture zone LD1. Simulations are performed using a combination of three-dimensional flow model and corresponding two-dimensional transport models, and the MOTIF finite-element code. It should be emphasized that the primary purpose of the present study it to investigate the relative importance of the various possible features in the rock in the immediate vicinity of the vault. Detailed numerical modelling of the effectiveness of various engineered barriers that could be used to mitigate any negative effects of such features is beyond the scope of this study

  7. Mechanical tunnel excavation in welded tuff

    International Nuclear Information System (INIS)

    Sperry, P.E.

    1991-01-01

    The Technical Review Board for the US high-level radioactive waste facility at Yucca Mountain has recommended maximum use of open-quotes the most modern mechanical excavation techniques...in order to reduce disturbance to the rock walls and to achieve greater economy of time and cost.close quotes Tunnels for the waste repository at Yucca Mountain can be economically constructed with mechanical excavation equipment. This paper presents the results of mechanical excavation of a tunnel in welded tuff, similar to the tuffs of Yucca Mountain. These results are projected to excavation of emplacement drifts in Yucca Mountain using a current state-of-the-art tunnel boring machine (TBM)

  8. First Workshop on Design and Construction of Deep Repositories - Theme: Excavation through water-conducting major fracture zones

    International Nuclear Information System (INIS)

    Baeckblom, G.; Svemar, C.

    1994-01-01

    Final disposal of high-level nuclear waste has not yet been carried out in any country today. The concepts under development are all based on geological repositories, i.e., disposal at a sufficient depth below the surface to provide stable mechanical, hydrological and chemical conditions during the period the waste needs to be isolated from man. In the cases where crystalline bedrock is considered the proposed repository depths vary between 300-1000 m. The construction, operation and sealing of a deep geological repository must meet various criteria that in many respects are more detailed and more demanding than usual in underground construction projects today. The work shall be done so that occupational safety is ensured. The work also shall conform to whatever restrictions are necessary for ensuring pre-closure operational safety and post-closure long-term safety. March 1993 SKB arranged a two-day international workshop to discuss design and construction of repositories. Close to 40 participants from eight countries shared experiences regarding passage of major water-conducting fracture zones and other matters. This report summarizes the contributions to the workshop

  9. Layer disturbances and the radio-echo free zone in ice sheets

    Directory of Open Access Journals (Sweden)

    R. Drews

    2009-08-01

    Full Text Available Radio-echo sounding of the Antarctic and Greenlandic ice sheets often reveals a layer in the lowest hundreds of meters above bedrock more or less free of radio echoes, known as the echo-free zone (EFZ. The cause of this feature is unclear, so far lacking direct evidence for its origin. We compare echoes around the EPICA drill site in Dronning Maud Land, Antarctica, with the dielectric properties, crystal orientation fabrics and optical stratigraphy of the EPICA-DML ice core. We find that echoes disappear in the depth range where the dielectric contrast is blurred, and where the coherency of the layers in the ice core is lost due to disturbances caused by the ice flow. At the drill site, the EFZ onset at ~2100 m marks a boundary, below which the ice core may have experienced flow induced disturbances on various scales. The onset may indicate changing rheology which needs to be accounted for in the modeling of ice sheet dynamics.

  10. Characterization of textural and hydric heterogeneities in argillaceous geo-materials using induced polarization method: application to the excavation damaged zone (EDZ) of the Tournemire experimental station; Caracterisation des heterogeneites texturales et hydriques des geomateriaux argileux par la methode de Polarisation Provoquee: Application a l'EDZ de la station experimentale de Tournemire

    Energy Technology Data Exchange (ETDEWEB)

    Okay, Gonca

    2011-03-25

    This Ph-D thesis investigates the potential of clay rocks for deep geological disposal of radioactive waste. Underground excavations are responsible in their vicinity a region, where the clay-rock is damaged or disturbed. This region must to be characterized to ensure the safety of repositories. The extension of the excavation damaged zone (EDZ) and its evolution over time have been investigated thought electrical resistivity and induced polarization methods from three galleries belonging to the French Institute of Radioprotection and Nuclear Safety (IRSN)'s experimental underground research laboratory of Tournemire (Aveyron, France). Time domain induced polarisation indicates the presence of mineralization (e.g., especially pyrite) located in the structural discontinuities such as tectonic fractures (mm-cm), tectonic fault (m) and calcareous nodules (cm). Combined electrical resistivity and Induced Polarization methods show the possibility to delineate textural changes associated to desaturation of the clay-rock induced by the ventilation of galleries. The impact of the desaturation is particularly observed on the gallery's walls. In addition, Spectral Induced Polarization (SIP) tomography results can be used to discriminate the responses of the de-saturated zones from the fractured zones. We have performed laboratory experiments (in the range 1.4 mHz - 12 kHz) using saturated unconsolidated sand-clay mixtures. The results illustrate that the amplitude of polarization is strongly affected by the surface properties of these mixtures (e.g., cation exchange capacity, specific surface area) and by the volumetric clay content. However, the amplitude of polarization is independent of the concentration of electrolyte. The SIP response is also strongly sensitive to the mineralogy of the clays. (author)

  11. Excavation multiple up drafting tunnels in coastal mountains: A simple solution to resist against the severe drought in sub tropical zones

    Science.gov (United States)

    Daei, Mohammad Ali; Daei, Manizheh; Daei, Bijan

    2017-04-01

    At many sub tropical places in the globe, including the Persian Gulf in the south of Iran, there is continuously a tremendous amount of steam in the air, but it fails to transform to cloud because of the surrounding overheated lands. Reduction in precipitation in these regions has been extraordinary in recent years. The most probable reason is the global warming phenomena. Many dried forest remains, in these regions are referring to much more precipitations not long ago. All around the Persian Gulf, Oman Sea, Arab sea, and red sea there are enough steam to produce good precipitation nearly year round. The main missed requirement in this zone is the coldness. This fact can be well understand from a narrow green strip in Dhofar which is indebted to a cold oceanic stream that approaches to local shore during four months yearly. This natural cold stream helps a better condensation of water vapor and more precipitation but only in a narrow mountainous land. Based on this natural phenomenon, we hypothesize a different design to cool the water vapor with the same result. Prevention of close contact between the water vapors and hot lands by shooting the steam directly into the atmosphere may help to produce more cloud and rain. Making multiple vertical tunnels in mountains for upright conducting of humid air into the atmosphere can be a solution. Fortunately there are a few high mountain ranges alongside of the coastline in south part of Iran. So excavation of drafting tunnels in these mountains seems reasonable. These structures act passively, but for long term do their work without consuming energy, and making pollution. These earth tubes in some aspects resemble to Kariz, another innovative structure which invented by ancient Iranians, thousands of years ago in order to extract water from dry lands in deserts. Up drafting earth channels can be supposed as a wide vertical kariz which conduct water vapor into the atmosphere from the hot land near a warm sea, something

  12. 300 Area Disturbance Report

    Energy Technology Data Exchange (ETDEWEB)

    LL Hale; MK Wright; NA Cadoret

    1999-01-07

    The objective of this study was to define areas of previous disturbance in the 300 Area of the U.S. Department of Energy (DOE) Hanford Site to eliminate these areas from the cultural resource review process, reduce cultural resource monitoring costs, and allow cultural resource specialists to focus on areas where subsurface disturbance is minimal or nonexistent. Research into available sources suggests that impacts from excavations have been significant wherever the following construction activities have occurred: building basements and pits, waste ponds, burial grounds, trenches, installation of subsurface pipelines, power poles, water hydrants, and well construction. Beyond the areas just mentioned, substrates in the' 300 Area consist of a complex, multidimen- sional mosaic composed of undisturbed stratigraphy, backfill, and disturbed sediments; Four Geographic Information System (GIS) maps were created to display known areas of disturbance in the 300 Area. These maps contain information gleaned from a variety of sources, but the primary sources include the Hanford GIS database system, engineer drawings, and historic maps. In addition to these maps, several assumptions can be made about areas of disturbance in the 300 Area as a result of this study: o o Buried pipelines are not always located where they are mapped. As a result, cultural resource monitors or specialists should not depend on maps depicting subsurface pipelines for accurate locations of previous disturbance. Temporary roads built in the early 1940s were placed on layers of sand and gravel 8 to 12 in. thick. Given this information, it is likely that substrates beneath these early roads are only minimally disturbed. Building foundations ranged from concrete slabs no more than 6 to 8 in. thick to deeply excavated pits and basements. Buildings constructed with slab foundations are more numerous than may be expected, and minimally disturbed substrates may be expected in these locations. Historic

  13. Disturbance and coastal forests: a strategic approach to forest management in hurricane impact zones

    Science.gov (United States)

    John A. Stanturf; Scott L. Goodrick; Kenneth W. Outcalt

    2007-01-01

    The Indian Ocean Tsunami focused world attention on societal responses to environmental hazards and the potential of natural systems to moderate disturbance effects. Coastal areas are critical to the welfare of up to 50% of the world's population. Coastal systems in the southern United States are adapted to specific disturbance regimes of tropical cyclones (...

  14. Acute Appendicitis, Somatosensory Disturbances ("Head Zones"), and the Differential Diagnosis of Anterior Cutaneous Nerve Entrapment Syndrome (ACNES).

    Science.gov (United States)

    Roumen, Rudi M H; Vening, Wouter; Wouda, Rosanne; Scheltinga, Marc M

    2017-06-01

    Anterior cutaneous nerve entrapment syndrome (ACNES) is a neuropathic abdominal wall pain syndrome typically characterized by locally altered skin sensations. On the other hand, visceral disease may also be associated with similar painful and altered skin sensations ("Head zones"). Aim of the study was to determine if patients with acute appendicitis demonstrated somatosensory disturbances in the corresponding right lower quadrant Head zone. The presence of somatosensory disturbances such as hyperalgesia, hypoesthesia, altered cool perception, or positive pinch test was determined in 100 patients before and after an appendectomy. Potential associations between altered skin sensations and various items including age, sex, history, body temperature, C-reactive protein (CRP), leukocyte count, and type of appendicopathy (normal, inflamed, necrotic, or perforated) were assessed. A total of 39 patients demonstrated at least one right lower abdominal quadrant skin somatosensory disturbance before the laparoscopic appendectomy. However, locoregional skin sensation normalized in all but 2 patients 2 weeks postoperatively. No differences were found concerning patient characteristics or type of appendicopathy between populations with or without altered lower abdominal skin sensations. A substantial portion of patients with acute appendicitis demonstrate right lower abdominal somatosensory disturbances that are similar as observed in acute ACNES. Both may be different sides of the same coin and are possibly expressions of segmental phenomena as described by Head. McBurney's point, a landmark area of maximum pain in acute appendicitis, is possibly a trigger point within a Head zone. Differentiating acute appendicitis from acute ACNES is extremely difficult, but imaging and observation may aid in the diagnostic process.

  15. DECOVALEX-THMC Project. Task C. Hydro-mechanical response of the Tournemire argillite to the underground openings excavation: unsaturated zones and mine-by-test experiment. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Rejeb, A.; Rouabhi, A. (Ecole des Mines de Paris (France)); Millard, A. (Commissariat d' Energie Atomique (France)); Massmann, J. (Hannover Univ. (DE)); Uehara, S. (Kyoto Univ. (Japan))

    2008-06-15

    This report describes the final results of Task C of the international DECOVALEX-THMC project devoted to Excavation Damaged Zone (EDZ) in argillaceous rock at the Tounemire site in France. Task C is aimed to develop adequate numerical models for interpretation of observed damaged zones around three openings excavated at different times. The research teams are asked to model the evolution of the EDZ with time and to compare their results with measurements that were performed at the site. The main objective is to investigate the hydro-mechanical behavior of Tounemire argillite around the three openings (1881 tunnel, 1996 gallery, 2003 gallery) of Tournemire site. The work was divided into 3 parts: 1. Modelling of the unsaturated zones around the three openings; 2. Modelling of the mine-by-test experiment around the 2003 gallery; 3. EDZ modeling around the 3 openings. Each research team has performed its own HM numerical calculations based on the principal following considerations: The hydraulic time dependent boundary condition at each opening wall was calculated by the Kelvin equation using the provided humidities and temperatures; The effective stress approach of partially saturated medium was used; The swelling-shrinkage of Tournemire argillite was taken into account; The capillary pressure curve was assumed to be given by the Van Genuchten relation and calibrated from the provided data of the two successful laboratory tests; The influence of the degree of saturation on liquid water permeability was modelled using a relative permeability function which is based also on the Van Genuchten model; The intrinsic permeability was calibrated in order to get a better fit with experimental data. To achieve the first objective, the three research teams act as follows: 2D HM coupled simulations have been undertaken by ISEB-BGR team. Hydraulic and mechanical anisotropies were considered; 2D HM coupled simulations have been also undertaken by CEA-IRSN team. Only mechanical

  16. Current status and future plan of the research on the rock deformation and disturbed zone within the Hades project

    International Nuclear Information System (INIS)

    Neerdael, Bernard; Bruyn, D.de; Volckaert, Geert

    1994-01-01

    In the framework of the high activity disposal experimental site (HADES) project managed by the Belgian Nuclear Research Establishment, an in situ research program was launched in 1980. An underground research facility was built in a deep Tertiary clay formation. The various issues related to the site characterization were investigated, including the performance of engineered barriers. Most of the research has been performed under the contract with the Commission of European Communities (CEC) and the Belgian Waste Management Authority (ONDRF/NIRAS). Various civil engineering works and underground experiments haave been carried out to assess the technical feasibility of building a high level waste repository in a plastic clay formaiton. Further information has been collected on the extent and the evolution of the disturbance caused in clay mass by underground structures. The study on clay behavior was extended to the near field conditions after disposal when the host rocks underwent the thermal effect of heat-emitting waste. The general background of the Boom clay, the mechanical behavior of the Boom clay, the numerical simulation of excavation progress and backfill materials are reported. (K.I.)

  17. Crane and Excavator Operator.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    Developed as part of the Marine Corps Institute (MCI) correspondence training program, this course on crane and excavator operation is designed to enable the crane and excavator operator to perform his/her duties more proficiently. Introductory materials include specific information for MCI students, a course introduction, and a study guide…

  18. The essence of excavators

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Competition is hotting-up between rope shovel and hydraulic excavator manufacturers as demand mounts for surface loading equipment. The article gives an overview of major players and gives details of their popular models of excavators and rope shovels. It compares surface loading equipment from P & H, Bucyrus, THYI, OMZ, Komatsu, Hirachi, O & K and Liebherr. 4 tabs., 3 photos.

  19. Principles of Mechanical Excavation

    International Nuclear Information System (INIS)

    Lislerud, A.

    1997-12-01

    Mechanical excavation of rock today includes several methods such as tunnel boring, raiseboring, roadheading and various continuous mining systems. Of these raiseboring is one potential technique for excavating shafts in the repository for spent nuclear fuel and dry blind boring is promising technique for excavation of deposition holes, as demonstrated in the Research Tunnel at Olkiluoto. In addition, there is potential for use of other mechanical excavation techniques in different parts of the repository. One of the main objectives of this study was to analyze the factors which affect the feasibility of mechanical rock excavation in hard rock conditions and to enhance the understanding of factors which affect rock cutting so as to provide an improved basis for excavator performance prediction modeling. The study included the following four main topics: (a) phenomenological model based on similarity analysis for roller disk cutting, (b) rock mass properties which affect rock cuttability and tool life, (c) principles for linear and field cutting tests and performance prediction modeling and (d) cutter head lacing design procedures and principles. As a conclusion of this study, a test rig was constructed, field tests were planned and started up. The results of the study can be used to improve the performance prediction models used to assess the feasibility of different mechanical excavation techniques at various repository investigation sites. (orig.)

  20. Principles of Mechanical Excavation

    Energy Technology Data Exchange (ETDEWEB)

    Lislerud, A. [Tamrock Corp., Tampere (Finland)

    1997-12-01

    Mechanical excavation of rock today includes several methods such as tunnel boring, raiseboring, roadheading and various continuous mining systems. Of these raiseboring is one potential technique for excavating shafts in the repository for spent nuclear fuel and dry blind boring is promising technique for excavation of deposition holes, as demonstrated in the Research Tunnel at Olkiluoto. In addition, there is potential for use of other mechanical excavation techniques in different parts of the repository. One of the main objectives of this study was to analyze the factors which affect the feasibility of mechanical rock excavation in hard rock conditions and to enhance the understanding of factors which affect rock cutting so as to provide an improved basis for excavator performance prediction modeling. The study included the following four main topics: (a) phenomenological model based on similarity analysis for roller disk cutting, (b) rock mass properties which affect rock cuttability and tool life, (c) principles for linear and field cutting tests and performance prediction modeling and (d) cutter head lacing design procedures and principles. As a conclusion of this study, a test rig was constructed, field tests were planned and started up. The results of the study can be used to improve the performance prediction models used to assess the feasibility of different mechanical excavation techniques at various repository investigation sites. (orig.). 21 refs.

  1. Stability of underground excavations in a repository system

    International Nuclear Information System (INIS)

    Calash, A.Y.; Greer, J.C.; Andrea, S.J.; Chowdhury, A.H.; Nguyen, V.V.

    1988-01-01

    The DOE is investigating the feasibility of constructing a deep geologic repository at the Hanford Site, Washington, for the permanent disposal of nuclear waste. The underground openings associated with the repository design include shafts, tunnels, emplacement rooms and boreholes. The stability of these underground openings, the extent and characteristics of the disturbed zones due to excavation, and their effects on groundwater flow path and travel time have a primary influence on the performance assessment of the Hanford Site as a nuclear waste repository. This study is being done in accordance with the requirements of the NRC. Results of structural analyses of shafts and tunnels under in situ stresses and/or medium weight are presented in this paper. Four different analyses were carried out to analyze the shaft: a plane strain model, axisymmetric model, 3-D model of a single material medium, and 3-D model of a three material medium

  2. OPTIMIZING UPPER EXCAVATOR

    Directory of Open Access Journals (Sweden)

    Dragos Vasile VÎGA

    2016-05-01

    Full Text Available An essential element when establishing the balance of a bucket wheel excavator is the determination of the barycentre, the best results being thus obtained by weighting after having installed all the components. The lack of correct balance for bucket wheel excavators determines their operation in an inadequate dynamic mode, or in extreme cases, there is the danger of losing stability by tilting over the excavator respectively suffering huge material and human loss. It is compulsory to verify for the correctness of the position and mass value of balance because there might be substantial error sources leading to compromise the operation. One of the most popular methods is that of weighting the entire equipment from the superior platform of the excavator. The weighting process implies the lifting of the excavators in three spots with hydraulic cylinders, the measurement of the forces, as well as the measurement of pressure inside the cylinders and of the stroke of each cylinder. The data measurement and rehashing installation is destined to determine the dimensions that finally define the weighting process of excavators or other operating machineries to which the balancing and control of stability is imposed.

  3. Sediment Dynamics Within Buffer Zone and Sinkhole Splay Areas Under Extreme Soil Disturbance Conditions.

    Science.gov (United States)

    Schoonover, Jon E; Crim, Jackie F; Williard, Karl W J; Groninger, John W; Zaczek, James J; Pattumma, Klairoong

    2015-09-01

    Sedimentation dynamics were assessed in sinkholes within training areas at Ft. Knox Military Installation, a karst landscape subjected to decades of tracked vehicle use and extreme soil disturbance. Sinkholes sampled were sediment-laden and behaved as intermittent ponds. Dendrogeomorphic analyses were conducted using willow trees (Salix spp.) located around the edge of 18 sinkholes to estimate historical sedimentation rates, and buried bottles were installed in 20 sinkholes at the center, outer edge, and at the midpoint between the center and edge to estimate annual sedimentation rates. Sedimentation data were coupled with vegetation characteristics of sinkhole buffers to determine relationships among these variables. The dendrogeomorphic method estimated an average accumulation rate of 1.27 cm year(-1) translating to a sediment loss rate of 46.1 metric ton year(-1) from the training areas. However, sediment export to sinkholes was estimated to be much greater (118.6 metric ton year(-1)) via the bottle method. These data suggest that the latter method provided a more accurate estimate since accumulation was greater in the center of sinkholes compared to the periphery where dendrogeomorphic data were collected. Vegetation data were not tightly correlated with sedimentation rates, suggesting that further research is needed to identify a viable proxy for direct measures of sediment accumulation in this extreme deposition environment. Mitigation activities for the sinkholes at Ft. Knox's tank training area, and other heavily disturbed karst environments where extreme sedimentation exists, should consider focusing on flow path and splay area management.

  4. Modelling of excavation depth and fractures in rock caused by tool indentation

    Energy Technology Data Exchange (ETDEWEB)

    Kou Shaoquan; Tan Xiangchun; Lindqvist, P.A. [Luleaa Univ. of Technology (Sweden)

    1997-10-01

    The hydraulic regime after excavation in the near-field rock around deposition holes and deposition tunnels in a spent nuclear fuel repository is of concern for prediction of the saturation process of bentonite buffer and tunnel backfill. The hydraulic condition of main interest in this context is a result of the fracture network that is caused by the excavation. Modelling of the excavation disturbed zone in hard rocks caused by mechanical excavation has been carried out in the Division of Mining Engineering since 1993. This report contains an overview of the work conducted. The mechanical excavation is reasonably simplified as an indentation process of the interaction between rigid indenters and rocks. A large number of experiments have been carried out in the laboratory, and the results used for identifying crushed zones and fracture systems in rock under indentation are presented based on these experiments. The indentation causes crushing and damage of the rock and results in a crushed zone and a cracked zone. The indenter penetrates the rock with a certain depth when the force is over a threshold value relevant to the rock and tool. Outside the cracked zone there are basically three systems of cracks: median cracks, radial cracks, and side cracks. Fully developed radial cracks on each side of the indented area can connect with each other and join with median crack. This forms the so-called radial/median crack system. The influence of the mechanical properties of the rock is discussed based on our conceptual model, and the main factors governing the indentation event are summarised. The cracked zone is dealt with by an analytical fracture model. The side crack is simulated by applying the boundary element method coupled with fracture mechanics. Functional relationships are established relating either the indentation depth or the length of radial/median cracks to the various quantities characterising the physical event, namely the shape and the size of the

  5. Modelling of excavation depth and fractures in rock caused by tool indentation

    International Nuclear Information System (INIS)

    Kou Shaoquan; Tan Xiangchun; Lindqvist, P.A.

    1997-10-01

    The hydraulic regime after excavation in the near-field rock around deposition holes and deposition tunnels in a spent nuclear fuel repository is of concern for prediction of the saturation process of bentonite buffer and tunnel backfill. The hydraulic condition of main interest in this context is a result of the fracture network that is caused by the excavation. Modelling of the excavation disturbed zone in hard rocks caused by mechanical excavation has been carried out in the Division of Mining Engineering since 1993. This report contains an overview of the work conducted. The mechanical excavation is reasonably simplified as an indentation process of the interaction between rigid indenters and rocks. A large number of experiments have been carried out in the laboratory, and the results used for identifying crushed zones and fracture systems in rock under indentation are presented based on these experiments. The indentation causes crushing and damage of the rock and results in a crushed zone and a cracked zone. The indenter penetrates the rock with a certain depth when the force is over a threshold value relevant to the rock and tool. Outside the cracked zone there are basically three systems of cracks: median cracks, radial cracks, and side cracks. Fully developed radial cracks on each side of the indented area can connect with each other and join with median crack. This forms the so-called radial/median crack system. The influence of the mechanical properties of the rock is discussed based on our conceptual model, and the main factors governing the indentation event are summarised. The cracked zone is dealt with by an analytical fracture model. The side crack is simulated by applying the boundary element method coupled with fracture mechanics. Functional relationships are established relating either the indentation depth or the length of radial/median cracks to the various quantities characterising the physical event, namely the shape and the size of the

  6. Strengthening carbonate roof rock of workings by the use of resins in Karst disturbance zones

    Energy Technology Data Exchange (ETDEWEB)

    Timofeev, O.V.; Gerovich, E.G.

    1977-12-01

    Test results are given for a proposed method of injection strengthening of rock in sinkhole areas in order to stabilize the rock of mining areas. Tests were made of appropriately selected NaOH solutions to act as catalysts in the injection of resins. Relationships are given between the hardening time of the aqueous resin solutions and the concentration of the NaOH catalyst, the relationship between the viscosity of the resin solutions and the temperature at specific ratios, between the hardness of the polymer materials and age, and between the resinous mixture compression strength and its age at specific temperatures. A diagram is presented of the injection equipment, and data are presented on the number of boreholes receiving the injected resin in relation to physical measurements. The tests of the resinated areas indicate that the rock hardness of the treated zones approaches that of the fissured zones so that props with less supporting power can be used, and work safety is increased. 3 references, 6 figures, 1 table.

  7. Excavation of LSS1

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Excavation of the long straight-section LSS1 by an Alpine boring machine. View of the connection chamber, in the background, the roofs of the enlarged sections (8.5 m and 6 m). On the right, the access tunnel to PP1.

  8. Excavating the Spartans

    Directory of Open Access Journals (Sweden)

    John Wilkes

    1997-11-01

    Full Text Available Few ancient Greek place names are so embedded in Western consciousness as Sparta, evoking as it does courage, harsh training, stern duty and endurance. By the 2nd century AD it had become a "heritage centre " admired by visiting Romans, and it flourished again in the Byzantine period. The Institute has been involved in new excavations at Sparta since 1989.

  9. Lightweight Robotic Excavation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Robust, lightweight, power-efficient excavation robots are mission enablers for lunar outposts and surface systems. Lunar excavators of this type cost-effectively...

  10. Choice of rock excavation methods for the Swedish deep repository for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Baeckblom, Goeran [Conrox, Stockholm (Sweden); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Lagerstedt, Leif [SwedPower AB, Stockholm (Sweden)

    2004-09-01

    Choice of rock excavation methods will or may have implications for a number of issues like repository layout, long term and operational safety, environmental impact, design of and operation of transport vehicles and methodology for backfilling the repository before closure as well as effects on costs and schedules. To fully analyse the issues at hand related to selection of excavation methods, SKB organized a project with the objectives: To investigate and compare principal technical solutions for rock excavation, both methods that are used at present but also methods that may be feasible 10 years from now; To assess how the selection of excavation method influences the design and operation of the deep repository; To present a definition of the Excavation Damaged/Disturbed Zone and practical methods for measurements of EDZ; To present advantages and disadvantages with different excavation methods for the various tunnels and underground openings as a basis for selection of preferred excavation methods; To present the Design Justification Statement for the selection of particular excavation methods for the different tunnels and openings in the deep repository to underpin a decision on excavation method; and To present background data that may be required for the evaluation of the long term safety of the deep repository. Main alternatives studied are very smooth blasting, excavation with a tunnel-boring machine (TBM) and excavation with horizontal pull-reaming using more or less conventional raise-boring equipment. The detailed studies were carried through in co-operation with major suppliers and end-users of the technology. An observation in this study is that all excavation technologies are mature; no major breakthroughs are foreseen within a 10 year period but it is likely that for any technology selected, SKB would specifically fine-tune the design of the equipment and work procedures in view of requirements and site specific conditions. Excavation methods have

  11. Choice of rock excavation methods for the Swedish deep repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Baeckblom, Goeran; Christiansson, Rolf; Lagerstedt, Leif

    2004-09-01

    Choice of rock excavation methods will or may have implications for a number of issues like repository layout, long term and operational safety, environmental impact, design of and operation of transport vehicles and methodology for backfilling the repository before closure as well as effects on costs and schedules. To fully analyse the issues at hand related to selection of excavation methods, SKB organized a project with the objectives: To investigate and compare principal technical solutions for rock excavation, both methods that are used at present but also methods that may be feasible 10 years from now; To assess how the selection of excavation method influences the design and operation of the deep repository; To present a definition of the Excavation Damaged/Disturbed Zone and practical methods for measurements of EDZ; To present advantages and disadvantages with different excavation methods for the various tunnels and underground openings as a basis for selection of preferred excavation methods; To present the Design Justification Statement for the selection of particular excavation methods for the different tunnels and openings in the deep repository to underpin a decision on excavation method; and To present background data that may be required for the evaluation of the long term safety of the deep repository. Main alternatives studied are very smooth blasting, excavation with a tunnel-boring machine (TBM) and excavation with horizontal pull-reaming using more or less conventional raise-boring equipment. The detailed studies were carried through in co-operation with major suppliers and end-users of the technology. An observation in this study is that all excavation technologies are mature; no major breakthroughs are foreseen within a 10 year period but it is likely that for any technology selected, SKB would specifically fine-tune the design of the equipment and work procedures in view of requirements and site specific conditions. Excavation methods have

  12. Modeling of damage, permeability changes and pressure responses during excavation of the TSX tunnel in granitic rock at URL, Canada

    Science.gov (United States)

    Rutqvist, Jonny; Börgesson, Lennart; Chijimatsu, Masakazu; Hernelind, Jan; Jing, Lanru; Kobayashi, Akira; Nguyen, Son

    2009-05-01

    This paper presents numerical modeling of excavation-induced damage, permeability changes, and fluid-pressure responses during excavation of a test tunnel associated with the tunnel sealing experiment (TSX) at the Underground Research Laboratory (URL) in Canada. Four different numerical models were applied using a wide range of approaches to model damage and permeability changes in the excavation disturbed zone (EDZ) around the tunnel. Using in situ calibration of model parameters, the modeling could reproduce observed spatial distribution of damage and permeability changes around the tunnel as a combination of disturbance induced by stress redistribution around the tunnel and by the drill-and-blast operation. The modeling showed that stress-induced permeability increase above the tunnel is a result of micro and macrofracturing under high deviatoric (shear) stress, whereas permeability increase alongside the tunnel is a result of opening of existing microfractures under decreased mean stress. The remaining observed fracturing and permeability changes around the periphery of the tunnel were attributed to damage from the drill-and-blast operation. Moreover, a reasonably good agreement was achieved between simulated and observed excavation-induced pressure responses around the TSX tunnel for 1 year following its excavation. The simulations showed that these pressure responses are caused by poroelastic effects as a result of increasing or decreasing mean stress, with corresponding contraction or expansion of the pore volume. The simulation results for pressure evolution were consistent with previous studies, indicating that the observed pressure responses could be captured in a Biot model using a relatively low Biot-Willis’ coefficient, α ≈ 0.2, a porosity of n ≈ 0.007, and a relatively low permeability of k ≈ 2 × 10-22 m2, which is consistent with the very tight, unfractured granite at the site.

  13. What Happens in the Burn Zone Doesn't Stay in the Burn Zone: How Markets Distribute Disturbances Across the Landscape

    Science.gov (United States)

    Sloggy, M. R.; Plantinga, A.; Latta, G.

    2017-12-01

    The goal of this study is to examine how the interaction between human systems and land systems influences the extent and severity of forest disturbances. We show that human adaptation to forest disturbance has both long term and short term effects on future timber harvest patterns. We utilize a novel economic model of the forest sector which can be coupled to the Community Land Model (CLM). By simulating both pine beetle outbreaks and wildfires, we are able to model the forest sector's response to these disturbances. We then quantify and report the degree to which natural forest disturbance induces additional disturbances through timber harvest. We find that in the short run, a scarcity of forest products from the affected area increases prices which stimulate harvests in other regions not affected by the disturbance. In the long-run, we find that permanent effects that the natural disturbances have on the forest sector are translated into permanent effects on the pattern of timber harvest. The effects of forest disturbances are not localized, but instead can be distributed across the landscape by their interaction with the human system. Not accounting for this affect could mean a significant underestimation of the forest disturbance attributable to natural disturbance events. Furthermore, our novel economic model can be used with CLM to explore how this feedback may affect other aspects of the environmental system. The results from this study show the importance of accounting for how markets interact with the landscape, and how those results can be used to improve our understanding of both the natural impacts and social impacts of forest disturbance.

  14. Excavating a transfer tunnel

    CERN Multimedia

    Laurent Guiraud

    2000-01-01

    The transfer tunnel being dug here will take the 450 GeV beam from the SPS and inject it into the LHC where the beam energies will be increased to 7 TeV. In order to transfer this beam from the SPS to the LHC, two transfer tunnels are used to circulate the beams in opposite directions. When excavated, the accelerator components, including magnets, beam pipes and cryogenics will be installed and connected to both the SPS and LHC ready for operation to begin in 2008.

  15. Safety excavation; Seguranca em escavacoes

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Walter Manoel [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    In the construction and maintenance services of buried pipelines, the excavation is the activity that contains larger risk, could cause serious accidents. Norms, procedures and technical articles, national and international goods, should be followed for legal and technical aspects. This paper - Safety in Excavations - has purpose to gather all the technical concepts and of safety in a document denominated Procedure of Safety Excavation, serving as instrument to systematize and control the execution of excavation services in construction civil, assembly and pipelines repairs, seeking the people, facilities and the environment's safety. (author)

  16. Room 209 excavation response test in the underground research laboratory

    International Nuclear Information System (INIS)

    Lang, P.A.

    1989-01-01

    An in situ excavation response test was conducted at the Canadian Underground Research Laboratory (URL) in conjunction with excavation of a tunnel (Room 209) through a near-vertical water-bearing fracture oriented perpendicular to the tunnel axis. Encountering a fracture with such desirable characteristics provided a unique opportunity during construction of the URL to try out instrumentation and analytical methods for use in the Excavation Response Experiment (ERE) planned as one of the major URL experiments. The test has produced a valuable data set for validating numerical models. Four modelling groups predicted the response that would be monitored by the instruments. The predictions of the mechanical response were generally good. However, the predictions of the permeability and hydraulic pressure changes in the fracture, and the water flows into the tunnel, were poor. It is concluded that we may not understand the mechanisms that occur in the fracture in response to excavation. Laboratory testing, and development of a contracting joint code, has been initiated to further investigate this phenomenon. Preliminary results indicate that the excavation damaged zone in the walls and crown is less than 0.5 m thick and has relatively low permeability. The damaged zone in the floor is at least 1 m thick and has relatively high permeability. The damage in the floor could be reduced in future excavations by using controlled blasting methods similar to those used for the walls and crown

  17. Excavation research with chemical explosives

    International Nuclear Information System (INIS)

    Vandenberg, William E.; Day, Walter C.

    1970-01-01

    The US Army Engineer Nuclear Cratering Group (NCG) is located at the Lawrence Radiation Laboratory in Livermore, California. NCG was established in 1962 and assigned responsibility for technical program direction of the Corps of Engineers Nuclear Excavation Research Program. The major part of the experimental program has been the execution of chemical explosive excavation experiments. In the past these experiments were preliminary to planned nuclear excavation experiments. The experience gained and technology developed in accomplishing these experiments has led to an expansion of NCG's research mission. The overall research and development mission now includes the development of chemical explosive excavation technology to enable the Corps of Engineers to more economically accomplish Civil Works Construction projects of intermediate size. The current and future chemical explosive excavation experiments conducted by NCG will be planned so as to provide data that can be used in the development of both chemical and nuclear excavation technology. In addition, whenever possible, the experiments will be conducted at the specific sites of authorized Civil Works Construction Projects and will be designed to provide a useful portion of the engineering structures planned in that project. Currently, the emphasis in the chemical explosive excavation program is on the development of design techniques for producing specific crater geometries in a variety of media. Preliminary results of two such experiments are described in this paper; Project Pre-GONDOLA III, Phase III, Reservoir Connection Experiment; and a Safety Calibration Series for Project TUGBOAT, a small boat harbor excavation experiment

  18. Excavation research with chemical explosives

    Energy Technology Data Exchange (ETDEWEB)

    Vandenberg, William E; Day, Walter C [U.S. Army Engineer Nuclear Cratering Group, Lawrence Radiation Laboratory, Livermore, CA (United States)

    1970-05-01

    The US Army Engineer Nuclear Cratering Group (NCG) is located at the Lawrence Radiation Laboratory in Livermore, California. NCG was established in 1962 and assigned responsibility for technical program direction of the Corps of Engineers Nuclear Excavation Research Program. The major part of the experimental program has been the execution of chemical explosive excavation experiments. In the past these experiments were preliminary to planned nuclear excavation experiments. The experience gained and technology developed in accomplishing these experiments has led to an expansion of NCG's research mission. The overall research and development mission now includes the development of chemical explosive excavation technology to enable the Corps of Engineers to more economically accomplish Civil Works Construction projects of intermediate size. The current and future chemical explosive excavation experiments conducted by NCG will be planned so as to provide data that can be used in the development of both chemical and nuclear excavation technology. In addition, whenever possible, the experiments will be conducted at the specific sites of authorized Civil Works Construction Projects and will be designed to provide a useful portion of the engineering structures planned in that project. Currently, the emphasis in the chemical explosive excavation program is on the development of design techniques for producing specific crater geometries in a variety of media. Preliminary results of two such experiments are described in this paper; Project Pre-GONDOLA III, Phase III, Reservoir Connection Experiment; and a Safety Calibration Series for Project TUGBOAT, a small boat harbor excavation experiment.

  19. Damage-induced permeability changes around underground excavations

    International Nuclear Information System (INIS)

    Coll, C.

    2005-07-01

    The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

  20. Imaging disturbance zones ahead of a tunnel by elastic full-waveform inversion: Adjoint gradient based inversion vs. parameter space reduction using a level-set method

    Directory of Open Access Journals (Sweden)

    Andre Lamert

    2018-03-01

    Full Text Available We present and compare two flexible and effective methodologies to predict disturbance zones ahead of underground tunnels by using elastic full-waveform inversion. One methodology uses a linearized, iterative approach based on misfit gradients computed with the adjoint method while the other uses iterative, gradient-free unscented Kalman filtering in conjunction with a level-set representation. Whereas the former does not involve a priori assumptions on the distribution of elastic properties ahead of the tunnel, the latter introduces a massive reduction in the number of explicit model parameters to be inverted for by focusing on the geometric form of potential disturbances and their average elastic properties. Both imaging methodologies are validated through successful reconstructions of simple disturbances. As an application, we consider an elastic multiple disturbance scenario. By using identical synthetic time-domain seismograms as test data, we obtain satisfactory, albeit different, reconstruction results from the two inversion methodologies. The computational costs of both approaches are of the same order of magnitude, with the gradient-based approach showing a slight advantage. The model parameter space reduction approach compensates for this by additionally providing a posteriori estimates of model parameter uncertainty. Keywords: Tunnel seismics, Full waveform inversion, Seismic waves, Level-set method, Adjoint method, Kalman filter

  1. Remote excavation using the telerobotic small emplacement excavator

    International Nuclear Information System (INIS)

    Thompson, D.H.; Burks, B.L.; Killough, S.M.

    1993-01-01

    Oak Ridge National Laboratory is developing remote excavation technologies for the Office of Technology Development, Robotics Technology Development Program. This work is being done to meet the need for remote excavation and removal of radioactive and contaminated buried waste at several DOE sites. System requirements are based on the need to uncover and remove waste from burial sites in a way that does not cause unnecessary personnel exposure or additional environmental contamination. Goals for the current project are to demonstrate dexterous control of a backhoe with force feedback and to implement robotic operations that will improve productivity. The Telerobotic Small Emplacement Excavator is a prototype system that incorporates the needed robotic and telerobotic capabilities on a commercially available platform. The ability to add remote dexterous teleoperation and robotic operating modes is intended to be adaptable to other commercially available excavator systems

  2. RATDAMPER - A Numerical Model for Coupling Mechanical and Hydrological Properties within the Disturbed Rock Zone at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    RATH, JONATHAN S.; PFEIFLE, T.W.; HUNSCHE, U.

    2000-01-01

    A numerical model for predicting damage and permeability in the disturbed rock zone (DRZ) has been developed. The semi-empirical model predicts damage based on a function of stress tensor invariant. For a wide class of problems hydrologic/mechanical coupling is necessary for proper analysis. The RATDAMPER model incorporates dilatant volumetric strain and permeability. The RATDAMPER model has been implemented in a weakly coupled code, which combines a finite element structural code and a finite difference multi-phase fluid flow code. Using the development of inelastic volumetric strain, a value of permeability can be assigned. This flexibility allows empirical permeability functional relationships to be evaluated

  3. Drilling and coring methods that minimize the disturbance of cuttings, core, and rock formation in the unsaturated zone, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Hammermeister, D.P.; Blout, D.O.; McDaniel, J.C.

    1985-01-01

    A drilling-and-casing method (Odex 115 system) utilizing air as a drilling fluid was used successfully to drill through various rock types within the unsaturated zone at Yucca Mountain, Nevada. This paper describes this method and the equipment used to rapidly penetrate bouldery alluvial-colluvial deposits, poorly consolidated bedded and nonwelded tuff, and fractured, densely welded tuff to depths of about 130 meters. A comparison of water-content and water-potential data from drill cuttings with similar measurements on rock cores indicates that drill cuttings were only slightly disturbed for several of the rock types penetrated. Coring, sampling, and handling methods were devised to obtain minimally disturbed drive core from bouldery alluvial-colluvial deposits. Bulk-density values obtained from bulk samples dug from nearby trenches were compared to bulk-density values obtained from drive core to determine the effects of drive coring on the porosity of the core. Rotary coring methods utilizing a triple-tube core barrel and air as the drilling fluid were used to obtain core from welded and nonwelded tuff. Results indicate that the disturbance of the water content of the core was minimal. Water-content distributions in alluvium-colluvium were determined before drilling occurred by drive-core methods. After drilling, water-content distributions were determined by nuclear-logging methods. A comparison of the water-content distributions made before and after drilling indicates that Odex 115 drilling minimally disturbs the water content of the formation rock. 10 refs., 12 figs., 4 tabs

  4. Customized excavators beat the odds

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    Blackstone Mining, launched in 1983, is based in eastern Ohio, near Cadiz and specializes in stripping small properties for Ohio Edison. Specially modified hydraulic excavators and an efficient mining technique allow the mining of marginal coal deposits. In 1986 Ken McBeth, the company's founder begun using a Cat 245 hydraulic excavator to cleanly and efficiently load coal and also remove overburden. Modifications include: a mass excavator boom 5 feet longer to better reach over the sides of haul trucks and load from higher benches; and larger hydraulic cylinders to maintain earthmoving production. McBeth also devised a fast economical technique for extracting coal from the thin, narrow seams. Soft cover material is removed by excavator; the remaining sand and limestone are blasted to within 2 feet of the seam; the remaining material is removed by an agricultural tractor with a blade; an excavator loads the coal into haul trucks starting at the toe of the face and working backwards. Haul trucks are not placed directly on the seam. This prevents contamination, reducing the price of the coal. There is no wash plant; the coal is hauled direct to the utility. 4 photos.

  5. Disturbances of bird embryo development in fall-out contaminated biocenoses of the Chernobyl NPP 30-km zone

    International Nuclear Information System (INIS)

    Galinskaya, I.A.; Gaber, N.A.

    1994-01-01

    Special features of bird reproduction in Chernobyl 30-km zone are analyzed. On the areas with higher degree of contamination a decrease of hatching indices, an increase of both embryo death-rate and embryo per cent of inherent disorders have been noticed. The more frequent cases of inherent disorders for different bird species have been considered. The trend to a bird reproduction successfulness decrease has been fixed

  6. Disturbed zone modelling SVC validation drift using UDEC-BB, models 1 to 8 - Stripa phase 3

    International Nuclear Information System (INIS)

    Monsen, K.; Makurat, A.; Barton, N.

    1991-01-01

    Several rock mechanics studies were performed within the site characterization and validation (SCV) project at Stripa. Joints represented in Harwell's stochastically generated 8m x 8m x 8m cubes were used to select four possible joints geometries for two-dimensional rock mechanics simulations of the 2.8 x 2.2 m validation drift, and the rock mass response to its excavation. The joints intersecting the four end faces of these cubes were set up in distinct element UDEC-BB models, and loaded with boundary stresses of 10 MPa vertically and 14 to 18 MPa horizontally. In numerical models 1, 2, 3 and 4 average values of the Barton Bandis joint parameters JRC, JCS and φ r were utilized for all joints, irrespective of length. These values were obtained from NGI's index characterization of 220 joints in 100 mm core and from 200 mm diameter and 1 x 1 2m block testing were coupled closure-shear-flow testing (CSFT) was also performed. In numerical models 5, 6, 7, 8 the same joint geometries were utilized with length-dependent values of JRC, JCS and φ r . The longest joints were given low values representing mineralized persistent discontinuities, while the shortest joints were given high values. Detailed analyses were made of the tangential and radial stress magnitudes that were obtained in the four UDEC-BB discontinuum models 5, 6, 7 and 8. Results were presented for all sectors of the models as a function of radius from the drift walls. These stress magnitudes were compared with those from an equivalent continuum model which showed, as expected, much more predictable stress gradients. Modelled drift closures ranged from 2 to 3 mm in the jointed models and from 1 to 1.5 mm in the continuum model. Local tensile stress development maximum 28 MPa, and local shearing of individual joints, maximum 1.0 mm, were a feature of the jointed models. Peak tangential stresses locally reached 54 to 74 MPa in the jointed models compared to 43 MPa in the continuum model. (au)

  7. Finite-element modelling of geomechanical and hydraulic responses to the room 209 heading extension excavation response experiment 2: post-excavation analysis of experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Chan, T; Griffith, P; Nakka, B W; Khair, K R

    1993-07-01

    An in situ excavation response test was conducted at the 240 Level of the Underground Research Laboratory (URL) in conjunction with the excavation of a tunnel (Room 209) through a narrow, near-vertical, water-bearing fracture oriented almost perpendicular to the tunnel axis. This report presents a post-excavation analysis of the predicted mechanical response of the granitic rock mass to the tunnel excavation and the near-field hydraulic response of the fracture zone, compares the numerical modelling predictions with the actual measured response, provides information on the rock mass and fracture from back-analysis of the responses, and makes recommendations for future experiments. Results indicate that displacements and stress changes were reasonably well predicted. Pressure drops at hydrology boreholes and inflow to the tunnel were overpredicted, and fracture permeability changes were underpredicted. The permeability change is considered too large to be solely stress-induced. The back-calculated deformation modulus indicated nonlinear softening of the rock within 3.5 m of the tunnel wall. This is likely due to both excavation damage and the confining stress dependence of the modulus. For future excavation experiments it is recommended that mechanical excavation should replace the drill-and-blast technique; excavation damage should be incorporated into mechanical models; an improved hydraulic fracture model should be developed; and a coupled geomechanical-hydraulic analysis of fracture flow should be developed. (author). 16 refs., 15 tabs., 156 figs.

  8. Finite-element modelling of geomechanical and hydraulic responses to the room 209 heading extension excavation response experiment 2: post-excavation analysis of experimental results

    International Nuclear Information System (INIS)

    Chan, T.; Griffith, P.; Nakka, B.W.; Khair, K.R.

    1993-07-01

    An in situ excavation response test was conducted at the 240 Level of the Underground Research Laboratory (URL) in conjunction with the excavation of a tunnel (Room 209) through a narrow, near-vertical, water-bearing fracture oriented almost perpendicular to the tunnel axis. This report presents a post-excavation analysis of the predicted mechanical response of the granitic rock mass to the tunnel excavation and the near-field hydraulic response of the fracture zone, compares the numerical modelling predictions with the actual measured response, provides information on the rock mass and fracture from back-analysis of the responses, and makes recommendations for future experiments. Results indicate that displacements and stress changes were reasonably well predicted. Pressure drops at hydrology boreholes and inflow to the tunnel were overpredicted, and fracture permeability changes were underpredicted. The permeability change is considered too large to be solely stress-induced. The back-calculated deformation modulus indicated nonlinear softening of the rock within 3.5 m of the tunnel wall. This is likely due to both excavation damage and the confining stress dependence of the modulus. For future excavation experiments it is recommended that mechanical excavation should replace the drill-and-blast technique; excavation damage should be incorporated into mechanical models; an improved hydraulic fracture model should be developed; and a coupled geomechanical-hydraulic analysis of fracture flow should be developed. (author). 16 refs., 15 tabs., 156 figs

  9. A remotely operated excavator [HAZ-TRAK

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    HAZ-TRAK is a remotely operated excavator and material handling system for nuclear waste site characterization, waste site remediation, and the decommissioning of nuclear facilities. HAZ-TRAK combines the power and mobility of a commercial excavator, with the dexterity and controllability of a force feedback manipulator system: when operating HAZ-TRAK as an excavator, the operator can feel buried objects. A master/slave control method enables the operator to intuitively control all the excavator arm functions with one hand. The main features of the excavator are described in this article. (author)

  10. Predictive hydro-mechanical excavation simulation of a mine-by test at the Mont Terri rock laboratory

    International Nuclear Information System (INIS)

    Krug, St.; Shao, H.; Hesser, J.; Nowak, T.; Kunz, H.; Vietor, T.

    2010-01-01

    Niche 2 in the Mont Terri URL. The simulation time begins at 1 April 2008 and ends at 30 June 2009. Four different material groups represent the undisturbed anisotropic rock mass, the excavation disturbed zone around the gallery and the niche, the shotcrete lining around Gallery 08 and the rock in Niche 2 being excavated during the simulation. A comparison between blindly calculated RockFlow results and measured pore water pressures is shown. In a next step the model is going to be validated by measured pore water pressure and convergence evolutions. This validation work, results and gained knowledge about clay rock behaviour during excavation will be described in the paper

  11. Excavating wide inclines in weak strata

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, N N [Ukrspetsstroiproekt (USSR)

    1990-09-01

    Discusses schemes for excavation of transport inclines in surface mines under conditions of weak, unstable rocks characterized by a high water content. The schemes are aimed at maximum reduction of excavation operations without infringing the safety of personnel. Use of walking draglines (the EhSh-20/90, EhSh-100/100 and EhSh-10/70) is evaluated. Optimum schemes for incline excavation and determining optimum slope inclination are described on the example of the Berezovsk brown coal surface mine in the USSR. Efficiency of optimum schemes is analyzed: range of excavation, safety degree, landslide hazards, water influx rate, accident rate, etc.

  12. Disturbing forest disturbances

    Energy Technology Data Exchange (ETDEWEB)

    Volney, W.J.A.; Hirsch, K.G. [Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, AB (Canada)

    2005-10-01

    This paper described the role that disturbances play in maintaining the ecological integrity of Canadian boreal forests. Potential adaptation options to address the challenges that these disturbances present were also examined. Many forest ecosystems need fire for regeneration, while other forests rely on a cool, wet disintegration process driven by insects and commensal fungi feeding on trees to effect renewal. While there are characteristic natural, temporal and spatial patterns to these disturbances, recent work has demonstrated that the disturbances are being perturbed by climatic change that has been compounded by anthropogenic disturbances in forests. Fire influences species composition and age structure, regulates forest insects and diseases, affects nutrient cycling and energy fluxes, and maintains the productivity of different habitats. Longer fire seasons as a result of climatic change will lead to higher intensity fires that may more easily evade initial attacks and become problematic. Fire regimes elevated beyond the range of natural variation will have a dramatic effect on the regional distribution and functioning of forest ecosystems and pose a threat to the safety and prosperity of people. While it was acknowledged that if insect outbreaks were to be controlled on the entire forest estate, the productivity represented by dead wood would be lost, it was suggested that insects such as the forest tent caterpillar and the spruce bud worm may also pose a greater threat as the climate gets warmer and drier. Together with fungal associates, saproxylic arthropods are active in nutrient cycling and ultimately determine the fertility of forest sites. It was suggested that the production of an age class structure and forest mosaic would render the forest landscape less vulnerable to the more negative aspects of climate change on vegetation response. It was concluded that novel management design paradigms are needed to successfully reduce the risk from threats

  13. Silica exposure to excavation workers during the excavation of a low level radiological waste pit and tritium disposal shafts

    International Nuclear Information System (INIS)

    Wilson, K.M.

    1995-01-01

    This study evaluated the task-length average (TLA) respirable dust and respirable silica airborne concentrations to which construction workers excavating volcanic tuff at Los Alamos National Laboratory (LANL) were exposed. These workers were excavating a low level radiological waste disposal pit of final dimensions 720 feet long, 132 feet wide and 60 feet deep. The objectives of this study were as follows: (1) evaluate exposures; (2) determine if the type of machinery used affects the respirable dust concentration in the breathing zone of the worker; (3) evaluate the efficacy of wetting the pit to reduce the respirable dust exposure; and (4) determine if exposure increases with increasing depth of pit due to the walls of the pit blocking the cross wind ventilation

  14. Slope excavation quality assessment and excavated volume calculation in hydraulic projects based on laser scanning technology

    Directory of Open Access Journals (Sweden)

    Chao Hu

    2015-04-01

    Full Text Available Slope excavation is one of the most crucial steps in the construction of a hydraulic project. Excavation project quality assessment and excavated volume calculation are critical in construction management. The positioning of excavation projects using traditional instruments is inefficient and may cause error. To improve the efficiency and precision of calculation and assessment, three-dimensional laser scanning technology was used for slope excavation quality assessment. An efficient data acquisition, processing, and management workflow was presented in this study. Based on the quality control indices, including the average gradient, slope toe elevation, and overbreak and underbreak, cross-sectional quality assessment and holistic quality assessment methods were proposed to assess the slope excavation quality with laser-scanned data. An algorithm was also presented to calculate the excavated volume with laser-scanned data. A field application and a laboratory experiment were carried out to verify the feasibility of these methods for excavation quality assessment and excavated volume calculation. The results show that the quality assessment indices can be obtained rapidly and accurately with design parameters and scanned data, and the results of holistic quality assessment are consistent with those of cross-sectional quality assessment. In addition, the time consumption in excavation quality assessment with the laser scanning technology can be reduced by 70%–90%, as compared with the traditional method. The excavated volume calculated with the scanned data only slightly differs from measured data, demonstrating the applicability of the excavated volume calculation method presented in this study.

  15. Toxic hazards of underground excavation

    International Nuclear Information System (INIS)

    Smith, R.; Chitnis, V.; Damasian, M.

    1982-09-01

    Inadvertent intrusion into natural or man-made toxic or hazardous material deposits as a consequence of activities such as mining, excavation or tunnelling has resulted in numerous deaths and injuries in this country. This study is a preliminary investigation to identify and document instances of such fatal or injurious intrusion. An objective is to provide useful insights and information related to potential hazards due to future intrusion into underground radioactive-waste-disposal facilities. The methodology used in this study includes literature review and correspondence with appropriate government agencies and organizations. Key categories of intrusion hazards are asphyxiation, methane, hydrogen sulfide, silica and asbestos, naturally occurring radionuclides, and various mine or waste dump related hazards

  16. Toxic hazards of underground excavation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.; Chitnis, V.; Damasian, M.; Lemm, M.; Popplesdorf, N.; Ryan, T.; Saban, C.; Cohen, J.; Smith, C.; Ciminesi, F.

    1982-09-01

    Inadvertent intrusion into natural or man-made toxic or hazardous material deposits as a consequence of activities such as mining, excavation or tunnelling has resulted in numerous deaths and injuries in this country. This study is a preliminary investigation to identify and document instances of such fatal or injurious intrusion. An objective is to provide useful insights and information related to potential hazards due to future intrusion into underground radioactive-waste-disposal facilities. The methodology used in this study includes literature review and correspondence with appropriate government agencies and organizations. Key categories of intrusion hazards are asphyxiation, methane, hydrogen sulfide, silica and asbestos, naturally occurring radionuclides, and various mine or waste dump related hazards.

  17. GPS-Based Excavation Encroachment Notification

    Science.gov (United States)

    2011-10-31

    Excavation damage is the primary threat to the integrity of the natural gas distribution system. According to the Common Ground Alliance, the two primary root causes of excavation damage are failure to notify the one-call center and careless excavati...

  18. AECL's excavation stability study - summary of observations

    International Nuclear Information System (INIS)

    Read, R.S.; Chandler, N.A.

    1996-05-01

    The Excavation Stability Study (ESS) was conducted at the 420 Level of the Underground Research Laboratory (URL) to evaluate stability and the extent of excavation damage in tunnels as a function of tunnel geometry and orientation, geology, and excavation method. A series of ovaloid and circular openings were used to achieve different boundary stress levels and near-field stress distributions to assess the effect of tunnel geometry on damage development. Several of these openings had sections in both granite and granodiorite lithology, providing a comparison of damage in rock types with different strength characteristics. Damage around circular tunnels (one excavated by drill-and-blast, the other by mechanical means) was also investigated. The study.showed that mechanically stable openings can be excavated in the most adverse stress conditions at the 420 Level of the URL. In addition, it was shown that tunnel stability is sensitive to tunnel shape, variations in geology, and to some extent, the excavation method. Findings of the study are relevant in developing design criteria, and in assessing the feasibility of constructing large ovaloid openings in adverse stress conditions. This report summarizes the preliminary observations related to tunnel stability and excavation damage. (author). 8 refs., 7 tabs., 23 figs

  19. 100 Area excavation treatability test plan

    International Nuclear Information System (INIS)

    1993-08-01

    This test plan documents the requirements for a treatability study on field radionuclide analysis and dust control techniques. These systems will be used during remedial actions involving excavation. The data from this treatability study will be used to support the feasibility study (FS) process. Excavation is one of the high-priority, near-term, treatability study needs identified in the program plan (DOE-RL 1992f). Excavation of contaminated soils and buried solid wastes is included in several of the alternatives identified in the 100 Area FS. Although a common activity, excavation has only been used occasionally at the Hanford Site for waste removal applications. The most recent applications are excavation of the 618-9 burial ground and partial remediation of the 316-5 process trenches (DOE-RL 1992a, 1992b). Both projects included excavation of soil and dust control (using water sprays). Excavation is a well-developed technology and equipment is readily available; however, certain aspects of the excavation process require testing before use in full-scale operations. These include the following: Measurement and control of excavation-generated dust and airborne contamination; verification of field analytical system capabilities; demonstration of soil removal techniques specific to the 100 Area waste site types and configurations. The execution of this treatability test may produce up to 500 yd 3 of contaminated soil, which will be used for future treatability tests. These tests may include soil washing with vitrification of the soil washing residuals. Other tests will be conducted if soil washing is not a viable alternative

  20. Summary report of soil removal preliminary excavations

    International Nuclear Information System (INIS)

    Wickland, C.E.

    1975-01-01

    This report discusses a proposed technique to remove small areas, less than 2,000 m 2 , of contaminated soil and the results of an actual excavation. Based on the results of a trial excavation in uncontaminated soil and an excavation of two trenches in contaminated soil, it is concluded that the techniques described are a satisfactory means of contaminated soil removal. It can be done safely with a release of airborne plutonium a factor of 10 or more below the Environmental Protection Administration (EPA) limit

  1. Impact of Drill and Blast Excavation on Repository Performance Confirmation

    International Nuclear Information System (INIS)

    Keller, R.; Francis, N.; Houseworth, J.; Kramer, N.

    2000-01-01

    There has been considerable work accomplished internationally examining the effects of drill and blast excavation on rock masses surrounding emplacement openings of proposed nuclear waste repositories. However, there has been limited discussion tying the previous work to performance confirmation models such as those proposed for Yucca Mountain, Nevada. This paper addresses a possible approach to joining the available information on drill and blast excavation and performance confirmation. The method for coupling rock damage data from drill and blast models to performance assessment models for fracture flow requires a correlation representing the functional relationship between the peak particle velocity (PPV) vibration levels and the potential properties that govern water flow rates in the host rock. Fracture aperture and frequency are the rock properties which may be most influenced by drill and blast induced vibration. If it can be shown (using an appropriate blasting model simulation) that the effect of blasting is far removed from the waste package in an emplacement drift, then disturbance to the host rock induced in the process of drill and blast excavation may be reasonably ignored in performance assessment calculations. This paper proposes that the CANMET (Canada Center for Mineral and Energy Technology) Criterion, based on properties that determine rock strength, may be used to define a minimum PPV. This PPV can be used to delineate the extent of blast induced damage. Initial applications have demonstrated that blasting models can successfully be coupled with this criterion to predict blast damage surrounding underground openings. The Exploratory Studies Facility at Yucca Mountain has used a blasting model to generate meaningful estimates of near-field vibration levels and damage envelopes correlating to data collected from pre-existing studies conducted. Further work is underway to expand this application over a statistical distribution of geologic

  2. Report on Excavations at Sedgeford, Norfolk 1996

    Directory of Open Access Journals (Sweden)

    Nick Cook

    1997-11-01

    Full Text Available Excavations were undertaken as part of the ongoing work of the Sedgeford Hall Archaeological Research Project, which was set up in 1995 with the aim of investigating the archaeological history of the parish of Sedgeford, west Norfolk.

  3. The huge ATLAS cavern now fully excavated

    CERN Multimedia

    2002-01-01

    Excavation of the ATLAS cavern is now complete! At the end of two years' work involving a tremendous technical challenge, the civil engineering contractors have succeeded in digging out one of the biggest experimental caverns in the world. Bravo!

  4. BILATERAL CHOROIDAL EXCAVATION IN JUVENILE LOCALIZED SCLERODERMA.

    Science.gov (United States)

    Franklin, Mackenzie L; Day, Shelley

    2018-01-01

    To describe a case of bilateral choroidal excavation in a patient with juvenile localized scleroderma. Case report. An asymptomatic 12-year-old boy with localized scleroderma presented for examination and was found to have bilateral areas of choroidal excavation temporal to the fovea. Previous reports of ocular complications of localized scleroderma have primarily described adnexal and anterior segment changes. This is the second report of choroidal changes in a patient with localized scleroderma, and the first in a pediatric patient.

  5. Mechanical excavator performance in Yucca Mountain tuffs

    International Nuclear Information System (INIS)

    Ozdemir, L.; Hansen, F.D.

    1991-01-01

    A research effort of four phases is in progress at the Colorado School of Mines. The overall program will evaluate the cutability of welded tuff and other lithologies likely to be excavated at Yucca Mountain in the site characterization process. Several mechanical systems are considered with emphasis given to the tunnel boring machine. The research comprises laboratory testing, linear drag bit and disc cutter tests and potentially large-scale laboratory demonstrations to support potential use of a tunnel boring machine in welded tuff. Preliminary estimates of mechanical excavator performance in Yucca Mountain tuff are presented here. As phases of the research project are completed, well quantified estimates will be made of performance of mechanical excavators in the Yucca Mountain tuffs. 3 refs., 2 tabs

  6. Mechanical excavator performance in Yucca Mountain tuffs

    International Nuclear Information System (INIS)

    Ozdemir, L.; Hansen, F.D.

    1991-01-01

    A research effort of four phases is in progress at the Colorado School of Mines. The overall program will evaluate the cutability of welded tuff and other lithologies likely to be excavated at Yucca Mountain in the site characterization process. Several mechanical systems are considered with emphasis given to the tunnel boring machine. The research comprises laboratory testing, linear drag bit and disc cutter tests, and potentially large-scale lab. demonstrations to support potential use of a tunnel boring machine in welded tuff. Preliminary estimates of mechanical excavator performance in Yucca Mountain tuff are presented here. As phases of the research project are completed, well-quantified estimates will be made of performance of mechanical excavators in the Yucca Mountain tuffs

  7. Stability of Large Parallel Tunnels Excavated in Weak Rocks: A Case Study

    Science.gov (United States)

    Ding, Xiuli; Weng, Yonghong; Zhang, Yuting; Xu, Tangjin; Wang, Tuanle; Rao, Zhiwen; Qi, Zufang

    2017-09-01

    Diversion tunnels are important structures for hydropower projects but are always placed in locations with less favorable geological conditions than those in which other structures are placed. Because diversion tunnels are usually large and closely spaced, the rock pillar between adjacent tunnels in weak rocks is affected on both sides, and conventional support measures may not be adequate to achieve the required stability. Thus, appropriate reinforcement support measures are needed, and the design philosophy regarding large parallel tunnels in weak rocks should be updated. This paper reports a recent case in which two large parallel diversion tunnels are excavated. The rock masses are thin- to ultra-thin-layered strata coated with phyllitic films, which significantly decrease the soundness and strength of the strata and weaken the rocks. The behaviors of the surrounding rock masses under original (and conventional) support measures are detailed in terms of rock mass deformation, anchor bolt stress, and the extent of the excavation disturbed zone (EDZ), as obtained from safety monitoring and field testing. In situ observed phenomena and their interpretation are also included. The sidewall deformations exhibit significant time-dependent characteristics, and large magnitudes are recorded. The stresses in the anchor bolts are small, but the extents of the EDZs are large. The stability condition under the original support measures is evaluated as poor. To enhance rock mass stability, attempts are made to reinforce support design and improve safety monitoring programs. The main feature of these attempts is the use of prestressed cables that run through the rock pillar between the parallel tunnels. The efficacy of reinforcement support measures is verified by further safety monitoring data and field test results. Numerical analysis is constantly performed during the construction process to provide a useful reference for decision making. The calculated deformations are in

  8. Experimental research data on stress state of salt rock mass around an underground excavation

    Science.gov (United States)

    Baryshnikov, VD; Baryshnikov, DV

    2018-03-01

    The paper presents the experimental stress state data obtained in surrounding salt rock mass around an excavation in Mir Mine, ALROSA. The deformation characteristics and the values of stresses in the adjacent rock mass are determined. Using the method of drilling a pair of parallel holes in a stressed area, the authors construct linear relationship for the radial displacements of the stress measurement hole boundaries under the short-term loading of the perturbing hole. The resultant elasticity moduli of rocks are comparable with the laboratory core test data. Pre-estimates of actual stresses point at the presence of a plasticity zone in the vicinity of the underground excavation. The stress state behavior at a distance from the excavation boundary disagrees with the Dinnik–Geim hypothesis.

  9. Pajarito Plateau archaeological surveys and excavations. II

    Energy Technology Data Exchange (ETDEWEB)

    Steen, C R

    1982-04-01

    Los Alamos National Laboratory continues its archaeological program of data gathering and salvage excavations. Sites recently added to the archaeological survey are described, as well as the results of five excavations. Among the more interesting and important discoveries are (1) the apparently well-established local use of anhydrous lime, and (2) a late pre-Columbian use of earlier house sites and middens for garden plots. Evidence indicated that the local puebloan population was the result of an expansion of upper Rio Grande peoples, not an influx of migrants.

  10. Modeling of excavation induced coupled hydraulic-mechanical processes in claystone

    Energy Technology Data Exchange (ETDEWEB)

    Massmann, Jobst

    2009-07-01

    induced hydraulic and mechanical response for a time period of at least ten years. An explanation can be given for the delayed development of an excavation damaged zone. It is caused by the desaturation induced shrinkage. (orig.)

  11. Modeling of excavation induced coupled hydraulic-mechanical processes in claystone

    Energy Technology Data Exchange (ETDEWEB)

    Massmann, Jobst

    2009-07-01

    hydraulic and mechanical response for a time period of at least ten years. An explanation can be given for the delayed development of an excavation damaged zone. It is caused by the desaturation induced shrinkage. (orig.)

  12. Modeling of excavation induced coupled hydraulic-mechanical processes in claystone

    International Nuclear Information System (INIS)

    Massmann, Jobst

    2009-01-01

    hydraulic and mechanical response for a time period of at least ten years. An explanation can be given for the delayed development of an excavation damaged zone. It is caused by the desaturation induced shrinkage. (orig.)

  13. Underground excavation methods for a high-level waste repository

    International Nuclear Information System (INIS)

    Peshel, J.; Gupta, D.; Nataraja, M.

    1990-01-01

    This paper reports on rock excavation methods for a High-Level Waste repository that should be selected to limit the potential for creating preferential pathways for groundwater to travel to the waste packages or for radionuclides to migrate to the accessible environment. The use of water and other foreign substances should be controlled so that the repository performance is not compromised. The excavated openings should remain stable so that operations can be carried out safely and the retrievability option maintained. As per the current conceptual designs presented by the Department of Energy, the exploratory shaft facility becomes a part of the repository if the Yucca Mountain site is found suitable for repository development. Therefore, the methods of constructing the underground openings should be compatible with the performance requirements for the repository. Also, the degree of damage to the rock surrounding the openings and the extent of the damage zone should not preclude adequate site characterization. The ESf construction and operation should be compatible with the site data gathering activities, such as geological, thermomechanical, hydrological and geochemical testing

  14. Case Studies and Monitoring of Deep Excavations

    NARCIS (Netherlands)

    Korff, M.

    2017-01-01

    Several case histories from Dutch underground deep excavation projects are presented in this paper, including the lessons learned and the learning processes involved. The focus of the paper is on how the learning takes places and how it is documented. It is necessary to learn in a systematic and

  15. Heathrow Terminal 5 Excavation Archive (Data Paper

    Directory of Open Access Journals (Sweden)

    Framework Archaeology

    2014-06-01

    Full Text Available Framework Archaeology is a Joint Venture agreement between Oxford Archaeology (OA and Wessex Archaeology (WA to provide archaeological services to BAA (formerly British Airports Authority, now Heathrow Airport Holdings Ltd. Given the potential scale of some of BAA's projects, the joint venture enables Framework Archaeology to draw on the full resources of both OA and WA, including site staff, specialist managers, administrative support, and technical facilities. In 1993, BAA plc and Heathrow Airport Limited submitted a joint planning application to develop an additional passenger terminal complex (Terminal 5, together with the provision of aircraft aprons and taxiways, and include the realignment of rivers and landscaping. The resulting archaeological excavations were undertaken as three main phases of work. Excavations in 1996 by the Museum of London Archaeology Service of approximately 4 ha of sludge stockpile areas (site code POK96. Between 1999-2000 Framework Archaeology excavated approximately 21 ha in the Perry Oaks sludge works and adjacent areas (WPR98. Framework Archaeology also undertook excavations between 2002-2007 as part of the construction of Terminal 5 (PSH02, TEC05 covering a further 50 hectares. Importantly the aim of the Terminal 5 archaeological programme was to move beyond the description and recovery of archaeological remains and to arrive at an understanding of the history of human inhabitation and the practical ways in which people established their presence in the material, social and political conditions of their day.

  16. Stepwise excavation in a permanent molar

    DEFF Research Database (Denmark)

    Lima, Fernanda Ferruzzi; Pascotto, Renata Corrêa; Benetti, Ana Raquel

    2010-01-01

    with zinc oxide cement were performed to minimize the risk of pulp exposure during excavation. After 45 days, the remaining carious tissue was removed and a restoration with glass-ionomer lining (Vitrebond) and resin composite (P-50) was performed. Satisfactory morphology and function of the restoration...

  17. Dilmun revisited: excavations at Saar, Bahrain

    Directory of Open Access Journals (Sweden)

    Harriet Crawford

    1997-11-01

    Full Text Available About 2000 BC the island of Bahrain was at the centre of a prosperous trading community - the Early Dilmun civilization - that stretched from Mesopotamia to the Indus Valley. Excavations at the site of Saar have, since 1989, recovered much new information about the layout of the settlement and its local economy and social system.

  18. 100 area excavation treatability test plan

    International Nuclear Information System (INIS)

    1993-05-01

    This test plan documents the requirements for a treatability study on field radionuclide analysis and dust control techniques. These systems will be used during remedial actions involving excavation. The data from this treatability study will be used to support the feasibility study (FS) process. Development and screening of remedial alternatives for the 100 Area, using existing data, have been completed and are documented in the 100 Area Feasibility Study, Phases 1 and 2 (DOE-RL 1992a). Based on the results of the FS, the Treatability Study Program Plan (DOE-RL 1992b) identifies and prioritizes treatability studies for the 100 Area. The data from the treatability study program support future focused FS, interim remedial measures (IRM) selection, operable unit final remedy selection, remedial design, and remedial actions. Excavation is one of the high-priority, near-term, treatability study needs identified in the program plan (DOE-RL 1992b). Excavation of contaminated soils and buried solid wastes is included in several of the alternatives identified in the 100 Area FS. Although a common activity, excavation has only been used occasionally at the Hanford Site for waste removal applications

  19. Technical summary of AECL's Mine-by Experiment phase I: Excavation response

    International Nuclear Information System (INIS)

    Read, R.S.; Martin, C.D.

    1996-02-01

    The first phase of the Mine-by Experiment was conducted at the 420 Level of the Underground Research Laboratory (URL) to investigate the response induced in the rock mass by excavating a 3.5-m-diameter circular tunnel using a non-explosive technique. The main objective of the experiment was to study the processes involved in progressive failure and the development of excavation-induced damage around underground openings. To this end, state-of-the-art geomechanical and geophysical instrumentation was used to monitor the excavation of the 46-m-long Mine-by Experiment test tunnel. The results from the experiment show that progressive failure in compressive regions around the tunnel initiates at stresses about 50% of the rock strength measured in uniaxial compression tests in the laboratory. The difference between the laboratory and in situ behaviour is attributed to complex stress changes that occur during excavation of the tunnel, especially in the vicinity of the advancing face. These effects are not simulated in standard laboratory tests. Numerical modelling and in situ characterization studies were conducted to establish the extent and characteristics of the damaged zone around the test tunnel. As part of this study, in situ stresses and material properties were established through back analysis of measured displacements and strains. Using these boundary conditions, it was shown that the damaged zone was limited to within 1 m of the original tunnel perimeter. The characteristics of the damaged zone, however, were found to be highly variable around the tunnel, and were dependent on the nature of the stress concentrations, geology, stress magnitudes and orientations and, to a lesser extent, the excavation method and sequence. (author) 136 refs., 14 tabs., 103 figs

  20. A rock mechanics study of fracture zone 2 at the Finnsjoen site

    International Nuclear Information System (INIS)

    Leijon, B.; Ljunggren, C.

    1992-01-01

    Comprehensive field investigations at the Finnsjoen study site have revealed a subhorizontal zone, termed Zone 2, that exhibits anomalous characteristics in terms of high hydraulic conductivity, governing the groundwater transport pattern on a regional scale. The present study provides an assessment of the characteristics of Zone 2. Thus, estimates of the deformational characteristics of the zone, based on available borehole information, show that the zone forms a diffuse and rather moderate mechanical contrast to the surrounding bedrock. As also verified by stress measurement results, major stress anomalies attributable to the zone are therefore not to be expected. Bound estimates of stress conditions during periods of glaciation and deglaciation are also derived, and possible impacts of these loadings on the fracture zone are discussed. It is concluded that glaciation represents stable conditions, whilst the complex loading mechanisms encountered during deglaciation may trigger reactivation of structures at shallow depth. Taking the above results as an example, implications of a feature like Zone 2 on the integrity of a hypothetical repository are discussed in more general terms. Considering the likely spatial extension of the mechanical disturbances related to the repository excavations and the fracture zone respectively, it is suggested that a mutual distance of the order of one hundred metres is sufficient to avoid mechanical interaction. (au)

  1. Simulation of hydraulic disturbances caused by the underground rock characterisation facility in Olkiluoto, Finland

    International Nuclear Information System (INIS)

    Loefman, J.; Ferenc, M.

    2004-01-01

    Spent fuel from the Finnish nuclear power plants will be disposed of in a repository to be excavated in crystalline bedrock at a depth of 400-700 metres in Olkiluoto. The extensive site investigations carried out since the early 1980's will next focus on the construction of an underground rock characterisation facility (ONKALO) in 2004-2010. The open tunnel system will constitute a major hydraulic disturbance for the site's groundwater conditions for hundreds of years. Especially, inflow of groundwater into the tunnels results in a drawdown of groundwater table and upcoming of deep saline groundwater, which the present study aimed to assess by means of a 3D finite element simulation. The modelled bedrock volume, which horizontally covered the whole Olkiluoto island, was conceptually divided into hydraulic units, planar fracture zones and sparsely fractured rock between the zones, which were both separately treated as porous media. The geometry of the fracture zones was based on the geological bedrock model. Simulations showed that without engineering measures (e.g. grouting) taken to limit inflow of groundwater into the open tunnels, the hydraulic disturbances could be drastic. The tunnels draw groundwater from all directions in the bedrock. A major part of inflow comes from the well-conductive subhorizontal fracture zones intersected by the access tunnel and the shaft. The simulations show that the resulting drawdown of groundwater table may be from tens to hundreds of metres and the depressed area may extend over the area of the island. The results also indicate that the salinity of groundwater is gradually rising around and below the tunnel system, and locally concentration (TDS) may rise rather high in the vicinity of the tunnels. However, the disturbances can significantly be reduced by the grouting of rock. (orig.)

  2. 118-B-1 excavation treatability test plan

    International Nuclear Information System (INIS)

    1994-07-01

    The Hanford 118-B-1 Burial Ground Treatability Study has been required by milestone change request number-sign M-15-93-04, dated September 30, 1993. The change request requires that a treatability test be conducted at the 100-B Area to obtain additional engineering information for remedial design of burial grounds receiving waste from 100 Area removal actions. This treatability study has two purposes: (1) to support development of the Proposed Plan (PP) and Record of Decision (ROD), which will identify the approach to be used for burial ground remediation, and (2) to provide specific engineering information for receiving waste generated from the 100 Area removal actions. Data generated from this test also will provide critical performance and cost information necessary for remedy evaluation in the detailed analysis of alternatives during preparation of the focused feasibility study (FFS). This treatability testing supports the following 100 Area alternatives: (1) excavation and disposal, and (2) excavation, sorting, (treatment), and disposal

  3. Excavating and loading equipment for peat mining

    Science.gov (United States)

    Mikhailov, A. V.; Zhigulskaya, A. I.; Yakonovskaya, T. B.

    2017-10-01

    Recently, the issues of sustainable development of Russian regions, related to ensuring energy security, are more urgent than ever. To achieve sustainable development, an integrated approach to the use of local natural resources is needed. Practically in all north regions of the Russian Federation, peat as a local natural resource is widespread, which has a practical application in the area of housing services. The paper presents the evaluation of technologies for open-pit peat mining, as well as analysis of technological equipment for peat production. Special attention is paid to a question of peat materials excavating and loading. The problem of equipment selection in a peat surface mine is complex. Many features, restrictions and criteria need to be considered. Use of low and ultra-low ground pressure excavators and low ground pressure front-end loaders with full-range tires to provide the necessary floatation in the peat bog environment is offered.

  4. Archeological Excavations at the Wanapum Cache Site

    International Nuclear Information System (INIS)

    T. E. Marceau

    2000-01-01

    This report was prepared to document the actions taken to locate and excavate an abandoned Wanapum cache located east of the 100-H Reactor area. Evidence (i.e., glass, ceramics, metal, and wood) obtained from shovel and backhoe excavations at the Wanapum cache site indicate that the storage caches were found. The highly fragmented condition of these materials argues that the contents of the caches were collected or destroyed prior to the caches being burned and buried by mechanical equipment. While the fiber nets would have been destroyed by fire, the specialized stone weights would have remained behind. The fact that the site might have been gleaned of desirable artifacts prior to its demolition is consistent with the account by Riddell (1948) for a contemporary village site. Unfortunately, fishing equipment, owned by and used on behalf of the village, that might have returned to productive use has been irretrievably lost

  5. CLASSIFICATION OF THE MGR SUBSURFACE EXCAVATION SYSTEM

    International Nuclear Information System (INIS)

    R. Garrett

    1999-01-01

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) subsurface excavation system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

  6. Mining technology development for hard rock excavation

    International Nuclear Information System (INIS)

    Hustrulid, W.; Cudnick, R.; Trent, R.; Holmberg, R.

    1980-01-01

    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

  7. The underground research laboratory room 209 excavation response test

    International Nuclear Information System (INIS)

    Simmons, G.R.

    1992-02-01

    The response of the rock mass to excavation is an important factor in the design and performance of underground excavations and installations. This is particularly true in the excavation of vaults for the disposal of nuclear fuel waste, where the conditions in the rock mass around the disposal areas may affect the performance of engineered sealing systems installed to isolate the waste. The factors influencing, and mechanisms controlling, rock mass response to excavation must be understood in order to accommodate excavation response effects in disposal vault design and construction

  8. Mine-by experiment committee report phase 1: excavation response summary and implications

    International Nuclear Information System (INIS)

    Martin, C.D.; Kaiser, P.K.

    1996-05-01

    The first phase of the Mine-by Experiment, i.e., excavation of a 3.5-m-diameter tunnel, was carried out at the 420 Level of the Underground Research Laboratory to investigate rock mass damage and progressive failure around a circular opening in brittle unfractitred Lac du Bonnet granite. The tunnel was excavated without explosives, and state-of-the-art instrumentation comprising both geomechanical and geophysical instruments was used to monitor the failure process. The experiment showed that rock mass damage begins once the deviatoric stress (0'1 - 0'3) near the advancing face of the tunnel exceeds a critical level. Crack propagation can lead to progressive failure around the tunnel; however, it is limited to a region, referred to as the excavation damaged zone, of less than one tunnel radius. Within the damaged zone, stabbing (a typical form of brittle failure) began at stress levels equivalent to about 50% of the short-term laboratory unconfined compressive strength. This reduction in strength between laboratory and in situ conditions occurs because the in situ loading path is far more complex than the monotonic loading path used to test laboratory samples. There is no evidence to suggest that the stabbing failure process would extend beyond the depth of damage defined by the deviatoric stress criterion. The stabbing process stops when the tunnel face has advanced sufficiently (approximately 2 tunnel diameters) such that the rock mass is no longer subjected to excavation-induced stress changes. The strength of the rock mass in the damaged zone must be back-calculated from in situ tests, because the loading path cannot be duplicated readily in the laboratory. Thus, the back-calculated damaged strength must be used to evaluate the stability of the excavation. Sealing systems to reduce the permeability in the axial direction of a tunnel must be keyed into the rock mass beyond the radial extent of the damaged zone. The shape of the seals must be designed so as to

  9. DECOVALEX II project. Nirex RCF Shaft Excavation Task 1C - Coupled hydro-mechanical effects of shaft sinking within Sector 7

    International Nuclear Information System (INIS)

    Hakami, H.

    1999-12-01

    Mohr-Coulomb and Hoek-Brown failure criteria - that takes care of the onset of a brittle failure more explicitly, numerical analyses were carried out in order to capture the Excavation Damage Zone, a feature that could not be studied under the failure criterion and the input data incorporated in the first modelling approach. Regardless of which of the two failure criteria was active in the simulations, the deformational disturbances caused by the numerical excavation of the shaft were typical for stiff and competent crystalline rock masses. The mechanically disturbed zone did not effectively extend farther than about three times the diameter of the shaft, beyond which the disturbance was insignificant. Also, the convergence of the shaft was confined to about 3 mm at the most, once again typical for the hard rocks. As was expected, there was a very significant difference in flow characteristics associated with the two model set-ups; with and without the outstanding flow zones. While both the modelled rock matrices had almost similar flow properties, the flow zones only appearing in the second model were supplied with uppermost values of the permeability and porosity from ranges estimated from the site and laboratory investigations. The extreme values were between x - y order of magnitudes greater than the corresponding values from the rock matrix. Extremely low volumes of water, up to about 2.5 lit/min percolated into a 20-m long section of the shaft, by using the first model set-up with no flow zones included. On the other hand much greater values; e.g. as high as about 260 lit/min flowed into the same section of the shaft, having the three flow zones active. The latter case may be considered as a possible upper bound for the inflow into the shaft over a section of 20 meters long that may take place. An Excavation Damage Zone was numerically captured that extended, at certain points, to about 60 centimetres into the rock from the shaft walls. The thickness of the

  10. DECOVALEX II project. Nirex RCF Shaft Excavation Task 1C - Coupled hydro-mechanical effects of shaft sinking within Sector 7

    Energy Technology Data Exchange (ETDEWEB)

    Hakami, H. [Itasca Geomekanik AB, Stockholm (Sweden)

    1999-12-01

    from both Mohr-Coulomb and Hoek-Brown failure criteria - that takes care of the onset of a brittle failure more explicitly, numerical analyses were carried out in order to capture the Excavation Damage Zone, a feature that could not be studied under the failure criterion and the input data incorporated in the first modelling approach. Regardless of which of the two failure criteria was active in the simulations, the deformational disturbances caused by the numerical excavation of the shaft were typical for stiff and competent crystalline rock masses. The mechanically disturbed zone did not effectively extend farther than about three times the diameter of the shaft, beyond which the disturbance was insignificant. Also, the convergence of the shaft was confined to about 3 mm at the most, once again typical for the hard rocks. As was expected, there was a very significant difference in flow characteristics associated with the two model set-ups; with and without the outstanding flow zones. While both the modelled rock matrices had almost similar flow properties, the flow zones only appearing in the second model were supplied with uppermost values of the permeability and porosity from ranges estimated from the site and laboratory investigations. The extreme values were between x - y order of magnitudes greater than the corresponding values from the rock matrix. Extremely low volumes of water, up to about 2.5 lit/min percolated into a 20-m long section of the shaft, by using the first model set-up with no flow zones included. On the other hand much greater values; e.g. as high as about 260 lit/min flowed into the same section of the shaft, having the three flow zones active. The latter case may be considered as a possible upper bound for the inflow into the shaft over a section of 20 meters long that may take place. An Excavation Damage Zone was numerically captured that extended, at certain points, to about 60 centimetres into the rock from the shaft walls. The thickness of

  11. MBC model analysis for predicting the rock behavior in excavating the Mizunami Underground Research Laboratory

    International Nuclear Information System (INIS)

    Mori, Takayuki; Iwano, Keita; Nakajima, Makoto; Morikawa, Seiji; Tabei, Kazuto

    2005-03-01

    As a Phase 1 of MIU project (Mizunami Underground Research Laboratory project), through the laboratory and borehole in-situ tests, JNC Tono Geoscience Center plans to constitute the comprehensive geological model and predicts the rock behaviors in excavating the shaft and gallery. These model and results leads to be reflected by the next step research projects. So far, the Phase 1 of MIU project is coming to final stage, and the Phase 2 will start at next year in which the in-situ researches are planned through the excavation. In this study, the comprehensive geometrical model was drawn out through the Phase 1 data, and MBC model analysis was carried out to predict the rock mass behavior around the shaft and gallery. The following results are obtained. 1. With MIZ-1 borehole core, artificial joints, which are assumed to be produced by rock blasting, were formed through the Brazilian test. And through the rock shear test for these joints, these mechanical properties were obtained. 2. By examining the MIZ-1 borehole research data, Mizunami site was classified by mechanical and joint properties and the Geomechanical model were made up. 3. Through the MBC model, the shaft and gallery cases were analyzed which depend on the rock mass classification, Excavation Damaged Zone, and the direction of the galleries. These results showed that in most cases, the joint opening were little because of the rock stiffness, but by the existence of high inclined joints, the side wall of the galleries were damaged by the excavation. (author)

  12. Numerical Simulation of Blast Vibration and Crack Forming Effect of Rock-Anchored Beam Excavation in Deep Underground Caverns

    Directory of Open Access Journals (Sweden)

    XinPing Li

    2017-01-01

    Full Text Available Aiming at surrounding rock damage induced by dynamic disturbance from blasting excavation of rock-anchored beam in rock mass at moderate or far distance in underground cavern, numerical model of different linear charging density and crustal stress in underground cavern is established by adopting dynamic finite element software based on borehole layout, charging, and rock parameter of the actual situation of a certain hydropower station. Through comparison in vibration velocity, contour surface of rock mass excavation, and the crushing extent of excavated rock mass between calculation result and field monitoring, optimum linear charging density of blast hole is determined. Studies are also conducted on rock mass vibration in moderate or far distance to blasting source, the damage of surrounding rock in near-field to blasting source, and crushing degree of excavated rock mass under various in situ stress conditions. Results indicate that, within certain range of in situ stress, the blasting vibration is independent of in situ stress, while when in situ stress is increasing above certain value, the blasting vibration velocity will be increasing and the damage of surrounding rock and the crushing degree of excavated rock mass will be decreasing.

  13. Safety analysis of autonomous excavator functionality

    International Nuclear Information System (INIS)

    Seward, D.; Pace, C.; Morrey, R.; Sommerville, I.

    2000-01-01

    This paper presents an account of carrying out a hazard analysis to define the safety requirements for an autonomous robotic excavator. The work is also relevant to the growing generic class of heavy automated mobile machinery. An overview of the excavator design is provided and the concept of a safety manager is introduced. The safety manager is an autonomous module responsible for all aspects of system operational safety, and is central to the control system's architecture. Each stage of the hazard analysis is described, i.e. system model creation, hazard definition and hazard analysis. Analysis at an early stage of the design process, and on a system that interfaces directly to an unstructured environment, exposes certain issues relevant to the application of current hazard analysis methods. The approach taken in the analysis is described. Finally, it is explained how the results of the hazard analysis have influenced system design, in particular, safety manager specifications. Conclusions are then drawn about the applicability of hazard analysis of requirements in general, and suggestions are made as to how the approach can be taken further

  14. A STRUCTURAL MODEL OF AN EXCAVATOR WORKFLOW CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    A. Gurko

    2016-12-01

    Full Text Available Earthwork improving is connected with excavators automation. In this paper, on the basis of the analysis of problems that a hydraulic excavator control system have to solve, the hierarchical structure of a control system have been proposed. The decomposition of the control process had been executed that allowed to develop the structural model which reflects the characteristics of a multilevel space-distributed control system of an excavator workflow.

  15. Theory and technology of rock excavation for civil engineering

    CERN Document Server

    Zou, Dingxiang

    2017-01-01

    This book summarizes the technical advances in recent decades and the various theories on rock excavation raised by scholars from different countries, including China and Russia. It not only focuses on rock blasting but also illustrates a number of non-blasting methods, such as mechanical excavation in detail. The book consists of 3 parts: Basic Knowledge, Surface Excavation and Underground Excavation. It presents a variety of technical methods and data from diverse sources in the book, making it a valuable theoretical and practical reference resource for engineers, researchers and postgraduates alike.

  16. Development of excavator training simulator using leap motion controller

    Science.gov (United States)

    Fahmi, F.; Nainggolan, F.; Andayani, U.; Siregar, B.

    2018-03-01

    Excavator is a heavy machinery that is used for many industries purposes. Controlling the excavator is not easy. Its operator has to be trained well in many skills to make sure it is safe, effective, and efficient while using the excavator. In this research, we proposed a virtual reality excavator simulator supported by a device called Leap Motion Controller that supports finger and hand motions as an input. This prototype will be developed than in the virtual reality environment to give a more real sensing to the user.

  17. Middle Stone Age stratigraphy and excavations at Die Kelders Cave 1 (Western Cape Province, South Africa): the 1992, 1993, and 1995 field seasons.

    Science.gov (United States)

    Marean, C W; Goldberg, P; Avery, G; Grine, F E; Klein, R G

    2000-01-01

    Die Kelders Cave 1, first excavated under the direction of Franz Schweitzer in 1969-1973, was re-excavated between 1992 and 1995 by a combined team from the South African Museum, SUNY at Stony Brook, and Stanford University. These renewed excavations enlarged the artefactual and faunal samples from the inadequately sampled and less intensively excavated lower Middle Stone Age (MSA) layers, increased our understanding of the complex site formation processes within the cave, enlarged the hominid sample from the MSA deposits, and generated ESR, TL, and OSL dates for the MSA layers. Importantly, these new excavations dramatically improved our comprehension of the vertical and lateral characteristics of the MSA stratigraphy. Surface plotting of the MSA layers has led to the identification of at least two major zones of subsidence that significantly warped the layers, draping some along the eroding surface contours of major blocks of fallen limestone roof rock. A third zone of subsidence is probably present in the older excavations. Dramatic roof falls of very large limestone blocks occurred at least twice-once in the middle of Layer 4/5 where the roof blocks were only slightly weathered after collapse, and at the top of Layer 6 where the blocks weathered heavily after collapse, producing a zone of decomposed rock around the blocks. Many of the sandy strata are cut by small and localized faults and slippages. All of the strata documented by Schweitzer's excavations are present throughout the exposed area to the west of his excavated area, where many of them thicken and become more complex. Layer 6, the thickest MSA layer, becomes less diagenetically altered and compressed to the west. Copyright 2000 Academic Press.

  18. Coupled hydrological-mechanical effects due to excavation of underground openings in unsaturated fractured rocks

    International Nuclear Information System (INIS)

    Montazer, P.

    1985-01-01

    One of the effects of excavating an underground opening in fractured rocks is a modification of the state of the stress in the rock mass in the vicinity of the opening. This effect causes changes in the geometry of the cross sections of the fracture planes, which in turn results in modification of the hydrologic properties of the fractures of the rock mass. The significance of the orientation of the fractures and their stiffness on the extent of the modification of the hydrologic properties as a result of excavation of underground openings is demonstrated. A conceptual model is presented to illustrate the complexity of the coupled hydrological-mechanical phenomena in the unsaturated zone. This conceptual model is used to develop an investigative program to assess the extent of the effect at a proposed repository site for storing high-level nuclear wastes

  19. Modelling bucket excavation by finite element

    Science.gov (United States)

    Pecingina, O. M.

    2015-11-01

    Changes in geological components of the layers from lignite pits have an impact on the sustainability of the cup path elements and under the action of excavation force appear efforts leading to deformation of the entire assembly. Application of finite element method in the optimization of components leads to economic growth, to increase the reliability and durability of the studied machine parts thus the machine. It is obvious usefulness of knowledge the state of mechanical tensions that the designed piece or the assembly not to break under the action of tensions that must cope during operation. In the course of excavation work on all bucket cutting force components, the first coming into contact with the material being excavated cutting edge. Therefore in the study with finite element analysis is retained only cutting edge. To study the field of stress and strain on the cutting edge will be created geometric patterns for each type of cup this will be subject to static analysis. The geometric design retains the cutting edge shape and on this on the tooth cassette location will apply an areal force on the abutment tooth. The cutting edge real pattern is subjected to finite element study for the worst case of rock cutting by symmetrical and asymmetrical cups whose profile is different. The purpose of this paper is to determine the displacement and tensions field for both profiles considering the maximum force applied on the cutting edge and the depth of the cutting is equal with the width of the cutting edge of the tooth. It will consider the worst case when on the structure will act both the tangential force and radial force on the bucket profile. For determination of stress and strain field on the form design of cutting edge profile will apply maximum force assuming uniform distribution and on the edge surface force will apply a radial force. After geometric patterns discretization on the cutting knives and determining stress field, can be seen that at the

  20. 118-B-1 excavation treatability test procedures

    International Nuclear Information System (INIS)

    Frain, J.M.

    1994-01-01

    This treatability study has two purposes: to support development of the approach to be used for burial ground remediation, and to provide specific engineering information for the design of burial grounds receiving waste generated from the 100 Area removal actions. Data generated from this test will also provide performance and cost information necessary for detailed analysis of alternatives for burial ground remediation. Further details on the test requirements, milestones and data quality objectives are described in detail in the 118-B-1 Excavation Treatability Test Plan (DOE/RL-94-43). These working procedures are intended for use by field personnel to implement the requirements of the milestone. A copy of the detailed Test Plan will be kept on file at the on-site field support trailer, and will be available for review by field personnel

  1. Development of excavation technologies at the Canadian underground research laboratory

    International Nuclear Information System (INIS)

    Kuzyk, Gregory W.; Martino, Jason B.

    2008-01-01

    Several countries, Canada being among them, are developing concepts for disposal of used fuel from power generating nuclear reactors. As in underground mining operations, the disposal facilities will require excavation of many kilometres of shafts and tunnels through the host rock mass. The need to maintain the stability of excavations and safety of workers will be of paramount importance. Also, excavations required for many radioactive waste repositories will ultimately need to be backfilled and sealed to maintain stability and minimize any potential for migration of radionuclides, should they escape their disposal containers. The method used to excavate the tunnels and shafts, and the rock damage that occurs due to excavation, will greatly affect the performance characteristics of repository sealing systems. The underground rock mechanics and geotechnical engineering work performed at the Canadian Underground Research Laboratory (URL) has led to the development of excavation technologies that reduce rock damage in subsurface excavations. This paper discusses the excavation methods used to construct the URL and their application in planning for the construction of similar underground laboratories and repositories for radioactive wastes. (author)

  2. THE IMPROVEMENT OF THE EXCAVATION METHODS IN BAUXITE DEPOSITS

    Directory of Open Access Journals (Sweden)

    Borislav Perić

    1990-12-01

    Full Text Available The underground bauxite excavation in Yugoslavia is getting more important recently due to gradual exploitation of shallow deposits. The main excavation method is sublevel caving method. That technology of exploitation is characterized by high excavation loosses reaching even to 50% due to mixing of bauxite with waste. By beds with competent limestone roof which are not liable to direct caving are formed unplanned open spaces so the work safety is often dangercd by sudden caving. That was the reason for carrying out the observations in situ and investigations on mathematical models to define boundary of excavated space stability. This investigation were the basis for the new conception of further excavation of the »Jukići-Didare« mine with the application of even three exploitation methods maximally adapted to the characteristics of the remaining part of deposit.

  3. Assessment of technologies for hazardous waste site remediation: Non-treatment technologies and pilot scale facility implementation -- excavation -- storage technology -- safety analysis and review statement. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, H.R.; Overbey, W.K. Jr.; Koperna, G.J. Jr.

    1994-02-01

    The purpose of this study is to assess the state-of-the-art of excavation technology as related to environmental remediation applications. A further purpose is to determine which of the excavation technologies reviewed could be used by the US Corp of Engineers in remediating contaminated soil to be excavated in the near future for construction of a new Lock and Dam at Winfield, WV. The study is designed to identify excavation methodologies and equipment which can be used at any environmental remediation site but more specifically at the Winfield site on the Kanawha River in Putnam County, West Virginia. A technical approach was determined whereby a functional analysis was prepared to determine the functions to be conducted during the excavation phase of the remediation operations. A number of excavation technologies were identified from the literature. A set of screening criteria was developed that would examine the utility and ranking of the technologies with respect to the operations that needed to be conducted at the Winfield site. These criteria were performance, reliability, implementability, environmental safety, public health, and legal and regulatory compliance. The Loose Bulk excavation technology was ranked as the best technology applicable to the Winfield site. The literature was also examined to determine the success of various methods of controlling fugitive dust. Depending upon any changes in the results of chemical analyses, or prior remediation of the VOCs from the vadose zone, consideration should be given to testing a new ``Pneumatic Excavator`` which removes the VOCs liberated during the excavation process as they outgas from the soil. This equipment however would not be needed on locations with low levels of VOC emissions.

  4. Assessment of technologies for hazardous waste site remediation: Non-treatment technologies and pilot scale facility implementation -- excavation -- storage technology -- safety analysis and review statement

    International Nuclear Information System (INIS)

    Johnson, H.R.; Overbey, W.K. Jr.; Koperna, G.J. Jr.

    1994-02-01

    The purpose of this study is to assess the state-of-the-art of excavation technology as related to environmental remediation applications. A further purpose is to determine which of the excavation technologies reviewed could be used by the US Corp of Engineers in remediating contaminated soil to be excavated in the near future for construction of a new Lock and Dam at Winfield, WV. The study is designed to identify excavation methodologies and equipment which can be used at any environmental remediation site but more specifically at the Winfield site on the Kanawha River in Putnam County, West Virginia. A technical approach was determined whereby a functional analysis was prepared to determine the functions to be conducted during the excavation phase of the remediation operations. A number of excavation technologies were identified from the literature. A set of screening criteria was developed that would examine the utility and ranking of the technologies with respect to the operations that needed to be conducted at the Winfield site. These criteria were performance, reliability, implementability, environmental safety, public health, and legal and regulatory compliance. The Loose Bulk excavation technology was ranked as the best technology applicable to the Winfield site. The literature was also examined to determine the success of various methods of controlling fugitive dust. Depending upon any changes in the results of chemical analyses, or prior remediation of the VOCs from the vadose zone, consideration should be given to testing a new ''Pneumatic Excavator'' which removes the VOCs liberated during the excavation process as they outgas from the soil. This equipment however would not be needed on locations with low levels of VOC emissions

  5. Damage-induced permeability changes around underground excavations; Endommagement des roches argileuses et permeabilite induite au voisinage d'ouvrages souterrains

    Energy Technology Data Exchange (ETDEWEB)

    Coll, C

    2005-07-15

    The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

  6. Damage-induced permeability changes around underground excavations; Endommagement des roches argileuses et permeabilite induite au voisinage d'ouvrages souterrains

    Energy Technology Data Exchange (ETDEWEB)

    Coll, C

    2005-07-15

    The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

  7. Methods to ensure the quality of excavated soil material from geogenically metalliferous sites

    Science.gov (United States)

    Liebhard, Peter; Sager, Manfred

    2017-04-01

    Soils at geogenically metalliferous sites might exceed heavy metal threshold levels with respect to agricultural use, apart from anthropogenic contamination sources. As a fundamental substrate for green plants and green plant production, soil is not easily renewable, its formation needs long time (e.g. 500 years for 20 mm). In Austria, about 10ha of soil get sealed every day, resulting in complete loss of its biological functions. Excavated soil material has been classified as waste from a legal point of view, which made 33 mill. tons resp. 48% of total waste in Austria in 2010. Recycling of excavated soil material for agricultural use will be an important task to reduce future waste and to enlarge agricultural substrate volumes, but methods to ensure proper qualities are needed to improve regulations. Within this investigation, the transfer of various metals from geogenically metalliferous soils to various crop plants will be investigated, and correlated with various simple soil test methods. Four excavated soil materials from the metalliferous schist zone within the Austrian province of Styria (Kraubath/Mur, Übelbach) and a low-metal reference sample have been taken as substrates to grow raygrass (lolium multiflorum) as a green cover, salad (Lactuca sativa) as a vegetable food item, oats (Avena sativa), maize (Zea mais) and stinging nettle (Urtica dioica) as a hyperaccumulating species. Results and recommendations will be presented.

  8. Simulating the time-dependent behaviour of excavations in hard rock

    CSIR Research Space (South Africa)

    Malan, DF

    2002-10-01

    Full Text Available (1993) estimated the rock disintegration of the roof of the Swedish repository at Forsmark where the excavation is intersected by a fracture zone. By generalising the structure to be one of regular layers of blocks and applying a log- time creep law, he... and secondary closure in squeezing tunnels. Tertiary movements can be considered by providing suitable laws relating the values of the mechanical parameters (such as viscosity) to the irreversible part of the time-dependent strain. These rheological models...

  9. Results of the Schooner excavation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tewes, Howard A [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    Project Schooner, a nuclear detonation in interlayered hard and soft, partially saturated volcanic rock, was executed as a part of the Plowshare Program for development of nuclear excavation techniques. The primary objectives of this experiment were: (a) to obtain experimental data on crater development and size in a new medium to further verify existing rock mechanics computer codes and calculational techniques; and (b) to determine the fractional release of radioactivity from a nuclear detonation in wet rock. As was noted in the case of the Sedan experiment, appreciable (though relatively small) amounts of radioactivity were released to the environment from this detonation in hard, partially saturated rock. Although the thermo-nuclear explosive used in this experiment gave a yield of approximately 31 kilotons, only the equivalent of the fission products from about 370 tons of fission were distributed in both fallout and cloud. Data which have been reduced to date indicate that this released radioactivity underwent only a moderate amount of chemical fractionation, being much more similar in this respect to Sedan than to Danny Boy. (author)

  10. Summary of nuclear-excavation applications

    Energy Technology Data Exchange (ETDEWEB)

    Toman, John [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    Although many nuclear-excavation applications have been proposed, few have been seriously considered and none have been brought to fruition. This paper summarizes and discusses specific examples of a canal, a harbor, a highway cut and a nuclear quarry, all of which have been studied in some detail. It is believed that useful demonstration projects - such as a deep-water harbor and a nuclear quarry - can be safely accomplished with existing technology. Current assessments of the feasibility of constructing a sea-level canal in either Panama or Colombia appear to be favorable from a technical viewpoint. The concept of close spacing in row-charge designs has made it possible to greatly reduce the estimated required salvo yields for both proposed canals. Salvo yields have been reduced from 35 Mt to 13 Mt in Colombia and 11 Mt in Panama. As a result, the seismic motions predicted for large cities in these countries are similar to motions produced in populated areas in the United States by nuclear tests and earthquakes in which no real damage to residential or high-rise structures was noted. (author)

  11. Summary of nuclear-excavation applications

    International Nuclear Information System (INIS)

    Toman, John

    1970-01-01

    Although many nuclear-excavation applications have been proposed, few have been seriously considered and none have been brought to fruition. This paper summarizes and discusses specific examples of a canal, a harbor, a highway cut and a nuclear quarry, all of which have been studied in some detail. It is believed that useful demonstration projects - such as a deep-water harbor and a nuclear quarry - can be safely accomplished with existing technology. Current assessments of the feasibility of constructing a sea-level canal in either Panama or Colombia appear to be favorable from a technical viewpoint. The concept of close spacing in row-charge designs has made it possible to greatly reduce the estimated required salvo yields for both proposed canals. Salvo yields have been reduced from 35 Mt to 13 Mt in Colombia and 11 Mt in Panama. As a result, the seismic motions predicted for large cities in these countries are similar to motions produced in populated areas in the United States by nuclear tests and earthquakes in which no real damage to residential or high-rise structures was noted. (author)

  12. Results of the Schooner excavation experiment

    International Nuclear Information System (INIS)

    Tewes, Howard A.

    1970-01-01

    Project Schooner, a nuclear detonation in interlayered hard and soft, partially saturated volcanic rock, was executed as a part of the Plowshare Program for development of nuclear excavation techniques. The primary objectives of this experiment were: (a) to obtain experimental data on crater development and size in a new medium to further verify existing rock mechanics computer codes and calculational techniques; and (b) to determine the fractional release of radioactivity from a nuclear detonation in wet rock. As was noted in the case of the Sedan experiment, appreciable (though relatively small) amounts of radioactivity were released to the environment from this detonation in hard, partially saturated rock. Although the thermo-nuclear explosive used in this experiment gave a yield of approximately 31 kilotons, only the equivalent of the fission products from about 370 tons of fission were distributed in both fallout and cloud. Data which have been reduced to date indicate that this released radioactivity underwent only a moderate amount of chemical fractionation, being much more similar in this respect to Sedan than to Danny Boy. (author)

  13. Archaeological Excavations on the BTC Pipeline, Azerbaijan

    Directory of Open Access Journals (Sweden)

    Paul Michael Taylor

    2011-06-01

    Full Text Available The archaeology and history of the Republic of Azerbaijan is not widely known in comparison with that of its neighbours. A recent summary of work in the Caucasus (Smith and Rubinson 2003 contained no specific references to results from Azerbaijan, although the studies were directly comparable and overlapped in period and geography. The reasons for this are many, perhaps the most influential is the presentation of material from Azerbaijan being confused with southern Azerbaijan in Iran in the wider academic audience and the use of the Cyrillic alphabet for reports written in the Azeri language over the past century. The Baku-Tbilisi-Ceyhan (BTC and South Caucasus Pipelines (SCP were constructed through Azerbaijan, Georgia and Turkey during the period 2003-5. BTC was built first from the Caspian Coast to the Georgian border during 2003 and 2004, while the SCP pipeline was built from the Georgian border towards the Caspian and parallel to the BTC in 2005. To investigate and mitigate the effects of this construction, a four year archaeological fieldwork programme (2001-2005 was carried out, followed by a further six-year post-excavation programme that ended in early 2011. This article draws on this extensive archaeological project that combines both the broad corpus of material known in Azerbaijan and new techniques introduced in the Republic for the first time and used on a range of sites that are of both national and international significance.

  14. Fatigue crack behaviour in mine excavator

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Y.; Grondin, G.Y.; Elwi, A.E. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

    2006-05-15

    Fatigue cracking in excavation equipment represents a significant operating cost for oil sands operators. It is caused by high impact loads, the high frequency of load cycles, and large component sizes found in oil sands processing facilities. Monitoring and repair strategies for fatigue cracks are typically based on vendor specifications and the experience of maintenance personnel. This paper provided details of an optimized crack management program applied to a BE 395B shovel boom. The proposed crack management tool uses a chart to predict the remaining life of a corner crack in the shovel boom. Predictions are based on limited field measurements of operating loads as well as on data obtained from fatigue testing of boom material, and a finite element analysis of the shovel boom. Field and laboratory data are used along with fracture mechanics and finite element modelling to predict crack life. It was concluded that the tool will allow inspectors and planners to schedule repairs based on safe service life. The tool is applicable for any components subjected to fatigue loading. 3 refs., 21 tabs., 64 figs.

  15. Radon in an underground excavation site in Helsinki

    International Nuclear Information System (INIS)

    Venelampi, E.

    2004-01-01

    The paper reports on radon measurements and actions taken in a large underground excavation site in Helsinki, where a coal store was excavated underneath an existing power plant. The measurements were carried out by taking grab samples using Lucas type scintillation cells. Large variations in radon concentrations were observed during the three-year study. The reasons for variations are discussed and recommendations are given for radon monitoring procedures in underground excavation sites. The importance of ventilation to reduce the radon level is stressed. (P.A.)

  16. Post-excavation analysis of a revised hydraulic model of the Room 209 fracture, URL, Manitoba, Canada

    International Nuclear Information System (INIS)

    Winberg, A.; Tin Chan; Griffiths, P.; Nakka, B.

    1989-10-01

    An excavation response test was conducted in the Room 209 on the 240 m level of the AECL Underground Research Laboratory. Model predictions prior to excavation were made of the geomechanical response of the rock mass and the hydraulic response of an intercepted fracture. The model results were compared with excavation response data collected in a comprehensive instrument array. The work performed has addressed discrepancies between calculated and in-situ measured hydraulic response as part of a post-test analysis. Already existing hydraulic conceptual models of the fracture were revised and any available information was included in the new model. The model reproduced the pre-excavation hydraulic head distribution and hydraulic test results in terms of normalized flow rate within 5% and 75%, respectively. It was also found that the model reproduced the results of cross-hole hydraulic interference tests at least from a qualitative standpoint. The next stage of the modelling addressed the response of the model to a simulation of the excavated pilot tunnel. The preliminary results suggested the presence of a skin of different permeability in a thin zone around the periphery of the tunnel. By altering the permeability in the floor and along the walls and roof of the periphery, a better correspondence between calculated and measured drawdown was obtained. The same also applied for measured groundwater inflow in quantity, though not for the actual distribution on inflow. As probable causes for the interpreted positive skin in the crown and wall, temporary partial unsaturation and propulsion of debris into the fracture were suggested. The negative skin in the floor was interpreted as an effect of the dense and high energy charges used in the excavation process. (authors)

  17. Numerical Simulation of Rock Mass Damage Evolution During Deep-Buried Tunnel Excavation by Drill and Blast

    Science.gov (United States)

    Yang, Jianhua; Lu, Wenbo; Hu, Yingguo; Chen, Ming; Yan, Peng

    2015-09-01

    Presence of an excavation damage zone (EDZ) around a tunnel perimeter is of significant concern with regard to safety, stability, costs and overall performance of the tunnel. For deep-buried tunnel excavation by drill and blast, it is generally accepted that a combination of effects of stress redistribution and blasting is mainly responsible for development of the EDZ. However, few open literatures can be found to use numerical methods to investigate the behavior of rock damage induced by the combined effects, and it is still far from full understanding how, when and to what degree the blasting affects the behavior of the EDZ during excavation. By implementing a statistical damage evolution law based on stress criterion into the commercial software LS-DYNA through its user-subroutines, this paper presents a 3D numerical simulation of the rock damage evolution of a deep-buried tunnel excavation, with a special emphasis on the combined effects of the stress redistribution of surrounding rock masses and the blasting-induced damage. Influence of repeated blast loadings on the damage extension for practical millisecond delay blasting is investigated in the present analysis. Accompanying explosive detonation and secession of rock fragments from their initial locations, in situ stress in the immediate vicinity of the excavation face is suddenly released. The transient characteristics of the in situ stress release and induced dynamic responses in the surrounding rock masses are also highlighted. From the simulation results, some instructive conclusions are drawn with respect to the rock damage mechanism and evolution during deep-buried tunnel excavation by drill and blast.

  18. Further excavations of the submerged city of Dwarka

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, S.R.

    Since 1983 the Marine Archaeology Unit of the National Institute of Oceanography is engaged in the offshore exploration and excavation of the legendary city of Dwaraka in the coastal waters of Dwarka in Gujarat. Brief accounts of the findings...

  19. MPED: An ISRU Bucket Ladder Excavator Demonstrator System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a planetary surface tool called the Multi Purpose Excavation Demonstrator (MPED), which is intended to both extract Lunar Soil to feed an...

  20. Remote Excavation of Heavily Contaminated UXO Sites. The Range Master

    National Research Council Canada - National Science Library

    Crandall, Alan L

    2007-01-01

    USA Environmental, Inc., and Timberline Environmental Services, Inc., developed the Range Master, a remote controlled scraper with an integrated power screen, to excavate and sift the top 12 inches of heavily contaminated UXO sites...

  1. Impact-Actuated Digging Tool for Lunar Excavation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Honeybee Robotics proposes to develop a vacuum compatible, impact-actuated digging tool for the excavation of frozen and compacted regolith on the lunar surface and...

  2. Telerobotic Excavator Designed to Compete in NASA's Lunabotics Mining Competition

    Science.gov (United States)

    Nash, Rodney; Santin, Cara; Yousef, Ahmed; Nguyen, Thien; Helferty, John; Pillapakkam, Shriram

    2011-01-01

    The second annual NASA Lunabotics Mining competition is to be held in May 23-28, 2011. The goal of the competition is for teams of university level students to design, build, test and compete with a fully integrated lunar excavator on a simulated lunar surface. Our team, named Lunar Solutions I, will be representing Temple University's College of Engineering in the competition. The team's main goal was to build a robot which is able to compete with other teams, and ultimately win the competition. The main challenge of the competition was to build a wireless robot that can excavate and collect a minimum of 10 kilograms of the regolith material within 15 minutes. The robot must also be designed to operate in conditions similar to those found on the lunar surface. The design of the lunar excavator is constrained by a set of requirements determined by NASA and detailed in the competition's rulebook. The excavator must have the ability to communicate with the "main base" wirelessly, and over a Wi-Fi network. Human operators are located at a remote site approximately 60 meters away from the simulated lunar surface upon which the robot must excavate the lunar regolith surface. During the competition, the robot will operate in a separate area from the control room in an area referred to as the "Lunarena." From the control room, the operators will have to control the robot using visual feedback from cameras placed both within the arena and on the robot. Using this visual feedback the human operators control the robots movement using both keyboard and joystick commands. In order to place in the competition, a minimum of 10 kg of regolith material has to be excavated, collected, and dumped into a specific location. For that reason, the robot must be provided with an effective and powerful excavation system. Our excavator uses tracks for the drive system. After performing extensive research and trade studies, we concluded that tracks would be the most effective method for

  3. Excavated rock materials from tunnels for sprayed concrete

    OpenAIRE

    Luong, Judy Yuen Wah; Aarstad, Kari; De Weerdt, Klaartje; Bjøntegaard, Øyvind

    2017-01-01

    Sand extracted from natural resources is widely used in concrete production nowadays. The increase in demand for concrete production has resulted in shortage of natural sand resources, especially in terms of suitable materials for concrete production. At the same time, large amounts of excavated rock materials are and have been generated from tunnelling projects and discarded. Hence, there is an opportunity to use these excavated rock materials as aggregates for concrete production. The chall...

  4. Radiological safety research for nuclear excavation projects - Interoceanic canal studies

    International Nuclear Information System (INIS)

    Klement, A.W. Jr.

    1969-01-01

    The general radiological problems encountered in nuclear cratering and nuclear excavation projects are discussed. Procedures for assessing radiological problems in such projects are outlined. Included in the discussions are source term, meteorology, fallout prediction and ecological factors. Continuing research requirements as well as pre- and post-excavation studies are important considerations. The procedures followed in the current interoceanic canal feasibility studies provide examples of radiological safety problems, current solutions and needed research. (author)

  5. Radiological safety research for nuclear excavation projects - Interoceanic canal studies

    Energy Technology Data Exchange (ETDEWEB)

    Klement, Jr, A W [U.S. Atomic Energy Commission, Las Vegas, NV (United States)

    1969-07-01

    The general radiological problems encountered in nuclear cratering and nuclear excavation projects are discussed. Procedures for assessing radiological problems in such projects are outlined. Included in the discussions are source term, meteorology, fallout prediction and ecological factors. Continuing research requirements as well as pre- and post-excavation studies are important considerations. The procedures followed in the current interoceanic canal feasibility studies provide examples of radiological safety problems, current solutions and needed research. (author)

  6. Determining the productivity of frontal-selective excavation equipment

    Energy Technology Data Exchange (ETDEWEB)

    Baikenzhin, A E; Ermekov, T E

    1979-01-01

    The engineering parameters of the VMF-2 frontal-selective excavation machine are given. Calculation formulae are given for determining the feed speed of the working tool relative to the difference in the motion of the arm of the working tool and the feed speed of the hydraulic jack lifter. A methodology is developed for calculating the productivity of the excavator depending on various engineering conditions, accounting for modifications in its design.

  7. Greenhouse Gas Emissions from Excavation on Residential Construction Sites

    Directory of Open Access Journals (Sweden)

    Perry Forsythe

    2014-12-01

    Full Text Available Despite considerable research concerning the manifestation of greenhouse gases in the usage of buildings, little has been done concerning emissions arising from the construction process itself. This paper specifically examines emissions arising from cut and fill excavation on residential construction sites. Even though such excavation is often seen as being economical in terms of providing a flat base for concrete raft slab construction, the environmental consequences of this approach need to be considered more fully in terms of impact on the environment. This is particularly important when steeply sloping sites are involved and for different soil types. The paper undertakes a study that quantitatively assesses the cumulative greenhouse gas emissions caused by cut and fill excavation on 52 residential projects in Australia for a range of slope and soil types. The paper presents results from the study and concludes that greenhouse gas emissions increase as site slope increases; the building footprint area (as distinct from Gross Floor Area, exposes the need to reduce the area of the building to reduce greenhouse gas emissions; excavation of rock soils creates higher emissions than other soil types; and cut and fill excavation on steeply slope sites increase emissions. Potential alternative construction includes suspended floor construction systems which involve less excavation.

  8. Greenhouse Gas Emissions from Excavation on Residential Construction Sites

    Directory of Open Access Journals (Sweden)

    Perry Forsythe

    2014-12-01

    Full Text Available Despite considerable research concerning the manifestation of greenhouse gases in the usage of buildings, little has been done concerning emissions arising from the construction process itself. This paper specifically examines emissions arising from cut and fill excavation on residential construction sites. Even though such excavation is often seen as being economical in terms of providing a flat base for concrete raft slab construction, the environmental consequences of this approach need to be considered more fully in terms of impact on the environment. This is particularly important when steeply sloping sites are involved and for different soil types. The paper undertakes a study that quantitatively assesses the cumulative greenhouse gas emissions caused by cut and fill excavation on 52 residential projects in Australia for a range of slope and soil types. The paper presents results from the study and concludes that greenhouse gas emissions increase as site slope increases; the building footprint area (as distinct from Gross Floor Area, exposes the need to reduce the area of the building to reduce greenhouse gas emissions; excavation of rock soils creates higher emissions than other soil types; and cut and fill excavation on steeply slope sites increase emissions. Potential alternative construction includes suspended floor construction systems which involve less excavation

  9. Choroidal Excavation in Eye with Normal Tension Glaucoma

    Directory of Open Access Journals (Sweden)

    Kazunobu Asao

    2014-05-01

    Full Text Available Purpose: To report the case of an eye with normal tension glaucoma and a choroidal excavation. Methods: This is an observational case report. Results: A 59-year-old woman with normal tension glaucoma had a choroidal excavation in the left eye. Her best-corrected visual acuity and intraocular pressure were within normal limits and had been stable for 5 years. Fundus examination showed a small white lesion inferior to the macula and a nerve fiber layer defect at the inferior edge of the optic disc. Humphrey Field Analyzer (HFA showed visual field defects corresponding to the nerve fiber layer defect with C30-2, and a central scotoma superior to the macula with C10-2. Optical coherence tomography (OCT showed a 150-µm deep choroidal excavation. Disruptions of the IS/OS line were detected only in the area inferior to the choroidal excavation. During the 5 months of follow-up, her best-corrected visual acuity remained at 1.0 and the IOP ranged from 12 to 14 mm Hg in the left eye. The fundus and OCT images did not deteriorate and the choroidal excavation did not enlarge. Conclusions: The disruption of the inner/outer segment (IS/OS line was detected only at the area surrounding the choroidal excavation. OCT examinations are useful in assessing the area of the residual IS/OS line, and HFA can be used to estimate the residual central visual field.

  10. Research on Trajectory Planning and Autodig of Hydraulic Excavator

    Directory of Open Access Journals (Sweden)

    Bin Zhang

    2017-01-01

    Full Text Available As the advances in computer control technology keep emerging, robotic hydraulic excavator becomes imperative. It can improve excavation accuracy and greatly reduce the operator’s labor intensity. The 12-ton backhoe bucket excavator has been utilized in this research work where this type of excavator is commonly used in engineering work. The kinematics model of operation device (boom, arm, bucket, and swing in excavator is established in both Denavit-Hartenberg coordinates for easy programming and geometric space for avoiding blind spot. The control approach is based on trajectory tracing method with displacements and velocities feedbacks. The trajectory planning and autodig program is written by Visual C++. By setting the bucket teeth’s trajectory, the program can automatically plan the velocity and acceleration of each hydraulic cylinder and motor. The results are displayed through a 3D entity simulation environment which can present real-time movements of excavator kinematics. Object-Oriented Graphics Rendering Engine and skeletal animation are used to give accurate parametric control and feedback. The simulation result shows that a stable linear autodig can be achieved. The errors between trajectory planning command and simulation model are analyzed.

  11. Evolution of mud-capped dredge pits following excavation: sediment trapping and slope instability

    Science.gov (United States)

    Obelcz, J.; Xu, K.; Bentley, S. J.; Li, C.; Miner, M. D.; O'Connor, M. C.; Wang, J.

    2016-02-01

    Many fluvial channels incised the Northern Gulf of Mexico inner continental shelf during the late Quaternary. Mud-capped dredge pits (MCDPs), which are generally elongate and deep (8-10 m) excavations, target sandy fluvial channel deposits for coastal restoration projects. The morphological evolution of dredge excavations in noncohesive sandy substrate is well studied, but MCDPs have up to a several-meter-thick veneer of Holocene shelf mud overlying sandy channel deposits. This stratigraphy is hypothesized to result in more complex post-dredge morphology than pit walls simply slumping to the angle of repose shortly after excavation. Numerical modeling of MCDP post-dredge response conducted prior to excavation indicates pit walls may retrogressively fail, which is accounted for in pit design by assigning no-dredge setback buffers from pipelines or cultural and environmental resources. To validate model results and test effectiveness of setback buffers, a geophysical survey of the Sandy Point MCDP (20 km west of the Mississippi River Delta in 10m deep water), where 1.7 million m3 of sandy sediment was excavated in 2012, was conducted May 2015. A total of 84 line-km of high-resolution chirp subbottom and a 27 km2 grid of swath bathymetry and sidescan sonar were collected. The data indicate the dredge pit walls are differentially slumping, with the western pit wall in a more active state of failure than the eastern wall. The western failures morphologically resemble features observed along the muddy Mississippi River Delta Front at water depths of 20-100 m, including bowl-shaped collapse failures and retrogressive stair-stepped slumps; these failures may play a key role in evaluating the distance of setback buffer zone to pipelines. These features indicate the cohesive mud overlying the sandy infill has a prominent role in pit wall stability. A 0.5-1 m thick acoustically transparent package overlies the entire pit floor (interpreted as a possible fluid mud layer

  12. Heart rot hotel: fungal communities in red-cockaded woodpecker excavations

    Science.gov (United States)

    Michelle A. Jusino; Daniel L. Lindner; Mark T. Banik; Jeffrey R. Walters

    2015-01-01

    Tree-cavity excavators such as woodpeckers are ecosystem engineers that have potentially complex but poorly documented associations with wood decay fungi. Fungi facilitate cavity excavation by preparing and modifying excavation sites for cavity excavators. Associations between fungi and endangered red-cockaded woodpeckers (RCWs) are particularly interesting because...

  13. Identifying the cutting tool type used in excavations using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Jonak, J.; Gajewski, J. [Lublin University of Technology, Lublin (Poland). Faculty of Mechanical Engineering

    2006-03-15

    The paper presents results of preliminary research on utilising neural networks to identify excavating cutting tool's type used in multi-tool excavating heads of mechanical coal miners. Such research is necessary to identify rock excavating process with a given head, and construct adaptation systems for control of excavating process with such a head.

  14. Archaeological Excavation and Deep Mapping in Historic Rural Communities

    Directory of Open Access Journals (Sweden)

    Carenza Lewis

    2015-09-01

    Full Text Available This paper reviews the results of more than a hundred small archaeological “test pit” excavations carried out in 2013 within four rural communities in eastern England. Each excavation used standardized protocols in a different location within the host village, with the finds dated and mapped to create a series of maps spanning more than 3500 years, in order to advance understanding of the spatial development of settlements and landscapes over time. The excavations were all carried out by local volunteers working physically within their own communities, supported and advised by professional archaeologists, with most test pits sited in volunteers’ own gardens or those of their friends, family or neighbors. Site-by-site, the results provided glimpses of the use made by humans of each of the excavated sites spanning prehistory to the present day; while in aggregate the mapped data show how settlement and land-use developed and changed over time. Feedback from participants also demonstrates the diverse positive impacts the project had on individuals and communities. The results are presented and reviewed here in order to highlight the contribution archaeological test pit excavation can make to deep mapping, and the contribution that deep mapping can make to rural communities.

  15. The Excavation and Remediation of the Sandia National Laboratories Chemical Waste Landfill

    International Nuclear Information System (INIS)

    KWIECINSKI, DANIEL ALBERT; METHVIN, RHONDA KAY; SCHOFIELD, DONALD P.; YOUNG, SHARISSA G.

    1999-01-01

    The Chemical Waste Landfill (CWL) at Sandia National Laboratories/New Mexico (SNL/NM) is a 1.9-acre disposal site that was used for the disposal of chemical wastes generated by many of SNL/NM research laboratories from 1962 until 1985. These laboratories were primarily involved in the design, research and development of non-nuclear components of nuclear weapons and the waste generated by these labs included small quantities of a wide assortment of chemical products. A Resource Conservation and Recovery Act (RCRA) Closure Plan for the Chemical Waste Landfill was approved by the New Mexico Environment Department (NMED) in 1992. Subsequent site characterization activities identified the presence of significant amounts of chromium in the soil as far as 80 feet below ground surface (fbgs) and the delineation of a solvent plume in the vadose zone that extends to groundwater approximately 500 fbgs. Trichloroethylene (TCE) was detected in some groundwater samples at concentrations slightly above the drinking water limit of 5 parts per billion. In 1997 an active vapor extraction system reduced the size of the TCE vapor plume and for the last six quarterly sampling events groundwater samples have not detected TCE above the drinking water standard. A source term removal, being conducted as a Voluntary Corrective Measure (VCM), began in September 1998 and is expected to take up to two years. Four distinct disposal areas were identified from historical data and the contents of disposal pits and trenches in these areas, in addition to much of the highly contaminated soil surrounding the disposal cells, are currently being excavated. Buried waste and debris are expected to extend to a depth of 12 to 15 fbgs. Excavation will focus on the removal of buried debris and contaminated soil in a sequential, area by area manner and will proceed to whatever depth is required in order to remove all pit contents. Up to 50,000 cubic yards of soil and debris will be removed and managed during

  16. Excavations at Kainapirina (SAC), Watom Island, Papua New Guinea

    International Nuclear Information System (INIS)

    Green, R.C.; Anson, D.

    1998-01-01

    This paper is the final report on excavations in 1985 at the locality of Kainapirina (site SAC), situated on the Reber mission station adjacent to Rakival village on Watom Island. It backgrounds previous investigations there, the objectives of the 1985 endeavours, and the excavation strategies undertaken to achieve them. The occupation sequence based on stratigraphy, dating, and associated structural features is described and illustrated. Aspects of the human skeletal remains recovered are briefly reviewed; the economic evidence is discussed in detail. Analyses are provided of the various portable artefacts from these Lapita contexts, particularly stone adzes. obsidian, and pottery. These document an 'exotic to Watom' exchange component among the local manufactures. It is concluded that these 1985 excavations at SAC currently best enable an understanding of the significance of the entire Reber-Rakival Lapita site. (author)

  17. In situ measurements of rock salt permeability changes due to nearby excavation

    International Nuclear Information System (INIS)

    Stormont, J.C.; Howard, C.L.; Daemen, J.J.K.

    1991-07-01

    The Small-Scale Mine-By was an in situ experiment to measure changes in brine and gas permeability of rock salt as a result of nearby excavation. A series of small-volume pressurized brine- and gas-filled test intervals were established 8 m beneath the floor of Room L1 in the WIPP underground. The test intervals were isolated in the bottom of the 4.8-cm diameter monitoring boreholes with inflatable rubber packers, and are initially pressurized to about 2 MPa. Both brine- and gas-filled test intervals were located 1.25, 1.5, 2, 3, and 4 r from the center of a planned large-diameter hole, where r is the radius of the large-diameter hole. Prior to the drilling of the large-diameter borehole, the responses of both the brine- and gas-filled test intervals were consistent with the formation modeled as a very low permeability, low porosity porous medium with a significant pore (brine) pressure and no measurable gas permeability. The drilling of the mine-by borehole created a zone of dilated, partially saturated rock out to about 1.5 r. The formation pressure increases from near zero at 1.5 r to the pre-excavation value at 4 r. Injection tests reveal a gradient of brine permeabilities from 5 x 10 -18 m 2 at 1.25 r to about the pre-excavation value (10 -21 m 2 ) by 3 r. Gas-injection tests reveal measurable gas permeability is limited to within 1.5 r. 17 refs., 24 figs., 6 tabs

  18. Remotely operated excavator needs assessment/site visit summary

    Energy Technology Data Exchange (ETDEWEB)

    Straub, J.; Haller, S.; Worsley, R. [Westinghouse Environmental Management Co. of Ohio, Cincinnati, OH (United States); King, M. [THETA Technology Inc. (United States)

    1992-12-02

    The Uranium in Soils Integrated Demonstration requested an assessment of soil excavation needs relative to soil remediation. The following list identifies the DOE sites assessed: Mound Laboratory, Paducah Gaseous Diffusion Plant, Portsmouth Gaseous Diffusion Plant, Nevada Test Site, Lawrence Livermore National Laboratory, Rocky Flats Plant, Los Alamos National Laboratory, Sandia National Laboratory, Idaho National Engineering Laboratory, Hanford Site, and Fernald Site. The reviewed sites fall into one or more of the following three categories: production, EPA National Priorities List, or CERCLA (superfund) designation. Only three of the sites appear to have the need for a remotely operated excavator rope. Hanford and Idaho Falls have areas of high-level radioactive contamination either buried or in/under buildings. The Fernald site has a need for remote operated equipment of different types. It is their feeling that remote equipment can be used to remove the health dangers to humans by removing them from the area. Most interviewees stated that characterization technologies needs are more immediate concern over excavation. In addition, the sites do not have similar geographic conditions which would aid in the development of a generic precision excavator. The sites visited were not ready to utilize or provide the required design information necessary to draft a performance specification. This creates a strong case against the development of one type of ROPE for use at these sites. Assuming soil characterization technology/methodology is improved sufficiently to allow accurate and real time field characterization then development of a precision excavator might be pursued based on FEMP needs, since the FEMP`s sole scope of work is remediation. The excavator could then be used/tested and then later modified for other sites as warranted.

  19. Remote Excavation System technology evaluation report: Buried Waste Robotics Program

    International Nuclear Information System (INIS)

    1993-09-01

    This document describes the results from the Remote Excavation System demonstration and testing conducted at the Idaho National Engineering Laboratory during June and July 1993. The purpose of the demonstration was to ascertain the feasibility of the system for skimming soil and removing various types of buried waste in a safe manner and within all regulatory requirements, and to compare the performances of manual and remote operation of a backhoe. The procedures and goals of the demonstration were previously defined in The Remote Excavation System Test Plan, which served as a guideline for evaluating the various components of the system and discussed the procedures used to conduct the tests

  20. Support system, excavation arrangement, and process of supporting an object

    Science.gov (United States)

    Arnold, Bill W.

    2017-08-01

    A support system, an excavation arrangement, and a process of supporting an object are disclosed. The support system includes a weight-bearing device and a camming mechanism positioned below the weight-bearing device. A downward force on the weight-bearing device at least partially secures the camming mechanism to opposing surfaces. The excavation arrangement includes a borehole, a support system positioned within and secured to the borehole, and an object positioned on and supported by the support system. The process includes positioning and securing the support system and positioning the object on the weight-bearing device.

  1. Geotechnical characterization and construction methods for SSC tunnel excavation

    International Nuclear Information System (INIS)

    Nelson, P.P.; Lundin, T.K.

    1990-06-01

    The site for the Superconducting Super Collider (SSC) facility was selected in 1988 after a nationwide proposal competition. The selected site is located in Ellis County, Texas, surrounding the town of Waxahachie which is about 30 miles (48 km) south of the City of Dallas central business district. This paper will describe the geotechnical conditions anticipated for excavation at the SSC site. A general geologic and geomechanical description of the rock present will be followed by a summary of the site-specific conceptual design for the tunneled components of the SSC machine. The Supercollider project will include about 70 miles (113) km of tunnel excavation

  2. Excavations at Pukearuhe (N99/49), North Taranaki, 1968

    International Nuclear Information System (INIS)

    Lawrence, J.; Prickett, N.

    1984-01-01

    The 1968 salvage excavations at Pukearuhe (N99/49), north Taranaki, are reported. Pukearuhe was for long a Ngati Tama fortification; in the period 1865-1885 it was occupied by european forces, firstly, imperial troops and Taranaki military settlers, later, armed constabulary. Ngati Tama and european occupation was based on the powerful strategic situation of Pukearuhe at the northern gateway into Taranaki. Excavations revealed evidence of the Maori and European occupation. Radiocarbon dates were obtained for Maori occupation. European material adds to the knowledge of sites relating to the period of military conflict in Taranaki which extended from 1860 to the early 1880s

  3. Outline and results of study on excavation response of rock mass around shaft in shaft excavation effects project

    International Nuclear Information System (INIS)

    Sugihara, Kozo; Matsui, Hiroya; Sato, Toshinori

    1993-01-01

    A shaft, with a diameter of 6 m and a depth of 150 m, has been newly excavated in sedimentary rock and excavation response of rock mass around the shaft has been measured and analyzed. Excavation response has been evaluated based on the results of measurement of rock mass movement, such as displacement and strain, and change of rock property, such as deformability and permeability. This study indicates that rock property has been changed with in about 1 m from the shaft wall, and rock mass movement and property change has been influenced by rock facies, fracture and re-distributed stress. The relation between property change and these factors is remained to be evaluated in future study. (author)

  4. Preliminary results of excavations at Lincoln Cave, Sterkfontein, South Africa

    CSIR Research Space (South Africa)

    Reynolds, SC

    2003-05-01

    Full Text Available , sandwiched between two flowstone layers which could be dated using uranium series methods. The excavation furthermore yielded good indications that a portion of an older breccia has been eroded and that fauna and artefacts from this older, reworked breccia...

  5. Investigation of the impact of excavation (reinforced) on the seismic ...

    African Journals Online (AJOL)

    Every year, as a result of earthquake, abundant losses may be created as result of roof motion and sliding and rupture. Under normal conditions, the ground and soils forming the ground tolerate and transfer the existing stresses and any kind of action like excavation and release of trench and applying dynamic load could ...

  6. A new bee species that excavates sandstone nests

    Science.gov (United States)

    Many wonder why animals act in seemingly injurious ways. Understanding the behavior of pollinators such as bees is especially important because of the necessary ecosystem service they provide. The new species Anthophora pueblo, discovered excavating sandstone nests, provides a model system for addre...

  7. 29 CFR 1926.651 - Specific excavation requirements.

    Science.gov (United States)

    2010-07-01

    ...) Exposure to vehicular traffic. Employees exposed to public vehicular traffic shall be provided with, and... containing a concentration of a flammable gas in excess of 20 percent of the lower flammable limit of the gas... ensure proper operation. (3) If excavation work interrupts the natural drainage of surface water (such as...

  8. MATHEMATICAL MODEL OF ATTITUDE CONTROL BUCKET‐WHEEL EXCAVATOR

    Directory of Open Access Journals (Sweden)

    Ivana ONDERKOVÁ

    2013-07-01

    Full Text Available This lecture deals with the application problems of convertibility GPS system at paddle excavator K 800. The claims of the modern operating surface mining of the excavators requires a lot of information for monitoring of mining process, capacity mining, selective extraction etc. The utilization of monitoring the excavator setting by GPS system proved to be the only one proper because the receivers are resistant to the vibration, dust, temperature divergence and weather changeable. Only the direct contact with communications satellite is required. It means that they can´t be located in a metal construction space (shadow caused by construction elements, influence of electrical high voltage cables even they can´t be located close to the paddle wheel on the paddle boom (shadow possibility caused by cuttinng edge created during lower gangplanks mining. This is the reason that GPS receivers are set uppermost on the metal construction excavator and the mathematical formulation is required for determination of paddle wheel petting. The relations for calculation of the paddle wheel coordinate were defined mathematically and after that the mathematical model was composed.

  9. Detecting defects in diaphragm walls prior to excavation

    NARCIS (Netherlands)

    Spruit, R.; Hopman, V.; Van Tol, A.F.; Broere, W.

    2011-01-01

    Recent incidents with leaking diaphragm walls during construction of subway lines in Amsterdam and Rotterdam (Netherlands) have led to reconsideration of the diaphragm wall as a retaining wall construction for deep excavations. In our opinion the joints between the panels are the weak spot. During

  10. Estimating RMR Values for Underground Excavations in a Rock Mass

    Directory of Open Access Journals (Sweden)

    Vítor Santos

    2018-02-01

    Full Text Available During underground excavations for civil or mining engineering purposes, the variations in rock mass quality are important, especially for the design of the most suitable support to be applied to ensure stability. The aim of this investigation is to model the expected behavior of the ground, and thus to predict the scenarios indicating potential variations in the quality of the rock mass during underground excavation. When considering the rock mass rating (RMR values observed at the excavation face in six study cases, which together total more than 27 km in length of underground excavation by drilling and blasting (D&B, and based on the observed RMR values at the face, the most probable value (1–100 is estimate for the RMR index at the five subsequent front advances. It is concluded that, up to about 20 m ahead of the current face, the quality of the rock mass for the next advances is close to the quality observed at the present face, and that, with increasing distance, there is a greater deviation of RMR values with respect to the quality observed at the current face.

  11. Archaeological excavations at Gamzigrad - Romuliana in 2007-2008

    Directory of Open Access Journals (Sweden)

    Petković Sofija

    2013-01-01

    , comprising the scarce fragments of the Early and Late Iron Age pottery; Virgin soil consists of yellow clay starting from a level of 184.00 m in the west and of 183.60 m in the east. In 2008, the remains of an earlier building were discovered beneath the floor of the apodyterium of Galerius' bath found in 2002 and below the foundation of the sudatorium and the tepidarium of the same structure, which were found in 2005. Also, for the purposes of conservation and restoration of the thermae, an apsidal room next to the west wall of the apodyterium, so called 'Galerius' dressing room', was completely filled with construction rubble, among which was found a part of an abraded vault (Fig. 6. Excavations proved that the apsidal room had been a pool with cold water, a frigidarium, which was twice renovated and was decorated with mosaic made of black, white and grey stone cubes (Fig. 7. The phases of reconstruction of the frigidarium could also be noticed in its eastern wall (Fig. 8. Also in the rubble inside the pool, glass mosaic cubes of deep blue and golden colours were discovered, indicating the decoration of the vault. In the latest phase, two pillars were constructed to carry the stairs made of stone slabs (Fig. 8. The earliest phase of this room, which had a rectangular layout and a mortar floor, could be part of the building dating back to before Galerius' bath (Plan 2. During the cleaning of the eastern wall of the frigidarium, a semicircular niche with a fresco decoration of geometrical and figural motives, painted in black, dark red, orange and blue on an ochre surface, was discovered (Fig. 3. Under Galerius' bath, a large earlier building was investigated (trenches 1-5/08. Only its foundation zone is preserved. The walls of the Imperial bath were founded on the earlier walls, which were 0.65 m thick and had foundations which were 0.90 m thick (Plan 2. The pilaster of the west faeade of the thermae was also founded on the earlier wall, but it destroyed a water canal

  12. Lichen Persistence and Recovery in Response to Varied Volcanic Disturbances

    Science.gov (United States)

    Nelson, P.; Wheeler, T. B.

    2015-12-01

    Volcanic eruptions produce many ecological disturbances that structure vegetation. While lichens are sensitive to disturbances, little is known about their responses to volcanic disturbances, except for colonization of lava. We examined lichen community responses through time to different disturbances produced by the May 1, 2008 eruption of Volcan Chaiten in south-central Chile. Pre-eruption vegetation near the volcano was old-growth Valdivian temperate rainforest dominated by closed-canopy Nothofagus sp... In 2012, we installed thirteen 1-acre plots across volcanic disturbance zones on which a time-constrained search was done for all macrolichen species, each of which was assigned an approximate log10 categorical abundance. We also installed a 0.2 m2 quadrat on two representative trees per plot for repeat photography of lichen cover. We remeasured at least one plot per disturbance zone in 2014 and re-photographed tree quadrats in 2013 and 2014. We then analyzed species composition and abundance differences among disturbance zones. In 2012, the blast (pyroclastic density flow), scorch (standing scorched forest at the edge of the blast) and deep tephra (>10 cm) zones had the lowest lichen species richness (5-13 species), followed by reference (unimpacted) and shallow (lichen species since 2012 while the light tephra and reference were essentially unchanged. Gravel rain, gravel rain + pumice and flooded forest plots all had about the same number of species in 2014 as 2012. Lichen colonization and growth in tree quadrats varied widely, from very little colonization in the blast to prolific colonization in the gravel rain + pumice zone. Lichen's varied responses to different volcanic disturbances were attributable to varying degrees of mortality and subsequent availability of substrate, quantity of light and removal of competitors. While sensitive to disturbance, lichens are apparently resilient to and can quickly recolonize after a variety of large, violent volcanic

  13. Mechanical and hydrological characterization of the near-field surrounding excavations in a geologic salt formation

    Energy Technology Data Exchange (ETDEWEB)

    Howard, Clifford L. [Sandia National Laboratories, Albuquerque, NM (United States)

    2014-09-01

    The technical basis for salt disposal of nuclear waste resides in salt’s favorable physical, mechanical and hydrological characteristics. Undisturbed salt formations are impermeable. Upon mining, the salt formation experiences damage in the near-field rock proximal to the mined opening and salt permeability increases dramatically. The volume of rock that has been altered by such damage is called the disturbed rock zone (DRZ).

  14. Differential reactions to anthropogenic disturbance by two ground ...

    African Journals Online (AJOL)

    Both ABO and KG significantly altered their behavioural responses to disturbance from pre-breeding to breeding. These results emphasise the need to have a buffer zone surrounding breeding areas excluding human presence to allow for the successful breeding of ABO. Keywords: African Black Oystercatcher, buffer zone, ...

  15. Chip shape and secondary fragmentation through TBM excavation

    International Nuclear Information System (INIS)

    Tsusaka, Kimikazu; Tanimoto, Chikaosa; Ueno, Takaaki; Koizumi, Yu; Nakane, Tatsuto

    2008-01-01

    The chips through TBM tunneling are well-known for one of useful indices to reflect the geological conditions. The flat and elongated chips whose width are equal to the spacing of cutter trace indicate the cutting face with less joints and good practice of TBM excavation with less secondary fragmentation rate. Through a case history in granitic rock, the authors proposed the new index, which is the ratio of length of major axis to thickness. Also the authors studied the relationship between the index and the excavation efficiencies. In conclusion, it was clarified that chips with the new index over 3.5 were generally observed when a TBM drove with less than 30% the secondary fragmentation rate. (author)

  16. End effectors and attachments for buried waste excavation equipment

    International Nuclear Information System (INIS)

    King, R.H.

    1993-09-01

    The Buried Waste Integrated Demonstration (BWID) supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that form a comprehensive remediation system for the effective and efficient remediation of buried waste. Their efforts are identified and coordinated in support of the U.S. Department of Energy (DOE), Environmental Restoration and Waste Management (ER ampersand WM) Department's needs and objectives. The present focus of BWID is to support retrieval and ex-situ treatment configuration options. Future activities will explore and support containment, and stabilization efforts in addition to the retrieval/ex situ treatment options. This report presents a literature search on the state-of-the-art in end effectors and attachments in support of excavator of buried transuranic waste. Included in the report are excavator platforms and a discussion of the various attachments. Also included is it list of vendors and specifications

  17. The Montana ALE (Autonomous Lunar Excavator) Systems Engineering Report

    Science.gov (United States)

    Hull, Bethanne J.

    2012-01-01

    On May 2 1-26, 20 12, the third annual NASA Lunabotics Mining Competition will be held at the Kennedy Space Center in Florida. This event brings together student teams from universities around the world to compete in an engineering challenge. Each team must design, build and operate a robotic excavator that can collect artificial lunar soil and deposit it at a target location. Montana State University, Bozeman, is one of the institutions selected to field a team this year. This paper will summarize the goals of MSU's lunar excavator project, known as the Autonomous Lunar Explorer (ALE), along with the engineering process that the MSU team is using to fulfill these goals, according to NASA's systems engineering guidelines.

  18. Interaction between groundwater and TBM (Tunnel Boring Machine) excavated tunnels

    OpenAIRE

    Font Capó, Jordi

    2012-01-01

    A number of problems, e.g. sudden inflows are encountered during tunneling under the piezometric level, especially when the excavation crosses high transmissivity areas. These inflows may drag materials when the tunnel crosses low competent layers, resulting in subsidence, chimney formation and collapses. Moreover, inflows can lead to a decrease in head level because of aquifer drainage. Tunnels can be drilled by a tunnel boring machine (TBM) to minimize inflows and groundwater impacts, restr...

  19. A Prototype Bucket Wheel Excavator for the Moon, Mars and Phobos

    Science.gov (United States)

    Muff, T.; Johnson, L.; King, R.; Duke, M. B.

    2004-02-01

    Excavation of surface regolith material is the first step in processes to extract volatile materials from planetary surface regolith for the production of propellant and life support consumables. Typically, concentrations of volatiles are low, so relatively large amounts of material must be excavated. A bucket wheel excavator is proposed, which has the capability of continuous excavation, which is readily adapted to granular regolith materials as found on the Moon, in drift deposits on Mars, and probably on the surface of asteroids and satellites, such as Phobos. The bucket wheel excavator is relatively simple, compared to machines such as front end loaders. It also has the advantage that excavation forces are principally horizontal rather than vertical, which minimizes the need for excavator mass and suits it to operations in reduced gravity fields. A prototype small bucket wheel excavator has been built at approximately the scale of the rovers that are carried to Mars on the Mars Exploration Rover Mission. The prototype allows the collection of data on forces exerted and power requirements for excavation and will provide data on which more efficient designs can be based. At excavation rates in the vicinity of one rover mass of material excavated per hour, tests of the prototype demonstrate that the power required is largely that needed to operate the excavator hardware and not related strongly to the amount of material excavated. This suggests that the excavation rate can be much larger for the same excavation system mass. Work on this prototype is continuing on the details of transfer of material from the bucket wheel to an internal conveyor mechanism, which testing demonstrated to be problematic in the current design.

  20. Tracking a major interplanetary disturbance

    International Nuclear Information System (INIS)

    Tappin, S.J.; Hewish, A.; Gapper, G.R.

    1983-01-01

    The severe geomagnetic storm which occurred during 27-29 August 1978 was remarkable because it arrived unexpectedly and was not related to a solar flare or long-lived coronal hole. Observations on 900 celestial radio sources show that the storm was associated with a large-scale region causing enhanced interplanetary scintillation which enveloped the Earth at the same time. The disturbance was first detected on 26 August, when the outer boundary had reached a distance of about 0.8 a.u. from the Sun and it was tracked until 30 August. The enhancement was followed by a fast solar wind stream and its shape suggests that it was a compression zone caused by the birth of the stream. (author)

  1. Hydrogeologic data for existing excavations and the Area 5 Radioactive Waste Management Site, Nevada Test Site, Nye County, Nevada

    International Nuclear Information System (INIS)

    1993-12-01

    The Special Projects Section of Reynolds Electrical ampersand Engineering Co., Inc. is responsible for characterizing the subsurface geology and hydrology of the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site (NTS) for the US Department of Energy, Nevada Operations Office (DOE/NV), Office of Environmental Restoration and Waste Management Waste Management Division. Geologic description, in situ testing, and laboratory analyses of alluvium exposed in existing excavations are important subparts to the Area 5 Site Characterization Program designed to determine the suitability of the RWMS for disposal of low level waste mixed waste and transuranic waste. The primary purpose of the Existing Excavation Project is two-fold: first, to characterize important hydrologic properties of the near surface alluvium, thought to play an important role in the infiltration and redistribution of water and solutes through the upper unsaturated zone at the Area 5 RWMS; and second, to provide guidance for the design of future sampling and testing programs. The justification for this work comes from the state of Nevada review of the original DOE/NV Part B Permit application submitted in 1988 for disposal of mixed wastes at the RWMS. The state of Nevada determined that the permit was deficient in characterization data concerning the hydrogeology of the unsaturated zone. DOE/NV agreed with the state and proposed the study of alluvium exposed in existing excavations as one step toward satisfying these important site characterization data requirements. Other components of the site characterization process include the Science Trench Borehole and Pilot Well Projects

  2. EZG08 project: acoustic experiments to monitor the EDZ during the gallery excavation process in the Mont Terri Underground Research Laboratory (Switzerland)

    International Nuclear Information System (INIS)

    Le Gonidec, Y.; Kergosien, B.; Schubnel, A.; Gueguen, Y.; Wassermann, J.; Gibert, D.; Sarout, J.; Nussbaum, C.

    2010-01-01

    Document available in extended abstract form only. In the Underground Research Laboratory (URL) at Mont Terri, a new gallery G08 was planned to be excavated in 2008 following an original process: the excavation process allowed to monitor the Excavation Damaged Zone (EDZ) from geophysical measurements designed and installed at the end of face of the EZ-G04 gallery during the excavation from the other side, i.e. the end face of the EZ-G08 gallery. The objectives of the project concern spatio-temporal changes of the EDZ: among the methodological developments adapted for the EZG08 project to provide complementary information, acoustic experiments have been prepared in horizontal boreholes to perform the continuous acoustic monitoring of the Excavation Damaged Zone (EDZ). The acoustic measurements, performed on acoustic arrays of several receivers, have been recorded during one month, following two main steps: - Active acoustic surveys: a source is introduced in a central borehole (BEZG5) allowing tomography experiments in the far field and in the near field, i.e. close to and far from BEZG5, respectively. - Acoustic emissions: during the excavation process, numerous acoustic emissions can be detected and associated to micro-seismic events due to rapid crack propagation, generated by the rock relaxation, or simply associated to the excavation process. From the tomography measurements, the acoustic wave velocity field can be estimated, with P and S-wave velocities roughly equal to 2500 m/s-3500 m/s, and 1500 m/s, respectively. The acoustic setup does not show variations of P-wave velocity during the campaign, but spatial variations which could be associated to anisotropic elastic properties of the rock with the maximum P-wave velocities close to the bedding plane. An original method based on a multifrequency approach puts in evidence a frequency dependence of the velocity, with a striking phenomena since the wave velocity decreases with increasing frequency. This effect

  3. Sudden Ionospheric Disturbances (SID)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sudden ionospheric disturbances (SID) are caused by solar flare enhanced X-rays in the 1 to 10 angstrom range. Solar flares can produce large increases of ionization...

  4. Depression Disturbs Germany

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The suicide of Robert Enke,the goalkeeper of the Germany national football team who had battled depression for years,stunned the country and cast depression into the national spotlight as a disturbing disease.

  5. BANGLES, BEADS AND BEDOUIN: EXCAVATING A LATE OTTOMAN CEMETERY IN JORDAN (ABSTRACT

    Directory of Open Access Journals (Sweden)

    Bethany J. Walker

    2001-01-01

    Full Text Available Transjordan witnessed significant social and economic changes in the last quarter of the nineteenth century. With the loss of agriculturally-rich territory in Europe, the Ottomans sought to make up for their economic losses by regaining control of their Arab provinces, some regions of which had been autonomous for nearly three hundred years. The application of Tanzimat legislation to the Transjordan was a success, to a large degree, in that it secured tax revenues and contributed to the general security of the region.The application of the 1858 Land Law, in which land was registered in a proprietor’s name for tax purposes, was particularly effective in transforming grazing land to productive agricultural properties. It, moreover, had a significant impact on Transjordanian society which was tribal and largely nomadic. The introduction of direct rule in the region by the Ottoman government transformed traditional tribal life, resulting in the settlement of formerly nomadic groups, the transition to an agrarian way of life, and the opening up of markets formerly inaccessible to indigenous tribal groups. A variety of urban, manufactured goods became readily available to all sectors of society throughout this frontier zone.“Bangles, Beads and Bedouin: Excavating a Late Ottoman Cemetery inJordan” considers the transformation of tribal funerary practices in the Belqa’ of central Jordan. The paper highlights the burial ground of one Transjordanian tribe, identified as the Adwan, excavated at Tall Hisban in 1998. Dated to the late nineteenth century on the basis of coins, this mass grave was one of the last of its kind, as permanent cemeteries replaced seasonal burial grounds by the early twentieth century. The composition of theburial goods indicates that members of the tribe participated in an exchange network that embraced the Red Sea, Greater Syria, and Europe.

  6. Analysis of disturbance

    International Nuclear Information System (INIS)

    Ciala-Wein, H.; Stegmaier, W.

    1977-12-01

    The analyses of disturbances are the supposition for the development of processes and plants. They are very important in the field of nuclear testing plants. In this report are described the possibilities to register the circumstances of the disturbance in a pilot waste processing facility and a computer programme to interpret them. This is a first scheme and it will be necessary to complete it. (orig.) [de

  7. Analysis of long-term closure in drifts excavated in Callovo-Oxfordian clay-stone: roles of anisotropy and hydro-mechanical couplings

    International Nuclear Information System (INIS)

    Guayacan Carrillo, Lina Maria

    2016-01-01

    The French National Radioactive Waste Management Agency (Andra) began in 2000 the construction of an Underground Research Laboratory (URL) with the main goal of demonstrating the feasibility of a geological repository in Callovo-Oxfordian clay-stone. Several research programs have taken place to improve the knowledge of the rock properties and its response to the excavation progress. A network of experimental drifts has been constructed with variations on: excavation method, structure geometry, supports system and orientations with respect to principal stresses' directions. In each drift different sections have been instrumented to monitor the hydro-mechanical behavior of the rock mass formation. Continuous monitoring of the excavated zone around the drifts in the main level (-490 m) revealed the development of a fractured zone (extensional and shear fractures) induced by the excavation. The extent of this fractured zone depends on the drift orientation regarding the in-situ stress field. Accordingly, the convergence measurements showed an anisotropic closure which depends also on the drifts' orientations. Moreover, marked overpressures and an anisotropic pore pressure field around the drifts have been also observed. The approach proposed in this work is mainly based on a direct analysis of the convergence measurements, for studying the anisotropic response of the rock formation during and after excavation. The convergence evolution is analyzed on the basis of the semi-empirical law proposed by Sulem et al. (1987) [Int J Rock Mech Min Sci Geomech Abstr 24: 145-154]. The monitoring and analysis of convergence data can provide a reliable approach of the interaction between rock mass and support. Therefore, the anisotropy and the variability of the closure are analyzed taking into account different field cases: drifts excavated in two different orientations (i.e. influence of the initial stress state), different methods, sizes and rates of excavation and

  8. Modelling the excavation damaged zone using a hydro-mechanical double-scale model

    NARCIS (Netherlands)

    van den Eijnden, A.P.; Bésuelle, P.; Collin, F.; Chambon, R.; Desrues, J.; Vardon, P.J.; Bykov, D.

    2016-01-01

    Disposal of spent nuclear fuel and long lived radioactive waste in deep clay geological formations is one of the promising options worldwide. In this concept of the geological disposal system, the Boom Clay is considered as a potential host rock when designing a generic waste repository in the

  9. Development of a teleoperated backhoe for buried waste excavation

    International Nuclear Information System (INIS)

    Burks, B.L.; Killough, S.M.; Thompson, D.H.

    1992-01-01

    For nearly five decades the United States (US) Department of Energy (DOE) and its predecessor agencies have engaged in broad-based research and development activities as well as nuclear weapons component production. As a by-product of these activities, large quantities of waste materials have been granted. One of the most common approaches used for solid waste storage was to bury waste containers in pits and trenches. With the current emphasis on environmental restoration, DOE now plans to either retrieve much of the legacy of buried waste or stabilize the waste in place via in situ vitrification or other means. Because of the variety of materials that have been buried over the years, the hazards of retrieval are significant if performed using conventional manned operations. The potential hazards, in addition to radiation exposure, include pyrophorics, toxic chemicals, and explosives. Although manifests exist for much of the buried waste, these records are often incomplete compared to today's requirements. Because of the potential hazards and uncertainty about waste contents and container integrity, it is highly desirable to excavate these wastes using remotely operated equipment. In this paper the authors describe the development of a teleoperated military tractor called the Small Emplacement Excavator (SEE). Development of the SEE is being funded jointly by both DOE and the US Army. The DOE sponsor is the Office of Technology Development (OTD) Robotics Program. The US Army sponsor is the Program Manager for Ammunition Logistics, Picatinny Arsenal. The primary interest for DOE is in the application to remote excavation of buried waste, while the primary emphasis for the US Army is in the remote retrieval of unexploded ordnance. Technical requirements for these two tasks are very similar and, therefore, justify a joint development project. 1 ref

  10. Excavation Technology for Hard Rock - Problems and Prospects

    International Nuclear Information System (INIS)

    Gillani, S.T.A.; Butt, N.

    2009-01-01

    Civil engineering projects have greatly benefited from the mechanical excavation of hard rock technology. Mining industry, on the other hand, is still searching for major breakthroughs to mechanize and then automate the winning of ore and drivage of access tunnels in its metalliferous sector. The aim of this study is to extend the scope of drag bits for road headers in hard rock cutting. Various factors that can impose limitations on the potential applications of drag bits in hard rock mining are investigated and discussed along with alternative technology options. (author)

  11. Rock samples from LEP/LHC tunnel excavation

    CERN Multimedia

    1985-01-01

    Rock samples taken from 0 to 170 m below ground on the CERN site when the LEP (Large Electron Positron collider) pit number 6 was drilled in Bois-chatton (Versonnex). The challenges of LHC civil engineering: A mosaic of works, structures and workers of differents crafts and origins. Three consulting consortia for the engineering and the follow-up of the works. Four industrial consortia for doing the job. A young team of 25 CERN staff, 30 surface buildings, 32 caverns of all sizes, 170 000 m3 of concrete, 420 000 m3 excavated. 1998-2004 : six years of work and 340 millions Swiss Francs.

  12. Effect of blasting on output increase of bucket wheel excavators

    Energy Technology Data Exchange (ETDEWEB)

    Musil, P.

    1987-12-01

    In brown coal surface mines, consolidated sediments become a problem as mining operations advance into greater depth below the original terrain. Owing to higher digging resistance, the output of bucket wheel excavators drops. This problem may be solved by blasting technology and using drilling machines with higher digging force. This paper describes the blasting operations at the Nastup Mines in Tusmice, Czechoslovakia. About 60% of blasting explosives used is a simple mixture of ammonium nitrate and fuel (ANFO), the rest falls on classic blasting gelatines and blasting explosives plasticized by slurry. It is found that blasting improves output by 30% while electric energy consumption is reduced.

  13. Assessment of the mechanical stability of underground excavations

    International Nuclear Information System (INIS)

    Kuroki, Shigemori; Taniguchi, Wataru

    1999-01-01

    Each tunnel in the underground high level radioactive waste repository must be mechanically stable to maintain safety throughout the construction, emplacement operations and closure phase. The mechanical stability of underground excavations were assessed using a theoretical analysis and a finite element method taking a wide range of geological environment in Japan into consideration to establish confidence in the construction of disposal facilities. The results show that it is possible to maintain the mechanical stability with adequate tunnel spacing and disposal pit pitch and proper mechanical support. The procedure used for the analysis of the mechanical stability in the H12 report and the results are described in this report. (author)

  14. Logs of Paleoseismic Excavations Across the Central Range Fault, Trinidad

    Science.gov (United States)

    Crosby, Christopher J.; Prentice, Carol S.; Weber, John; Ragona, Daniel

    2009-01-01

    This publication makes available maps and trench logs associated with studies of the Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. Our studies were conducted in 2001 and 2002. We mapped geomorphic features indicative of active faulting along the right-lateral, Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. We excavated trenches at two sites, the Samlalsingh and Tabaquite sites. At the Samlalsingh site, sediments deposited after the most recent fault movement bury the fault, and the exact location of the fault was unknown until we exposed it in our excavations. At this site, we excavated a total of eleven trenches, six of which exposed the fault. The trenches exposed fluvial sediments deposited over a strath terrace developed on Miocene bedrock units. We cleaned the walls of the excavations, gridded the walls with either 1 m X 1 m or 1 m X 0.5 m nail and string grid, and logged the walls in detail at a scale of 1:20. Additionally, we described the different sedimentary units in the field, incorporating these descriptions into our trench logs. We mapped the locations of the trenches using a tape and compass. Our field logs were scanned, and unit contacts were traced in Adobe Illustrator. The final drafted logs of all the trenches are presented here, along with photographs showing important relations among faults and Holocene sedimentary deposits. Logs of south walls were reversed in Illustrator, so that all logs are drafted with the view direction to the north. We collected samples of various materials exposed in the trench walls, including charcoal samples for radiocarbon dating from both faulted and unfaulted deposits. The locations of all samples collected are shown on the logs. The ages of seventeen of the charcoal samples submitted for radiocarbon analysis at the University of Arizona Accelerator Mass Spectrometry Laboratory in Tucson, Ariz., are given in Table 1. Samples found in

  15. Excavation of Site U14/1945, Oropi Valley, Tauranga

    International Nuclear Information System (INIS)

    Campbell, M.

    2004-01-01

    Site U14/1945 was originally recorded as two small terraces, with two probable kumara storage pits visible on the surface of the upper terrace, and shell midden visible on the surface of the lower terrace, on a low, approximately 4 m high, hill. The most unusual feature in the site, and my main purpose in writing this paper, was the oven scoop in Trench 1. This feature appeared rather unusual when excavated for a number of reasons. 6 refs., 6 figs., 1 tab

  16. A new bee species that excavates sandstone nests.

    Science.gov (United States)

    Orr, Michael C; Griswold, Terry; Pitts, James P; Parker, Frank D

    2016-09-12

    Humanity has long been fascinated by animals with apparently unfavorable lifestyles [1]. Nesting habits are especially important because they can limit where organisms live, thereby driving population, community, and even ecosystem dynamics [2]. The question arises, then, why bees nest in active termite mounds [3] or on the rim of degassing volcanoes, seemingly preferring such hardship [4]. Here, we present a new bee species that excavates sandstone nests, Anthophora (Anthophoroides) pueblo Orr (described in Supplemental Information, published with this article online), despite the challenges already inherent to desert life. Ultimately, the benefits of nesting in sandstone appear to outweigh the associated costs in this system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Topological representation of the porous structure and its evolution of reservoir sandstone under excavation-induced loads

    Directory of Open Access Journals (Sweden)

    Ju Yang

    2017-01-01

    Full Text Available The porous structure of a reservoir rock greatly influences its evolutive deformation and fracture behavior during excavation of natural resources reservoirs. Most numerical models for porous structures have been used to predict the quasi-static mechanical properties, but few are available to accurately characterize the evolution process of the porous structure and its influence on the macroscopic properties of reservoir rocks. This study reports a novel method to characterize the porous structure of sandstone using its topological parameters and to determine the laws that govern the evolutive deformation and failure of the topological structure under various uniaxial compressive loads. A numerical model of the porous sandstone was established based on the pore characteristics that were acquired using computed tomography imaging techniques. The analytical method that integrates the grassfire algorithm and the maximum inscribed sphere algorithm was proposed to create the 3-D topological model of the deformed porous structure, through which the topological parameters of the structure were measured and identified. The evolution processes of the porous structure under various loads were characterized using its equivalent topological model and parameters. This study opens a new way to characterize the dynamic evolution of the pore structure of reservoir sandstone under excavation disturbance.

  18. Tikal, Guatemala, and Emergent Maya Civilization: Excavations reveal evidence of early complex-living at a prime Maya Indian site.

    Science.gov (United States)

    Coe, W R

    1965-03-19

    It would be extravagant to claim that these pages have outlined meaningfully the early evolution of Tikal. Data have been provided largely for one excavation locus at a site which, for all its importance, merely has symptomatic value. We cannot claim to have, at present, sufficient material to document satisfyingly the conditions and products of community-wide living at any point in these early times. Present knowledge of Eb and Tzec ceramics and of all the usual archeological correlates (architecture and so on) is disturbingly incomplete. While we do have a good many data on residence throughout much of Preclassic time, considerably more information is needed before a solid evaluation of Preclassic Tikal society can be achieved. One can only hope that pending excavation programs will provide it. Yet, experience shows that probably only a tiny percentage of early cultural remains, regardless of their grandeur and importance at the time, would have survived the constant quest for construction fills to satisfy a seemingly interminable need to build and revamp.

  19. Disturbance recording system

    International Nuclear Information System (INIS)

    Chandra, A.K.; Deshpande, S.V.; Mayya, A.; Vaidya, U.W.; Premraj, M.K.; Patil, N.B.

    1994-01-01

    A computerized system for disturbance monitoring, recording and display has been developed for use in nuclear power plants and is versatile enough to be used where ever a large number of parameters need to be recorded, e.g. conventional power plants, chemical industry etc. The Disturbance Recording System (DRS) has been designed to continuously monitor a process plant and record crucial parameters. The DRS provides a centralized facility to monitor and continuously record 64 process parameters scanned every 1 sec for 5 days. The system also provides facility for storage of 64 parameters scanned every 200 msec during 2 minutes prior to and 3 minutes after a disturbance. In addition the system can initiate, on demand, the recording of 8 parameters at a fast rate of every 5 msec for a period of 5 sec. and thus act as a visicorder. All this data is recorded in non-volatile memory and can be displayed, printed/plotted and used for subsequent analysis. Since data can be stored densely on floppy disks, the volume of space required for archival storage is also low. As a disturbance recorder, the DRS allows the operator to view the state of the plant prior to occurrence of the disturbance and helps in identifying the root cause. (author). 10 refs., 7 figs

  20. Archaeological excavation of T10/993 at Matarangi

    International Nuclear Information System (INIS)

    Furey, L.

    1999-01-01

    This report describes the excavation of a small midden site, T10/993, representative of a number of like sites in the sand dunes at Matarangi on the east coast of the Coromandel Peninsula. Few sites of this type have been investigated archaeologically yet they are the remains of a very important part of the Maori economic cycle. The sites could be termed shellfish processing sites. The excavation was a condition imposed by Historic Places Trust on the granting of an authority to modify sites T10/993 and 994 (HPT Authority no. 1997/42), prior to destruction of the sites (Furey 1998). Matarangi Beach Estates commissioned the author to undertake an archaeological site survey of a grassed area at Matarangi Beach which was to be Stage 14 of the urban housing development. The area was in excess of 13 hectares. Two sites were found, T10/993 and 994, and recommendations made for monitoring of the dunes as the topsoil was removed (Furey 1997a). (author). 15 refs., 6 figs., 2 tabs

  1. Shaft Boring Machine: A method of mechanized vertical shaft excavation

    International Nuclear Information System (INIS)

    Goodell, T.M.

    1991-01-01

    The Shaft Boring Machine (SBM) is a vertical application of proven rock boring technology. The machine applies a rotating cutter wheel with disk cutters for shaft excavation. The wheel is thrust against the rock by hydraulic cylinders and slews about the shaft bottom as it rotates. Cuttings are removed by a clam shell device similar to conventional shaft mucking and the muck is hoisted by buckets. The entire machine moves down (and up) the shaft through the use of a system of grippers thrust against the shaft wall. These grippers and their associated cylinders also provide the means to maintain verticality and stability of the machine. The machine applies the same principles as tunnel boring machines but in a vertical mode. Other shaft construction activities such as rock bolting, utility installation and shaft concrete lining can be accomplished concurrent with shaft boring. The method is comparable in cost to conventional sinking to a depth of about 460 meters (1500 feet) beyond which the SBM has a clear host advantage. The SBM has a greater advantage in productivity in that it can excavate significantly faster than drill and blast methods

  2. FROM EXCAVATIONS TO WEB: A GIS FOR ARCHAEOLOGY

    Directory of Open Access Journals (Sweden)

    M. G. D'Urso

    2017-05-01

    Full Text Available The study and the protection of Cultural Heritage in recent years have undergone a revolution about the search tools and the reference disciplines. The technological approach to the problem of the collection, organization and publication of archaeological data using GIS software has completely changed the essence of the traditional methods of investigation, paving the way to the development of several application areas, up to the Cultural Resource Management. A relatively recent specific sector of development for archaeological GIS development sector is dedicated to the intra - site analyses aimed to recording, processing and display information obtained during the excavations. The case - study of the archaeological site located in the south - east of San Pietro Vetere plateau in Aquino, in the Southern Lazio, is concerned with the illustration of a procedure describing the complete digital workflow relative to an intra-site analysis of an archaeological dig. The GIS project implementation and its publication on the web, thanks to several softwares, particularly the FOSS (Free Open Source Software Quantum - GIS, are an opportunity to reflect on the strengths and the critical nature of this particular application of the GIS technology. For future developments in research it is of fundamental importance the identification of a digital protocol for processing of excavations (from the acquisition, cataloguing, up data insertion, also on account of a possible future Open Project on medieval Aquino.

  3. Evaluation of excavation experience: Pierre shale. Final report

    International Nuclear Information System (INIS)

    Abel, J.F. Jr.; Gentry, D.W.

    1975-01-01

    Pierre shale and its stratigraphic equivalents represent a potentially favorable geologic environment for underground storage of hazardous waste products. These rock formations cover great areal and vertical extents, and represent some of the least permeable rock formations within the continental United States. There are, however, several engineering problems associated with constructing underground openings in Pierre shale. This formation is relatively weak and tends to deteriorate rather rapidly if not protected from the mine environment. It will be necessary to place all underground openings below the surficially weathered upper 50 to 70 feet of Pierre shale which contains groundwater moving on fracture permeability. The optimum site for disposal of hazardous waste in Pierre shale, or its stratigraphic equivalents, would be a seismically stable platform bounded on all sides by faults. The optimum size of individual openings would be the minimum necessary for access, storage, and retrieval of waste components. Underground excavations in Pierre shale must be made with care, must be of limited dimensions, must be widely spaced, must be protected from prolonged contact with the mine environment, must be supported immediately after excavation, and must be sited to avoid areas of faulting and(or) intense jointing. Underground openings constructed with boring machines and supported with wet shotcrete are recommended

  4. Sleep disturbances in Parkinsonism.

    Science.gov (United States)

    Askenasy, J J M

    2003-02-01

    The present article is meant to suggest an approach to the guidelines for the therapy of sleep disturbances in Parkinson's Disease (PD) patients.The factors affecting the quality of life in PD patients are depression, sleep disturbances and dependence. A large review of the literature on sleep disturbances in PD patients, provided the basis for the following classification of the sleep-arousal disturbances in PD patients. We suggest a model based on 3 steps in the treatment of sleep disturbances in PD patients. This model allowing the patient, the spouse or the caregiver a quiet sleep at night, may postpone the retirement and the institutionalization of the PD patient. I. Correct diagnosis of sleep disorders based on detailed anamnesis of the patient and of the spouse or of the caregiver. One week recording on a symptom diary (log) by the patient or the caregiver. Correct diagnosis of sleep disorders co morbidities. Selection of the most appropriate sleep test among: polysomnography (PSG), multiple sleep latency test (MSLT), multiple wake latency test (MWLT), Epworth Sleepiness Scale, actigraphy or video-PSG. II. The nonspecific therapeutic approach consists in: a) Checking the sleep effect on motor performance, is it beneficial, worse or neutral. b) Psycho-physical assistance. c) Dopaminergic adjustment is necessary owing to the progression of the nigrostriatal degeneration and the increased sensitivity of the terminals, which alter the normal modulator mechanisms of the motor centers in PD patients. Among the many neurotransmitters of the nigro-striatal pathway one can distinguish two with a major influence on REM and NonREM sleep. REM sleep corresponds to an increased cholinergic receptor activity and a decreased dopaminergic activity. This is the reason why REM sleep deprivation by suppressing cholinergic receptor activity ameliorates PD motor symptoms. L-Dopa and its agonists by suppressing cholinergic receptors suppress REM sleep. The permanent adjustment

  5. Summary report of soil removal preliminary excavations. (Report No. ES-389-75-171)

    International Nuclear Information System (INIS)

    Wickland, C.E.

    1975-07-01

    A proposed technique to remove small areas, 2 , of contaminated soil is discussed along with the results of an actual excavation. Based on the results of a trial excavation in uncontaminated soil and an excavation of two trenches in contaminated soil, it is concluded that the techniques described are a satisfactory means of contaminated soil removal. It can be done safely with a release of airborne plutonium a factor of 10 or more below the Environmental Protection Administration (EPA) limit

  6. A study experiment of auto idle application in the excavator engine performance

    Energy Technology Data Exchange (ETDEWEB)

    Purwanto, Wawan, E-mail: wawan5527@gmail.com; Maksum, Hasan; Putra, Dwi Sudarno, E-mail: dwisudarnoputra@ft.unp.ac.id; Wahyudi, Retno [State University of Padang, West Sumatera (Indonesia); Azmi, Meri, E-mail: meriazmi@gmail.com [State Polytechnic of Padang, West Sumatera (Indonesia)

    2016-03-29

    The purpose of this study was to analyze the effect of applying auto idle to excavator engine performance, such as machine unitization and fuel consumption in Excavator. Steps to be done are to modify the system JA 44 and 67 in Vehicle Electronic Control Unit (V-ECU). The modifications will be obtained from the pattern of the engine speed. If the excavator attachment is not operated, the engine speed will return to the idle speed automatically. From the experiment results the auto idle reduces fuel consumption in excavator engine.

  7. Parametric Optimization and Prediction Tool for Excavation and Prospecting Tasks, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Honeybee Robotics therefore proposed to develop a software tool for facilitating prospecting and excavation system trades in support of selecting an optimal...

  8. Numerical simulation of excavation and supporting of pit slope of the pump room in XNPC

    International Nuclear Information System (INIS)

    Hu Mengqian; Zhu Xiuyun; Ji Zhonghua; Lu Yu; Sun Feng

    2014-01-01

    The research simulates the excavation and supporting of pit slope of the pump room in XNPC. According to the designing of excavation and supporting plan of slope, the numerical simulation of excavation and supporting of pit slope is conducted using the ANSYS finite element numerical simulation software. The simulation results show that, the displacement and stress caused by the excavation of above stage slope and pit slope are both small after taking some measures, including deep mixing pile reinforcement, retaining piles and prestressed anchor cable. Thus the slope is steady. (authors)

  9. Long-range terrain characterization for productive regolith excavation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed research will develop long-range terrain characterization technologies for autonomous excavation in planetary environments. This work will develop a...

  10. Predictive modelling of an excavation test in indurated clay

    International Nuclear Information System (INIS)

    Garitte, B.; Vaunat, J.; Gens, A.; Vietor, T.

    2010-01-01

    Document available in extended abstract form only. This Abstract presents the predictive hydro-mechanical (HM) modelling of an excavation performed in Opalinus clay in the Mont Terri underground laboratory. Niche 2 was excavated in the shaly facies of Opalinus clay from gallery 08. The area surrounding the gallery was intensively instrumented. The geology of Mont Terri is described in Thury and Bosssart (1999) and the parameters used in the analysis were taken from Bock (2009). The stress state is derived from Martin and Lanyion (2003). Gallery 08 is horseshoe shaped and has a mean radius of 2.25 m. It was excavated with a road header at a mean velocity of 1 m/day starting on January 30, 2008 (Gallery chainage 43.8) and ending on June 30, 2008 (Gallery chainage 123.8) with a stop from March 18, to April 24, to instrument the area of niche 2. Niche 2 was excavated by successive blastings 1.3 m deep until reaching a distance of 24 m from the gallery 08 wall. Advance was continuous from October 13, to November 7 with the exception of three stops of 3, 5 and 4 days. The niche has an average diameter of 4.5 m and has a slight upward slope of 0.98%. The excavation of gallery 08 from chainage 43.8 to chainage 123.8 and of the niche was simulated by relaxing the normal total stress and water pressure from the value before excavation to 0. The gallery advance rate was simulated in an approximate manner by applying successively the excavation procedure to 9 m long gallery sections. In the case of the niche, the blasting scheme and the application of the shotcrete was closely reproduced. The three dimensional geometry used in the simulation is shown. The coupled hydro-mechanical formulation used for the analysis is based on the simultaneous solution of the balance equation for solid mass, water mass and momentum (equilibrium). In accordance with field observations, it has been assumed that the medium remains saturated throughout. The formulation was completed with a number of

  11. Nutritional disturbances by adolescent

    OpenAIRE

    Stassart, Martine

    2011-01-01

    The nutritional disturbances are frequent by adolescents. That is a psychological defense against dependance toward the mother but also a middle to remain in a childish position i.e. either as a fat baby - in the fall of obesity- or as the ideal pre- or bisexual great child - in the case of anorexia.

  12. PERFUGIA AS A MECHANISM FOR THE RECOVERY OF SOIL FAUNA AFTER ECOSYSTEM DISTURBANCES

    Directory of Open Access Journals (Sweden)

    K. B. Gongalsky

    2017-12-01

    Full Text Available Disturbances such as forest fires, industrial pollution, etc. are almost always heterogeneous, leaving less disturbed patches within the boundaries of disturbances. In addition to the traditionally considered source of soil invertebrates’ restoration by immigration from the surrounding unchanged biotopes, the role of locally undisturbed areas within the impact zones is shown. The presence of perfugia within the impact areas of various origin is revealed. Perfugia are locally less disturbed or undisturbed areas within a disturbed ecosystem where specimens or remnants of soil biota communities survive a disturbance. They are characterized by higher diversity and abundance of soil fauna in comparison to the main disturbed area. The heterogeneity of soil environment, the heterogeneity of its disturbance and the presence of perfugia serve as one of the factors in the recovery of soil fauna after the disturbances.

  13. Coastal dune dynamics in response to excavated foredune notches

    Science.gov (United States)

    Ruessink, B. G.; Arens, S. M.; Kuipers, M.; Donker, J. J. A.

    2018-04-01

    Dune management along developed coasts has traditionally focussed on the suppression of the geomorphic dynamics of the foredune to improve its role in sea defence. Because a stabilized foredune acts as an almost total barrier to aeolian transport from the beach, the habitat diversity in the more landward dunes has degraded. With the overarching objective to mitigate this undesirable loss in biodiversity, dune management projects nowadays increasingly intend to restore aeolian dynamics by reconnecting the beach-dune system with notches excavated through the foredune. Here, we use repeat topographic survey data to examine the geomorphic response of a coastal dune system in the Dutch National Park Zuid-Kennemerland to five notches excavated in 2012-2013 within an 850-m stretch of the 20-m high established foredune. The notches were dug in a V-shape (viewed onshore), with a width between approximately 50 and 100 m at the top, a (cross-dune) length between 100 and 200 m, and excavation depths between 9 and 12.5 m. The 1 × 1 m digital terrain models, acquired with airborne Lidar and UAV photogrammetry, illustrate that during the 3-year survey period the notches developed into a U-shape because of wall deflation, and that up to 8-m thick and 150-m long depositional lobes formed landward of the notches. Sand budget computations showed that the sand volume of the entire study area increased by about 22,750 m3/year, which, given the 850-m width of the study area, corresponds to an aeolian input from the beach of approximately 26.5 m3/m/year. Between 2006 and 2012 all wind-blown beach sand deposited on the seaward side of the foredune; since 2013, the notches have caused 75% of the sand to be deposited landward of the foredune. This highlights that the notches are highly effective conduits for aeolian transport into the back dunes. Future monitoring is required to determine for how long the notches will stimulate aeolian dynamics and if (and when) vegetation eventually

  14. Shaft Excavation in Frozen Ground at Point 5

    CERN Document Server

    Osborne, J

    2000-01-01

    Construction work on the 112 MCHF civil engineering contract started at Point 5 in August 1998. The new surface buildings and underground structures are necessary to accommodate the CMS detector for the LHC Project. The principal underground works consist of two new shafts, two parallel caverns separated by a supporting pillar, and a number of small connection tunnels and service galleries. The two shafts are to be sunk through approximately 50 m of water-bearing moraine to the underlying molasse rock. From a number of possible construction methods, ground freezing of the moraine was considered to be most appropriate. The ground freezing is used to control the groundwater and to support temporarily the moraine during excavation and lining of the shafts. The aim of this paper is to present the ground-freezing technique and to discuss the advantages and disadvantages of the system in the light of its first few months of running on the Point 5 site.

  15. Optical dating of potteries excavated from Pungnabtoseong earthen wall, Seoul

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myung Jin; Park, Mi Seon [Neosiskorea Co., Daejeon (Korea, Republic of); Lee, Sung Joon; Nah, Hye Rim; Hong, Hyung Woo [National Research Institute of Cultural Heritage, Daejeon (Korea, Republic of)

    2012-05-15

    Thermoluminescence (TL) and optically stimulated luminescence (OSL) emitted from natural crystalline mineral, usually quartz, feldspar, and so on, are mainly used to evaluate the paleodose for the age determination of archaeological and geological sample and the equivalent dose for retrospective dosimetry. TL/OSL age can be calculated as the ratio of paleodose to total annual dose rate which is determined from surrounding soil. In this study, we chemically extracted the quartz samples from potteries excavated in Pungnabtoseong earthen wall and observed the TL/OSL characteristics for paleodose determination. With the converted annual dose rate from the concentration of radioactive isotopes in its surrounding soil, optical date was evaluated and finally illustrated for interpreting the construction stage of Pungnabtoseong

  16. Stability assessment for underground excavations and key construction techniques

    CERN Document Server

    Zhu, Hanhua; Zhao, Yu; Niu, Fusheng

    2017-01-01

    This book examines how the state of underground structures can be determined with the assistance of force, deformation and energy. It then analyzes mechanized shield methods, the New Austrian tunneling method (NATM) and conventional methods from this new perspective. The book gathers a wealth of cases reflecting the experiences of practitioners and administrators alike. Based on statistical and engineering studies of these cases, as well as lab and field experiments, it develops a stability assessment approach incorporating a stable equilibrium, which enables engineers to keep the structure and surrounding rocks safe as long as the stable equilibrium and deformation compliance are maintained. The book illustrates the implementation of the method in various tunneling contexts, including soil-rock mixed strata, tunneling beneath operating roads, underwater tunnels, and tunnel pit excavation. It offers a valuable guide for researchers, designers and engineers, especially those who are seeking to understand the u...

  17. Excavations at Cook's Cove, Tolaga Bay, New Zealand

    International Nuclear Information System (INIS)

    Walter, R.; Jacomb, C.; Brooks, E.

    2011-01-01

    The Cook's Cove site (Z17/311) on the East Coast of the North Island of New Zealand is an unusual example of an archaeological site spanning close to the full duration of the New Zealand prehistoric sequence. In addition to a record of Polynesian activities, the site is also well known as the type site for the North Island Holocene stratigraphy. Recent excavations at Cook's Cove have resulted in a reinterpretation of the nature of Polynesian occupation and adaptation in this part of the North Island. The application of an 'event phase' interpretative approach provides the means for reconstructing a detailed history of environmental processes and their relationships to cultural activities over a period of 700 years. (author). 61 refs., 17 figs., 13 tabs.

  18. Application of neutron radiography to restoration of an excavated sword

    International Nuclear Information System (INIS)

    Masuzawa, Fumitake; Murata, Tadashige; Ozaki, Makoto

    1992-01-01

    An excavated sword had turned to fragments of corrosion covered with grit and rust. There are two holes at the pommel and the guard which have elaborate inner walls. The original sword must have had the pommel and the guard, whose shapes had been the same as those of the holes. What were materials of them? Why have they disappeared to have changed into holes? No key which answers these questions has been gotten with macrography and X-ray radiography. Then neutron radiography was tried to examine that. Images which were not recognized on X-ray radiographs appeared on neutron ones. Above-mentioned questions were solved by investigation of them. This paper describes that the sword were well conserved and restored on the basis of it. (author)

  19. Bucket wheel excavator performances at Neyveli lignite mine

    Energy Technology Data Exchange (ETDEWEB)

    Kumaraswamy, S; Mozumdar, B K

    1987-03-01

    Bucket-wheel excavators have been in use at the Neyveli Lignite Mine in the State of Tamil Nadu, India, since the early nineteen-sixties. The mining environment has been particularly harsh for BWE application. The adverse influencing factors are the hardness of the over-burden formation, high abrasivity of rock and artesian ground water conditions. In this paper, the performances of the BWEs at Neyveli have been statistically analysed to determine the effects of physico-mechanical properties of overburden, blasting and rainfall on machine productivity, availability, wear-and-tear of bucket teeth, power consumption, production efficiency and cost of mining. An empirical relationship between the production efficiency, defined as the ratio of actual production rate to the theoretical one, and the bench height and width, height of slices, specific cutting resistance of the overburden material and its clay content, consumption of explosives, and conveyor length has been established.

  20. Theoretical study of short pile effect in tunnel excavation

    Science.gov (United States)

    Tian, Xiao-yan; Liu, Jing; Gao, Xiao-mei; Li, Yuan

    2017-09-01

    The Misaki Sato Go ideal elastoplastic model is adopted and the two stage analysis theory is used to study the effect of tunnel excavation on short pile effect in this paper. In the first stage, the free field vertical displacement of the soil at the corresponding pile location is obtained by using empirical formula. In the second stage, the displacement is applied to the corresponding pile location. The equilibrium condition of micro physical differential equation settlement of piles. Then through logical deduction and the boundary condition expressions of the settlement calculation, obtain the pile side friction resistance and axial force of the week. Finally, an engineering example is used to analyze the influence of the change of main parameters on their effects.

  1. Characterization of enameled glass excavated from Laem Pho, southern Thailand

    Science.gov (United States)

    Dhanmanonda, W.; Won-in, K.; Tancharakorn, S.; Tantanuch, W.; Thongleurm, C.; Kamwanna, T.; Dararutana, P.

    2012-07-01

    Laem Pho in Surat Thani, southern province of Thailand is one of the most important historic site on the eastern shore of the Gulf of Thailand. In this work, the enameled glass fragments which looked-like Islamic glass mainly excavated from this site were analyzed using SEM-EDS, PIXE and μ-XRF, in order to understand the chemical composition by comparing the archaeological data and topology. The structure of the enameled decoration was also studied. The resulting data indicated that high-magnesia alkali-lime silicate glass was produced. The presence of transition metals such as copper, iron and manganese were affected on the glass colorations. Typological classifications, technological observations and comparative studies serve to clarify the development and cultural inter-relationships of various glass objects along the trade and exchange networks in ancient maritime.

  2. Groundwater flow modelling of the excavation and operational phases - Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Urban (Computer-aided Fluid Engineering AB, Lyckeby (Sweden)); Rhen, Ingvar (SWECO Environment AB, Falun (Sweden))

    2010-12-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study reported here presents calculated inflow rates, drawdown of the groundwater table and upconing of deep saline water for different levels of grouting efficiency during the excavation and operational phases of a final repository at Laxemar. The inflow calculations were accompanied by a sensitivity study, which among other matters handled the impact of different deposition hole rejection criteria. The report also presents tentative modelling results for the duration of the saturation phase, which starts once the used parts of the repository are being backfilled

  3. The Application of Foundation Pit Monitoring Technology to the Excavation

    Directory of Open Access Journals (Sweden)

    Qiu Jin

    2015-01-01

    Full Text Available The foundation pit monitoring plays an important role in the foundation pit supporting projects especially in those deep foundation pit projects. Through the whole monitoring of the foundation pit construction from the excavation to the backfill, we can learn about the forcing and deforming process of the foundation pit supporting system, and grasp the impact of external condition changes on the foundation pit. This paper takes a project in Jinan as an example to establish a specific monitoring program, and then conducts the analysis and evaluation of the monitoring data; the real-time grasp of the foundation pit deformation and internal force changes can help to further ensure the security status of the foundation pit, thus better guiding the construction.

  4. Characterization of enameled glass excavated from Laem Pho, southern Thailand

    International Nuclear Information System (INIS)

    Dhanmanonda, W; Won-in, K; Tancharakorn, S; Tantanuch, W; Thongleurm, C; Kamwanna, T; Dararutana, P

    2012-01-01

    Laem Pho in Surat Thani, southern province of Thailand is one of the most important historic site on the eastern shore of the Gulf of Thailand. In this work, the enameled glass fragments which looked-like Islamic glass mainly excavated from this site were analyzed using SEM-EDS, PIXE and μ-XRF, in order to understand the chemical composition by comparing the archaeological data and topology. The structure of the enameled decoration was also studied. The resulting data indicated that high-magnesia alkali-lime silicate glass was produced. The presence of transition metals such as copper, iron and manganese were affected on the glass colorations. Typological classifications, technological observations and comparative studies serve to clarify the development and cultural inter-relationships of various glass objects along the trade and exchange networks in ancient maritime.

  5. Pajarito Plateau archaeological survey and excavations. [Los Alamos Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Steen, C.R.

    1977-05-01

    Los Alamos Scientific Laboratory lands were surveyed to locate pre-Columbian Indian ruins. The survey results will permit future construction to be planned so that most of the ancient sites in the area can be preserved. Indian occupation of the area occurred principally from late Pueblo III times (late 13th century) until early Pueblo V (about the middle of the 16th century). There are evidences of sporadic Indian use of the area for some 10,000 years. One Folsom point has been found, as well as many other archaic varieties of projectile points. Continued use of the region well into the historic period is indicated by pictographic art that portrays horses. In addition to an account of the survey, the report contains summaries of excavations made on Laboratory lands between 1950 and 1975.

  6. Assessment on the mechanical stability of underground excavations

    International Nuclear Information System (INIS)

    Kuroki, Shigemori; Taniguchi, Wataru; Sugino, Hiroyuki; Koo, Shigeru; Hasegawa, Hiroshi; Kubota, Shigeru; Dewa, Katsuyuki

    1999-11-01

    It is planned to construct the tunnels and emplace waste packages at several hundred meters to 1,000 meters under the ground for the repository of high-level radioactive waste based on a policy to assure the safe life environment. It is required to be mechanically stable for the tunnels to assure the work safety throughout the construction, operation and closure phase. In this report, the mechanical stability of tunnels, that is a factor of design requisites, was evaluated by the analyses to present an outline of the technical reliability of geological disposal. To put it concretely, the tunnel sections were determined to have the required areas and shapes, and the analyses on the mechanical stability at tunnel excavations and earthquake, at tunnel intersections were conducted by the theoretical analysis and finite element method. The results obtained by these investigations are shown below: It will be able to construct the tunnels with present techniques. The mechanical stability of tunnels will be assured if proper supports are given, and adequate tunnel spacing and disposal-pit pitches are set. The mechanical stability will be assured at the tunnel intersections if proper reinforcement measures are taken. The reinforcement will be required for the intersection areas over the distance of 1D (D: diameter of tunnels) on the obtuse angle side, and 4D on the acute angle side, when intersection angle is set at 30 degrees. The investigations were conducted on the assumption that the experienced big earthquake occurred. The results show that the effect of earthquake on the mechanical stability of tunnels is small, and tunnels are stable at the earthquake when the mechanical stability at tunnel excavations is assured. (author)

  7. Omaha Soil Mixing Study: Redistribution of Lead in Remediated Residential Soils Due to Excavation or Homeowner Disturbance.

    Science.gov (United States)

    Urban soils within the Omaha Lead Superfund Site have been contaminated with lead (Pb) from atmospheric deposition of particulate materials from lead smelting and recycling activities. In May of 2009 the Final Record of Decision stated that any residential soil exceeding the pre...

  8. Postoperative circadian disturbances

    DEFF Research Database (Denmark)

    Gögenur, Ismail

    2010-01-01

    ) in urine the first night after both minor and major surgery. This delay after major surgery was correlated to the duration of surgery. The amplitude in the melatonin rhythm was unchanged the first night but increased in the second night after major surgery. The amplitude in AMT6s was reduced the first...... night after minimally invasive surgery. The core body temperature rhythm was disturbed after both major and minor surgery. There was a change in the sleep wake cycle with a significantly increased duration of REM-sleep in the day and evening time after major surgery compared with preoperatively....... There was also a shift in the autonomic nervous balance after major surgery with a significantly increased number of myocardial ischaemic episodes during the nighttime period. The circadian activity rhythm was also disturbed after both minor and major surgery. The daytime AMT6s excretion in urine after major...

  9. 29 CFR 1926.913 - Blasting in excavation work under compressed air.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Blasting in excavation work under compressed air. 1926.913... Use of Explosives § 1926.913 Blasting in excavation work under compressed air. (a) Detonators and... connecting wires are connected up. (b) When detonators or explosives are brought into an air lock, no...

  10. Bucket wheel excavators for open-cast mining all over the world

    Energy Technology Data Exchange (ETDEWEB)

    Durst, W.

    1979-04-01

    A report is given on the use of bucket wheel excavators, spreaders and tripper cars in open-cast mining of brown coal, oilsand and other minerals in Australia, Canada, India, Spain, USA and Yugoslavia as well as on the use of bucket wheel excavators for land reclamation in Singapore.

  11. Real-time support for precision excavation of radionuclide-contaminated soils

    International Nuclear Information System (INIS)

    Durham, L. A.; Johnson, R. L.

    2003-01-01

    Traditional approaches to excavation design for sites with radionuclide-contaminated soils generally involve work plans with fixed excavation footprints and post-excavation verification sampling. Recent advancements in real-time data collection systems, combined with data loggers, location control systems, and secure project-support Web sites, allow for an alternative, more precise approach to excavation design and implementation. In this mode, traditional work plans are replaced with dynamic work plans. Excavation efforts are organized by lift, with real-time dig face screening performed and the data for each lift analyzed, before excavation continues. Rather than specifying excavation footprints, dynamic work plans identify the decision logic that will be used to determine footprints based on real-time data collection. The level of investment in excavation support data collection can be balanced against potential cost savings realized through waste stream minimization. Secure project support Web sites ensure that data sets generated during the remediation process are readily accessible to all who need to see them, whether they are on site or not. These include regulators, program managers, and technical support staff. This type of Web site allows for quick problem resolution, increased transparency in field decision making, and more efficient allocation of expensive technical staff time

  12. Drill, baby, drill: the influence of woodpeckers on post-fire vertebrate communities through cavity excavation

    Science.gov (United States)

    Gina L. Tarbill; Patricia N. Manley; Angela M. White

    2015-01-01

    Several studies have addressed the importance of woodpeckers as ecological engineers in forests due to their excavation of cavities. Although research in green, unburned forests has identified the influence of different excavators on secondary use by cavity-dependent species, little is known about the relative importance of cavities created by woodpeckers in recently...

  13. Investigation of Hexavalent Chromium Flux to Groundwater at the 100-C-7:1 Excavation Site

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Vermeul, Vincent R.; Fritz, Brad G.; Mackley, Rob D.; Horner, Jacob A.; Johnson, Christian D.; Newcomer, Darrell R.

    2012-11-16

    Deep excavation of soil has been conducted at the 100-C-7 and 100-C-7:1 waste sites within the 100-BC Operable Unit at the Department of Energy (DOE) Hanford Site to remove hexavalent chromium (Cr(VI)) contamination with the excavations reaching to near the water table. Soil sampling showed that Cr(VI) contamination was still present at the bottom of the 100-C-7:1 excavation. In addition, Cr(VI) concentrations in a downgradient monitoring well have shown a transient spike of increased Cr(VI) concentration following initiation of excavation. Potentially, the increased Cr(VI) concentrations in the downgradient monitoring well are due to Cr(VI) from the excavation site. However, data were needed to evaluate this possibility and to quantify the overall impact of the 100-C-7:1 excavation site on groundwater. Data collected from a network of aquifer tubes installed across the floor of the 100-C-7:1 excavation and from temporary wells installed at the bottom of the entrance ramp to the excavation were used to evaluate Cr(VI) releases into the aquifer and to estimate local-scale hydraulic properties and groundwater flow velocity.

  14. Deformations and damage to buildings adjacent to deep excavations in soft soils

    NARCIS (Netherlands)

    Korff, M.

    2009-01-01

    The objective of this study is to gain insight into mechanisms of soil-structure interaction for buildings adjacent to deep excavations and to find a reliable method to design and monitor deep excavations in urban areas with soft soil conditions. The research focuses on typical Dutch conditions. The

  15. Rehabilitation of disturbed land

    Energy Technology Data Exchange (ETDEWEB)

    Bell, L.C. [Australian Centre for Minesite Rehabilitation Research, Kenmore, Qld. (Australia)

    1996-12-31

    This chapter discusses the objectives of rehabilitation of lands in Australian disturbed by mining. It gives advice on rehabilitation planning and outlines the factors influencing post-mining land use and rehabilitation strategies, including climate, topography, hydrology, properties of soils, overburden and mineral processing wastes, flora and fauna and social considerations. Finally, the key elements of a rehabilitation plan are discussed, namely: landscape reconstruction; selective handling of overburden; and establishment and maintenance of a vegetative cover. 12 figs., 1 tab.

  16. Dam geology and basic treatment(2). Adit substitution technique and measures against landslide involved in excavation

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Kin' ichi [Kinki Geological Center, Co. Ltd., Kyoto, Japan (JP)

    1988-12-25

    This paper discusses the adit substitution technique which is a method for special treatment of dams and measures against landslide involved in excavation. The adit substitution technique consists of excavating an adit in the natural ground, excavating another adit which is in contact with the first adit and is at a level higher than the first adit, placing concrete from the upper adit to the lower adit to fill first adit completely with concrete, excavating a third adit, filling the second adit with concrete similarly, and proceeding with this process to construct a water barrier within the natural ground until the water barrier reaches the required height. The paper explains examples of this technique used on four dams. It also explains examples of measures against excavation-induced landslide adopted on three dams. 13 refs., 8 figs., 2 tabs.

  17. Dig-face monitoring during excavation of a radioactive plume at Mound Laboratory, Ohio

    International Nuclear Information System (INIS)

    Josten, N.E.; Gehrke, R.J.; Carpenter, M.V.

    1995-12-01

    A dig-face monitoring system consists of onsite hardware for collecting information on changing chemical, radiological, and physical conditions in the subsurface soil during the hazardous site excavation. A prototype dig-face system was take to Mount Laboratory for a first trial. Mound Area 7 was the site of historical disposals of 232 Th, 227 Ac, and assorted debris. The system was used to monitor a deep excavation aimed at removing 227 Ac-contaminated soils. Radiological, geophysical, and topographic sensors were used to scan across the excavation dig-face at four successive depths as soil was removed. A 3-D image of the contamination plumes was developed; the radiation sensor data indicated that only a small portion of the excavated soil volume was contaminated. The spatial information produced by the dig-face system was used to direct the excavation activities into the area containing the 227 Ac and to evaluate options for handling the separate 232 Th plume

  18. Study on Excavation of Particular Part of Underground Cavern for Hydropower Station

    Science.gov (United States)

    Yang, Yang; Zhang, Feng; Shang, Qin; Zheng, Huakang

    2018-01-01

    In the present study, regarding four particular parts of underground cavern for hydropower station, i.e., crown, high sidewall, the intersection between high sidewall and tunnel and tailrace tunnel, by summarizing the previous construction experience, we have proposed the excavation approach based on “middle first and edge later, soft first and hard later”, “layered construction by excavating the thin layer first and supporting as the layer advances”, “tunnel first and wall later, small tunnels into large ones” and “excavating tunnels supported by separation piers”. In addition, the proposed excavation approach has been analyzed and verified with finite element numerical simulation. The result has indicated that the proposed special approach is reasonable and effective to reduce the turbulence on surrounding rocks, lower the influence of unloading during excavating and enhance the local and global stability of caverns and surrounding rocks.

  19. Climate change and forest disturbances

    Science.gov (United States)

    Virginia H. Dale; Linda A. Joyce; Steve McNulty; Ronald P. Neilson; Matthew P. Ayres; Michael D. Flannigan; Paul J. Hanson; Lloyd C. Irland; Ariel E. Lugo; Chris J. Peterson; Daniel Simberloff; Frederick J. Swanson; Brian J. Stocks; Michael Wotton

    2001-01-01

    This article examines how eight disturbances influence forest structure, composition, and function, and how climate change may influence the severity, frequency, and magnitude of disturbances to forests. We focus on examples from the United States, although these influences occur worldwide. We also consider options for coping with disturbance under changing climate....

  20. Digging Deep: Is Lunar Mantle Excavated Around the Imbrium Basin?

    Science.gov (United States)

    Klima, R. L.; Bretzfelder, J.; Buczkowski, D.; Ernst, C. M.; Greenhagen, B. T.; Petro, N. E.; Shusterman, M. L.

    2017-12-01

    The Moon has experienced over a dozen impacts resulting in basins large enough to have excavated mantle material. With many of those basins concentrated on the lunar near side, and extensive regolith mixing since the lunar magma ocean crystallized, one might expect that some mantle material would have been found among the lunar samples on Earth. However, so far, no mantle clasts have been definitively identified in lunar samples [1]. From orbit, a number of olivine-bearing localities, potentially sourced from the mantle, have been identified around impact basins [2]. Based on analysis of near-infrared (NIR) and imaging data, [3] suggest that roughly 60% of these sites represent olivine from the mantle. If this is the case and the blocks are coherent and not extensively mixed into the regolith, these deposits should be ultramafic, containing olivine and/or pyroxenes and little to no plagioclase. In the mid-infrared, they would thus exhibit Christiansen features at wavelengths in excess of 8.5 μm, which has not been observed in global studies using the Diviner Lunar Radiometer [4]. We present an integrated study of the massifs surrounding the Imbrium basin, which, at over 1000 km wide, is large enough to have penetrated through the lunar crust and into the mantle. These massifs are clearly associated with the Imbrium basin-forming impact, but existing geological maps do not distinguish between whether they are likely ejecta or rather uplifted from beneath the surface during crustal rebound [5]. We examine these massifs using vis, NIR and Mid IR data to determine the relationships between and the bulk mineralogy of local lithologies. NIR data suggest that the massifs contain exposures of four dominant minerals: olivine, Mg-rich orthopyroxene, a second low-Ca pyroxene, and anorthite. Mid IR results suggest that though many of these massifs are plagioclase-rich, portions of some may be significantly more mafic. We will present our growing mineralogical map of the

  1. Disturbance by optimal discrimination

    Science.gov (United States)

    Kawakubo, Ryûitirô; Koike, Tatsuhiko

    2018-03-01

    We discuss the disturbance by measurements which unambiguously discriminate between given candidate states. We prove that such an optimal measurement necessarily changes distinguishable states indistinguishable when the inconclusive outcome is obtained. The result was previously shown by Chefles [Phys. Lett. A 239, 339 (1998), 10.1016/S0375-9601(98)00064-4] under restrictions on the class of quantum measurements and on the definition of optimality. Our theorems remove these restrictions and are also applicable to infinitely many candidate states. Combining with our previous results, one can obtain concrete mathematical conditions for the resulting states. The method may have a wide variety of applications in contexts other than state discrimination.

  2. Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus clay at the Mont Terri underground rock laboratory (Switzerland)

    International Nuclear Information System (INIS)

    Thoeny, R.

    2014-01-01

    Clay rock formations are potential host rocks for deep geological disposal of nuclear waste. However, they exhibit relatively low strength and brittle failure behaviour. Construction of underground openings in clay rocks may lead to the formation of an excavation damage zone (EDZ) in the near-field area of the tunnel. This has to be taken into account during risk assessment for waste-disposal facilities. To investigate the geomechanical processes associated with the rock mass response of faulted Opalinus Clay during tunnelling, a full-scale ‘mine-by’ experiment was carried out at the Mont Terri Underground Rock Laboratory (URL) in Switzerland. In the ‘mine-by’ experiment, fracture network characteristics within the experimental section were characterized prior to and after excavation by integrating structural data from geological mapping of the excavation surfaces and from four pre- and post-excavation boreholes.The displacements and deformations in the surrounding rock mass were measured using geo-technical instrumentation including borehole inclinometers, extensometers and deflectometers, together with high-resolution geodetic displacement measurements and laser scanning measurements on the excavation surfaces. Complementary data was gathered from structural and geophysical characterization of the surrounding rock mass. Geological and geophysical techniques were used to analyse the structural and kinematic relationships between the natural and excavation-induced fracture network surrounding the ‘mine-by’ experiment. Integrating the results from seismic refraction tomography, borehole logging, and tunnel surface mapping revealed that spatial variations in fault frequency along the tunnel axis alter the rock mass deformability and strength. Failure mechanisms, orientation and frequency of excavation-induced fractures are significantly influenced by tectonic faults. On the side walls, extensional fracturing tangential to the tunnel circumference was the

  3. Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus clay at the Mont Terri underground rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Thoeny, R.

    2014-07-01

    Clay rock formations are potential host rocks for deep geological disposal of nuclear waste. However, they exhibit relatively low strength and brittle failure behaviour. Construction of underground openings in clay rocks may lead to the formation of an excavation damage zone (EDZ) in the near-field area of the tunnel. This has to be taken into account during risk assessment for waste-disposal facilities. To investigate the geomechanical processes associated with the rock mass response of faulted Opalinus Clay during tunnelling, a full-scale ‘mine-by’ experiment was carried out at the Mont Terri Underground Rock Laboratory (URL) in Switzerland. In the ‘mine-by’ experiment, fracture network characteristics within the experimental section were characterized prior to and after excavation by integrating structural data from geological mapping of the excavation surfaces and from four pre- and post-excavation boreholes.The displacements and deformations in the surrounding rock mass were measured using geo-technical instrumentation including borehole inclinometers, extensometers and deflectometers, together with high-resolution geodetic displacement measurements and laser scanning measurements on the excavation surfaces. Complementary data was gathered from structural and geophysical characterization of the surrounding rock mass. Geological and geophysical techniques were used to analyse the structural and kinematic relationships between the natural and excavation-induced fracture network surrounding the ‘mine-by’ experiment. Integrating the results from seismic refraction tomography, borehole logging, and tunnel surface mapping revealed that spatial variations in fault frequency along the tunnel axis alter the rock mass deformability and strength. Failure mechanisms, orientation and frequency of excavation-induced fractures are significantly influenced by tectonic faults. On the side walls, extensional fracturing tangential to the tunnel circumference was the

  4. Sleep Disturbances in Neurodevelopmental Disorders.

    Science.gov (United States)

    Robinson-Shelton, Althea; Malow, Beth A

    2016-01-01

    Sleep disturbances are extremely prevalent in children with neurodevelopmental disorders compared to typically developing children. The diagnostic criteria for many neurodevelopmental disorders include sleep disturbances. Sleep disturbance in this population is often multifactorial and caused by the interplay of genetic, neurobiological and environmental overlap. These disturbances often present either as insomnia or hypersomnia. Different sleep disorders present with these complaints and based on the clinical history and findings from diagnostic tests, an appropriate diagnosis can be made. This review aims to provide an overview of causes, diagnosis, and treatment of sleep disturbances in neurodevelopmental disorders that present primarily with symptoms of hypersomnia and/or insomnia.

  5. Defining Disturbance for Microbial Ecology.

    Science.gov (United States)

    Plante, Craig J

    2017-08-01

    Disturbance can profoundly modify the structure of natural communities. However, microbial ecologists' concept of "disturbance" has often deviated from conventional practice. Definitions (or implicit usage) have frequently included climate change and other forms of chronic environmental stress, which contradict the macrobiologist's notion of disturbance as a discrete event that removes biomass. Physical constraints and disparate biological characteristics were compared to ask whether disturbances fundamentally differ in microbial and macroorganismal communities. A definition of "disturbance" for microbial ecologists is proposed that distinguishes from "stress" and other competing terms, and that is in accord with definitions accepted by plant and animal ecologists.

  6. Groundwater flow modelling of the excavation and operational phases - Forsmark

    International Nuclear Information System (INIS)

    Svensson, Urban; Follin, Sven

    2010-07-01

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different climate conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study reported here presents calculated inflow rates, drawdown of the groundwater table and upconing of deep saline water for different levels of grouting efficiency during the excavation and operational phases of a final repository at Forsmark. The inflow calculations are accompanied by a sensitivity study, which among other matters handles the impact of parameter heterogeneity, different deposition hole rejection criteria, and the SFR facility (the repository for short-lived radioactive waste located approximately 1 km to the north of the investigated candidate area for a final repository at Forsmark). The report also presents tentative modelling results for the duration of the saturation phase, which starts once the used parts of the repository are being backfilled

  7. Combined Optimal Control System for excavator electric drive

    Science.gov (United States)

    Kurochkin, N. S.; Kochetkov, V. P.; Platonova, E. V.; Glushkin, E. Y.; Dulesov, A. S.

    2018-03-01

    The article presents a synthesis of the combined optimal control algorithms of the AC drive rotation mechanism of the excavator. Synthesis of algorithms consists in the regulation of external coordinates - based on the theory of optimal systems and correction of the internal coordinates electric drive using the method "technical optimum". The research shows the advantage of optimal combined control systems for the electric rotary drive over classical systems of subordinate regulation. The paper presents a method for selecting the optimality criterion of coefficients to find the intersection of the range of permissible values of the coordinates of the control object. There is possibility of system settings by choosing the optimality criterion coefficients, which allows one to select the required characteristics of the drive: the dynamic moment (M) and the time of the transient process (tpp). Due to the use of combined optimal control systems, it was possible to significantly reduce the maximum value of the dynamic moment (M) and at the same time - reduce the transient time (tpp).

  8. Groundwater flow modelling of the excavation and operational phases - Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Urban (Computer-aided Fluid Engineering AB, Lyckeby (Sweden)); Follin, Sven (SF GeoLogic AB, Taeby (Sweden))

    2010-07-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different climate conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study reported here presents calculated inflow rates, drawdown of the groundwater table and upconing of deep saline water for different levels of grouting efficiency during the excavation and operational phases of a final repository at Forsmark. The inflow calculations are accompanied by a sensitivity study, which among other matters handles the impact of parameter heterogeneity, different deposition hole rejection criteria, and the SFR facility (the repository for short-lived radioactive waste located approximately 1 km to the north of the investigated candidate area for a final repository at Forsmark). The report also presents tentative modelling results for the duration of the saturation phase, which starts once the used parts of the repository are being backfilled.

  9. Does Avalanche Shovel Shape Affect Excavation Time: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Kurt Schindelwig

    2017-05-01

    Full Text Available In Europe and North America, approximately 150 fatalities occur as a result of avalanches every year. However, it is unclear whether certain shovel shapes are more effective than others in snow removal during avalanche victim recovery. The objective was to determine the performance parameters with a developed standardized test using different shovel shapes and to determine sex-specific differences. Hence, several parameters were determined for clearing the snow from a snow filled box (15 men, 14 women. A flat (F and a deep (D shovel blade with the shaft connected straight (S or in clearing mode (C were used for the investigation of the shovel shapes FS, DC and the subsequent use of DC&DS. Mean snow mass shifted per unit time increased significantly from 1.50 kg/s with FS to 1.71 kg/s (14% with DS and further to 1.79 kg/s (4% with DC&DS for all participants. Snow mass shifted per unit time was 44% higher (p < 0.05 for men than for women. In excavation operations, the sex-specific physical performance should be taken into account. The results were limited to barely binding snow, because only with this snow did the tests show a high reliability.

  10. EXCAVATION OF PITS (CHANNELS BY IMPACT OF PULSE POWER LOADING

    Directory of Open Access Journals (Sweden)

    Anakhaev Koshkinbai Nazirovich

    2017-08-01

    Full Text Available The paper provides an innovative hydromechanical solution of the problem of profiles development of pits and channels by impact of pulse (blasting power load on a surface of homogeneous soil mass, for example, when excavating solid rocks, frozen soil, etc. Thus, soil would be considered as an ideal heavy liquid (disregarding its mechanical strength and plastic properties. The solution of this problem is achieved by the method of consecutive conformal mappings of physical flow region (in the form of Kirchhoff complex on the region of complex potential (in the form of a rectangle. Thus, the new technique of geometrical image generation of the latter in the presence in the flow region of a fixed point with discontinuous variations of pressure head-flow function and the direction of speed of flow and representation of an elliptic sine of Jacobi by means of elementary functions are used. The received analytical functional dependencies allow to determine an outline of a funnel of the soil ejection and all the required hydromechanical characteristics of flow (head-flow function, function of flow, speed of flow, etc.. Thus, the soil ejection funnel outline (for a benchmark problem completely coincides with subproduct of the known rigorous solution of Lavrentyev-Kuznetsov.

  11. Numerical study on lateral wall displacement of deep excavation supported by IPS earth retention system

    Directory of Open Access Journals (Sweden)

    Tugen Feng

    2017-12-01

    Full Text Available The objective of this study is to investigate the 3D behavior characteristics of an excavation supported by an innovative prestressed support (IPS earth retention system. A numerical simulation was conducted in order to provide insight into the IPS system behavior by using the FLAC3D package. Prior to the parametric study, validation work was conducted by means of a comparison of the deformation between the field test data and numerical analysis results, and strong agreement was obtained. The reasonable excavation location, layered excavation thickness, and blocked excavation sequence are presented according to variable parameter analysis. In view of the previous findings, certain measurements are proposed in order to control the foundation pit deformation. The results indicate that prestress compensation has a significant effect on the IPS system behavior, while an optimized excavation sequence slightly improves its behavior. With the conclusion proposed based on the numerical results, the aim is to provide reference data for optimization design and the construction sequence. Keywords: FLAC3D, IPS system, Prestress compensation, Layered excavation, Blocked excavation, Deformation control

  12. Utilization of thin-layer chromatography for confirmational sampling during remedial excavation

    International Nuclear Information System (INIS)

    Burton, P.J.

    1996-01-01

    Thin-layer chromatography (TLC) is a simple, efficient, inexpensive, and accurate method of chemical analysis. This method is applicable to field testing for confirming the limits of excavation during excavation of petroleum, oil, and/or lubricant (POL) contamination. Traditionally, excavation at contaminated sites suffers from a time delay due to the need to obtain laboratory confirmation of the limits of excavation. All suspected contaminated material is removed for stockpiling or remediation. The remaining soils need to be sampled to confirm that no contaminated material remains in the excavation. The site scientist collects samples and sends them out for analysis at a certified laboratory. The laboratory requires, even for a rush order, several days to analyze the samples. This time delay interferes with the efficiency of the operation. The excavations either have to be left open (which is a safety hazard) or reopened if additional material must be excavated. TLC samples can be collected and analyzed in several hours allowing for a short turnaround time for analytical results. The TLC method can be easily performed by a technician. Results of a case study from a subarctic Alaskan site will be reported. Simple operational TLC procedures will be shared. The equipment required for TLC analysis will be outlined. Correlation data between TLC and laboratory analysis will be presented

  13. Slope Stability Evaluation And Equipment Setback Distances For Burial Ground Excavations

    International Nuclear Information System (INIS)

    Mcshane, D.S.

    2010-01-01

    After 1970 Transuranic (TRU) and suspect TRU waste was buried in the ground with the intention that at some later date the waste would be retrieved and processed into a configuration for long term storage. To retrieve this waste the soil must be removed (excavated). Sloping the bank of the excavation is the method used to keep the excavation from collapsing and to provide protection for workers retrieving the waste. The purpose of this paper is to document the minimum distance (setback) that equipment must stay from the edge of the excavation to maintain a stable slope. This evaluation examines the equipment setback distance by dividing the equipment into two categories, (1) equipment used for excavation and (2) equipment used for retrieval. The section on excavation equipment will also discuss techniques used for excavation including the process of benching. Calculations 122633-C-004, 'Slope Stability Analysis' (Attachment A), and 300013-C-001, 'Crane Stability Analysis' (Attachment B), have been prepared to support this evaluation. As shown in the calculations the soil has the following properties: Unit weight 110 pounds per cubic foot; and Friction Angle (natural angle of repose) 38 o or 1.28 horizontal to 1 vertical. Setback distances are measured from the top edge of the slope to the wheels/tracks of the vehicles and heavy equipment being utilized. The computer program utilized in the calculation uses the center of the wheel or track load for the analysis and this difference is accounted for in this evaluation.

  14. Field Observation of Soil Displacements Resulting Due Unsupported Excavation and Its Effects on Proposed Adjacent Piles

    Directory of Open Access Journals (Sweden)

    Ala Nasir Al-Jorany

    2016-06-01

    Full Text Available Soil movement resulting due unsupported excavation nearby axially loaded piles imposes significant structural troubles on geotechnical engineers especially for piles that are not designed to account for loss of lateral confinement. In this study the field excavation works of 7.0 m deep open tunnel was continuously followed up by the authors. The work is related to the project of developing the Army canal in the east of Baghdad city in Iraq. A number of selected points around the field excavation are installed on the ground surface at different horizontal distance. The elevation and coordinates of points are recorded during 23 days with excavation progress period. The field excavation process was numerically simulated by using the finite element package PLAXIS 3D foundation. The obtained analysis results regarding the displacements of the selected points are compared with the field observation for verification purpose. Moreover, finite element analysis of axially loaded piles that are presumed to be existed at the locations of the observation points is carried out to study the effect of excavation on full scale piles behaviors. The field observation monitored an upward movement and positive lateral ground movement for shallow excavation depth. Later on and as the excavation process went deeper, a downward movement and negative lateral ground movement are noticed. The analyses results are in general well agreed with the monitored values of soil displacements at the selected points. It is found also that there are obvious effects of the nearby excavation on the presumed piles in terms of displacements and bending moments.

  15. Electrical tomography monitoring of the EDZ during the excavation of the gallery Ga08 in the Mont Terri URL

    International Nuclear Information System (INIS)

    Nicollin, Florence; Gibert, Dominique; Lesparre, Nolwenn; Nussbaum, Christophe

    2010-01-01

    Document available in extended abstract form only. In the Mont Terri Underground Rock Laboratory, the excavation of the new gallery Ga08 provided a unique opportunity to monitor the excavation damaged zone (EDZ) in the Opalinus clay, at time scales ranging from hours to months. The excavation of the gallery Ga08 has started from the northern end of the URL and has progressed towards the South, ending by the junction with the end of the gallery Ga04. Several geophysical and geochemical methods were performed from the end face of the gallery Ga04, to observe the evolution of the rock mass located in the so-called EZ-G08 section during the progress of the excavation. Thus, electrical resistivity measurements were performed, with electrodes placed both on the Ga04 face and in boreholes perpendicular to the face. These experiments revealed a strong anisotropy of the electrical resistivity of the rock mass, and they allowed to study the temporal evolution of the electrical resistivity in the EDZ. An array of more than 700 electrodes was installed on the rough face according to a square mesh with a mean side of 30 cm. On each line of the mesh, the electrodes were equally spaced every 15 cm. 4 horizontal boreholes, 8 m long and 56 mm in diameter, were equipped with lines of 64 electrodes equally spaced every 5 cm. Finally, 2 groups of 4 boreholes, 1 m long and spaced about 20 cm, were equipped with lines of 16 electrodes equally spaced every 5 cm. Using the electrode array of the face, Wenner profiles were acquired along both the horizontal and the vertical lines, highlighting a strong anisotropy of electrical resistivity since the values depend on the direction in which they are measured. In order to characterize this anisotropy, other measurements were done using the array of the face and the lines of the short boreholes, with the so-called square array configuration where the electrodes are located at the corners of squares with different orientations. On the face

  16. Fuzzy mathematics method for theoretical analysis of ground movements due to underground excavation

    Energy Technology Data Exchange (ETDEWEB)

    Li Wenxiu (Changsa Research Institute of Mining and Metallurgy, Changsa (China))

    1991-07-01

    The analysis of the rock mass movements due to excavation operations is one of the many important problems of rock mass mechanics. It is difficult to calculate the ground movements due to underground excavation accurately because of the complexity of the problem. In this paper, the application is described of the fuzzy probability measures to the analysis of ground movements. Based on the definition of the fuzzy probability measure, the theories for both the two-dimensional and three-dimensional problems are developed and are applied to the analysis of ground movements due to underground excavation. 31 refs., 5 figs.

  17. Geological mappability of bored versus drill and blast excavations for radioactive waste repositories

    International Nuclear Information System (INIS)

    Nilsen, B.; Ozdemir, L.

    1992-01-01

    The issue of accurate geological mappability has been subject of intense debate in the selection of bored versus drill and blast excavation for radioactive waste repositories. This paper is intended to provide an assessment of the problems usually encountered in mappability on the basis of field experience from a large number of completed tunnels, mainly as part of the Norwegian hydropower projects. The main conclusion is that mapping in a mechanically excavated underground opening, with very few exceptions, reflects the in-situ conditions more accurately than mapping in a drill and blast tunnel. This is due to the overbreak effects of drill and blast excavation, primarily

  18. Assessment of surface and subsurface ground disturbance due to underground mining

    International Nuclear Information System (INIS)

    Khair, A.W.

    1994-01-01

    This paper presents highlights of the research carried out at West Virginia University in order to assess surface and subsurface ground disturbance due to longwall mining. Extensive instrumentation and measurements have been made over three longwall mines in northern West Virginia during a three-year period. Various monitoring techniques including full profile borehole extensometer, full profile borehole inclinometers, time domain reflectometry, sonic reflection technique, a unique mechanical grouting method, photographic and visual observations, standard surveying, and water-level measurements were utilized. The paper's emphasis is first on surface ground movement and its impact on integrity of surface ground and structures and second on type and magnitude of subsurface ground movements associated with mine geometry and geology. A subsidence prediction model based on implementation of both mechanisms of ground movement around the excavation and the geologic and geotechnical properties of the rock/coal surrounding the excavation has been developed. 8 refs., 14 figs., 1 tab

  19. Disturbance hydrology: Preparing for an increasingly disturbed future

    Science.gov (United States)

    Mirus, Benjamin B.; Ebel, Brian A.; Mohr, Christian H.; Zegre, Nicolas

    2017-01-01

    This special issue is the result of several fruitful conference sessions on disturbance hydrology, which started at the 2013 AGU Fall Meeting in San Francisco and have continued every year since. The stimulating presentations and discussions surrounding those sessions have focused on understanding both the disruption of hydrologic functioning following discrete disturbances, as well as the subsequent recovery or change within the affected watershed system. Whereas some hydrologic disturbances are directly linked to anthropogenic activities, such as resource extraction, the contributions to this special issue focus primarily on those with indirect or less pronounced human involvement, such as bark-beetle infestation, wildfire, and other natural hazards. However, human activities are enhancing the severity and frequency of these seemingly natural disturbances, thereby contributing to acute hydrologic problems and hazards. Major research challenges for our increasingly disturbed planet include the lack of continuous pre- and post-disturbance monitoring, hydrologic impacts that vary spatially and temporally based on environmental and hydroclimatic conditions, and the preponderance of overlapping or compounding disturbance sequences. In addition, a conceptual framework for characterizing commonalities and differences among hydrologic disturbances is still in its infancy. In this introduction to the special issue, we advance the fusion of concepts and terminology from ecology and hydrology to begin filling this gap. We briefly explore some preliminary approaches for comparing different disturbances and their hydrologic impacts, which provides a starting point for further dialogue and research progress.

  20. The antler finds at Bilzingsleben, excavations 1969-1993

    Directory of Open Access Journals (Sweden)

    Jürgen Vollbrecht

    2000-09-01

    Full Text Available 2820 antler remains from the Lower Palaeolithic site of Bilzingsleben, Thuringia, Germany (excavations 1969-1993 were the subject of detailed investigations. The two major goals were: 1.the consideration of taphonomic aspects 2.the critical evaluation of suggestions about artificial modifications to the antler material A detailed morphological description of the antler material provided the basis for the investigation. A prerequisite was the transfer of provenance data onto an x-y coordinate grid. Taphonomic aspects considered in this work include the relative frequencies of antler elements, estimates regarding the minimum number of individual deer, their age structure and seasonality, and, insofar as the condition of the antlers allowed, the classification of surface preservation, size classes and spatial distribution of the finds. The assemblage of antler finds, the majority of which seems to have come from red deer, is dominated by small fragments, mostly of tines. About one quarter of the finds are larger than 150 mm. Lower beams are more abundant than upper beams (e.g. crowns. Detailed counting, substantiated by systematic reconstruction, shows that in general the antlers are incomplete. After reconstruction of unshed antlers, it was possible to assess the minimum number of heads at 150 animals. Preliminary counting of postcranial and cranial (non antler cervid material points to about 70 cervids. Intentional accumulation of antlers by hominids can only be accepted as the reason for these disproportionate figures if other site formation processes can be ruled out. In fact, the correlation between sediment thickness and maximum antler densities, at least for finds smaller than 120mm, suggests that fluvial accumulation has to be taken into account as a probable element of the site formation history. Further, the mixture of unifacially abraded finds together with finds that exhibit bifacial abrasion points to a succession of changing fluvial

  1. Thermoluminescence dating of potteries excavated at Bhagwanpura and Mathura

    International Nuclear Information System (INIS)

    Nambi, K.S.V.; Sasidharan, R.; Soman, S.D.

    1979-01-01

    Thermoluminescence (TL) dating attempts were made on sherds of freshly excavated potteries from Bhagwanpura and Mathura sites. TL measurements were generally made from the fine grains of the potsherds; attempts were also made to separate the quartz inclusions from some of the potsherds and evaluate the TL. Dose-rate estimations were made from an analysis of natural radioactivity of the samples; TLD estimation of the environmental gamma dose-rate component was also attempted for the Mathura sites. The TL age estimates ranged between 2000 and 5000 years, B.P. for the Bhagwanpura series and between 1400 and 3000 years, B.P. for the Mathura series. Distinctly different trends were seen in the ages of graywares and redwares from Bhagwanpura: with increasing depth at the site, the grayware ages diminished (upto 1.3 depth beyond which they do not occur) while the redware ages remain the same upto 1.3 m depth and increase regularly beyond. In the case of eight Mathura potsherds for which the archaeologists' expected age values were available, a good to fair (+- 2 to +- 19%) agreement with the TL ages could be seen for four sherds. The estimated accuracies of the TL ages range between +- 9 to +- 19% and such a high value stems from the generous allowance made for all possible values of water content in pottery and soil over the archaeological period; if reasonable values for the actual degree of wetness could be provided, the TL ages can be estimated with accuracies of the order of +- 5%. (auth.)

  2. Prediction of seismic motion from contained and excavation nuclear detonations

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, R A [Environmental Research Corp., Alexandria, VA (United States)

    1970-05-15

    Capability to predict ground motions from nuclear events is developed on empirical and theoretical bases. Analyses of the experimental data provide basic predictions of peak particle motions and spectra which follow a (yield){sup m} times (distance){sup -n} relationship. The exponents on yield and distance are frequency dependent and derived from experiment and theory. Theory provides a physical understanding of the phenomena which allows extrapolation to off-NTS and atypical events. For example, yield scaling theory predicts significantly higher frequency motions and consequently larger ground accelerations for overburied events such as Gasbuggy, Rulison, Wasp and Wagon Wheel. These conclusions are observed from Gasbuggy (26 kt) which generated ground accelerations comparable to a normal buried event of 200 kt. This result is important in avoiding personal injury and assessing the probability of property damage. Conversely, theory predicts lower ground accelerations and seismic efficiencies for excavation events; these effects are observed from the Cabriolet and Schooner events and consequently predicted for the Sturtevant and Yawl events. With regard to the distance exponent, scattering theory determines a distance exponent which predicts greater attenuation effects on higher frequency motions. This trend is verified experimentally by regression analyses on a large number of data points which determine the distance exponent to range from -1.1 at low frequencies to -1.6 at high frequencies. Results indicate that cube root similarity scaling is not appropriate in the far field except possibly for peak particle displacements at the low frequency end of the spectrum. In addition to the source and transmission factors, current ground motion prediction techniques, on and off-NTS, take into account local site characteristics. Experimental evidence and theoretical models--layered media elastic theory, finite element modeling, and building response modeling

  3. Measuring radon flux across active faults: Relevance of excavating and possibility of satellite discharges

    Energy Technology Data Exchange (ETDEWEB)

    Richon, Patrick, E-mail: patrick.richon@cea.f [CEA, DAM, DIF, F-91297 Arpajon (France); Institut de Physique du Globe de Paris, Equipe Geologie des Systemes Volcaniques, 4 place Jussieu, UMR-7154 CNRS, F-75005 Paris (France); Klinger, Yann; Tapponnier, Paul [Institut de Physique du Globe de Paris, Equipe de Seismotectonique, 4 place Jussieu, UMR-7154 CNRS, F-75005 Paris (France); Li Chenxia [Institute of Geology, Chinese Earthquake Administration, P.O. Box 9803, 100029 Beijing (China); Van Der Woerd, Jerome [Institut de Physique du Globe de Strasbourg, CNRS, UMR-7516, INSU, Universite Louis Pasteur, Strasbourg I, 5 Rue Rene Descartes, F-67084 Strasbourg Cedex (France); Perrier, Frederic [Institut de Physique du Globe de Paris, Equipe de Geomagnetisme, 4 place Jussieu, UMR-7154 CNRS et Universite Paris 7 Denis-Diderot, F-75005 Paris (France)

    2010-02-15

    Searching for gas exhalation around major tectonic contacts raises important methodological issues such as the role of the superficial soil and the possible long distance transport. These effects have been studied on the Xidatan segment of the Kunlun Fault, Qinghai Province, China, using measurement of the radon-222 and carbon dioxide exhalation flux. A significant radon flux, reaching up to 538 +- 33 mBq m{sup -2} s{sup -1} was observed in a 2-3 m deep trench excavated across the fault. On the soil surface, the radon flux varied from 7 to 38 mBq m{sup -2} s{sup -1}, including on the fault trace, with an average value of 14.1 +- 1.0 mBq m{sup -2} s{sup -1}, similar to the world average. The carbon dioxide flux on the soil surface, with an average value of 12.9 +- 3.3 g m{sup -2} day{sup -1}, also remained similar to regular background values. It showed no systematic spatial variation up to a distance of 1 km from the fault, and no clear enhancement in the trench. However, a high carbon dioxide flux of 421 +- 130 g m{sup -2} day{sup -1} was observed near subvertical fractured phyllite outcrops on a hill located about 3 km north of the fault, at the boundary of the large-scale pull-apart basin associated with the fault. This high carbon dioxide flux was associated with a high radon flux of 607 +- 35 mBq m{sup -2} s{sup -1}. These preliminary results indicate that, at the fault trace, it can be important to measure gas flux at the bottom of a trench to remove superficial soil layers. In addition, gas discharges need to be investigated also at some distance from the main fault, in zones where morphotectonics features support associated secondary fractures.

  4. In situ radiological characterization to support a test excavation at a liquid waste disposal site

    International Nuclear Information System (INIS)

    Keele, B.D.; Bauer, R.G.; Blewett, G.R.; Troyer, G.L.

    1994-05-01

    An in situ radiological detection system was developed to support a small test excavation at a liquid waste disposal site at the Hanford Site in Richland, Washington. Instrumentation, calibration and comparisons to samples are discussed

  5. Energy-saving analysis of hydraulic hybrid excavator based on common pressure rail.

    Science.gov (United States)

    Shen, Wei; Jiang, Jihai; Su, Xiaoyu; Karimi, Hamid Reza

    2013-01-01

    Energy-saving research of excavators is becoming one hot topic due to the increasing energy crisis and environmental deterioration recently. Hydraulic hybrid excavator based on common pressure rail (HHEC) provides an alternative with electric hybrid excavator because it has high power density and environment friendly and easy to modify based on the existing manufacture process. This paper is focused on the fuel consumption of HHEC and the actuator dynamic response to assure that the new system can save energy without sacrificing performance. Firstly, we introduce the basic principle of HHEC; then, the sizing process is presented; furthermore, the modeling period which combined mathematical analysis and experiment identification is listed. Finally, simulation results show that HHEC has a fast dynamic response which can be accepted in engineering and the fuel consumption can be reduced 21% to compare the original LS excavator and even 32% after adopting another smaller engine.

  6. Exploration and excavation of shipwrecks in Goa and adjoining waters 2004-2005

    Digital Repository Service at National Institute of Oceanography (India)

    Anon

    As a part of the Institutional Project, 'Application of geological and geophysical methods in marine archaeology and underwater explorations' (STS 0004), exploration and excavation of shipwrecks have been carried out from Nov 24-Dec 02, 2005 for 06...

  7. Exploration and excavation of shipwrecks in Goa and adjoining waters 2005-2006

    Digital Repository Service at National Institute of Oceanography (India)

    As a part of the institutional project, 'Application of Geological and Geophysical methods in Marine Archaeology and Underwater Explorations, (OLP 0008)', exploration and excavation of shipwrecks have been carried out from 23 Jan 2006 to 21 Feb 2006...

  8. Calculation of the Chilling Requirement for Air Conditioning in the Excavation Roadway

    Directory of Open Access Journals (Sweden)

    Yueping Qin

    2015-10-01

    Full Text Available To effectively improve the climate conditions of the excavation roadway in coal mine, the calculation of the chilling requirement taking air conditioning measures is extremely necessary. The temperature field of the surrounding rock with moving boundary in the excavation roadway was numerically simulated by using finite volume method. The unstable heat transfer coefficient between the surrounding rock and air flow was obtained via the previous calculation. According to the coupling effects of the air flow inside and outside air duct, the differential calculation mathematical model of air flow temperature in the excavation roadway was established. The chilling requirement was calculated with the selfdeveloped computer program for forecasting the required cooling capacity of the excavation roadway. A good air conditioning effect had been observed after applying the calculated results to field trial, which indicated that the prediction method and calculation procedure were reliable.

  9. Sleep Disturbances in Mood Disorders.

    Science.gov (United States)

    Rumble, Meredith E; White, Kaitlin Hanley; Benca, Ruth M

    2015-12-01

    The article provides an overview of common and differentiating self-reported and objective sleep disturbances seen in mood-disordered populations. The importance of considering sleep disturbances in the context of mood disorders is emphasized, because a large body of evidence supports the notion that sleep disturbances are a risk factor for onset, exacerbation, and relapse of mood disorders. In addition, potential mechanisms for sleep disturbance in depression, other primary sleep disorders that often occur with mood disorders, effects of antidepressant and mood-stabilizing drugs on sleep, and the adjunctive effect of treating sleep in patients with mood disorders are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Modeling and stability of electro-hydraulic servo of hydraulic excavator

    Science.gov (United States)

    Jia, Wenhua; Yin, Chenbo; Li, Guo; Sun, Menghui

    2017-11-01

    The condition of the hydraulic excavator is complicated and the working environment is bad. The safety and stability of the control system is influenced by the external factors. This paper selects hydraulic excavator electro-hydraulic servo system as the research object. A mathematical model and simulation model using AMESIM of servo system is established. Then the pressure and flow characteristics are analyzed. The design and optimization of electro-hydraulic servo system and its application in engineering machinery is provided.

  11. Disturbance Hydrology: Preparing for an Increasingly Disturbed Future

    Science.gov (United States)

    Mirus, Benjamin B.; Ebel, Brian A.; Mohr, Christian H.; Zegre, Nicolas

    2017-12-01

    This special issue is the result of several fruitful conference sessions on disturbance hydrology, which started at the 2013 AGU Fall Meeting in San Francisco and have continued every year since. The stimulating presentations and discussions surrounding those sessions have focused on understanding both the disruption of hydrologic functioning following discrete disturbances, as well as the subsequent recovery or change within the affected watershed system. Whereas some hydrologic disturbances are directly linked to anthropogenic activities, such as resource extraction, the contributions to this special issue focus primarily on those with indirect or less pronounced human involvement, such as bark-beetle infestation, wildfire, and other natural hazards. However, human activities are enhancing the severity and frequency of these seemingly natural disturbances, thereby contributing to acute hydrologic problems and hazards. Major research challenges for our increasingly disturbed planet include the lack of continuous pre and postdisturbance monitoring, hydrologic impacts that vary spatially and temporally based on environmental and hydroclimatic conditions, and the preponderance of overlapping or compounding disturbance sequences. In addition, a conceptual framework for characterizing commonalities and differences among hydrologic disturbances is still in its infancy. In this introduction to the special issue, we advance the fusion of concepts and terminology from ecology and hydrology to begin filling this gap. We briefly explore some preliminary approaches for comparing different disturbances and their hydrologic impacts, which provides a starting point for further dialogue and research progress.

  12. Performance prediction of mechanical excavators from linear cutter tests on Yucca Mountain welded tuffs

    International Nuclear Information System (INIS)

    Gertsch, R.; Ozdemir, L.

    1992-09-01

    The performances of mechanical excavators are predicted for excavations in welded tuff. Emphasis is given to tunnel boring machine evaluations based on linear cutting machine test data obtained on samples of Topopah Spring welded tuff. The tests involve measurement of forces as cutters are applied to the rock surface at certain spacing and penetrations. Two disc and two point-attack cutters representing currently available technology are thus evaluated. The performance predictions based on these direct experimental measurements are believed to be more accurate than any previous values for mechanical excavation of welded tuff. The calculations of performance are predicated on minimizing the amount of energy required to excavate the welded tuff. Specific energy decreases with increasing spacing and penetration, and reaches its lowest at the widest spacing and deepest penetration used in this test program. Using the force, spacing, and penetration data from this experimental program, the thrust, torque, power, and rate of penetration are calculated for several types of mechanical excavators. The results of this study show that the candidate excavators will require higher torque and power than heretofore estimated

  13. Excavated pulmonary nodules: an unusual clinical presentation of lung metastasis in two cases

    Directory of Open Access Journals (Sweden)

    Lalya Issam

    2010-06-01

    Full Text Available Abstract Background Excavated pulmonary metastasis are rare. We present two cases of excavated pulmonary nodules proved to be metastases from osteosarcoma and gallblader lymphoma. Case presentation The first one is 39-year-old man in whom cholecystectomy made the diagnosis of primary non-Hodgkin's lymphoma of the gallbladder. He presented in chest CT scan excavated nodules that had been biopsied and confirmed the diagnosis of non hodgkin lymphoma. He underwent 8 courses of chemotherapy CHOP 21 with complete remission. The second one is an 21 years old man who presented a right leg osteoblastic osteosarcoma with only excavated pulmonary nodules in extension assessment. He had 3 courses of polychemotherapy API (doxorubicin, platinum, and ifosfamide with partial response. Unfortunately, he died following a septic shock. Review of the literature shows that excavated pulmonary nodules as metastasis are rare but we should consider this diagnosis every time we are in front of a cancer. Chest computed tomography is the best diagnosis imaging that could make this diagnosis. Differential diagnosis between benign and malignant bullous lesions is important because surgical excision affects survival in some malignancies. Conclusions Although pulmonary nodules are the most common cancer metastasis, a differential diagnosis of a concurrent primary malignancy should always be considered every time we have excavated lesions, even in patients with known malignant disease. Thorough chest evaluation is important, as multiple primary malignancies may occur concomitantly.

  14. The Use of Ground Penetrating Radar to extend the Results of Archaeological Excavation

    Science.gov (United States)

    Utsi, E.

    2009-04-01

    The condition of the Romano-British archaeological site in Wortley, Gloucestershire, UK is typical of sites of the period in that it has been heavily robbed out since it first fell into disuse. Building materials taken from the site have been re-used over the centuries to construct other local buildings. This makes both preservation of the extant remains and interpretation of the excavation problematic. Following the accidental discovery of the site in the 1980s, a programme of excavation was set in place. This excavation was run as a practical archaeological training school and, as a result, a wide range of archaeological and geophysical techniques were applied to the site. This included the introduction of Ground Penetrating Radar (GPR). The preliminary results of the first GPR used on site were not entirely satisfactory which led to the development of a new radar in the early 1990s, specifically developed for use on archaeological sites. The excavation and GPR results were published in a series of excavation reports [1] [2]. It was not possible to excavate fully for two reasons. Firstly the site crossed present day ownership boundaries and secondly the ownership of the excavation area changed. At this point the excavation was summarily terminated. In 2007, permission was given by the owner of an adjacent property to carry out a GPR survey over their land in order to derive additional information, if possible. An area survey was carried out in May 2007 with reduced transect spacing [3]. The radar data showed similar patterning to that of the original investigation i.e. substantial remains which had been subject to a high degree of post-occupational attrition. Time slices from the radar survey were matched to the principal excavation plans. It proved possible to deduce the full extent of certain partially excavated features, notably the courtyard and bath house. It was also possible to demonstrate that one part of the adjacent property did not contain similar

  15. The forecast of mining-induced seismicity and the consequent risk of damage to the excavation in the area of seismic event

    Directory of Open Access Journals (Sweden)

    Jan Drzewiecki

    2017-01-01

    Full Text Available The Central Mining Institute has developed a method for forecasting the amount of seismic energy created by tremors induced by mining operations. The results of geophysical measurements of S wave velocity anomalies in a rock mass or the results of analytic calculations of the values of pressure on the horizon of the elastic layers are used in the process of calculating the energy. The calculation program which has been developed and adopted has been modified over recent years and it now enables not only the prediction of the energy of dynamic phenomena induced by mining but also the forecasting of the devastating range of seismic shock. The results obtained from this calculation, usually presented in a more readable graphic form, are useful for the macroscopic evaluation of locations that are potential sources of seismic energy. Forecasting of the maximum energy of seismic shock without prior knowledge of the location of the shock's source, does not allow shock attenuation that results from, for example, a distance of tremor source from the excavation which will be affected by seismic energy, to be taken into consideration. The phenomena of energy dissipation, which is taken into account in the forecasts, create a new quality of assessment of threat to the excavation. The paper presents the principle of a method of forecasting the seismic energy of a shock and the risk of damage to the excavation as a result of the impact of its energy wave. The solution assumes that the source of the energy shock is a resilient layer in which the sum of the gravitational stresses, resulting from natural disturbances and those induced by the conducted or planned mining exploitation, is estimated. The proposed solution assumes a spherical model for the tremor source, for which seismic energy is forecasted as a function of the longwall advance and the elementary value of seismic energy destroying the excavation. Subsequently, the following are calculated for the

  16. Ionospheric disturbance dynamo

    International Nuclear Information System (INIS)

    Blanc, M.; Richmond, A.D.

    1980-01-01

    A numerical simulation study of the thermospheric winds produced by auroral heating during magnetic storms, and of their global dynamo effects, establishes the main features of the ionospheric disturbanc dynamo. Driven by auroral heating, a Hadley cell is created with equatorward winds blowing above about 120 km at mid-latitudes. The transport of angular momentum by these winds produces a subrotation of the midlatitude thermosphere, or westward motion with respect to the earth. The westward winds in turn drive equatorward Pedersen currents which accumulate charge toward the equator, resulting in the generation of a poleward electric field, a westward E x B drift, and an eastward current. When realistic local time conductivity variations are simulated, the eastward mid-latitude current is found to close partly via lower latitudes, resulting in an 'anti-Sq' type of current vortex. Both electric field and current at low latitudes thus vary in opposition to their normal quiet-day behavior. This total pattern of distrubance winds, electric fields, and currents is superimposed upon the background quiet-day pattern. When the neutral winds are artificially confined on the nightside, the basic pattern of predominantly westward E x B plasma drifts still prevails on the nightside but no longer extends into the dayside. Considerable observational evidence exists, suggesting that the ionospheric disturbance dynamo has an appreciable influence on storm-time ionospheric electric fields at middle and low latitudes

  17. RHYTHM DISTURBANCES DURING COLONOSCOPY

    Directory of Open Access Journals (Sweden)

    D. Jordanov

    2012-08-01

    Full Text Available Purpose: The purpose of this study is to assess the risk of inducing rhythm disturbances of the heart during colonoscopy.Patients and methods used: 80 patients had undergone colonoscopyper formed by two experienced specialists of endoscopy for the period from March to December 2011. The endoscopies were performed without premedication and sedation. Holter was placed on each patient one hour before the endoscopic examination, and the record continued one hour after the manipulation. The blood pressure was measured before, during and after the procedure.Results: During colonoscopy 25 patients (31,25% manifested rhythm disorders. In 15 patients (18,75% sinus tachycardia occurred. In 7 patients (8,75% suptraventricular extra systoles were observed and in 3 patients (3,75% - ventricular extra systoles. No ST-T changes were found. Highest values of the blood pressure were measured before and during the endoscopy, but the values did not exceed 160/105 mmHg. In 10 patients (12,5% a hypotensive reaction was observed, bur the values were not lower than 80/ 50. In 2 patients there was a short bradycardia with a heart frequency 50-55 /min.Conclusions: Our results showed that the rhythm disorders during lower colonoscopy occur in approximately 1/3 of the examined patients, there is an increase or decrease of the blood pressure in some patients, but that doesn’t require physician’s aid and the examination can be carried out safely without monitoring.

  18. Sleep disturbances and glucose homeostasis

    NARCIS (Netherlands)

    Barf, R. Paulien; Scheurink, Anton J.W.

    2011-01-01

    Sleep disturbances, induced by either lifestyle, shift work or sleeping disorders, have become more prevalent in our 24/7 Western society. Sleep disturbances are associated with impaired health including metabolic diseases such as obesity and type 2 diabetes. The question remains whether there is a

  19. Disturbance-mediated facilitation by an intertidal ecosystem engineer.

    Science.gov (United States)

    Wright, Jeffrey T; Gribben, Paul E

    2017-09-01

    Ecosystem engineers facilitate communities by providing a structural habitat that reduces abiotic stress or predation pressure for associated species. However, disturbance may damage or move the engineer to a more stressful environment, possibly increasing the importance of facilitation for associated communities. In this study, we determined how disturbance to intertidal boulders (i.e., flipping) and the subsequent movement of a structural ecosystem engineer, the tube-forming serpulid worm Galeolaria caespitosa, from the bottom (natural state, low abiotic stress) to the top (disturbed state, high abiotic stress) surface of boulders influenced the importance of facilitation for intertidal communities across two intertidal zones. Theory predicts stronger relative facilitation should occur in the harsher environments of the top of boulders and the high intertidal zone. To test this prediction, we experimentally positioned boulders with the serpulids either face up or face down for 12 months in low and high zones in an intertidal boulder field. There were very different communities associated with the different boulders and serpulids had the strongest facilitative effects on the more stressful top surface of boulders with approximately double the species richness compared to boulders lacking serpulids. Moreover, within the serpulid matrix itself there was also approximately double the species richness (both zones) and abundance (high zone only) of small invertebrates on the top of boulders compared to the bottom. The high relative facilitation on the top of boulders reflected a large reduction in temperature by the serpulid matrix on that surface (up to 10°C) highlighting a key role for modification of the abiotic environment in determining the community-wide facilitation. This study has demonstrated that disturbance and subsequent movement of an ecosystem engineer to a more stressful environment increased the importance of facilitation and allowed species to

  20. The TIMODAZ project: Thermal impact on the damaged zone around a radioactive waste disposal in clay host rocks

    International Nuclear Information System (INIS)

    XiangLing, L.

    2009-01-01

    The management of spent nuclear fuel and other long-lived radio active waste is an important environmental issue today. Disposal in deep clay geological formations is one of the promising options to dispose of these wastes. In this context, the related research activities in the Euratom Framework Programme of European Commission are continually taking on an enhanced significance. The TIMODAZ is one of the STREP projects (Specific Targeted Research Project) in the Sixth EURATOM Framework Programme and contributes to the research related to the geological disposal of radioactive waste. The consortium is composed of a strong multidisciplinary team involving both European radioactive waste management organizations and nuclear research institutes, universities, industrial partners as well as consultancy companies (SME's). Totally, 15 partners coming from 8 countries are involved with a total budget of about 4000k EURO. Being the coordinator (through the EURIDICE expertise group), SCK-CEN plays the leading role in the project. Meanwhile, SCK-CEN participates the research in different work packages covering the laboratory tests, in-situ tests as well as the integration of TIMODAZ results within the safety case. An important item for the long-term safety of underground disposal is the proper evaluation of the DZ (damaged zone) in the clay host rock. The DZ is defined here as the zone of host rock that experiences THMC (Thermo-Hydro-Mechanical-Chemical) modifications induced by the repository, with potential major changes in the transport properties for radionuclides. The DZ is first initiated during the repository construction. Its behaviour is dynamic, dependent on changing conditions that vary from the open-drift period, to initial closure period and to the entire heating-cooling cycle of the decaying waste. The early THMC disturbances created by the excavation, the operational phase and the thermal load might be the most severe transient that the repository will undergo

  1. Investigation of Influence Zones Induced by Shallow Tunnelling in Soft Soils

    NARCIS (Netherlands)

    Vu Minh, N.; Broere, W.; Bosch, J.W.

    2017-01-01

    The extent of the influence zone affected by shallow tunnelling depends on the value of volume loss which normally represents the amount of over-excavation and stress changes induced in the soil. This paper combines upper and lower estimates of volume loss for different soft soils and

  2. Sampling and Hydrogeology of the Vadose Zone Beneath the 300 Area Process Ponds

    International Nuclear Information System (INIS)

    Bjornstad, Bruce N.

    2004-01-01

    Four open pits were dug with a backhoe into the vadose zone beneath the former 300 Area Process Ponds in April 2003. Samples were collected about every 2 feet for physical, chemical, and/or microbiological characterization. This reports presents a stratigraphic and geohydrologic summary of the four excavations

  3. Myostatin and carbohydrate disturbances.

    Science.gov (United States)

    Assyov, Yavor S; Velikova, Tsvetelina V; Kamenov, Zdravko A

    2017-05-01

    Purpose/aim of the study: Myostatin is a myokine that has been shown to inhibit muscle growth and to have potentially deleterious effects on metabolism. The aim of the current study was to compare its circulating serum levels in subjects from the whole spectrum of carbohydrate disturbances leading to diabetes. A total of 159 age-, sex-, and BMI-matched subjects participated in the study - 50 had normal glucose tolerance (NGT), 60 had prediabetes (PreDM), and 49 had type 2 diabetes mellitus (T2D). Oral glucose tolerance testing was used to determine glucose tolerance. Serum myostatin was quantified by means of ELISA. Circulating serum myostatin levels were highest in patients with T2D, lower in subjects with prediabetes, and lowest in subjects with normoglycemia (all p Myostatin was shown to be positively associated with fasting plasma glucose, HOMA-IR, hepatic enzymes, uric acid, and FINDRISC questionnaire scores in both sexes. ROC analyses determined circulating myostatin levels to be of value for differentiating subjects with T2D (AUC = 0.72, p = 0.002 in men; AUC = 0.70, p = 0.004 in women) in the study population. After adjustment for potential confounders, in a multiple binary logistic regression model, serum myostatin added further information to traditional risk estimates in distinguishing subjects with T2D. Serum myostatin levels are higher with deterioration of carbohydrate tolerance. Furthermore, circulating myostatin is positively associated with traditional biochemical estimates of poor metabolic health. These data add to evidence of the involvement of this myokine in the pathogenesis of T2D.

  4. Lucas Heights buffer zone: plan of management

    International Nuclear Information System (INIS)

    1986-01-01

    This plan is being used by the Commission as a guide for its management of the Lucas Heights buffer zone, which is essentially a circular area having a 1-6 km radius around the HIFAR reactor. Aspects covered by this plan include past uses, current use, objectives for buffer zone land management, emergency evacuation, resource conservation, archaeology, fire, access, rehabilitation of disturbed areas, resource management and plan implementation

  5. SLOPE STABILITY EVALUATION AND EQUIPMENT SETBACK DISTANCES FOR BURIAL GROUND EXCAVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    MCSHANE DS

    2010-03-25

    After 1970 Transuranic (TRU) and suspect TRU waste was buried in the ground with the intention that at some later date the waste would be retrieved and processed into a configuration for long term storage. To retrieve this waste the soil must be removed (excavated). Sloping the bank of the excavation is the method used to keep the excavation from collapsing and to provide protection for workers retrieving the waste. The purpose of this paper is to document the minimum distance (setback) that equipment must stay from the edge of the excavation to maintain a stable slope. This evaluation examines the equipment setback distance by dividing the equipment into two categories, (1) equipment used for excavation and (2) equipment used for retrieval. The section on excavation equipment will also discuss techniques used for excavation including the process of benching. Calculations 122633-C-004, 'Slope Stability Analysis' (Attachment A), and 300013-C-001, 'Crane Stability Analysis' (Attachment B), have been prepared to support this evaluation. As shown in the calculations the soil has the following properties: Unit weight 110 pounds per cubic foot; and Friction Angle (natural angle of repose) 38{sup o} or 1.28 horizontal to 1 vertical. Setback distances are measured from the top edge of the slope to the wheels/tracks of the vehicles and heavy equipment being utilized. The computer program utilized in the calculation uses the center of the wheel or track load for the analysis and this difference is accounted for in this evaluation.

  6. Energy substrate used by workers of leaf-cutting ants during nest excavation

    Directory of Open Access Journals (Sweden)

    Roberto S. Camargo

    2013-12-01

    Full Text Available Energy substrate used by workers of leaf-cutting ants during nest excavation. In this study we aimed to ascertain whether leaf-cutting ant workers lose body reserves (fat or sugars as a function of nest excavation. For each treatment, we isolated 10 workers of Atta sexdens into two experimental groups, Control (C- without excavation and Soil (S- with excavation, which were kept for different time intervals (0, 24, 48 or 72 hours, totaling 700 tested workers. We then determined the concentration of soluble carbohydrates and total lipid content in them. The total carbohydrates were determined colorimetrically, based on the reaction between carbohydrates and sulfuric acid-phenol. For determination of lipids, the insects were immersed in organic solvent until they reached a constant weight. Our results showed that carbohydrates are consumed during nest excavation activities. In the experimental groups S24, S48 and S72, there was an average reduction of 5.82 (20.42%, 14.31 (44.96% and 13.27 (43.96% µ.mg-1 in soluble sugar when compared with the experimental groups that did not excavate. Furthermore, the lipids were not used during this activity. With respect to dry mass of the workers, their values were C0 = 8%, C24 = 10.4%, C48 = 9.2%, C72 = 10%, S24 = 9.2%, S48 = 8.7% and S72 = 8.5%. Our results show experimentally that the source of energy for nest excavation is carbohydrates, whereas lipids are conserved for other activities.

  7. Sound Zones

    DEFF Research Database (Denmark)

    Møller, Martin Bo; Olsen, Martin

    2017-01-01

    Sound zones, i.e. spatially confined regions of individual audio content, can be created by appropriate filtering of the desired audio signals reproduced by an array of loudspeakers. The challenge of designing filters for sound zones is twofold: First, the filtered responses should generate...... an acoustic separation between the control regions. Secondly, the pre- and post-ringing as well as spectral deterioration introduced by the filters should be minimized. The tradeoff between acoustic separation and filter ringing is the focus of this paper. A weighted L2-norm penalty is introduced in the sound...

  8. Physical soil properties and slope treatments effects on hydraulic excavator productivity for forest road construction.

    Science.gov (United States)

    Parsakho, Aidin; Hosseini, Seyed Ataollah; Jalilvand, Hamid; Lotfalian, Majid

    2008-06-01

    Effects of moisture, porosity and soil bulk density properties, grubbing time and terrain side slopes on pc 220 komatsu hydraulic excavator productivity were investigated in Miana forests road construction project which located in the northern forest of Iran. Soil moisture and porosity determined by samples were taken from undisturbed soil. The elements of daily works were measured with a digital stop watch and video camera in 14 observations (days). The road length and cross section profiles after each 20 m were selected to estimate earthworks volume. Results showed that the mean production rates for the pc 220 komatsu excavators were 60.13 m3 h(-1) and earthwork 14.76 m h(-1) when the mean depth of excavation or cutting was 4.27 m3 m(-1), respectively. There was no significant effects (p = 0.5288) from the slope classes' treatments on productivity, whereas grubbing time, soil moisture, bulk density and porosity had significantly affected on excavator earthworks volume (p < 0.0001). Clear difference was showed between the earthwork length by slope classes (p = 0.0060). Grubbing time (p = 0.2180), soil moisture (p = 0.1622), bulk density (p = 0.2490) and porosity (p = 0.2159) had no significant effect on the excavator earthworks length.

  9. Design of the human computer interface on the telerobotic small emplacement excavator

    International Nuclear Information System (INIS)

    Thompson, D.H.; Killough, S.M.; Burks, B.L.; Draper, J.V.

    1995-01-01

    The small emplacement excavator (SEE) is a ruggedized military vehicle with backhoe and front loader used by the U.S. Army for explosive ordinance disposal (EOD) and general utility excavation activities. This project resulted from a joint need in the U.S. Department of Energy (DOE) for a remote controlled excavator for buried waste operations and the U.S. Department of Defense for remote EOD operations. To evaluate the feasibility of removing personnel from the SEE vehicle during high-risk excavation tasks, a development and demonstration project was initiated. Development of a telerobotic SEE (TSEE) was performed by the Oak Ridge National Laboratory in a project funded jointly by the U.S. Army and the DOE. The TSEE features teleoperated driving, a telerobotic backhoe with four degrees of freedom, and a teleoperated front loader with two degrees of freedom on the bucket. Remote capabilities include driving (forward, reverse, brake, steering), power takeoff shifting to enable digging modes, deploying stabilizers, excavation, and computer system booting

  10. In Appreciation of Claude Warren and Susan Rose's "William Pengelly's Techniques of Archaeological Excavation"

    Directory of Open Access Journals (Sweden)

    David L. Browman

    1997-11-01

    Full Text Available The short (40 pages pamphlet by Warren and Rose (1994 provides the answer to a complex question regarding credit for an important archaeological methodology, stratigraphic excavation. Let me set the stage for this appreciation. Continuing research on the beginnings of stratigraphic excavations in North America (Browman and Givens 1996, I sought the origins of the idea of actually excavating by strata, rather than post-facto interpretation, seen in North American as early as 1895 in the work of Henry Chapman Mercer, but not really introduced into the repertoire of American techniques until the work of Gamio, Kidder and Nelson between 1911 and 1914. The roots of the latter three seemed to lie with individuals such as Reisner, Boas, Uhle, who in turn seemed to rely on Hugo Obennaier, Gabriel de Mortillet, Marcellin Boule, and perhaps Pitt-Rivers, while Mercer's work could be traced to Boule and Albert Gaudry. Doggedly following back the roots, I found that Chapman (1989 could make a reasonable case that Pitt-Rivers had actually learned of the idea of strati­graphic excavation from Evans, Prestwich, and Lubbock, from the British scientists working with the Upper and Middle Paleolithic excavations during 1858-1868.

  11. Physico-chemical properties of excavated plastic from landfill mining and current recycling routes.

    Science.gov (United States)

    Canopoli, L; Fidalgo, B; Coulon, F; Wagland, S T

    2018-06-01

    In Europe over 5.25 billion tonnes of waste has been landfilled between 1995 and 2015. Among this large amount of waste, plastic represents typically 5-25 wt% which is significant and has the potential to be recycled and reintroduced into the circular economy. To date there is still however little information available of the opportunities and challenges in recovering plastics from landfill sites. In this review, the impacts of landfill chemistry on the degradation and/or contamination of excavated plastic waste are analysed. The feasibility of using excavated plastic waste as feedstock for upcycling to valuable chemicals or liquid fuels through thermochemical conversion is also critically discussed. The limited degradation that is experienced by many plastics in landfills (>20 years) which guarantee that large amount is still available is largely due to thermooxidative degradation and the anaerobic conditions. However, excavated plastic waste cannot be conventionally recycled due to high level of ash, impurities and heavy metals. Recent studies demonstrated that pyrolysis offers a cost effective alternative option to conventional recycling. The produced pyrolysis oil is expected to have similar characteristics to petroleum diesel oil. The production of valuable product from excavated plastic waste will also increase the feasibility of enhanced landfill mining projects. However, further studies are needed to investigate the uncertainties about the contamination level and degradation of excavated plastic waste and address their viability for being processed through pyrolysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. A study on in-situ measuring method and modeling technique of an unsaturated zone

    Energy Technology Data Exchange (ETDEWEB)

    Imai, Hisashi [Hazama Corp., Tsukuba, Ibaraki (Japan). Technical Research Inst.; Amemiya, Kiyoshi; Nishida, Kaoru; Lin, Weiren; Lei, Xinglin

    1997-03-01

    It is generally considered that an unsaturated zone is generated in the vicinity of a drift after excavation. In such a zone, invasion of air containing oxygen possibly changes geochemical environment (redox condition) of the rock mass. However, no measurement technique for quantitative understanding of this unsaturated zone is currently available. This study has been started to develop the measuring method in the several years. This year, fundamental information has been obtained through analysis, laboratory experiments using homogeneous rock samples and field measurement described below. (1) experiments on the mechanism of undersaturation in rock. (2) experiments on the measuring method of the extend of unsaturated zone. (author)

  13. Apparatus and method of measuring fluctuations of excavated mud amount in a slurry line

    International Nuclear Information System (INIS)

    Yamazaki, H.; Kubota, R.; Uchida, Y.; Kasuya, T.; Seki, N.

    1976-01-01

    An apparatus and method for measuring fluctuations in amount of soil in slurry or soil-containing fluid line is described. Each system of feeding the slurry typically to tunneling face and draining it therefrom in the slurry line is provided with gamma-ray densimeter and electromagnetic flow-meter to obtain respective amounts of soil only (dry-soil amounts) in the slurry flowing through each of said systems from respective outputs of these meters in each system, so that actually excavated amount through ground layer of a shielded excavator at the tunneling face can be measured by the difference between the respective dry-soil amounts. The excavator will be advanced depending on this measured amount

  14. The evolution of competitive settlement strategies in Fijian prehistory : results of excavations and radiometric dating

    International Nuclear Information System (INIS)

    Field, J.S.

    2003-01-01

    A series of excavations were completed between June 2001 and March 2002 in the Fiji Islands. The goal of this research was to investigate the evolution of competitive settlement strategies in Fijian prehistory from an archaeological and evolutionary ecological perspective. Twelve sites were excavated and mapped in the Sigatoka Valley, located in the southwestern corner of the main island of Viti Levu. Excavations were focused on determining the chronology of fortifications in the region, and the collected samples were compared to expectations based on GIS-based analyses of land productivity and historical documents pertaining to late-period warfare. Over four hundred archaeological sites have been identified in the Sigatoka Valley, and of these roughly one-third are purely defensive in configuration, with no immediate access to water or arable land. The Waikato Archaeological Dating Fund provided four radiometric dates for three defensive sites, and one site associated with a production area. (author). 6 refs., 1 fig

  15. Alternative cytoskeletal landscapes: cytoskeletal novelty and evolution in basal excavate protists

    Science.gov (United States)

    Dawson, Scott C.; Paredez, Alexander R.

    2016-01-01

    Microbial eukaryotes encompass the majority of eukaryotic evolutionary and cytoskeletal diversity. The cytoskeletal complexity observed in multicellular organisms appears to be an expansion of components present in genomes of diverse microbial eukaryotes such as the basal lineage of flagellates, the Excavata. Excavate protists have complex and diverse cytoskeletal architectures and life cycles – essentially alternative cytoskeletal “landscapes” – yet still possess conserved microtubule- and actin-associated proteins. Comparative genomic analyses have revealed that a subset of excavates, however, lack many canonical actin-binding proteins central to actin cytoskeleton function in other eukaryotes. Overall, excavates possess numerous uncharacterized and “hypothetical” genes, and may represent an undiscovered reservoir of novel cytoskeletal genes and cytoskeletal mechanisms. The continued development of molecular genetic tools in these complex microbial eukaryotes will undoubtedly contribute to our overall understanding of cytoskeletal diversity and evolution. PMID:23312067

  16. The Method of Validity Evaluation of Hard Coal Excavation in Residual Seam Parts

    Science.gov (United States)

    Wodarski, Krzysztof; Bijańska, Jolanta; Gumiński, Adam

    2017-12-01

    The excavation of residual seam parts should be justified by positive assessment of the purposefulness, technical feasibility and economic effectiveness. The results of the profitability evaluation are crucial in a decision making process. The excavation of residual seam parts, even if it is possible from a technical point of view, should not be implemented if it is economically inefficient or when accompanied by a very high risk of non-recovery of invested capital resources. The article presents the evaluation method of possibilities of excavating hard coal from residual seam parts, and the example of its use in one of collieries in the Upper Silesian Coal Basin. Working in line with the developed method, allows to indicate the variant of residual seam part exploitation, which is feasible to implement from a technical point of view, and which is characterized by the highest economic effectiveness and lowest risk.

  17. Using Landsat time series for characterizing forest disturbance dynamics in the coupled human and natural systems of Central Europe.

    Science.gov (United States)

    Senf, Cornelius; Pflugmacher, Dirk; Hostert, Patrick; Seidl, Rupert

    2017-08-01

    Remote sensing is a key information source for improving the spatiotemporal understanding of forest ecosystem dynamics. Yet, the mapping and attribution of forest change remains challenging, particularly in areas where a number of interacting disturbance agents simultaneously affect forest development. The forest ecosystems of Central Europe are coupled human and natural systems, with natural and human disturbances affecting forests both individually and in combination. To better understand the complex forest disturbance dynamics in such systems, we utilize 32-year Landsat time series to map forest disturbances in five sites across Austria, the Czech Republic, Germany, Poland, and Slovakia. All sites consisted of a National Park and the surrounding forests, reflecting three management zones of different levels of human influence (managed, protected, strictly protected). This allowed for a comparison of spectral, temporal, and spatial disturbance patterns across a gradient from natural to coupled human and natural disturbances. Disturbance maps achieved overall accuracies ranging from 81% to 93%. Disturbance patches were generally small, with 95% of the disturbances being smaller than 10 ha. Disturbance rates ranged from 0.29% yr -1 to 0.95% yr -1 , and differed substantially among management zones and study sites. Natural disturbances in strictly protected areas were longer in duration (median of 8 years) and slightly less variable in magnitude compared to human-dominated disturbances in managed forests (median duration of 1 year). However, temporal dynamics between natural and human-dominated disturbances showed strong synchrony, suggesting that disturbance peaks are driven by natural events affecting managed and unmanaged areas simultaneously. Our study demonstrates the potential of remote sensing for mapping forest disturbances in coupled human and natural systems, such as the forests of Central Europe. Yet, we also highlight the complexity of such systems in

  18. Apparatus and method for large tunnel excavation in soft and incompetent rock or ground

    International Nuclear Information System (INIS)

    Altseimer, J.H.; Hanold, R.J.

    1975-01-01

    A tunneling machine is described for producing large tunnels in soft rock or wet, clayey, unconsolidated or bouldery earth by simultaneously detaching the tunnel core by thermal melting a boundary kerf into the tunnel face and forming a supporting excavation wall liner by deflecting the molten materials against the excavation walls to provide, when solidified, a continuous wall supporting liner, and detaching the tunnel face circumscribed by the kerf with powered mechanical earth detachment means and in which the heat required for melting the kerf and liner material is provided by a compact nuclear reactor. (U.S.)

  19. Selection of Excavators for Earth Work on the Basis of their Performance

    Science.gov (United States)

    Vondráčková, Terezie; Voštová, Věra

    2017-10-01

    For the specific construction of the reconstruction of the railway section Ostrov nad Oslavou and Žďár nad Sázavou will be done removed the railway superstructure and the partial adjustment of the substructure including drainage. For the earthwork will be used excavators of the company Komatsu, with the possibility of adjustment of parameters of the working tool - the length of the bracket and the volume of the shovel. The determined value will be purely indicative, as it does not affect how the operator of the excavator handles the discharge of cargo means.

  20. Plan for the testing of radiation measurement instrumentation intended for use at an excavation site

    International Nuclear Information System (INIS)

    Gehrke, R.J.

    1994-11-01

    This plan describes performance tests to be made with ionizing radiation measurement instrumentation designed and built for in-field assay at an excavation site. One instrument measures gross gamma-ray and neutron fields and the other identifies gamma-ray emitting radionuclides and also is capable of assaying for selected hazardous materials. These instruments will be operationally tested to verify that original specifications have been met and performance tested to establish and verify that they have the potential to function as intended at an excavation site

  1. National Advanced Drilling and Excavation Technologies Institute. Status report, March 1997

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, C.

    1997-12-31

    The National Advanced Drilling and Excavation Technologies (NADET) program is intended to pool support, talent, and technologies of the industries dependent upon drilling and excavation technologies to initiate, coordinate, and sustain programs capable of developing substantial technological advances. The NADET Institute has been funded by the DOE Office of Geothermal Technologies and is now supporting seven projects aimed at advanced geothermal drilling technologies. The Institute seeks to broaden its base of funding and technological support from both government and industry sources. Encouraging progress has been made with the support of dues-paying industrial members and industrial sponsorship of a substantial drilling research study.

  2. Coastal zone

    International Nuclear Information System (INIS)

    2002-01-01

    The report entitled Climate Change Impacts and Adaptation : A Canadian Perspective, presents a summary of research regarding the impacts of climate change on key sectors over the past five years as it relates to Canada. This chapter on the coastal zone focuses on the impact of climate change on Canada's marine and Great Lakes coasts with tips on how to deal with the impacts associated with climate change in sensitive environments. This report is aimed at the sectors that will be most affected by adaptation decisions in the coastal zone, including fisheries, tourism, transportation and water resources. The impact of climate change in the coastal zone may include changes in water levels, wave patterns, storm surges, and thickness of seasonal ice cover. The Intergovernmental Panel on Climate Change projects global average sea level will rise between 9 and 88 centimetres between 1990 to 2100, but not all areas of Canada will experience the same rate of future sea level change. The main physical impact would be shoreline change that could result in a range of biophysical and socio-economic impacts, some beneficial, some negative. The report focuses on issues related to infrastructure and communities in coastal regions. It is noted that appropriate human adaptation will play a vital role in reducing the extent of potential impacts by decreasing the vulnerability of average zone to climate change. The 3 main trends in coastal adaptation include: (1) increase in soft protection, retreat and accommodation, (2) reliance on technology such as geographic information systems to manage information, and (3) awareness of the need for coastal adaptation that is appropriate for local conditions. 61 refs., 7 figs

  3. U Plant Geographic Zone Cleanup Prototype

    International Nuclear Information System (INIS)

    Romine, L.D.; Leary, K.D.; Lackey, M.B.; Robertson, J.R.

    2006-01-01

    The U Plant geographic zone (UPZ) occupies 0.83 square kilometers on the Hanford Site Central Plateau (200 Area). It encompasses the U Plant canyon (221-U Facility), ancillary facilities that supported the canyon, soil waste sites, and underground pipelines. The UPZ cleanup initiative coordinates the cleanup of the major facilities, ancillary facilities, waste sites, and contaminated pipelines (collectively identified as 'cleanup items') within the geographic zone. The UPZ was selected as a geographic cleanup zone prototype for resolving regulatory, technical, and stakeholder issues and demonstrating cleanup methods for several reasons: most of the area is inactive, sufficient characterization information is available to support decisions, cleanup of the high-risk waste sites will help protect the groundwater, and the zone contains a representative cross-section of the types of cleanup actions that will be required in other geographic zones. The UPZ cleanup demonstrates the first of 22 integrated zone cleanup actions on the Hanford Site Central Plateau to address threats to groundwater, the environment, and human health. The UPZ contains more than 100 individual cleanup items. Cleanup actions in the zone will be undertaken using multiple regulatory processes and decision documents. Cleanup actions will include building demolition, waste site and pipeline excavation, and the construction of multiple, large engineered barriers. In some cases, different cleanup actions may be taken at item locations that are immediately adjacent to each other. The cleanup planning and field activities for each cleanup item must be undertaken in a coordinated and cohesive manner to ensure effective execution of the UPZ cleanup initiative. The UPZ zone cleanup implementation plan (ZCIP) [1] was developed to address the need for a fundamental integration tool for UPZ cleanup. As UPZ cleanup planning and implementation moves forward, the ZCIP is intended to be a living document that will

  4. Nest enlargement in leaf-cutting ants: relocated brood and fungus trigger the excavation of new chambers.

    Directory of Open Access Journals (Sweden)

    Daniela Römer

    Full Text Available During colony growth, leaf-cutting ants enlarge their nests by excavating tunnels and chambers housing their fungus gardens and brood. Workers are expected to excavate new nest chambers at locations across the soil profile that offer suitable environmental conditions for brood and fungus rearing. It is an open question whether new chambers are excavated in advance, or will emerge around brood or fungus initially relocated to a suitable site in a previously-excavated tunnel. In the laboratory, we investigated the mechanisms underlying the excavation of new nest chambers in the leaf-cutting ant Acromyrmex lundi. Specifically, we asked whether workers relocate brood and fungus to suitable nest locations, and to what extent the relocated items trigger the excavation of a nest chamber and influence its shape. When brood and fungus were exposed to unfavorable environmental conditions, either low temperatures or low humidity, both were relocated, but ants clearly preferred to relocate the brood first. Workers relocated fungus to places containing brood, demonstrating that subsequent fungus relocation spatially follows the brood deposition. In addition, more ants aggregated at sites containing brood. When presented with a choice between two otherwise identical digging sites, but one containing brood, ants' excavation activity was higher at this site, and the shape of the excavated cavity was more rounded and chamber-like. The presence of fungus also led to the excavation of rounder shapes, with higher excavation activity at the site that also contained brood. We argue that during colony growth, workers preferentially relocate brood to suitable locations along a tunnel, and that relocated brood spatially guides fungus relocation and leads to increased digging activity around them. We suggest that nest chambers are not excavated in advance, but emerge through a self-organized process resulting from the aggregation of workers and their density

  5. Geophysical monitoring of the EDZ during a gallery excavation in the Opalinus clay of the Mont Terri URL: anomalies of noble gases and self-potential associated with fractures and fluid dynamics in a horizontal borehole

    International Nuclear Information System (INIS)

    Maineult, A.; Mahiouz, K.; Lesparre, N.; Thomas, B.; Lavielle, B.; Nussbaum, C.; Wieczorek, K.; Gibert, D.; Kergosien, B.; Nicollin, F.

    2012-01-01

    . 13 days later, the major part of the electrodes had encountered similar positive change. No change occurred for the electrodes located in the shaly facies. The dynamic variations of SP with respect to the static anomaly reveal 8 localised anomalies occurring just after the drilling operations, all located in the sandy facies. The positive SP anomaly and the observed He loss in the first two meters has to be linked to the EDZ that developed in gallery Ga04 and to the related de-saturated zone, rather than to the transition between the shaly and sandy facies. The unusual observed He concentration profile through the EDZ is due to the presence of tectonic fractures within the EDZ which perturb the regular degassing of helium. The low He content values between 0 and 2 m should result from gas transfer between the clay-stone and the shallow reactivated fault system. The presence of air at atmospheric pressure in the reactivated fracture network induced suction associated with He depletion and noble gas enrichment. The dynamic SP anomalies can be the response to localized inflows of pore water into borehole BEZ-G5, limited in time, and supposed to come from the immediate vicinity of the boreholes. In Opalinus Clay, the mechanisms of expulsion of the water from the pores may be related to the extensional fracturing by unloading of joints and to the brittle reactivation of pre-existing fractures. The pore pressure measured in the close, packed-off boreholes was disturbed by the drilling operations, followed by a long-term re-equilibration. A downward flow could thus have occurred in the upper-part of the rock mass, in particular towards borehole BEZ-G5. The free water expulsed from the rock in the vicinity of the new boreholes circulates through the complex fracture network that serves as flow-paths, provided it is connected. The noble gas concentrations and initial SP anomaly thus evidenced that the first two meters of the rock mass behind the end-face of gallery Ga04

  6. Computer aided analysis of disturbances

    International Nuclear Information System (INIS)

    Baldeweg, F.; Lindner, A.

    1986-01-01

    Computer aided analysis of disturbances and the prevention of failures (diagnosis and therapy control) in technological plants belong to the most important tasks of process control. Research in this field is very intensive due to increasing requirements to security and economy of process control and due to a remarkable increase of the efficiency of digital electronics. This publication concerns with analysis of disturbances in complex technological plants, especially in so called high risk processes. The presentation emphasizes theoretical concept of diagnosis and therapy control, modelling of the disturbance behaviour of the technological process and the man-machine-communication integrating artificial intelligence methods, e.g., expert system approach. Application is given for nuclear power plants. (author)

  7. Managing Sleep Disturbances in Cirrhosis

    Directory of Open Access Journals (Sweden)

    Xun Zhao

    2016-01-01

    Full Text Available Sleep disturbances, particularly daytime sleepiness and insomnia, are common problems reported by patients suffering from liver cirrhosis. Poor sleep negatively impacts patients’ quality of life and cognitive functions and increases mortality. Although sleep disturbances can be an early sign of hepatic encephalopathy (HE, many patients without HE still complain of poor quality sleep. The pathophysiology of these disturbances is not fully understood but is believed to be linked to impaired hepatic melatonin metabolism. This paper provides an overview for the clinician of common comorbidities contributing to poor sleep in patients with liver disease, mainly restless leg syndrome and obstructive sleep apnea. It discusses nondrug and pharmacologic treatment options in these patients, such as the use of light therapy and histamine (H1 blockers.

  8. Probabilistic analysis of soil : Diaphragm wall friction used for value engineering of deep excavation, north/south metro Amsterdam

    NARCIS (Netherlands)

    Buykx, S.M.; Delfgaauw, S.; Bosch, J.W.

    2009-01-01

    The excavation of deep building pits often requires a check against failure by uplift of low permeability ground layers below excavation level. Whenever the weight of these soil layers is less than the pore-water pressure underneath, measures to resist buoyancy are to be considered. The measures

  9. A Comparative Evaluation of the Efficacy of Different Caries Excavation Techniques in reducing the Cariogenic Flora: An in vivo Study.

    Science.gov (United States)

    Hassan, Afrah Fatima; Yadav, Gunjan; Tripathi, Abhay Mani; Mehrotra, Mridul; Saha, Sonali; Garg, Nishita

    2016-01-01

    Caries excavation is a noninvasive technique of caries removal with maximum preservation of healthy tooth structure. To compare the efficacy of three different caries excavation techniques in reducing the count of cariogenic flora. Sixty healthy primary molars were selected from 26 healthy children with occlusal carious lesions without pulpal involvement and divided into three groups in which caries excavation was done with the help of (1) carbide bur; (2) polymer bur using slow-speed handpiece; and (3) ultrasonic tip with ultrasonic machine. Samples were collected before and after caries excavation for microbiological analysis with the help of sterile sharp spoon excavator. Samples were inoculated on blood agar plate and incubated at 37°C for 48 hours. After bacterial cultivation, the bacterial count of Streptococcus mutans was obtained. All statistical analysis was performed using SPSS 13 statistical software version. Kruskal-Wallis analysis of variance, Wilcoxon matched pairs test, and Z test were performed to reveal the statistical significance. The decrease in bacterial count of S. mutans before and after caries excavation was significant (p flora, while ultrasonic tip showed almost comparable results, while polymer bur showed least reduction in cariogenic flora after caries excavation. Hassan AF, Yadav G, Tripathi AM, Mehrotra M, Saha S, Garg N. A Comparative Evaluation of the Efficacy of Different Caries Excavation Techniques in reducing the Cariogenic Flora: An in vivo Study. Int J Clin Pediatr Dent 2016;9(3):214-217.

  10. Excavating Silences and Tensions of Agency|Passivity in Science Education Reform

    Science.gov (United States)

    Rivera Maulucci, Maria S.

    2010-01-01

    I reflect on studies by Rodriguez and Carlone, Haun-Frank, and Kimmel to emphasize the ways in which they excavate silences in the science education literature related to linguistic and cultural diversity and situating the problem of reform in teachers rather than contextual factors, such as traditional schooling discourses and forces that serve…

  11. Assessment of exposure to manganese in welding operations during the assembly of heavy excavation machinery accessories.

    Science.gov (United States)

    Smargiassi, A; Baldwin, M; Savard, S; Kennedy, G; Mergler, D; Zayed, J

    2000-10-01

    Welder exposure to metals in various industrial sectors is poorly characterized. We had the opportunity to carry out an exploratory study to characterize manganese exposure in welding operations in a recently established Quebec factory that assembled accessories for heavy excavation machinery. Ten workers were sampled for total manganese for at least two consecutive days out of three followed by two consecutive days for respirable manganese (with a size selective sampler with a median cut-off of 4 microns), during a typical week in the summer of 1998. Parts being welded were characterized as large or small. Small parts were those being welded on tables during subassembly. Workers were divided into two groups according to the parts they were welding. Seventy-eight percent of the total manganese exposure levels of welding operations during the assembly of large accessories of heavy excavation machinery exceeded the manganese American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 0.20 mg/m3 (GM 0.24 mg/m3, n = 14) while none exceeded the TLV during the assembly of small pieces (GM 0.06 mg/m3, n = 8). Welding operations during the assembly of large heavy excavation machinery accessories may pose a significant health hazard. Considering the importance of task-related variables affecting exposure among workers, further studies are needed to better characterize exposure determinants of welding operations during the assembly of heavy excavation machinery accessories.

  12. Supplement analysis for paleontological excavation at the National Ignition Facility at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    1997-01-01

    On December 15, 1997, contractor workers supporting the National Ignition Facility (NIF) construction uncovered bones suspected to be of paleontological importance. The NIF workers were excavating a utility trench near the southwest corner of the NIF footprint area, located at the northeast corner of the Lawrence Livermore National Laboratory (LLNL) Livermore Site, and were excavating at a depth of approximately 30 feet. Upon the discovery of bone fragments, the excavation in the immediate vicinity was halted and the LLNL archaeologist was notified. The archaeologist determined that there was no indication of cultural resources. Mark Goodwin, Senior Curator for the University of California Museum of Paleontology at the University of California, Berkeley, was then contacted. Mr. Goodwin visited the site on December 16th and confirmed that the bones consisted of a section of the skull, a portion of the mandible, several teeth, upper palate, and possibly the vertebrae of a mammoth, genus Mammuthus columbi. This supplement analysis evaluates the potential for adverse impacts of excavating skeletal remains, an activity that was only generally assessed by the NIF Project-Specific Analysis in the Final Programmatic Environmental impact Statement for Stockpile Stewardship and Management (SS and M PEIS) published in September 1996 (DOE/EIS-0236) and its Record of Decision published on December 19, 1996. This supplement analysis has been prepared pursuant to the DOE regulations implementing the National Environmental Policy Act (10 CFR 1021.314)

  13. Stepwise excavation may enhance pulp preservation in permanent teeth affected by dental caries

    DEFF Research Database (Denmark)

    Bjørndal, Lars

    2011-01-01

    ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Ways of enhancing pulp preservation by stepwise excavation-a systematic review. Hayashi M, Fujitani M, Yamaki C, Momoi Y. J Dent 2011;39(2):95-107. Epub 2010 Dec 3. REVIEWER: Lars Bjørndal, DDS, PhD, Dr Odont PURPOSE/QUESTION: To determine the clinical...

  14. Excavations at the Buller River Site (K29/8), January 2004

    International Nuclear Information System (INIS)

    Jacomb, C.; Tucker, B.; Walter, R.

    2004-01-01

    The Buller River Site (K29/8) is located on the south (true left) bank of the Buller, or Kawatiri, River directly across from Westport and approximately one kilometre from the present shoreline. This report describes the excavations at Buller River in February 2004, outlines the results to date and canvasses options for future research. 12 refs., 11 figs

  15. [Parasite eggs identified in material from archaeological excavations in Ribe (the viking age) (author's transl)].

    Science.gov (United States)

    Nansen, P; Jorgensen, R J

    1977-06-01

    Eggs of Fasciola hepatica, Ascaris sp., Taenia sp., and Trichuris sp. have been demonstrated in archaeological excavations from the early viking period (750--800 A.D.) in Ribe, the oldest urban society of Denmark. The origin of the faecal material is discussed. The parasitological examinations are continued and extended.

  16. Endoscopic excavation for the treatment of small esophageal subepithelial tumors originating from the muscularis propria.

    Science.gov (United States)

    Ye, Li-ping; Zhu, Lin-hong; Zhou, Xian-bin; Mao, Xin-li; Zhang, Yu

    2015-01-01

    This study was designed to evaluate the safety and efficacy of endoscopic excavation for esophageal subepithelial tumors originating from the muscularis propria. Forty-five patients with esophageal subepithelial tumors originating from the muscularis propria were treated with endoscopic excavation between January 2010 and June 2012. The key steps were: (1) making several dots around the tumor; (2) incising the mucosa along with the marker dots, and then seperating the tumor from the muscularis propria by using a hook knife or an insulated-tip knife; (3) closing the artificial ulcer with clips after the tumor was removed. The mean tumor diameter was 1.1 ± 0.6 cm. Endoscopic excavation was successfully performed in 43 out of 45 cases (95.6%), the other 2 cases were ligated with nylon rope. During the procedure perforation occurred in 4 (8.9%) patients, who recovered after conservative treatment. No massive bleeding or delayed bleeding occurred. Histologic diagnosis was obtained from 43 (95.6%) patients. Pathological diagnoses of these tumors were leiomyomas (38/43) and gastrointestinal stromal tumors (5/43). Endoscopic excavation is a safe and effective method for the treatment of small esophageal subepithelial tumors originating from the muscularis propria.

  17. The 2010-2011 excavation season at Al Zubarah, north-west Qatar

    DEFF Research Database (Denmark)

    Richter, Tobias; al-Naimi, Faisal; Yeomans, Lisa

    2012-01-01

    This paper briefly summarizes the results of the 2010–2011 archaeological fieldwork at the late eighteenth–twentieth-century abandoned city of al-Zubarah in north-west Qatar. The excavations in five areas inside the town, covering courtyard houses, a suq, a palatial compound, and a midden...

  18. Excavation-drier method of energy-peat extraction reduces long-term climatic impact

    Energy Technology Data Exchange (ETDEWEB)

    Silvan, N.; Silvan, K.; Laine, J. [Finnish Forest Research Inst., Parkano (Finland)], e-mail: niko.silvan@metla.fi; Vaisanen, S.; Soukka, R. [Lappeenranta Univ.of Techology (Finland)

    2012-11-01

    Climatic impacts of energy-peat extraction are of increasing concern due to EU emissions trading requirements. A new excavation-drier peat extraction method has been developed to reduce the climatic impact and increase the efficiency of peat extraction. To quantify and compare the soil GHG fluxes of the excavation drier and the traditional milling methods, as well as the areas from which the energy peat is planned to be extracted in the future (extraction reserve area types), soil CO{sub 2}, CH{sub 4} and N{sub 2}O fluxes were measured during 2006-2007 at three sites in Finland. Within each site, fluxes were measured from drained extraction reserve areas, extraction fields and stockpiles of both methods and additionally from the biomass driers of the excavation-drier method. The Life Cycle Assessment (LCA), described at a principal level in ISO Standards 14040:2006 and 14044:2006, was used to assess the long-term (100 years) climatic impact from peatland utilisation with respect to land use and energy production chains where utilisation of coal was replaced with peat. Coal was used as a reference since in many cases peat and coal can replace each other in same power plants. According to this study, the peat extraction method used was of lesser significance than the extraction reserve area type in regards to the climatic impact. However, the excavation-drier method seems to cause a slightly reduced climatic impact as compared with the prevailing milling method. (orig.)

  19. Excavation damage and organic growth in a 1.2m diameter borehole

    International Nuclear Information System (INIS)

    Everitt, R.A.; Gann, P.; Brown, D.A.; Boychuk, D.M.

    1994-01-01

    A 1.24m diameter borehole was drilled 5m into the floor of a typical drill-and-blast tunnel in unfractured granite, at AECL's Underground Research Laboratory. Three generations of excavation damage, characteristic of what may be encountered in boreholes excavated for in-hole emplacement of used fuel wastes was observed. These include: (1) damage related to the initial excavation of the room, (2) damage caused by the drilling of the borehole itself, and (3) damage due to subsequent stress-induced spalling of the borehole walls. A biofilm containing a variety of microorganisms has developed where seepage issues from the concrete-granite interface. The biota were introduced from surface water used for mining and drilling. Their growth has been stimulated by residues from blasting and drilling, which have concentrated iron and silicon by passive sorption and energy metabolism. Ferrous iron has been oxidized and precipitated as ferrihydrite/hematite to give an orange/brown colouration on the biofilm interface black. These observations, significant to the understanding and monitoring of excavation damage, highlight the importance of thorough, in situ, multi-disciplinary characterization for vault design

  20. The Li(f)e of the Self: Missing Persons and Auto/Archeological Excavations

    Science.gov (United States)

    Burdick, Jake

    2014-01-01

    This article describes and enacts a process of autobiographical inquiry, auto/archeology, which seeks to address problematic confluences of memory and identity in reconstructing one's historical narrative. Drawing on curriculum theory and Lacanian psychoanalysis, the author describes a process of excavation in which understandings of a prior…

  1. Stability calculation method of slope reinforced by prestressed anchor in process of excavation.

    Science.gov (United States)

    Li, Zhong; Wei, Jia; Yang, Jun

    2014-01-01

    This paper takes the effect of supporting structure and anchor on the slope stability of the excavation process into consideration; the stability calculation model is presented for the slope reinforced by prestressed anchor and grillage beam, and the dynamic search model of the critical slip surface also is put forward. The calculation model of the optimal stability solution of each anchor tension of the whole process is also given out, through which the real-time analysis and checking of slope stability in the process of excavation can be realized. The calculation examples indicate that the slope stability is changed with the dynamic change of the design parameters of anchor and grillage beam. So it is relatively more accurate and reasonable by using dynamic search model to determine the critical slip surface of the slope reinforced by prestressed anchor and grillage beam. Through the relationships of each anchor layout and the slope height of various stages of excavation, and the optimal stability solution of prestressed bolt tension design value in various excavation stages can be obtained. The arrangement of its prestressed anchor force reflects that the layout of the lower part of bolt and the calculation of slope reinforcement is in line with the actual. These indicate that the method is reasonable and practical.

  2. Lightweight Bulldozer Attachment for Construction and Excavation on the Lunar Surface

    Science.gov (United States)

    Mueller, Robert; Wilkinson, R. Allen; Gallo, Christopher A.; Nick, Andrew J.; Schuler, Jason M.; King, Robert H.

    2009-01-01

    A lightweight bulldozer blade prototype has been designed and built to be used as an excavation implement in conjunction with the NASA Chariot lunar mobility platform prototype. The combined system was then used in a variety of field tests in order to characterize structural loads, excavation performance and learn about the operational behavior of lunar excavation in geotechnical lunar simulants. The purpose of this effort was to evaluate the feasibility of lunar excavation for site preparation at a planned NASA lunar outpost. Once the feasibility has been determined then the technology will become available as a candidate element in the NASA Lunar Surface Systems Architecture. In addition to NASA experimental testing of the LANCE blade, NASA engineers completed analytical work on the expected draft forces using classical soil mechanics methods. The Colorado School of Mines (CSM) team utilized finite element analysis (FEA) to study the interaction between the cutting edge of the LANCE blade and the surface of soil. FEA was also used to examine various load cases and their effect on the lightweight structure of the LANCE blade. Overall it has been determined that a lunar bulldozer blade is a viable technology for lunar outpost site preparation, but further work is required to characterize the behavior in 1/6th G and actual lunar regolith in a vacuum lunar environment.

  3. Resisting English: Excavating English Ideologies of Young Boys through Chutkule at an Indian Orphanage

    Science.gov (United States)

    Bhattacharya, Usree

    2017-01-01

    The prevailing scholarship on Indians' beliefs about English has, with few exceptions, largely failed to capture ideological resistance. Given the supremacy of English within the hierarchically ordered and unequal linguistic landscape in India, this study intervenes within this limited area of research. This investigation excavates ideologies of…

  4. Aspects to improve cabin comfort of wheel loaders and excavators according to operators

    NARCIS (Netherlands)

    Kuijt-Evers, L.F.M.; Krause, F.; Vink, P.

    2003-01-01

    Comfort plays an increasingly important role in interior design of earth moving equipment. Although research has been conducted on vehicle interiors of wheel loaders and excavators, hardly any information is known about the operator's opinion. In this study a questionnaire was completed by machine

  5. The Disturbing Student and the Judicial Process

    Science.gov (United States)

    Ragle, John D.; Paine, Gage E.

    2009-01-01

    The Assessment-Intervention of Student Problems (AISP) model is a useful tool for preparing student affairs professionals to assess the problems of disturbed, disturbing, or disturbed/disturbing students and to make appropriate referrals. It is particularly useful because it emphasizes the necessity of developing an integrated system for this…

  6. The SNL/NM Classified Waste Landfill Excavation: Lessons Learned Moving from Planning to Implementation

    International Nuclear Information System (INIS)

    Galloway, Robert B; Slavin, Paula

    1999-01-01

    The Sandia National Laboratories/New Mexico (SNL/NM) Environmental Restoration Project is halfway through excavating the Classified Waste Landfill in Technical Area II, a disposal area for weapon components for approximately 40 years. While the planning phase of any project is important, it is only a means of getting to the field implementation phase where reality quickly sinks in. Documents outlining the general processes are developed, heavy equipment, supply needs, requisite skills, and staffing levels are anticipated, and contingencies for waste management are put in place. However, the nature of landfill excavation dictates that even the most detailed plans will probably change. This project is proving that trying to account for undefined variables and predicting the total cost of landfill remediation is very difficult if the contents are not well known. In landfill excavation, contingency cannot be minimized. During development of the waste management plan, it was recognized that even the best forecasting could not formulate the perfect cradle-to-grave processes because waste streams are rarely definable before excavation begins. Typically, as excavation progresses and waste streams are generated, new characterization information allows further definition of disposal options which, in turn, modify the generation/management process. A general plan combined with close involvement of waste management personnel to resolve characterization and packaging questions during generation has worked very well. And, as expected, each new pit excavated creates new waste management challenges. The material excavated consists primarily of classified weapon assemblies and related components, so disposition must include demilitarization and sanitization. The demilitarization task at the start of the project was provided by an SNL/NM group that has since lost their funding and operational capability. This project is having to take on the task of disassembly, destruction, and

  7. A low-cost approach for the documentation and monitoring of an archaeological excavation site

    Science.gov (United States)

    Hoffmeister, Dirk; Orrin, Joel; Richter, Jürgen

    2016-04-01

    The documentation of archaeological excavations and in particular a constant monitoring is often time-consuming and depending on humańs capabilities. Thus, remote sensing methods, which allow an objective reproduction of the current state of an excavation and additional information are of interest. Therefore, a low-cost approach was tested on an open-air excavation site for two days in September 2015. The Magdalenian excavation site of Bad Kösen-Lengefeld, Germany is one important site in a system of about 100 sites in the area of the small rivers Saale and Unstrut. The whole site and the surrounding area (200 by 200 m) was first observed by a GoPro Hero 3+ mounted on a DJI-Phantom 2 UAV. Ground control points were set-up in a regular grid covering the whole area. The achieved accuracy is 20 mm with a ground resolution of 45 mm. As a test, the GoPro Hero 3+ camera was additionally mounted on a small, extendable pole. With this second low-cost, easy to apply monitoring approach, pictures were automatically taken every second in a stop-and-go mode. In order to capture the excavation pit (7 by 4 m), two different angles were used for holding the pole, which focused on the middle and on the border of the pit. This procedure was repeated on the following day in order to document the excavation process. For the registration of the images, the already existing and measured excavation nails were used, which are equally distributed over the whole site in a 1 m grid. Thus, a high accurate registration of the images was possible (>10 mm). In order to approve the accuracy of the already derived data, the whole site was also observed by a Faro Focus 3D LS 120 laser scanner. The measurements of this device were registered by spherical targets, which were measured in the same reference system. The accuracy of the registration and the ground resolution for the image based approach for both days was about 4 mm. From these two measurements the process of the excavation was easily

  8. Endoscopic excavation for gastric heterotopic pancreas: an analysis of 42 cases from a tertiary center.

    Science.gov (United States)

    Zhang, Yu; Huang, Qin; Zhu, Lin-hong; Zhou, Xian-bin; Ye, Li-ping; Mao, Xin-li

    2014-09-01

    Because of the difficulty associated with making an accurate diagnosis of gastric heterotopic pancreas (HP) before surgery, surgical resection is usually performed in suspected cases. However, this is an invasive procedure and prone to certain surgical complications. This study was designed to evaluate the feasibility of endoscopic excavation for gastric HP, as well as the value of endoscopic ultrasonography (EUS) in diagnosing gastric HP. Between January 2007 and January 2013, 42 consecutive patients with gastric HP were enrolled in this retrospective study. Key steps: (1) Injection of a solution (100 ml saline + 2 ml indigo carmine + 1 ml epinephrine) into the submucosal layer after making several dots around the lesion; (2) Incision of the mucosa outside the marker dots with a needle-knife, and then circumferential excavation until complete resection of the lesion; (3) Closure of the artificial ulcer with several clips after tumor removal. In this study, 18 cases (42.9%) were suspected as gastric HP (assessed by two experienced endoscopists before endoscopic excavation), 8 (19.0%) were suspected as gastrointestinal stromal tumors, 7 (16.7%) as gastric polyp, and the remaining 9 cases (21.4%) were still unknown. The mean procedure duration was 28.6 min. En bloc resection by endoscopic excavation was achieved in 40 cases (95.2%), and no massive bleeding, delayed bleeding, perforation, or other severe complication occurred in these patients. Among the 42 lesions, a tube echo could be detected in 11 cases by EUS. Those 11 cases were diagnosed as gastric HP by histopathology. Endoscopic excavation appears to be a safe and feasible procedure for accurate histopathologic evaluation and curative treatment in gastric HP. Use of EUS has some value in the diagnosis of gastric HP before the procedure

  9. A study of feasibility, design and cost of excavations for underground siting of nuclear power plants

    International Nuclear Information System (INIS)

    1976-02-01

    A study conducted for the State Power Board on underground siting of nuclear power plants is presented. The report is divided into two chapters, both concerning the technical aspects of large underground openings. The first chapter gives a brief general survey of the problems involved, and the second outlines the technical aspects of a PWR project at a specific site. Details are given in 8 appendices and arrangement drawings. The project differs from conventional hydroelectric excavation schemes mainly in the fact that the spherical reactor containment requires a vault of 60m free span, and the turbine hall a cylindrical vault of 45m span, both of which exceed any span hitherto built for similar purposes. This requires a comparatively wide extrapolation of tested and available experience in underground excavations for permanent civil use. To what extent and under what circumstances such extrapolation is tenable must be tested in practice, preferably in a specially controlled prototype test. However the study indicates that conventional nuclear power plants can be sited underground when the topography and rock conditions are suitable. A 1000-2000 MW conventional plant adapted for underground siting will require large span caverns, tunnels and shafts, totalling about 1.0 mill. cubic metres of underground excavation. In addition access and cooling water tunnels, depending on the location, will require 0.2-0.5 mill. cubic metres of tunnel excavations. The excavations and support work can be completed within a construction time of about 2 1/2 years at an estimated total cost of 215 mill. Norwegian kroner (1975 value). (JIW)

  10. Investigation of the development and the effect of an excavation damaged zone at KAERI underground research tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, S.; Cho, W. J

    2008-01-15

    The understanding of the long term behavior of rock around an underground radioactive waste repository is essential for the safe design and operation of the repository and for assuring the safety and technical feasibility of geological disposal concept. The investigation of the influence of EDZ on rock mass behavior is important for the long term stability, economy, and safety points of view. In the case of underground repository, which requires high level safety criteria, the accurate prediction of the long and short term mechanical, hydraulic, and thermal behaviors is especially important. In this study, the size and characteristics of EDZ developed during the construction of the KAERI underground research tunnel, which was constructed by controlled blasting, were investigated using various methods. Goodman jack test for measuring deformation modulus, Georadar, rock core observation, MPBX, and stressmeter were carried out at KURT. The rock cores from the boreholes were tested in laboratory for estimating the EDZ size. Empirical and theoretical equations were also used for the prediction of EDZ. The results from laboratory and in situ tests were used in three-dimensional hydro-mechanical and thermo-mechanical analysis for the evaluation of the EDZ effect. The understanding of EDZ size and the property changes in EDZ from in situ and laboratory tests will be used for the planning, design, and analysis of in situ experiments in KURT. The results from the EDZ study will be helpful for the system design as well as safety analysis of a radioactive repository.

  11. Forest disturbances under climate change

    Czech Academy of Sciences Publication Activity Database

    Seidl, R.; Thom, D.; Kautz, M.; Martin-Benito, D.; Peltoniemi, M.; Vacchiano, G.; Wild, Jan; Ascoli, D.; Petr, M.; Honkaniemi, J.; Lexer, M. J.; Trotsiuk, V.; Mairota, P.; Svoboda, M.; Fabrika, M.; Nagel, T.A.; Reyer, C. P. O.

    2017-01-01

    Roč. 7, č. 6 (2017), s. 395-402 ISSN 1758-678X R&D Projects: GA MŠk(CZ) LD15158 Institutional support: RVO:67985939 Keywords : climate change * disturbance * forest Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 19.304, year: 2016

  12. Gastrointestinal disturbances in marathon runners.

    Science.gov (United States)

    Riddoch, C; Trinick, T

    1988-06-01

    The purpose of this survey was to investigate the prevalence of running-induced gastrointestinal (GI) disturbances in marathon runners. A questionnaire was completed by 471 of the estimated 1,750 competitors in the 1986 Belfast City Marathon. Eighty-three per cent of respondents indicated that they occasionally or frequently suffered one or more GI disturbances during or immediately after running. The urge to have a bowel movement (53%) and diarrhoea (38%) were the most common symptoms, especially among female runners (74% and 68% respectively). Upper GI tract symptoms were experienced more by women than men (p less than 0.05) and more by younger runners than older runners (p less than 0.01). Women also suffered more lower GI tract symptoms than men (p less than 0.05) with younger runners showing a similar trend. Both upper and lower tract symptoms were more common during a "hard" run than an "easy" run (p less than 0.01) and were equally as common both during and after running. Of those runners who suffered GI disturbances, 72% thought that running was the cause and 29% believed their performance to be adversely affected. There was no consensus among sufferers as to the causes of symptoms and a wide variety of "remedies" were suggested. GI disturbances are common amongst long-distance runners and their aetiology is unknown. Medical practitioners should be aware of this when dealing with patients who run.

  13. Climate-driven disturbances in the San Juan River sub-basin of the Colorado River

    Science.gov (United States)

    Bennett, Katrina E.; Bohn, Theodore J.; Solander, Kurt; McDowell, Nathan G.; Xu, Chonggang; Vivoni, Enrique; Middleton, Richard S.

    2018-01-01

    Accelerated climate change and associated forest disturbances in the southwestern USA are anticipated to have substantial impacts on regional water resources. Few studies have quantified the impact of both climate change and land cover disturbances on water balances on the basin scale, and none on the regional scale. In this work, we evaluate the impacts of forest disturbances and climate change on a headwater basin to the Colorado River, the San Juan River watershed, using a robustly calibrated (Nash-Sutcliffe efficiency 0.76) hydrologic model run with updated formulations that improve estimates of evapotranspiration for semi-arid regions. Our results show that future disturbances will have a substantial impact on streamflow with implications for water resource management. Our findings are in contradiction with conventional thinking that forest disturbances reduce evapotranspiration and increase streamflow. In this study, annual average regional streamflow under the coupled climate-disturbance scenarios is at least 6-11 % lower than those scenarios accounting for climate change alone; for forested zones of the San Juan River basin, streamflow is 15-21 % lower. The monthly signals of altered streamflow point to an emergent streamflow pattern related to changes in forests of the disturbed systems. Exacerbated reductions of mean and low flows under disturbance scenarios indicate a high risk of low water availability for forested headwater systems of the Colorado River basin. These findings also indicate that explicit representation of land cover disturbances is required in modeling efforts that consider the impact of climate change on water resources.

  14. Excavation induced damage evolution during a mine-by experiment in Opalinus Clay

    International Nuclear Information System (INIS)

    Vietor, T.; Armand, G.; Nyonoya, S.; Schuster, K.; Wieczorek, K.

    2010-01-01

    Document available in extended abstract form only. In Switzerland Opalinus Clay, a potential host rock formation for a nuclear waste repository, is intensively studied in the Mont Terri Underground Rock Laboratory (URL) in North-Western Switzerland. During the 2008 extension of the URL, the construction works were repeatedly interrupted to implement monitoring systems for a mine-by experiment. The future position of a 24 m long tunnel was instrumented with 36 different monitoring systems comprising approximately 200 sensors. Key features of this tunnel were chosen similar to the current Swiss concept for emplacement tunnels for High Level Radioactive Waste: circular section, full-face excavation following the geological bedding, support by a thin layer of shotcrete and 6 anchors every 1.3 m. For a mine-by experiment 26 boreholes were equipped with 7 multipoint extensometers, two multi segment inclinometer chains and 26 pore pressure chambers. The data acquisition system recorded 12 data sets per hour. For seismic transmission and acoustic emission monitoring, 8 piezo-electric emitters and 15 piezo-electric receivers were installed in 5 boreholes. The excavation of the instrumented tunnel took place in October/November 2008. The activities on the site were monitored with a web cam to separate spontaneous and excavation induced rock mass reactions. Daily mappings of the tunnel face and the sidewalls revealed the fracture pattern that was generated ahead of the advancing excavation. Three sets of excavation activated discontinuities could be clearly identified. These three sets develop within the framework of the pre-existing tectonic micro-faults that generally have a half-meter spacing. Where their density is high the intensity of excavation induced new slip planes apparently drops. Despite the presence of micro-faults the deformation monitoring around the advancing tunnel face showed a remarkably homogenous response to the excavation. Inclinometer chain segments

  15. Air Quality and Microclimatic Parameters During Excavation of Mala Kapela Tunnel

    Directory of Open Access Journals (Sweden)

    Mario Klanfar

    2015-06-01

    Full Text Available During excavation of the Mala Kapela tunnel, measurements of harmful gases concentration, ventilation parameters and microclimatic parameters were performed. Measurements were done in 17 occasions during period of 16 months, along the advance of the tunnel excavation. Consequently, large amount of data was obtained, in different tunnel chainages, ventilation ducts length, and in different work operations during the excavation. Main sources of harmful gases during tunnel excavation are explosives and diesel equipment. The concentration of the same mainly depends on explosive charge and overall diesel equipment power, present at the excavation face of the tunnel. Continuous measurements of the concentration of carbon monoxide (CO and dioxide (CO2, and nitrogen oxide (NO and dioxide (NO2 was performed during drilling, blasting, and loading and haulage operations. Measurements were done in 45 cases in total. Recorded data was analysed, where peak concentrations were joined to corresponding operation and the tunnel chainage. Regulations on threshold limit values were used to determine if concentrations rise above the permissible ones. In case they do, the time required for dilution of gases below permissible concentration was noted. Typically, concentrations of all measured gases rise rapidly after blasting. Afterwards, ventilation system acts to dilute them and maintain them relatively constant until the end of loading and haulage. According to measurements in this research, highest concentrations and longest time of dilution were found after blasting. At the same time, concentration of all measured gases exceeds permissible values. Carbon monoxide is found to exceed permissible values during all work operations. It shows most frequent transgression above the limit (in 33 to 100% of cases and highest time of dilution (up to 40 min. Air supply to the excavation face was measured in 25 cases. It was correlated to the length of ventilation ducts, as

  16. Self-sealing of excavation induced fractures in clay host rock

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chun-Liang [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Braunschweig (Germany)

    2015-07-01

    Excavation of an underground repository for disposal of radioactive waste in clay formations generates fractures around the openings, which may act as pathways for water transport and radionuclides migration. Because of the favorable properties of the clay rocks such as the rheological deformability and swelling capability, a recovery process of the excavation damaged zone (EDZ) can be expected due to the combined impact of rock compression, backfill resistance, and clay swelling during the post-closure phase. Another important issue is the impact of gases produced from anoxic corrosion of waste containers and other metallic components within the repository. The EDZ may act as a conduit for preferential gas flow, depending on the extent of the recovery process. For the safety assessment of a repository, the self-sealing behaviour and impact on water and gas transport through the EDZ have to be characterized, understood, and predicted. Recently, GRS has extensively investigated these important issues with various kinds of laboratory and in- situ experiments under relevant repository conditions. Test samples were taken from the Callovo-Oxfordian argillite at Bure in France and the Opalinus clay (shaly facies) at Mont Terri in Switzerland. Major findings are summarized as follows. As observed in laboratory and in-situ, the gas permeabilities of the claystones increase with stress-induced damage by several orders of magnitude from the impermeable state up to high levels of 10{sup -12}-10{sup -13} m{sup 2}. When hydrostatic confining stress is applied and increased, the fractures in the claystones tend to close up, leading to a decrease in gas permeability down to different levels of 10{sup -16}-10{sup -21} m{sup 2} at stresses in a range of 10 to 20 MPa. As water enters and flows through fractures, the clay matrix can take up a great amount of the water and expand into the interstices. Consequently, the hydraulic conductivity decreases dramatically by several orders of

  17. Explanation of Significant Differences for the Record of Decision for Interim Actions in Zone 1, East Tennessee Technology Park, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel Jacobs

    2011-02-01

    Zone 1 is a 1400-acre area outside the fence of the main plant at The East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. The Record of Decision for Interim Actions in Zone, ETTP (Zone 1 Interim ROD) (DOE 2002) identifies the remedial actions for contaminated soil, buried waste, and subsurface infrastructure necessary to protect human health and to limit further contamination of groundwater. Since the Zone 1 Interim Record of Decision (ROD) was signed, new information has been obtained that requires the remedy to be modified as follows: (1) Change the end use in Contractor's Spoil Area (CSA) from unrestricted industrial to recreational; (2) Remove Exposure Units (EU5) ZI-50, 51, and 52 from the scope of the Zone I Interim ROD; (3) Change the end use of the duct bank corridor from unrestricted industrial to restricted industrial; and (4) Remove restriction for the disturbance of soils below 10 feet in Exposure Unit (EU) Z1-04. In accordance with 40 Code of Federal Regulations (CFR) 300.435, these scope modifications are a 'significant' change to the Zone 1 Interim ROD. In accordance with CERCLA Sect. 117 (c) and 40 CFR 300.435 (c)(2)(i), such a significant change is documented with an Explanation of Significant Differences (ESD). The purpose of this ESD is to make the changes listed above. This ESD is part of the Administrative Record file, and it, and other information supporting the selected remedy, can be found at the DOE Information Center, 475 Oak Ridge Turnpike, Oak Ridge, Tennessee 37830, from 8:00 a.m. to 5:00 p.m., Monday through Friday. The ORR is located in Roane and Anderson counties, within and adjacent to the corporate city limits of Oak Ridge, Tennessee. ETTP is located in Roane County near the northwest corner of the ORR. ETTP began operation during World War II as part of the Manhattan Project. The original mission of ETTP was to produce enriched uranium for use in atomic weapons. The plant produced enriched uranium from

  18. The effect of deep excavation-induced lateral soil movements on the behavior of strip footing supported on reinforced sand

    Directory of Open Access Journals (Sweden)

    Mostafa El Sawwaf

    2012-10-01

    Full Text Available This paper presents the results of laboratory model tests on the influence of deep excavation-induced lateral soil movements on the behavior of a model strip footing adjacent to the excavation and supported on reinforced granular soil. Initially, the response of the strip footings supported on un-reinforced sand and subjected to vertical loads (which were constant during the test due to adjacent deep excavation-induced lateral soil movement were obtained. Then, the effects of the inclusion of geosynthetic reinforcement in supporting soil on the model footing behavior under the same conditions were investigated. The studied factors include the value of the sustained footing loads, the location of footing relative to the excavation, the affected depth of soil due to deep excavation, and the relative density of sand. Test results indicate that the inclusion of soil reinforcement in the supporting sand significantly decreases both vertical settlements and the tilts of the footings due to the nearby excavation. However, the improvements in the footing behavior were found to be very dependent on the location of the footing relative to excavation. Based on the test results, the variation of the footing measured vertical settlements with different parameters are presented and discussed.

  19. A Top Pilot Tunnel Preconditioning Method for the Prevention of Extremely Intense Rockbursts in Deep Tunnels Excavated by TBMs

    Science.gov (United States)

    Zhang, Chuanqing; Feng, Xiating; Zhou, Hui; Qiu, Shili; Wu, Wenping

    2012-05-01

    The headrace tunnels at the Jinping II Hydropower Station cross the Jinping Mountain with a maximum overburden depth of 2,525 m, where 80% of the strata along the tunnels consist of marble. A number of extremely intense rockbursts occurred during the excavation of the auxiliary tunnels and the drainage tunnel. In particular, a tunnel boring machine (TBM) was destroyed by an extremely intense rockburst in a 7.2-m-diameter drainage tunnel. Two of the four subsequent 12.4-m-diameter headrace tunnels will be excavated with larger size TBMs, where a high risk of extremely intense rockbursts exists. Herein, a top pilot tunnel preconditioning method is proposed to minimize this risk, in which a drilling and blasting method is first recommended for the top pilot tunnel excavation and support, and then the TBM excavation of the main tunnel is conducted. In order to evaluate the mechanical effectiveness of this method, numerical simulation analyses using the failure approaching index, energy release rate, and excess shear stress indices are carried out. Its construction feasibility is discussed as well. Moreover, a microseismic monitoring technique is used in the experimental tunnel section for the real-time monitoring of the microseismic activities of the rock mass in TBM excavation and for assessing the effect of the top pilot tunnel excavation in reducing the risk of rockbursts. This method is applied to two tunnel sections prone to extremely intense rockbursts and leads to a reduction in the risk of rockbursts in TBM excavation.

  20. Archaeological Excavation Report for Proposed Well 199-K-131 in Support of the 100-KR-4 Pump-and-Treat Project

    Energy Technology Data Exchange (ETDEWEB)

    Woody, Dave M.; Prendergast-Kennedy, Ellen L.

    2004-06-22

    An archaeological excavation was conducted at the site of proposed groundwater monitoring well 199-K-131 in support of the 100-KR-4 Pump-and-Treat Project between June 2 and 3, 2004. Excavations confirmed that there were no intact cultural deposits at the proposed well location. This report was prepared to document the findings of the test excavation.

  1. Temporal Activity Patterns of the Spider Wasp Pepsis montezuma Smith (Hymenoptera: Pompilidae in a Disturbed Lower Montane Rainforest (Manizales, Colombia

    Directory of Open Access Journals (Sweden)

    Carlos Restrepo-Giraldo

    2012-01-01

    Full Text Available We studied the temporal activity pattern of the spider wasp Pepsis montezuma Smith (Hymenoptera: Pompilidae in a disturbed lower montane rainforest, which is located in the city of Manizales, Colombia, at an altitude of 2,150 m. Females of this species are diurnal with two peaks of activity: one in the morning and the other in the afternoon. During the morning, nectar foraging occurred at Baccharis latifolia. During the afternoon, females hunted for tarantulas of the genus Pamphobeteus (Araneae: Theraphosidae, which were dragged backwards to the nest by the wasp. The nest was excavated before hunting. This is the first description of the behavior of Pepsis montezuma.

  2. Disturbances in small bowel motility.

    LENUS (Irish Health Repository)

    Quigley, E M

    2012-02-03

    Recently, the small intestine has become the focus of investigation as a potential site of dysmotility in the irritable bowel syndrome (IBS). A number of motor abnormalities have been defined in some studies, and include \\'clustered\\' contractions, exaggerated post-prandial motor response and disturbances in intestinal transit. The significance of these findings remains unclear. The interpretation of available studies is complicated by differences in subject selection, the direct influence of certain symptoms, such as diarrhoea and constipation, and the interference of compounding factors, such as stress and psychopathology. Dysmotility could also reflect autonomic dysfunction, disturbed CNS control and the response to heightened visceral sensation or central perception. While motor abnormalities may not explain all symptoms in IBS, sensorimotor interactions may be important in symptom pathogenesis and deserve further study.

  3. Postradiation disturbances of neuroendocrinal interaction

    International Nuclear Information System (INIS)

    Dedov, V.I.

    1980-01-01

    Analysis of data on the disturbances induced by ionizing irradiation in endocrine organs is given on the basis of experimental material. Mechanism and dynamics of the radiation pathology of such organs of endocrine system as hypothalamus, hypophysis, adrenal glands, thyroid, gonads are considered. Necessity of the determination of criteria of injury significance and study of delayed effects of ionizing radiation in perspective investigation of the problems of endocrine radiation pathology is pointed out

  4. Mechanical disturbances in superconducting magnets

    International Nuclear Information System (INIS)

    Sugimoto, Makoto

    1990-03-01

    The stress distribution in a small epoxy-impregnated Nb 3 Sn coil was calculated by the finite element method. Mechanical disturbances due to the electromagnetic force in the magnet are discussed. The coil stability in relation with the stress distribution is also discussed by using the experimental results. To evaluate such stresses, a calculation model was investigated. It was found that the model, which removed the internal bore element in the model magnet, gave a reasonable condition to estimate to stress. A quench mechanism due to mechanical disturbances in superconducting magnets is discussed. According to this mechanism, an internal slit was assumed as the reason for the mechanical disturbance. The internal slit is generated at the boundary between the superconductor and the bore element by the thermally induced stress. When charging a magnet, the induced electromagnetic force results in a stress concentration at the slit, and hence to an enlargement of it. During the enlargement of the internal slit, heat is generated at the top of it. Such heat generation from a mechanical disturbance can induce a quench. Through these investigations, the following coil manufacturing method can be proposed to reduce such stresses: the magnet should be manufactured to separate the bore element from the superconductor and this separation technique can reduce the boundary stress during cool-down. Actually, a thin teflon film at the boundary between the superconductor and the bore element can be used as a separator. Another separation technique is a teflon coating on the internal bore element. The separation technique should result in a stable epoxy-impregnated superconducting magnet. (J.P.N.)

  5. Excavating silences and tensions of agency|passivity in science education reform

    Science.gov (United States)

    Rivera Maulucci, Maria S.

    2010-12-01

    I reflect on studies by Rodriguez and Carlone, Haun-Frank, and Kimmel to emphasize the ways in which they excavate silences in the science education literature related to linguistic and cultural diversity and situating the problem of reform in teachers rather than contextual factors, such as traditional schooling discourses and forces that serve to marginalize science. I propose that the current push for top-down reform and accountability diminishes opportunities for receptivity, learning with and from students in order to transform teachers' practices and promote equity in science education. I discuss tensions of agency and passivity in science education reform and argue that attention to authentic caring constitutes another silence in the science education literature. I conclude that the current policy context positions teachers and science education researchers as tempered radicals struggling against opp(reg)ressive reforms and that there is a need for more studies to excavate these and other silences.

  6. Development of digital photogrammetry for measurements of displacements in underground excavation

    International Nuclear Information System (INIS)

    Ohnishi, Yuzo; Ohtsu, Hiroyasu; Nishiyama, Satoshi; Ono, Tetsu; Matsui, Hiroya

    2002-03-01

    Because deformations are important indicators of the degree of stability during construction of rock structures, monitoring of deformation is a key element of construction of tunnels and structures for the underground research laboratory. Especially in the construction and maintenance of underground excavation, monitoring of deformations is needed for obtaining useful information to control its stability. We have been developing the application of digital photogrammetry to monitoring techniques in rock structures. Photogrammetric process has undergone a remarkable evolution with its transformation into digital photogrammetry. Photogrammetry has the advantage of measuring deformation of an object by some photos with easy measurements and excellent cost performance. In this paper, we present that the digital photogrammetry can monitor the displacements of the underground excavation accurately along with a capability of real-time measurement. (author)

  7. Regolith Advanced Surface Systems Operations Robot (RASSOR) Phase 2 and Smart Autonomous Sand-Swimming Excavator

    Science.gov (United States)

    Sandy, Michael

    2015-01-01

    The Regolith Advanced Surface Systems Operations Robot (RASSOR) Phase 2 is an excavation robot for mining regolith on a planet like Mars. The robot is programmed using the Robotic Operating System (ROS) and it also uses a physical simulation program called Gazebo. This internship focused on various functions of the program in order to make it a more professional and efficient robot. During the internship another project called the Smart Autonomous Sand-Swimming Excavator was worked on. This is a robot that is designed to dig through sand and extract sample material. The intern worked on programming the Sand-Swimming robot, and designing the electrical system to power and control the robot.

  8. Relic excavated in western India is probably of Georgian Queen Ketevan.

    Science.gov (United States)

    Rai, Niraj; Taher, Nizamuddin; Singh, Manvendra; Chaubey, Gyaneshwer; Jha, Aditya Nath; Singh, Lalji; Thangaraj, Kumarasamy

    2014-01-01

    History has well documented the execution of Queen Ketevan of Georgia by the Persian Emperor of modern day Iran. Based on historical records, in 1624 two Augustinian friars unearthed the queen's remains and one of them brought the relic to the St. Augustine convent in Goa, India. We carried out ancient DNA analysis on the human bone remains excavated from the St. Augustine convent by sequencing and genotyping of the mitochondrial DNA. The investigations of the remains revealed a unique mtDNA haplogroup U1b, which is absent in India, but present in Georgia and surrounding regions. Since our genetic analysis corroborates archaeological and literary evidence, it is likely that the excavated bone belongs to Queen Ketevan of Georgia. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Limit values used in the European Union for managing excavated land and contaminated soils

    International Nuclear Information System (INIS)

    Soto Diaz, E.; Rodriguez Abad, R.

    2014-01-01

    In this paper, which is a summary of the minor thesis of the same title, a qualitative comparison is made between mean limit values applied in different member countries of the European Union (EU) for the proper management of excavated lands and contaminated soils. This management can be carried out as a byproduct through its reuse, recycling or previous treatment, or through its consideration as a waste and its subsequent admission to a particular type of landfill. Three types of comparisons of UE limit values are done in this paper: between those established in six member countries for the use of excavated lands as a byproduct, between those existing in 15 European countries for contaminated soils, and finally between those required in 12 EU countries for their land filling. (Author)

  10. Radiocarbon dating of a sutra container excavated at the Minagi Daibutsuyama site, Fukuoka Prefecture, Japan

    International Nuclear Information System (INIS)

    Oda, Hirotaka; Nakamura, Toshio; Tsukamoto, Toshio

    2004-01-01

    The historical age of a sutra container (Kyozutsu) excavated at the Minagi Daibutsuyama site was estimated by the AMS method. Radiocarbon ages for samples of the charred sutra kept in the container range from 950 to 1000 BP, corresponding to the first half of the 11th or the middle of the 12th century in the calibrated ages. The radiocarbon ages of wood charcoal blocks excavated around the container range from 1000 to 1100 BP, corresponding to calibrated ages from the 10th to the early 11th century. Since the radiocarbon age of wood charcoal can be decades older than the age of production as a result of the old wood effect, the historical age of the sutra container formation is estimated at the first half of the 11th century

  11. Excavations and chronology at the Redcliffs Flat site, Canterbury, New Zealand

    International Nuclear Information System (INIS)

    Jacomb, C.

    2009-01-01

    The Redcliffs Flat site is one of a number of early Maori archaeological sites that cluster near the mouth of the estuary of the Avon and Heathcote rivers. Although several have been the subject of archaeological investigations, the chronology and extent of the Redcliffs Flat site remain poorly understood. Recent excavations associated with the redevelopment of a suburban section allow some progress to be made on both fronts. A small excavation here yielded a surprising amount of faunal, lithic and stratigraphic information. The site is shown to have extended to close to the edge of the estuary at the time of occupation and a radiocarbon date on a fragment of moa eggshell confirms the fourteenth to early fifteenth century status of the site. The radiocarbon chronology of the sites of the wider Redcliffs area is reviewed in light of this result. (author). 41 refs., 6 figs., 3 tabs.

  12. Application of full-face round by the sequential blasting machine in tunnel excavation

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Y.D.; Park, B.K.; Lee, S.E.; Lim, H.U.

    1995-12-31

    Many methods and techniques have been developed to reduce ground vibrations. Some of them are an adoption of electric millisecond detonators with a sequential blasting machine and an improvement of initiating system with an adequate number of delay intervals. To reduce the level of ground vibration in tunnel excavation, the sequential blasting machine (S.B.M.) with decisecond detonators was adopted. A total of 134 blasts was recorded at various sites and the results were analyzed. The distances blast-to-structures were ranged from 20.3 to 42.0 meter, where charge weights were varied from 0.25 to 0.75kg per delay. It is proved that the sequential blasting in tunnel excavation is very effective to control ground vibration.

  13. Energy Consumption in the Process of Excavator-Automobile Complexes Distribution at Kuzbass Open Pit Mines

    Directory of Open Access Journals (Sweden)

    Panachev Ivan

    2017-01-01

    Full Text Available Every year worldwide coal mining companies seek to maintain the tendency of the mining machine fleet renewal. Various activities to maintain the service life of already operated mining equipment are implemented. In this regard, the urgent issue is the problem of efficient distribution of available machines in different geological conditions. The problem of “excavator-automobile” complex effective distribution occurs when heavy dump trucks are used in mining. For this reason, excavation and transportation of blasted rock mass are the most labor intensive and costly processes, considering the volume of transported overburden and coal, as well as diesel fuel, electricity, fuel and lubricants costs, consumables for repair works and downtime, etc. Currently, it is recommended to take the number of loading buckets in the range of 3 to 5, according to which the dump trucks are distributed to faces.

  14. Interaction Deep Excavation Adjacent Structure Numerical Two and Three Dimensional Modeling

    International Nuclear Information System (INIS)

    Abdallah, M.; Chehade, F. H.; Chehade, W.; Fawaz, A.

    2011-01-01

    Urban development often requires the construction of deep excavations near to buildings or other structures. We have to study complex material structure interactions where we should take into consideration several particularities. In this paper, we perform a numerical modeling with the finite element method, using PLAXIS software, of the interaction deep excavation-diaphragm wall-soil-structure in the case of non linear soil behavior. We focus our study on a comparison of the results given respectively by two and three dimensional modelings. This allows us to give some recommendations concerning the validity of twodimensional study. We perform a parametric study according to the initial loading on the structure and the struts number. (author)

  15. Remediating Contaminant Plumes in Groundwater with Shallow Excavations Containing Coarse Reactive Media.

    Science.gov (United States)

    Hudak, Paul F

    2018-02-01

    A groundwater flow and mass transport model tested the capability of shallow excavations filled with coarse, reactive media to remediate a hypothetical unconfined aquifer with a maximum saturated thickness of 5 m. Modeled as contaminant sinks, the rectangular excavations were 10 m downgradient of an initial contaminant plume originating from a source at the top of the aquifer. The initial plume was approximately 259 m long, 23 m wide, and 5 m thick, with a downgradient tip located approximately 100 m upgradient of the site boundary. The smallest trench capable of preventing offsite migration was 11 m long (measured perpendicular to groundwater flow), 4 m wide (measured parallel to groundwater flow), and 3 m deep. Results of this study suggest that shallow trenches filled with coarse filter media that partially penetrate unconfined aquifers may be a viable alternative for remediating contaminated groundwater at some sites.

  16. Neurobiological basis of parenting disturbance.

    Science.gov (United States)

    Newman, Louise K; Harris, Melissa; Allen, Joanne

    2011-02-01

    It has been proposed that early attachment relationships shape the structure and reactivity of social brain structures that underlie later social capacities. We provide a review of the literature surrounding the development of neurological regulatory systems during infancy and outline recent research suggesting these systems go on to underlie adaptive parental responses. We review evidence in the peer-reviewed psychiatric literature including (i) observational human literature on the neurobiological and social sequelae of early parenting experiences, (ii) experimental animal literature on the effects of early maternal care on neurological development, (iii) experimental animal literature on the neurobiological underpinnings of parenting behaviours, (iv) observational and fMRI evidence on the neurobiological correlates of parenting behaviours, (v) functional and volumetric imaging studies on adults affected by borderline personality disorder. The development of infant regulatory systems is influenced by early parenting experiences. These frontolimbic regulatory systems are also heavily implicated in normal parental responses to infant cues. These frontolimbic disturbances are also observed in studies of borderline personality disorder; a disorder associated with poor emotional regulation, early trauma and disturbed parenting. While the current literature is limited to animal models of abnormal care giving, existing disorders associated with deficits in regulatory capacity and abnormal frontolimbic functioning may yet provide a human model of the neurobiology of parenting disturbance.

  17. The Avaldsnes Royal Manor Project’s Research Plan and Excavation Objectives

    OpenAIRE

    Skre, Dagfinn

    2017-01-01

    This chapter provides an outline of the scholarly problems that the Avaldsnes Royal Manor Project was designed to address, the central theme explored being the political institutions and processes in the first millennium AD. The research plan was developed during the 2007–9 pilot project phase, and was adjusted and supplemented during the 2011–12 excavations and the research and publication phase in the subsequent years. The first of the research plan’s two sections, the results of which are ...

  18. Thermomechanical analysis of underground excavations in the vicinity of a nuclear waste isolation panel

    International Nuclear Information System (INIS)

    St John, C.M.

    1987-06-01

    This report summarizes the results of a series of analyses of excavations in the vicinity of waste emplacement panels. Specific consideration is given to the access drifts running between adjacent emplacement panels, the drift intersection at the entrance to the emplacement panels, and the waste emplacement excavations. Both horizontal and vertical emplacement models are considered, but greater emphasis is placed on the former. Three numerical modeling procedures were used in this study: a finite-element model was used for three-dimensional stress analysis of the tunnel intersection, a model based on the closed-form solution for point heat sources was used to predict temperatures and stresses in the vicinity of the emplacement panel, and simple two-dimensional boundary-element models were used to predict temperatures and stresses around excavations of various shapes. The results of two-dimensional stress analyses were postprocessed to determine the extent to which the strength of a rock mass, containing a set of vertical joints, was exceeded. The results presented in this report do not indicate that there will be any particular stability problems at the tunnel intersection investigated. Further, the effect of waste emplacement within the adjacent panels is to decrease the vertical rock stresses and increase the horizontal rock stresses at the intersection. These stress changes will tend to enhance the stability of larger-span excavations, including the tunnel intersection and the alcoves necessary for horizontal emplacement of waste canisters. The relatively high horizontal stresses experienced by the access were identified as a potential concern. However, evaluation of recent data on the thermomechanical properties of the rock mass modeled here has indicated that the stress changes will not be as severe as stated herein

  19. Robotic excavator trajectory control using an improved GA based PID controller

    Science.gov (United States)

    Feng, Hao; Yin, Chen-Bo; Weng, Wen-wen; Ma, Wei; Zhou, Jun-jing; Jia, Wen-hua; Zhang, Zi-li

    2018-05-01

    In order to achieve excellent trajectory tracking performances, an improved genetic algorithm (IGA) is presented to search for the optimal proportional-integral-derivative (PID) controller parameters for the robotic excavator. Firstly, the mathematical model of kinematic and electro-hydraulic proportional control system of the excavator are analyzed based on the mechanism modeling method. On this basis, the actual model of the electro-hydraulic proportional system are established by the identification experiment. Furthermore, the population, the fitness function, the crossover probability and mutation probability of the SGA are improved: the initial PID parameters are calculated by the Ziegler-Nichols (Z-N) tuning method and the initial population is generated near it; the fitness function is transformed to maintain the diversity of the population; the probability of crossover and mutation are adjusted automatically to avoid premature convergence. Moreover, a simulation study is carried out to evaluate the time response performance of the proposed controller, i.e., IGA based PID against the SGA and Z-N based PID controllers with a step signal. It was shown from the simulation study that the proposed controller provides the least rise time and settling time of 1.23 s and 1.81 s, respectively against the other tested controllers. Finally, two types of trajectories are designed to validate the performances of the control algorithms, and experiments are performed on the excavator trajectory control experimental platform. It was demonstrated from the experimental work that the proposed IGA based PID controller improves the trajectory accuracy of the horizontal line and slope line trajectories by 23.98% and 23.64%, respectively in comparison to the SGA tuned PID controller. The results further indicate that the proposed IGA tuning based PID controller is effective for improving the tracking accuracy, which may be employed in the trajectory control of an actual excavator.

  20. Study on provenance of ancient pottery excavated from Huating Ruins, Xinyi County by INAA

    International Nuclear Information System (INIS)

    Xu Anwu; Wang Changsui; Chi Jinqi; Satoshi Koshimizu; Kazai Manabu; Kushihara Koichi

    1997-01-01

    The ancient pottery excavated from Huating Ruins, Xinyi Country, Jiangsu Province, was measured and studied by INAA. The data were manipulated by multivariate statistic analysis, such as cluster and factor analysis. It has been shown that the specimens can be divided into two groups, which are related to Liangzhu Culture area and Dawenkou Culture area respectively. The result seems to support the viewpoint that the pottery specimens of Liangzhu Culture from Huating Ruins belong to war trophies

  1. Ground movement and deformation due to dewatering and open pit excavation

    International Nuclear Information System (INIS)

    Liu, B.; Yang, J.; Zhang, J.

    1996-01-01

    In the application of stochastic medium theory, it is assumed that ground movement process has the property of Markov Process. Based on superposition principle and rock consolidation principle, the ground movement and deformation due to dewatering and open pit excavation can be calculated. The comparison between the field measurements in Morwell Open Pit, Latrobe Valley (Victoria, Australia) and the calculated results shows the validity of the method in this paper. 5 refs

  2. Excavation and aggregation as organizing factors in de novo construction by mound-building termites.

    Science.gov (United States)

    Green, Ben; Bardunias, Paul; Turner, J Scott; Nagpal, Radhika; Werfel, Justin

    2017-06-14

    Termites construct complex mounds that are orders of magnitude larger than any individual and fulfil a variety of functional roles. Yet the processes through which these mounds are built, and by which the insects organize their efforts, remain poorly understood. The traditional understanding focuses on stigmergy, a form of indirect communication in which actions that change the environment provide cues that influence future work. Termite construction has long been thought to be organized via a putative 'cement pheromone': a chemical added to deposited soil that stimulates further deposition in the same area, thus creating a positive feedback loop whereby coherent structures are built up. To investigate the detailed mechanisms and behaviours through which termites self-organize the early stages of mound construction, we tracked the motion and behaviour of major workers from two Macrotermes species in experimental arenas. Rather than a construction process focused on accumulation of depositions, as models based on cement pheromone would suggest, our results indicated that the primary organizing mechanisms were based on excavation. Digging activity was focused on a small number of excavation sites, which in turn provided templates for soil deposition. This behaviour was mediated by a mechanism of aggregation, with termites being more likely to join in the work at an excavation site as the number of termites presently working at that site increased. Statistical analyses showed that this aggregation mechanism was a response to active digging, distinct from and unrelated to putative chemical cues that stimulate deposition. Agent-based simulations quantitatively supported the interpretation that the early stage of de novo construction is primarily organized by excavation and aggregation activity rather than by stigmergic deposition. © 2017 The Author(s).

  3. Microseism Induced by Transient Release of In Situ Stress During Deep Rock Mass Excavation by Blasting

    Science.gov (United States)

    Yang, Jianhua; Lu, Wenbo; Chen, Ming; Yan, Peng; Zhou, Chuangbing

    2013-07-01

    During deep rock mass excavation with the method of drill and blast, accompanying the secession of rock fragments and the formation of a new free surface, in situ stress on this boundary is suddenly released within several milliseconds, which is termed the transient release of in situ stress. In this process, enormous strain energy around the excavation face is instantly released in the form of kinetic energy and it inevitably induces microseismic events in surrounding rock masses. Thus, blasting excavation-induced microseismic vibrations in high-stress rock masses are attributed to the combined action of explosion and the transient release of in situ stress. The intensity of stress release-induced microseisms, which depends mainly on the magnitude of the in situ stress and the dimension of the excavation face, is comparable to that of explosion-induced vibrations. With the methods of time-energy density analysis, amplitude spectrum analysis, and finite impulse response (FIR) digital filter, microseismic vibrations induced by the transient release of in situ stress were identified and separated from recorded microseismic signals during a blast of deep rock masses in the Pubugou Hydropower Station. The results show that the low-frequency component in the microseismic records results mainly from the transient release of in situ stress, while the high-frequency component originates primarily from explosion. In addition, a numerical simulation was conducted to demonstrate the occurrence of microseismic events by the transient release of in situ stress, and the results seem to have confirmed fairly well the separated vibrations from microseismic records.

  4. Photogrammetric Recording in a Context of Preventive Archaeology : the "Place des Martyrs" Excavation (Algiers, Algeria)

    OpenAIRE

    SEGUIN, Maxime; Souq, François; Stiti, Kemal

    2014-01-01

    International audience; The construction of the underground station called Place des Martyrs in Algiers required preventive excavation. The context led us to favour recording methods leading to the rapid and exhaustive acquisition of data. Indeed digital photogrammetry made it possible to measure complex elements simply and rapidly. The originality of the solution implemented resided in the use of a free and open-source applications suite dedicated to scientific usage and making it possible t...

  5. The marble head of a statuette from Mediana (excavations in 2001)

    OpenAIRE

    Plemić Bojana

    2013-01-01

    During the archaeological excavations in Mediana in 2001, the head of a marble statuette of exceptional beauty and craftsmanship was discovered. It was an isolated discovery, the sculpture probably having been imported from some Greek artistic centre or an eastern Mediterranean workshop, presenting a part of a larger ensemble of sculptures that had adorned an imperial villa with peristyle. Since the head was found in pieces and being just part of a sculptural representation with no reliable a...

  6. MARSAME Radiological Release Report for Archaeological Artifacts Excavated from Area L

    Energy Technology Data Exchange (ETDEWEB)

    Ruedig, Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Whicker, Jeffrey Jay [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gillis, Jessica Mcdonnel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-03

    In 1991 Los Alamos National Laboratory’s (LANL’s) cultural resources team excavated archaeological site LA 4618 located at Technical Area 54, within Material Disposal Area L (MDA L). MDA L received non-radioactive chemical waste from the early 1960s until 1985. Further development of the MDA required excavation of several cultural sites under National Historic Preservation Act requirements; artifacts from these sites have been subsequently stored at LANL. The LANL cultural resources group would now like to release these artifacts to the Museum of Indian Arts and Culture in Santa Fe for curation. The history of disposal at Area L suggests that the artifact pool is unlikely to be chemically contaminated and LANL staff washed each artifact at least once following excavation. Thus, it is unlikely that the artifacts present a chemical hazard. LANL’s Environmental Stewardship group (EPC-ES) has evaluated the radiological survey results for the Area L artifact pool and found that the items described in this report meet the criteria for unrestricted radiological release under Department of Energy (DOE) Order 458.1 Radiation Protection of the Public and the Environment and are candidates for release without restriction from LANL control. This conclusion is based on the known history of MDA L and on radiation survey data.

  7. Three-Dimensional Laser Scanning for Geometry Documentation and Construction Management of Highway Tunnels during Excavation

    Science.gov (United States)

    Gikas, Vassilis

    2012-01-01

    Driven by progress in sensor technology, computer software and data processing capabilities, terrestrial laser scanning has recently proved a revolutionary technique for high accuracy, 3D mapping and documentation of physical scenarios and man-made structures. Particularly, this is of great importance in the underground space and tunnel construction environment as surveying engineering operations have a great impact on both technical and economic aspects of a project. This paper discusses the use and explores the potential of laser scanning technology to accurately track excavation and construction activities of highway tunnels. It provides a detailed overview of the static laser scanning method, its principles of operation and applications for tunnel construction operations. Also, it discusses the planning, execution, data processing and analysis phases of laser scanning activities, with emphasis given on geo-referencing, mesh model generation and cross-section extraction. Specific case studies are considered based on two construction sites in Greece. Particularly, the potential of the method is examined for checking the tunnel profile, producing volume computations and validating the smoothness/thickness of shotcrete layers at an excavation stage and during the completion of excavation support and primary lining. An additional example of the use of the method in the geometric documentation of the concrete lining formwork is examined and comparisons against dimensional tolerances are examined. Experimental comparisons and analyses of the laser scanning method against conventional surveying techniques are also considered. PMID:23112655

  8. The adoption of mechanized excavation techniques for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Laughton, C.; Nelson, P.; Lundin, T.

    1991-01-01

    The Superconducting Super Collider (SSC) is the latest and largest in a line of high-energy physics accelerator projects. The five increasingly energetic accelerators which make up the physics laboratory complex are to be housed almost entirely in subsurface structures, which will include over 100 km of small-diameter tunnel. Among other reasons, the Texas SSC site was chosen from a set of state proposals because of the suitability of the host rock materials for the performance of rapid and efficient excavation work. This site bedrock units are relatively soft and homogeneous and should allow for a maximum use of mechanical excavation plant for the various underground openings. This paper will review the site conditions and describe the developed understanding of geologic material behavior. With completion of planned large-scale in-situ studies of the ground behavior to provide acquisition of early site-specific excavation data, final design and construction detail of critical structures can be undertaken with the necessary degree of confidence to satisfy the stringent performance requirements. 5 refs., 4 figs., 6 tabs

  9. Our experience with the full-profile excavation of exploratory for tunnel pipes

    Directory of Open Access Journals (Sweden)

    Edita Lazarová

    2006-12-01

    Full Text Available The economic development of Slovakia places an emphasis on increasing the quality of transport infrastructure, which requires its modernization residing in building the transport network of international level and improving its efficiency and travel speed. The development of transport in Slovakia has been passing major changes related to the economic and political processes in the country. Regarding the geographical character of the land, the tunnel excavation is an inseparable feature of the road communications modernization. Approximately thirty kilometres of highway tunnels are planned for construction in Slovakia until 2020 and road tunnels should be constructed as well. The first modern highway tunnel Branisko, the longest one (4975 m in Slovakia was put into operation in 2003 with a preceding excavation of the Branisko exploratory gallery in the course of designed tunnel pipe. The tunnelling works on the exploratory gallery of Višňové tunnel started in January 1999 and finished in the late summer of 2002 due to unfavorable geological conditions. The excavation of a final profile of the Višňové tunnel is planned for 2007. The Horelica tunnel (605 m near Čadca was finished and put into operation in 2004. The tunnels Lučivná (250 m, Bôrik (999 m and Sitina (1440 m are in construction at present.

  10. Excavation of the Surikamigawa dam diversion tunnel. Surikamigawa dam karihaisui tunnel kantsu

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, T.; Konno, T. (Ministry of Construction, Tokyo (Japan))

    1994-04-01

    A bypass tunnel construction has been completed at the Surikamigawa dam (Japan). This paper describes the summary of the construction. The full-swing dam construction work is scheduled to begin in 1995. The soils distributed near the dam site consist of lapillus tuff containing andesite-based light stones and tuff-based conglomerates containing large gravels. Excavation of the dam diversion tunnel has used a blasting method, and the tunnel construction has adopted an automatic tunnel cross section marking system and a non-electric explosion method. This marking system is a system to irradiate a laser beam onto the facing to depict excavation lines that realizes labor saving and high-accuracy excavation. The error at the tunnel completion was found 20 mm. The non-electric explosion method ignites a coated explosive layer with an impact wave, which is electrostatically safe, and reduces blasting vibration. Electric detonators have also been used because of using ANFO explosives. The result obtained from measurements of inner space displacement necessary for the blasting process has indicated that the area near the dam site consists of stable mountains. 6 figs., 4 tabs.

  11. DEM modeling of failure mechanisms induced by excavations on the Moon

    Science.gov (United States)

    jiang, mingjing; shen, zhifu; Utili, Stefano

    2013-04-01

    2D Discrete Element Method (DEM) analyses were performed for excavations supported by retaining walls in lunar environment. The lunar terrain is made of a layer of sand (regolith) which differs from terrestrial sands for two main features: the presence of adhesive attractive forces due to van der Waals interactions and grains being very irregular in shape leading to high interlocking. A simplified contact model based on linear elasticity and perfect plasticity was employed. The contact model includes a moment - relative rotation law to account for high interlocking among grains and a normal adhesion law to account for the van der Waals interactions. Analyses of the excavations were run under both lunar and terrestrial environments. Under lunar environment, gravity is approximately one sixth than the value on Earth and adhesion forces between grains of lunar regolith due to van der Waals interactions are not negligible. From the DEM simulations it emerged that van der Waals interactions may significantly increase the bending moment and deflection of the retaining wall, and the ground displacements. Hence this study indicates that an unsafe estimate of the wall response to an excavation on the Moon would be obtained from physical experiments performed in a terrestrial environment, i.e., considering the effect of gravity but neglecting the van der Waals interactions.

  12. Optimization design of foundation excavation for Xiluodu super-high arch dam in China

    Directory of Open Access Journals (Sweden)

    Qixiang Fan

    2015-04-01

    Full Text Available With better understanding of the quality and physico-mechanical properties of rocks of dam foundation, and the physico-mechanical properties and structure design of arch dam in association with the foundation excavation of Xiluodu arch dam, the excavation optimization design was proposed for the foundation surface on the basis of feasibility study. Common analysis and numerical analysis results demonstrated the feasibility of using the weakly weathered rocks III1 and III2 as the foundation surface of super-high arch dam. In view of changes in the geological conditions at the dam foundation along the riverbed direction, the design of extending foundation surface excavation area and using consolidating grouting and optimizing structure of dam bottom was introduced, allowing for harmonization of the arch dam and foundation. Three-dimensional (3D geomechanics model test and finite element analysis results indicated that the dam body and foundation have good overload stability and high bearing capacity. The monitoring data showed that the behaviors of dam and foundation correspond with the designed patterns in the construction period and the initial operation period.

  13. Endoscopic en bloc resection of an exophytic gastrointestinal stromal tumor with suction excavation technique

    Science.gov (United States)

    Choi, Hyuk Soon; Chun, Hoon Jai; Kim, Kyoung-Oh; Kim, Eun Sun; Keum, Bora; Jeen, Yoon-Tae; Lee, Hong Sik; Kim, Chang Duck

    2016-01-01

    Here, we report the first successful endoscopic resection of an exophytic gastrointestinal stromal tumor (GIST) using a novel perforation-free suction excavation technique. A 49-year-old woman presented for further management of a gastric subepithelial tumor on the lesser curvature of the lower body, originally detected via routine upper gastrointestinal endoscopy. Abdominal computed tomography and endoscopic ultrasound showed a 4-cm extraluminally protruding mass originating from the muscularis propria layer. The patient firmly refused surgical resection owing to potential cardiac problems, and informed consent was obtained for endoscopic removal. Careful dissection and suction of the tumor was repeated until successful extraction was achieved without serosal injury. We named this procedure the suction excavation technique. The tumor’s dimensions were 3.5 cm × 2.8 cm × 2.5 cm. The tumor was positive for C-KIT and CD34 by immunohistochemical staining. The mitotic count was 6/50 high-power fields. The patient was followed for 5 years without tumor recurrence. This case demonstrated the use of endoscopic resection of an exophytic GIST using the suction excavation technique as a potential therapy without surgical resection. PMID:27340363

  14. Biofuel or excavation? - Life cycle assessment (LCA) of soil remediation options

    Energy Technology Data Exchange (ETDEWEB)

    Suer, Pascal; Andersson-Skoeld, Yvonne [Swedish Geotechnical Institute, 58193 Linkoeping (Sweden)

    2011-02-15

    The environmental consequences of soil remediation through biofuel or through dig-and-dump were compared using life cycle assessment (LCA). Willow (Salix viminalis) was actually grown in-situ on a discontinued oil depot, as a phytoremediation treatment. These data were used for the biofuel remediation, while excavation-and-refill data were estimated from experience. The biofuel remediation had great environmental advantages compared to the ex situ excavation remediation. With the ReCiPe impact assessment method, which included biodiversity, the net environmental effect was even positive, in spite of the fact that the wood harvest was not utilised for biofuel production, but left on the contaminated site. Impact from the Salix viminalis cultivation was mainly through land use for the short rotation coppice, and through journeys of control personnel. The latter may be reduced when familiarity with biofuel as a soil treatment method increases. The excavation-and-refill remediation was dominated by the landfill and the transport of contaminated soil and backfill. (author)

  15. Information-disturbance tradeoff in quantum measurements

    International Nuclear Information System (INIS)

    Maccone, Lorenzo

    2006-01-01

    We present a simple information-disturbance tradeoff relation valid for any general measurement apparatus: The disturbance between input and output states is lower bounded by the information the apparatus provides in distinguishing these two states

  16. 5-HTTLPR genotype potentiates the effects of war zone stressors on the emergence of PTSD, depressive and anxiety symptoms in soldiers deployed to iraq

    NARCIS (Netherlands)

    Telch, Michael J.; Beevers, Christopher G.; Rosenfield, David; Lee, Han Joo; Reijntjes, Albert; Ferrell, Robert E.; Hariri, Ahmad R.

    2015-01-01

    Exposure to war zone stressors is common, yet only a minority of soldiers experience clinically meaningful disturbance in psychological function. Identification of biomarkers that predict vulnerability to war zone stressors is critical for developing more effective treatment and prevention

  17. Disturbance Decoupling of Switched Linear Systems

    NARCIS (Netherlands)

    Yurtseven, E.; Heemels, W.P.M.H.; Camlibel, M.K.

    2010-01-01

    In this paper we consider disturbance decoupling problems for switched linear systems. We will provide necessary and sufficient conditions for three different versions of disturbance decoupling, which differ based on which signals are considered to be the disturbance. In the first version the

  18. Review of excavation methods and their implications for the near-field barrier of a deep underground repository

    International Nuclear Information System (INIS)

    Young, D.K.

    1993-01-01

    The report reviews excavation techniques for use in the construction of deep underground radioactive waste repositories, gives a summary of responses of the host rock to excavation and the means of measuring that response and discusses techniques for predicting that response. The review of excavation techniques included technical developments and current practice. To this end an extensive database was developed reviewing major excavations in rock types relevant to disposal and the techniques employed. Creation of an underground opening alters the properties of the rock mass around it. This study identifies stress, displacement, rock mass deformability and permeability as key parameters and reviews how they may be determined. Finally the report discusses the techniques available for predicting the behaviour of the near-field host rock. This concentrates on methods of numerical analysis since existing empirical or analytical methods are not considered suitable. (author)

  19. Experimental and Numerical Investigations of Soil Desiccation for Vadose Zone Remediation: Report for Fiscal Year 2007

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Andy L.; Oostrom, Mart; Bacon, Diana H.

    2008-02-04

    Apart from source excavation, the options available for the remediation of vadose zone metal and radionuclide contaminants beyond the practical excavation depth (0 to 15 m) are quite limited. Of the available technologies, very few are applicable to the deep vadose zone with the top-ranked candidate being soil desiccation. An expert panel review of the work on infiltration control and supplemental technologies identified a number of knowledge gaps that would need to be overcome before soil desiccation could be deployed. The report documents some of the research conducted in the last year to fill these knowledge gaps. This work included 1) performing intermediate-scale laboratory flow cell experiments to demonstrate the desiccation process, 2) implementing a scalable version of Subsurface Transport Over Multiple Phases–Water-Air-Energy (STOMP-WAE), and 3) performing numerical experiments to identify the factors controlling the performance of a desiccation system.

  20. Zone separator for multiple zone vessels

    Science.gov (United States)

    Jones, John B.

    1983-02-01

    A solids-gas contact vessel, having two vertically disposed distinct reaction zones, includes a dynamic seal passing solids from an upper to a lower zone and maintaining a gas seal against the transfer of the separate treating gases from one zone to the other, and including a stream of sealing fluid at the seal.

  1. Different Recovery Processes of Soil Ammonia Oxidizers from Flooding Disturbance.

    Science.gov (United States)

    Ye, Fei; Ma, Mao-Hua; Op den Camp, Huub J M; Chatzinotas, Antonis; Li, Lei; Lv, Ming-Quan; Wu, Sheng-Jun; Wang, Yu

    2018-04-11

    Understanding how microorganisms respond to environmental disturbance is one of the key focuses in microbial ecology. Ammonia-oxidizing bacteria (AOB) and archaea (AOA) are responsible for ammonia oxidation which is a crucial step in the nitrogen cycle. Although the physiology, distribution, and activity of AOA and AOB in soil have been extensively investigated, their recovery from a natural disturbance remains largely unknown. To assess the recovery capacities, including resistance and resilience, of AOA and AOB, soil samples were taken from a reservoir riparian zone which experienced periodically water flooding. The samples were classified into three groups (flooding, recovery, and control) for a high-throughput sequencing and quantitative PCR analysis. We used a relative quantitative index of both the resistance (RS) and resilience (RL) to assess the variation of gene abundance, alpha-diversity, and community composition. The AOA generally demonstrated a better recovery capability after the flooding disturbance compared to AOB. In particular, AOA were more resilient after the flooding disturbance. Taxa within the AOA and AOB showed different RS and RL values, with the most abundant taxa showing in general the highest RS indices. Soil NH 4 + and Fe 2+ /Fe 3+ were the main variables controlling the key taxa of AOA and AOB and probably influenced the resistance and resilience properties of AOA and AOB communities. The distinct mechanisms of AOA and AOB in maintaining community stability against the flooding disturbance might be linked to the different life-history strategies: the AOA community was more likely to represent r-strategists in contrast to the AOB community following a K-life strategy. Our results indicated that the AOA may play a vital role in ammonia oxidation in a fluctuating habitat and contribute to the stability of riparian ecosystem.

  2. Use of chemical explosives for emergency solar flare shelter construction and other excavations on the Martian surface

    International Nuclear Information System (INIS)

    Dick, R.D.; Blacic, J.D.; Pettitt, D.R.

    1985-01-01

    The necessity to shelter people on the Martian surface from solar flare particles at short notice and the need for long-term habitats with thick cosmic ray shielding suggests that explosives could be used effectively for excavation of such structures. Modern insensitive high explosives are safe, efficient, and reliable for rock breakage and excavation. Extensive Earth-bound experience leads us to propose several strategies for explosively-constructed shelters based on tunneling, cratering, and rock casting techniques

  3. Changes in geotechnical properties of sediments from the Central Indian Basin induced by disturbance experiment

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    -grained sediments from the study area showed change in geotechnical properties induced due to the disturbance. Marginal increase in natural water content and significant reduction in undrained shear strength at the 0-5 cm sediment layer of cores from the tow zone...

  4. 3D Numerical Modeling of Pile Group Responses to Excavation-Induced Stress Release in Silty Clay

    Directory of Open Access Journals (Sweden)

    M. A. Soomro

    2018-02-01

    Full Text Available Development of underground transportation systems consists of tunnels, basement construction excavations and cut and cover tunnels which may encounter existing pile groups during their construction. Since many previous studies mainly focus on the effects of excavations on single piles, settlement and load transfer mechanism of a pile group subjected to excavation-induced stress release are not well investigated and understood. To address these two issues, three-dimensional coupled-consolidation numerical analysis is conducted by using a hypoplastic model which takes small-strain stiffness into account. A non-linear pile group settlement was induced. This may be attributed to reduction of shaft resistance due to excavation induced stress release, the pile had to settle substantially to further mobilise end-bearing. Compared to the Sp of the pile group, induced settlement of the single pile is larger with similar settlement characteristics. Due to the additional settlement of the pile group, factor of safety for the pile group can be regarded as decreasing from 3.0 to 1.4, based on a displacement-based failure load criterion. Owing to non-uniform stress release, pile group tilted towards the excavation with value of 0.14%. Due to excavation-induced stress release and dragload, head load of rear piles was reduced and transferred to rear piles. This load transfer can increase the axial force in front piles by 94%.

  5. Modelling of the effect of discontinuities on the extent of the fracture zone surrounding deep tunnels

    CSIR Research Space (South Africa)

    Sellers, EJ

    2000-10-01

    Full Text Available - ments in sandstone and granite indicate that the breakout shape may be altered by the applied stress path, the strain rate, the boundary conditions and the excavation shape. (Ewy and Cook 1990a, 1990b; Gay 1973; Barla 1972... of sandstone containing cylindrical holes tested under increasing hy- drostatic pressures, up to 275 MPa, indicate that the extent of the fracture zone size increases with increasing pressure, until the entire sample fails (Gay...

  6. Construction of disturbed and intact soil blocks to develop percolating soil based treatment systems for dirty water from dairy farms.

    Science.gov (United States)

    Brookman, S K E; Chadwick, D R; Headon, D M

    2002-03-01

    Intact soil blocks with a surface area of 1.8 x 1.6 m, 1.0 m deep, were excavated in a coarse sandy loam. The sides of the soil blocks were supported with plywood before using hydraulic rams to force a steel cutting plate beneath them. Disturbed soil blocks of the same depth as the intact blocks were also established. Experiments were conducted to determine purification efficiencies for biological oxygen demand (BOD), molybdate reactive phosphorus (MRP), nitrate and ammonium-N after the application of dirty water. A preliminary experiment is described where a low application of dirty water was applied to the soil blocks, 2 mm day(-1). In addition, a chloride tracer was conducted for the duration of the experiment. Disturbed soil had a purification efficiency for BOD of 99% compared to 96% from intact soil (Pammonium-N were 100 and 99%, respectively, for the intact and disturbed soils. Nitrate-N concentration increased in leachate from both treatments reaching maximum concentrations of 15 and 8 mg l(-1) from disturbed and intact soils, respectively. Chloride traces for each soil block followed similar patterns with 47 and 51% loss from disturbed and intact soils, respectively.

  7. Assessment of disturbance at three spatial scales in two large tropical reservoirs

    Directory of Open Access Journals (Sweden)

    Letícia de Morais

    2016-12-01

    Full Text Available Large reservoirs are an increasingly common feature across tropical landscapes because of their importance for water supply, flood control and hydropower, but their ecological conditions are infrequently evaluated. Our objective was to assess the range of disturbances for two large tropical reservoirs and their influences on benthic macroinvertebrates. We tested three hypotheses: i a wide variation in the level of environmental disturbance can be observed among sites in the reservoirs; ii the two reservoirs would exhibit a different degree of disturbance level; and iii the magnitude of disturbance would influence the structure and composition of benthic assemblages. For each reservoir, we assessed land use (macroscale, physical habitat structure (mesoscale, and water quality (microscale. We sampled 40 sites in the littoral zones of both Três Marias and São Simão Reservoirs (Minas Gerais, Brazil. At the macroscale, we measured cover percentages of land use categories in buffer areas at each site, where each buffer was a circular arc of 250 m. At the mesoscale, we assessed the presence of human disturbances in the riparian and drawdown zones at the local (site scale. At the microscale, we assessed water quality at each macroinvertebrate sampling station using the Micro Disturbance Index (MDI. To evaluate anthropogenic disturbance of each site, we calculated an integrated disturbance index (IDI from a buffer disturbance index (BDI and a local disturbance index (LDI. For each site, we calculated richness and abundance of benthic macroinvertebrates, Chironomidae genera richness, abundance and percent Chironomidae individuals, abundance and percent EPT individuals, richness and percent EPT taxa, abundance and percent resistant individuals, and abundance and percent non-native individuals. We also evaluated the influence of disturbance on benthic macroinvertebrate assemblages at the entire-reservoir scale. The BDI, LDI and IDI had significantly

  8. Implications of recurrent disturbance for genetic diversity.

    Science.gov (United States)

    Davies, Ian D; Cary, Geoffrey J; Landguth, Erin L; Lindenmayer, David B; Banks, Sam C

    2016-02-01

    Exploring interactions between ecological disturbance, species' abundances and community composition provides critical insights for ecological dynamics. While disturbance is also potentially an important driver of landscape genetic patterns, the mechanisms by which these patterns may arise by selective and neutral processes are not well-understood. We used simulation to evaluate the relative importance of disturbance regime components, and their interaction with demographic and dispersal processes, on the distribution of genetic diversity across landscapes. We investigated genetic impacts of variation in key components of disturbance regimes and spatial patterns that are likely to respond to climate change and land management, including disturbance size, frequency, and severity. The influence of disturbance was mediated by dispersal distance and, to a limited extent, by birth rate. Nevertheless, all three disturbance regime components strongly influenced spatial and temporal patterns of genetic diversity within subpopulations, and were associated with changes in genetic structure. Furthermore, disturbance-induced changes in temporal population dynamics and the spatial distribution of populations across the landscape resulted in disrupted isolation by distance patterns among populations. Our results show that forecast changes in disturbance regimes have the potential to cause major changes to the distribution of genetic diversity within and among populations. We highlight likely scenarios under which future changes to disturbance size, severity, or frequency will have the strongest impacts on population genetic patterns. In addition, our results have implications for the inference of biological processes from genetic data, because the effects of dispersal on genetic patterns were strongly mediated by disturbance regimes.

  9. Charcoal records reveal past occurrences of disturbances in the forests of the Kisangani region, Democratic Republic of the Congo

    Science.gov (United States)

    Tshibamba Mukendi, John; Hubau, Wannes; Ntahobavuka, Honorine; Boyemba Bosela, Faustin; De Cannière, Charles; Beeckman, Hans

    2014-05-01

    Past disturbances have modified local density, structure and floristic composition of Central African rainforests. As such, these perturbations represent a driving force for forest dynamics and they were presumably at the origin of present-day forest mosaics. One of the most prominent disturbances within the forest is fire, leaving behind charcoal as a witness of past forest dynamics. Quantification and identification of ancient charcoal fragments found in soil layers (= pedoanthracology) allows a detailed reconstruction of forest history, including the possible occurrence of past perturbations. The primary objective of this study is to present palaeoenvironmental evidence for the existence of past disturbances in the forests of the Kisangani region (Democratic Republic of the Congo) using a pedoanthracological approach. We quantified and identified charcoal fragments from pedoanthracological excavations in the Yangambi, Yoko, Masako and Kole forest regions. Charcoal sampling was conducted in pit intervals of 10 cm, whereby pottery fragments were also registered and quantified. Floristic identifications were conducted using former protocols based on wood anatomy, which is largely preserved after charcoalification. 14 excavations were conducted and charcoal was found in most pit intervals. Specifically, 52 out of 56 sampled intervals from the Yangambi forest contained charcoal, along with 47 pit intervals from the Yoko forest reserve, 34 pit intervals from the Masako forest and 16 from the Kole forest. Highest specific anthracomasses were recorded in Yoko (167 mg charcoal per kg soil), followed by Yangambi (133 mg/kg), Masako (71,89 mg/kg) and finally Kole (42,4 mg/kg). Charcoal identifications point at a manifest presence of the family of Fabaceae (Caesalpinioideae). This family is characteristic for the tropical humid rainforest. The presence of charcoal fragments from these taxa, associated with pottery sherds on different depths within the profiles, suggests

  10. CASTLE3D - A Computer Aided System for Labelling Archaeological Excavations in 3D

    Science.gov (United States)

    Houshiar, H.; Borrmann, D.; Elseberg, J.; Nüchter, A.; Näth, F.; Winkler, S.

    2015-08-01

    Documentation of archaeological excavation sites with conventional methods and tools such as hand drawings, measuring tape and archaeological notes is time consuming. This process is prone to human errors and the quality of the documentation depends on the qualification of the archaeologist on site. Use of modern technology and methods in 3D surveying and 3D robotics facilitate and improve this process. Computer-aided systems and databases improve the documentation quality and increase the speed of data acquisition. 3D laser scanning is the state of the art in modelling archaeological excavation sites, historical sites and even entire cities or landscapes. Modern laser scanners are capable of data acquisition of up to 1 million points per second. This provides a very detailed 3D point cloud of the environment. 3D point clouds and 3D models of an excavation site provide a better representation of the environment for the archaeologist and for documentation. The point cloud can be used both for further studies on the excavation and for the presentation of results. This paper introduces a Computer aided system for labelling archaeological excavations in 3D (CASTLE3D). Consisting of a set of tools for recording and georeferencing the 3D data from an excavation site, CASTLE3D is a novel documentation approach in industrial archaeology. It provides a 2D and 3D visualisation of the data and an easy-to-use interface that enables the archaeologist to select regions of interest and to interact with the data in both representations. The 2D visualisation and a 3D orthogonal view of the data provide cuts of the environment that resemble the traditional hand drawings. The 3D perspective view gives a realistic view of the environment. CASTLE3D is designed as an easy-to-use on-site semantic mapping tool for archaeologists. Each project contains a predefined set of semantic information that can be used to label findings in the data. Multiple regions of interest can be joined under

  11. Disturbance in boreal forest ecosystems: human impacts and natural processes. Proceedings of the International Boreal Forest Research Association 1997 annual meeting; 1997 August 4-7; Duluth, Minnesota.

    Science.gov (United States)

    2000-01-01

    The papers in these proceedings cover a wide range of topics related to human and natural disturbance processes in forests of the boreal zone in North America and Eurasia. Topics include historic and predicted landscape change; forest management; disturbance by insects, fire, air pollution, severe weather, and global climate change; and carbon cycling.

  12. Characterization and functional correlation of multiple imaging modalities with focal choroidal excavation

    Directory of Open Access Journals (Sweden)

    Yun-Chen Chen

    2018-05-01

    Full Text Available Background: To investigate the clinical manifestations and imaging features of near-infrared autofluorescence (NIA, infrared reflectance (IR, fundus autofluorescence (FAF, indocyanine green angiography (ICGA and fluorescein angiography (FAG in the detection of patients with focal choroidal excavation (FCE identified by cross-sectional spectral-domain optical coherence tomography (SD-OCT. Methods: This retrospective cross-sectional study included 12 eyes of 10 Taiwanese patients with FCE diagnosed by SD-OCT. The areas and depths of FCE in serial cross-sectional and en-face OCT were compared in different imaging modalities. NIA, IR, FAF, ICGA and FAG images were obtained. Best corrected visual acuity, subjective distortion area in the Amsler grid and history of maculopathies were also recorded. Results: In areas where the choroid started to excavate as shown in SD-OCT, hypo-autofluorescence in NIA was noted. The area of hypo-fluorescence in NIA of all the FCE lesions showed good correlation with the size. The area of FCE was associated with complications such as choroidal neovascularization and central serous chorioretinopathy (p = 0.014, d.f = 1 and the volume (NIA area × Depth measured by SD-OCT × 1/3 was associated with subjective distortion strongly (p = 0.051, Spearman's correlation = 0.600. Conclusion: Among all image modalities, NIA was the most sensitive tool in area measurement of FCE and peripheral lesion detection. Also, the volume of FCE was associated with subjective distortion and the area was related to complications. Recording the area and volume of FCE could play an important role in monitoring complications. Keywords: Choroid-retina disease, Focal choroidal excavation, Near-infrared autofluorescence, Spectral-domain optical coherence tomography

  13. Design of Intelligent Hydraulic Excavator Control System Based on PID Method

    Science.gov (United States)

    Zhang, Jun; Jiao, Shengjie; Liao, Xiaoming; Yin, Penglong; Wang, Yulin; Si, Kuimao; Zhang, Yi; Gu, Hairong

    Most of the domestic designed hydraulic excavators adopt the constant power design method and set 85%~90% of engine power as the hydraulic system adoption power, it causes high energy loss due to mismatching of power between the engine and the pump. While the variation of the rotational speed of engine could sense the power shift of the load, it provides a new method to adjust the power matching between engine and pump through engine speed. Based on negative flux hydraulic system, an intelligent hydraulic excavator control system was designed based on rotational speed sensing method to improve energy efficiency. The control system was consisted of engine control module, pump power adjusted module, engine idle module and system fault diagnosis module. Special PLC with CAN bus was used to acquired the sensors and adjusts the pump absorption power according to load variation. Four energy saving control strategies with constant power method were employed to improve the fuel utilization. Three power modes (H, S and L mode) were designed to meet different working status; Auto idle function was employed to save energy through two work status detected pressure switches, 1300rpm was setting as the idle speed according to the engine consumption fuel curve. Transient overload function was designed for deep digging within short time without spending extra fuel. An increasing PID method was employed to realize power matching between engine and pump, the rotational speed's variation was taken as the PID algorithm's input; the current of proportional valve of variable displacement pump was the PID's output. The result indicated that the auto idle could decrease fuel consumption by 33.33% compared to work in maximum speed of H mode, the PID control method could take full use of maximum engine power at each power mode and keep the engine speed at stable range. Application of rotational speed sensing method provides a reliable method to improve the excavator's energy efficiency and

  14. Evaluation of focal choroidal excavation in the macula using swept-source optical coherence tomography.

    Science.gov (United States)

    Lim, F P M; Loh, B K; Cheung, C M G; Lim, L S; Chan, C M; Wong, D W K

    2014-09-01

    To evaluate imaging findings of patients with focal choroidal excavation (FCE) in the macula using swept-source optical coherence tomography (SS-OCT) and correlate it clinically. Prospective observational case series. Eleven consecutive patients (12 eyes) with FCE were described. Data on demographics and clinical presentation were collected and imaging findings (including color photography, fundus autofluorescence imaging, fluorescein angiography, indocyanine green angiography, spectral-domain optical coherence tomography, and SS-OCT) were analyzed. The primary diagnosis was epiretinal membrane (two eyes), choroidal neovascularization (one eye), polypoidal choroidal vasculopathy (three eyes), central serous chorioretinopathy (one eye), and dry age-related macular degeneration (two eyes). Eleven out of 12 of the lesions were conforming. One presented with a non-conforming lesion that progressed to a conforming lesion. One eye had multiFCE and two had two overlapping choroidal excavations. Using the SS-OCT, we found the choroid to be thinned out at the area of FCE but sclera remained normal. The choroidal tissue beneath the FCE was abnormal, with high internal reflectivity and poor visualization of choroidal vessels. There was loss of contour of the outer choroidal boundary that appeared to be pulled inward by this abnormal choroidal tissue. A suprachoroidal space was noted beneath this choroidal tissue and the choroidal-scleral interface was smooth. Repeat SS-OCT 6 months after presentation showed the area of excavation to be stable in size. FCE can be associated with epiretinal membrane, central serous chorioretinopathy, and age-related macular degeneration. The choroid was thinned out in the area of FCE.

  15. Numerical calculation of hydrodynamic characteristics of tidal currents for submarine excavation engineering in coastal area

    Directory of Open Access Journals (Sweden)

    Jian-hua Li

    2016-04-01

    Full Text Available In coastal areas with complicated flow movement, deposition and scour readily occur in submarine excavation projects. In this study, a small-scale model, with a high resolution in the vertical direction, was used to simulate the tidal current around a submarine excavation project. The finite volume method was used to solve Navier-Stokes equations and the Reynolds stress transport equation, and the entire process of the tidal current was simulated with unstructured meshes, generated in the irregular shape area, and structured meshes, generated in other water areas. The meshes near the bottom and free surface were densified with a minimum layer thickness of 0.05 m. The volume of fluid method was used to track the free surface, the volume fraction of cells on the upstream boundary was obtained from the volume fraction of adjacent cells, and that on the downstream boundary was determined by the water level process. The numerical results agree with the observed data, and some conclusions can be drawn: after the foundation trench excavation, the flow velocity decreases quite a bit through the foundation trench, with reverse flow occurring on the lee slope in the foundation trench; the swirling flow impedes inflow, leading to the occurrence of dammed water above the foundation trench; the turbulent motion is stronger during ebbing than in other tidal stages, the range with the maximum value of turbulent viscosity, occurring on the south side of the foundation trench at maximum ebbing, is greater than those in other tidal stages in a tidal cycle, and the maximum value of Reynolds shear stress occurs on the south side of the foundation trench at maximum ebbing in a tidal cycle. The numerical calculation method shows a strong performance in simulation of the hydrodynamic characteristics of tidal currents in the foundation trench, providing a basis for submarine engineering construction in coastal areas.

  16. Evaluation of focal choroidal excavation in the macula using swept-source optical coherence tomography

    Science.gov (United States)

    Lim, F P M; Loh, B K; Cheung, C M G; Lim, L S; Chan, C M; Wong, D W K

    2014-01-01

    Purpose To evaluate imaging findings of patients with focal choroidal excavation (FCE) in the macula using swept-source optical coherence tomography (SS-OCT) and correlate it clinically. Methods Prospective observational case series. Eleven consecutive patients (12 eyes) with FCE were described. Data on demographics and clinical presentation were collected and imaging findings (including color photography, fundus autofluorescence imaging, fluorescein angiography, indocyanine green angiography, spectral-domain optical coherence tomography, and SS-OCT) were analyzed. Results The primary diagnosis was epiretinal membrane (two eyes), choroidal neovascularization (one eye), polypoidal choroidal vasculopathy (three eyes), central serous chorioretinopathy (one eye), and dry age-related macular degeneration (two eyes). Eleven out of 12 of the lesions were conforming. One presented with a non-conforming lesion that progressed to a conforming lesion. One eye had multiFCE and two had two overlapping choroidal excavations. Using the SS-OCT, we found the choroid to be thinned out at the area of FCE but sclera remained normal. The choroidal tissue beneath the FCE was abnormal, with high internal reflectivity and poor visualization of choroidal vessels. There was loss of contour of the outer choroidal boundary that appeared to be pulled inward by this abnormal choroidal tissue. A suprachoroidal space was noted beneath this choroidal tissue and the choroidal–scleral interface was smooth. Repeat SS-OCT 6 months after presentation showed the area of excavation to be stable in size. Conclusion FCE can be associated with epiretinal membrane, central serous chorioretinopathy, and age-related macular degeneration. The choroid was thinned out in the area of FCE. PMID:24946847

  17. Archeological Excavations at Two Prehistoric Campsites Near Keystone Dam, El Paso, Texas.

    Science.gov (United States)

    1985-07-19

    Flotacion Microdebitate Analysis 246 Groundstone Artifacts 253 Slab Metates 253 Manos 253 PesLIes 253 Groundstone Fragments 263 Anvils 263 Polishing...important new information to our understanding of local prehistory. The bulk ot O’LaugnliLn’s (1980) work in the area was directed toward the excavation...contains or summarizes the bulk of L111 ptiiaisiitd( iaci on iitnic artiract frequenCies irom El Paso ’Ir’Ia Sites. fhese data, along with those from the

  18. Deformation and failure mechanism of excavation in clay subjected to hydraulic uplift

    CERN Document Server

    Hong, Yi

    2016-01-01

    This book presents the latest experimental and numerical analysis work in the field of ground deformation and base instability of deep excavations in soft clay subjected to hydraulic uplift. The authors’ latest research findings, based on dimensional analyses, well-instrumented full-scale field tests, systematic coupled-consolidation finite element analyses and centrifuge tests are reported. This book shows how to systematically approach a complex geotechnical problem, from identifying existing problems, reviewing literature, to dimensional and numerical analyses, validation through full-scale testing and centrifuge model testing. The methodologies are also introduced as major tools adopted in geotechnical research.

  19. New Design Concept for an Excavator Arms by Using Composite Material

    Science.gov (United States)

    Solazzi, L.; Assi, A.; Ceresoli, F.

    2018-06-01

    The purpose of the present paper is to lightweight design an excavator arms, by using a different materials and in particular composite material. Specifically, the research is based on the study of a commercial excavator, by determining its geometry and analyzing the load conditions to which it is exposed. These are determined in relation to either the load diagram of the machine or the possible utilities of the excavator, such as the rotation of the machine. The materials used and implemented in the different analytical and numerical elaborations are classic construction steel S 355 (UNI EN 10025-3), high-resistance steel S 890 (UNI EN 10025-6), aluminum Al 6063 T6 (UNI EN 573-3) and the composite material made by carbon fiber and epoxy resin. The adopted constraints for the design of new arms with different materials, non-conventional for these applications, are numerous. The new solutions must present a safety factor either with respect to the yield tensile strength or to the critical load of buckling greater than or equal to the one determined for the excavator in its original geometrical conformation. Another criterion, which has heavily conditioned the geometry of the arms, was given by the fact that the developed solutions must present a very similar value of the maximum displacement in the different load conditions analyzed. A new geometry for arms made by composite material was developed. It was an elliptical conic section, instead of the classic rectangular section, in order to use the filament winding technological process. As for the adoption of the composite material, we focused on the study and the design of this material as long as the interaction with the extremities (made of aluminum) which are interfaced either with the link between the arms or with the elements of the hydraulic plant which serves for the arms movement. From the results developed, it emerges that the solution developed by adopting composite materials is the one that permits the

  20. Natural diet of coral-excavating sponges consists mainly of dissolved organic carbon (DOC.

    Directory of Open Access Journals (Sweden)

    Benjamin Mueller

    Full Text Available Coral-excavating sponges are the most important bioeroders on Caribbean reefs and increase in abundance throughout the region. This increase is commonly attributed to a concomitant increase in food availability due to eutrophication and pollution. We therefore investigated the uptake of organic matter by the two coral-excavating sponges Siphonodictyon sp. and Cliona delitrix and tested whether they are capable of consuming dissolved organic carbon (DOC as part of their diet. A device for simultaneous sampling of water inhaled and exhaled by the sponges was used to directly measure the removal of DOC and bacteria in situ. During a single passage through their filtration system 14% and 13% respectively of the total organic carbon (TOC in the inhaled water was removed by the sponges. 82% (Siphonodictyon sp.; mean ± SD; 13 ± 17 μmol L(-1 and 76% (C. delitrix; 10 ± 12 μmol L(-1 of the carbon removed was taken up in form of DOC, whereas the remainder was taken up in the form of particulate organic carbon (POC; bacteria and phytoplankton despite high bacteria retention efficiency (72 ± 15% and 87 ± 10%. Siphonodictyon sp. and C. delitrix removed DOC at a rate of 461 ± 773 and 354 ± 562 μmol C h(-1 respectively. Bacteria removal was 1.8 ± 0.9 × 10(10 and 1.7 ± 0.6 × 10(10 cells h(-1, which equals a carbon uptake of 46.0 ± 21.2 and 42.5 ± 14.0 μmol C h(-1 respectively. Therefore, DOC represents 83 and 81% of the TOC taken up by Siphonodictyon sp. and C. delitrix per hour. These findings suggest that similar to various reef sponges coral-excavating sponges also mainly rely on DOC to meet their carbon demand. We hypothesize that excavating sponges may also benefit from an increasing production of more labile algal-derived DOC (as compared to coral-derived DOC on reefs as a result of the ongoing coral-algal phase shift.

  1. Natural diet of coral-excavating sponges consists mainly of dissolved organic carbon (DOC).

    Science.gov (United States)

    Mueller, Benjamin; de Goeij, Jasper M; Vermeij, Mark J A; Mulders, Yannick; van der Ent, Esther; Ribes, Marta; van Duyl, Fleur C

    2014-01-01

    Coral-excavating sponges are the most important bioeroders on Caribbean reefs and increase in abundance throughout the region. This increase is commonly attributed to a concomitant increase in food availability due to eutrophication and pollution. We therefore investigated the uptake of organic matter by the two coral-excavating sponges Siphonodictyon sp. and Cliona delitrix and tested whether they are capable of consuming dissolved organic carbon (DOC) as part of their diet. A device for simultaneous sampling of water inhaled and exhaled by the sponges was used to directly measure the removal of DOC and bacteria in situ. During a single passage through their filtration system 14% and 13% respectively of the total organic carbon (TOC) in the inhaled water was removed by the sponges. 82% (Siphonodictyon sp.; mean ± SD; 13 ± 17 μmol L(-1)) and 76% (C. delitrix; 10 ± 12 μmol L(-1)) of the carbon removed was taken up in form of DOC, whereas the remainder was taken up in the form of particulate organic carbon (POC; bacteria and phytoplankton) despite high bacteria retention efficiency (72 ± 15% and 87 ± 10%). Siphonodictyon sp. and C. delitrix removed DOC at a rate of 461 ± 773 and 354 ± 562 μmol C h(-1) respectively. Bacteria removal was 1.8 ± 0.9 × 10(10) and 1.7 ± 0.6 × 10(10) cells h(-1), which equals a carbon uptake of 46.0 ± 21.2 and 42.5 ± 14.0 μmol C h(-1) respectively. Therefore, DOC represents 83 and 81% of the TOC taken up by Siphonodictyon sp. and C. delitrix per hour. These findings suggest that similar to various reef sponges coral-excavating sponges also mainly rely on DOC to meet their carbon demand. We hypothesize that excavating sponges may also benefit from an increasing production of more labile algal-derived DOC (as compared to coral-derived DOC) on reefs as a result of the ongoing coral-algal phase shift.

  2. Detection of parasite eggs from archaeological excavations in the Republic of Korea

    Directory of Open Access Journals (Sweden)

    Eun-Taek Han

    2003-01-01

    Full Text Available Excavations at two sites dating from 2000 BC-1900 AD in southeastern areas of the Republic of Korea, revealed the remains of several structures. Examination of the contents suspected privies revealed the presence of eggs from 5 kinds of parasite: Ascaris, Trichuris, Clonorchis, and two species of unknown trematodes. Clonorchis sinensis eggs were found in a soil dating from around AD 668-935. This is the first record of C. sinensis eggs in archaeological materials in the Republic of Korea.

  3. Failure rate and reliability of the KOMATSU hydraulic excavator in surface limestone mine

    Science.gov (United States)

    Harish Kumar N., S.; Choudhary, R. P.; Murthy, Ch. S. N.

    2018-04-01

    The model with failure rate function of bathtub-shaped is helpful in reliability analysis of any system and particularly in reliability associated privative maintenance. The usual Weibull distribution is, however, not capable to model the complete lifecycle of the any with a bathtub-shaped failure rate function. In this paper, failure rate and reliability analysis of the KOMATSU hydraulic excavator/shovel in surface mine is presented and also to improve the reliability and decrease the failure rate of each subsystem of the shovel based on the preventive maintenance. The model of the bathtub-shaped for shovel can also be seen as a simplification of the Weibull distribution.

  4. Ecology and economic estimate of using of the underground excavation space

    International Nuclear Information System (INIS)

    Umnov, V.A.; Tarasov, V.F.; Tret'yakov, I.O.; Sheloumov, A.A.

    1995-01-01

    Stages of ecological and economic estimates of utilizing underground space, including evaluation of underground space resources, selection of its utilization trends and substantiation of optimal parameters for selected trends, are considered. Certain directions of possible repeated utilization of mining excavations are shown, including underground hydropower stations, underground energy storages, underground nuclear stations. Underground waste disposal is one of the most available directions in utilization of the underground space presently. Evaluation of the underground space utilization at all stages envisages complete account of all economical, social and ecological results

  5. Excavations in 2014 at Wade Street, Bristol - a documentary and archaeological analysis

    OpenAIRE

    Nick Corcos; Kamal Badreshany; Alejandra Gutiérrez; Rachel Heaton; Lorrain Higbee; Sarah Newns; Rachel Tyson

    2017-01-01

    A staged programme of historical research and archaeological fieldwork, involving a desk-based assessment in 2000 (Smith and Erskine 2000), an evaluation in 2013 (Mason 2013), and an excavation followed by a watching brief in 2014, the latter two by Avon Archaeology Ltd, was undertaken in order to mitigate the archaeological impact of a proposed residential development on a site of 1,260m² at the corner and on the north-west side of Little Anne Street and Wade Street, St Jude’s, Bristol. The ...

  6. Study on dynamic behavior of a shaft excavation through a faulted crystalline rock mass

    International Nuclear Information System (INIS)

    Hashizume, Shigeru; Matsui, Hiroya; Horiuchi, Yasuharu; Hata, Koji; Akiyoshi, Kenji; Sato, Shin; Shibata, Chihoko; Niunoya, Sumio; Noda, Masaru

    2013-01-01

    The 'Mizunami Underground Research Laboratory' has been studying and developing engineering technology for deep underground applications. These applications are multifaceted and are categorized as development of design and construction planning technology, development construction technology, development of countermeasure technology, and development of technology for construction and operation security. In this report, the dynamic behavior of shaft and the surrounding rock mass has been studied with respect to rock mass displacement and stress, the effect of using a concrete liner and excavating through faulted crystalline rock. (author)

  7. Excavation effects on tuff - recent findings and plans for investigations at Yucca Mountain

    International Nuclear Information System (INIS)

    Blejwas, T.E.; Zimmerman, R.M.; Shephard, L.E.

    1989-01-01

    Plans for site-characterization testing and constructing an exploratory shaft facility (ESF) at Yucca Mountain, Nevada, have been influenced by the construction and monitoring of stable openings in G-Tunnel on the Nevada Test Site. G-Tunnel provides access for testing in a thin bed of unsaturated welded tuff that is similar to that at Yucca Mountain. The data from the experiments in the ESF will be used to validate analytical methods for predicting the response of underground openings to the excavation process and to the heat generated by the waste

  8. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis

    OpenAIRE

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070-c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subse...

  9. Geotechnical issues and guidelines for storage of compressed air in excavated hard rock caverns

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Doherty, T.J.; Fossum, A.F.

    1982-04-01

    The results of a literature survey on the stability of excavated hard rock caverns are presented. The objective of the study was to develop geotechnical criteria for the design of compressed air energy storage (CAES) caverns in hard rock formations. These criteria involve geologic, hydrological, geochemical, geothermal, and in situ stress state characteristics of generic rock masses. Their relevance to CAES caverns, and the identification of required research areas, are identified throughout the text. This literature survey and analysis strongly suggests that the chief geotechnical issues for the development and operation of CAES caverns in hard rock are impermeability for containment, stability for sound openings, and hydrostatic balance.

  10. Disturbance maintains alternative biome states.

    Science.gov (United States)

    Dantas, Vinícius de L; Hirota, Marina; Oliveira, Rafael S; Pausas, Juli G

    2016-01-01

    Understanding the mechanisms controlling the distribution of biomes remains a challenge. Although tropical biome distribution has traditionally been explained by climate and soil, contrasting vegetation types often occur as mosaics with sharp boundaries under very similar environmental conditions. While evidence suggests that these biomes are alternative states, empirical broad-scale support to this hypothesis is still lacking. Using community-level field data and a novel resource-niche overlap approach, we show that, for a wide range of environmental conditions, fire feedbacks maintain savannas and forests as alternative biome states in both the Neotropics and the Afrotropics. In addition, wooded grasslands and savannas occurred as alternative grassy states in the Afrotropics, depending on the relative importance of fire and herbivory feedbacks. These results are consistent with landscape scale evidence and suggest that disturbance is a general factor driving and maintaining alternative biome states and vegetation mosaics in the tropics. © 2015 John Wiley & Sons Ltd/CNRS.

  11. The influence of cathode excavation of cathodic arc evaporator on thickness uniformity and erosion products angle distribution

    Directory of Open Access Journals (Sweden)

    D. V. Duhopel'nikov

    2014-01-01

    Full Text Available Cathodic arc evaporators are used for coating with functional films. Prolonged or buttend evaporators may be used for this purposes. In butt-end evaporator the cathode spots move continuously on the cathode work surface and evaporate cathode material. High depth excavation profile forms on the cathode work surface while the thick coating precipitation (tens or hundreds of microns. The cathode excavation profile is shaped like a “cup” with high walls for electrostatic discharge stabilization systems with axial magnetic fields. Cathode spots move on the bottom of the “cup”. It is very likely that high “cup” walls are formed as a result of lasting work time influence on the uniformity of precipitated films.In the present work the influence of excavation profile walls height on the uniformity of precipitated coating was carried out. The high profile walls are formed due to lasting work of DC vacuum arc evaporator. The cathode material used for tests was 3003 aluminum alloy. The extended substrate was placed parallel to the cathode work surface. Thickness distribution along the substrate length with the new cathode was obtained after 6 hours and after 12 hours of continuous operation.The thickness distribution of precipitated coating showed that the cathode excavation has an influence on the angular distribution of the matter escaping the cathode. It can be clearly seen from the normalized dependence coating thickness vs the distance from the substrate center. Also the angular distribution of the matter flow from the cathode depending on the cathode working time was obtained. It was shown that matter flow from the cathode differs from the LambertKnudsen law. The more the cathode excavation the more this difference.So, cathode excavation profile has an influence on the uniformity of precipitated coating and it is necessary to take in account the cathode excavation profile while coating the thick films.

  12. Radiation protection zoning

    International Nuclear Information System (INIS)

    2015-01-01

    Radiation being not visible, the zoning of an area containing radioactive sources is important in terms of safety. Concerning radiation protection, 2 work zones are defined by regulations: the monitored zone and the controlled zone. The ministerial order of 15 may 2006 settles the frontier between the 2 zones in terms of radiation dose rates, the rules for access and the safety standards in both zones. Radioprotection rules and the name of the person responsible for radiation protection must be displayed. The frontier between the 2 zones must be materialized and marked with adequate equipment (specific danger signs and tapes). Both zones are submitted to selective entrance, the access for the controlled zone is limited because of the radiation risk and of the necessity of confining radioactive contamination while the limitation of the access to the monitored zone is due to radiation risk only. (A.C.)

  13. Soil disturbance as a grassland restoration measure

    DEFF Research Database (Denmark)

    Schnoor, Tim; Bruun, Hans Henrik; Olsson, Pål Axel

    2015-01-01

    Soil disturbance is recognized as an important driver of biodiversity in dry grasslands, and can therefore be implemented as a restoration measure. However, because community re-assembly following disturbance includes stochastic processes, a focus only on species richness or establishment success...... to experimental disturbance treatments (ploughing or rotavation), and the vegetation was surveyed during four subsequent years of succession. Treated plots were compared with control plots representing untreated grassland, as well as nearby plots characterized by plant communities representing the restoration...

  14. A study on excavation of rock mass by lasers. Researching the possibility of utilizing low-power lasers

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Fumio [Taisei Corporation, Technology Research Center, Yokohama, Kanagawa (Japan)

    2000-03-01

    The object of this research is to develop the techniques of rock-mass excavation by laser irradiation. This rock-mass excavation technique by lasers has a characteristic of extremely little effect to the surroundings of an excavation site no matter how the target rock mass is with regard to geological aspects and given physical property. Moreover, it could be utilized in excavation of waste dump facilities, which need to be re-buried, and applied to excavation of long piles and tunnels, which are drilled through different kinds of strata, and to improvement of rock mass and ground. Lasers have a characteristic of concentrating the energy into a limited point and not only discontinue or cut a large area with a small output like sharp scissors but also block up the cracks deep inside the rock mass by fusing vitrification for its improvement. It leads to restrain the loss of energy, minimization of the effected environment, effective utilization of resources and energy, environmental restoration, and improvement of the working environment. In the field of nuclear fuel, which includes excavating dump pits, dismantling a furnace, and taking appropriate steps of mine remains, excavating, cutting, and fusing could be required to do within a limited space of rock mass or concrete. Up to the present, those things have been done mainly by large machines, but it is too scarce in possibility for them to improve their large size, heavy weight, difficulty in unmanned operation, limited shapes of cutting, and stabilization of waste. In this research the concrete system images have been examined, doing the fundamental researches about higher-power lasers, smaller sizing, transmitting by fibers to find our the breakthrough to realization of laser excavation, This year, as the summary of examining the laser excavation techniques, utilizing a low-power laser, which is thought to be highly effective in rock-mass improvement, will be examined, considering application of the technique

  15. Influence of disturbance on temperate forest productivity

    Science.gov (United States)

    Peters, Emily B.; Wythers, Kirk R.; Bradford, John B.; Reich, Peter B.

    2013-01-01

    Climate, tree species traits, and soil fertility are key controls on forest productivity. However, in most forest ecosystems, natural and human disturbances, such as wind throw, fire, and harvest, can also exert important and lasting direct and indirect influence over productivity. We used an ecosystem model, PnET-CN, to examine how disturbance type, intensity, and frequency influence net primary production (NPP) across a range of forest types from Minnesota and Wisconsin, USA. We assessed the importance of past disturbances on NPP, net N mineralization, foliar N, and leaf area index at 107 forest stands of differing types (aspen, jack pine, northern hardwood, black spruce) and disturbance history (fire, harvest) by comparing model simulations with observations. The model reasonably predicted differences among forest types in productivity, foliar N, leaf area index, and net N mineralization. Model simulations that included past disturbances minimally improved predictions compared to simulations without disturbance, suggesting the legacy of past disturbances played a minor role in influencing current forest productivity rates. Modeled NPP was more sensitive to the intensity of soil removal during a disturbance than the fraction of stand mortality or wood removal. Increasing crown fire frequency resulted in lower NPP, particularly for conifer forest types with longer leaf life spans and longer recovery times. These findings suggest that, over long time periods, moderate frequency disturbances are a relatively less important control on productivity than climate, soil, and species traits.

  16. Excavation and internment of depleted uranium and thorium soils, AHMC Jonesboro, Tennessee

    International Nuclear Information System (INIS)

    Bernhardt, D.E.; Prewett, S.V.; Boddy, J.R.

    1986-01-01

    This report describes the construction activities for the rockfilled berm and the excavation and disposal of contaminated soil, and the activities to certify the adequacy of the remedial activities. It focuses on the final closure. Mishu and Prewett in a paper in this proceeding provide additional information of the rockfilled wall. The final phase of the remedial program, referred to as the pond closure project, encompassed excavation of contaminated soil from the pond site and entombment of the waste in an encapsulating clay cell. The disposal cell was located at the pond site, and was situated above the level of the projected 100- and 500-year floods from Little Limestone Creek, which is adjacent to the site. The cell was built by completely enclosing the contaminated soil in a compacted clay liner and covering it with a compacted clay cap, each having a minimum thickness of four feet. Contaminated soil from the pond area and Aerojet Heavy Metals Company (AHMC) completed the remedial program for an inactive evaporation pond at its facility near Jonesboro, Tennessee during the summer of 1985. The pond had been used for process liquid wastes containing depleted uranium and thorium. Depleted uranium is a by-product of uranium richment, does not refer to use in a reactor, and does not contain Ra-226 or the associated decay products

  17. Fish Remains from Excavations near the Riverfront at Newcastle upon Tyne, England

    Directory of Open Access Journals (Sweden)

    Rebecca A. Nicholson

    1997-12-01

    Full Text Available The City of Newcastle, situated some 10 miles inland on the River Tyne in north-east England, is not now an important fishing port. Most of the fresh fish marketed in the city has been landed at the nearby coastal ports of North and South Shields. Excavations at two sites behind the present Quayside in Newcastle, however, have yielded quantities of fish bones, representing a wide variety of species. This is in contrast to excavations in other parts of the city, where few fish remains have been recovered, and suggests that the quayside in Newcastle was an important centre for the fishing industry during the medieval period. It seems likely that most of the fish remains represent waste from landing and processing fish on or near the quayside. Yet, when taphonomic factors are taken into account, the limitations of using even large bone assemblages to interpret processing activities is demonstrated. As always, the need for a programme of on-site sieving to obtain representative samples of fish bone is evident.

  18. A new technique in the excavation of ground-nest bee burrows (Hymenoptera: Apoidea

    Directory of Open Access Journals (Sweden)

    Diego Marinho

    2018-01-01

    Full Text Available Bees have a diversified natural history, thus the methods applied to study such diversity are varied. When it comes to studies of nesting biology, bees which nest in pre-existing cavities have been reasonably well studied since researchers started using trap-nests. However, bees whose nests are built underground are poorly studied due to the difficulty of finding natural nesting areas and the absence of a method that facilitates bee nest excavation. The latter is evidenced by the lack of accurate descriptions in literature of how nests are excavated. In this study we tested cylindrical rubber refills of eraser pen as a new material to be used as a tracer of underground nest galleries in a natural nesting area of two species of Epicharis Klug, 1807 (Apidae. We compared this technique directly with plaster in powder form mixed with water and our results with other methodological studies describing alternative methods and materials. The rubber refill technique overcame the main issues presented by materials such as plaster, molten metal alloys and bioplastic, namely: death of the organisms by high temperatures and/or formation of plugs and materials unduly following the roots inside the galleries. Keywords: Apidae, Apoidea, Brood cells, Methodology, Solitary bees

  19. Excavation-caused extra deformation of existing masonry residence in soft soil region

    Science.gov (United States)

    Tang, Y.; Franceschelli, S.

    2017-04-01

    Growing need for construction of infrastructures and buildings in fast urbanization process creates challenges of interaction between buildings under construction and adjacent existing buildings. This paper presents the mitigation of contradiction between two parties who are involved the interaction using civil engineering techniques. Through the in-depth analysis of the results of monitoring surveys and enhanced accuracy and reliability of surveys, a better understanding of the behavior of deformable buildings is achieved. Combination with the original construction documents, the two parties agree that both of them are responsible for building damages and a better understanding for the rehabilitation of the existing buildings is focused on. Two cases studies are used to demonstrate and describe the importance of better understanding of the behavior of existing buildings and their rehabilitations. The objective of this study is to insight into mechanisms of soil-structure interaction for buildings adjacent to deep excavations, which can result in a damage in existing masonry residence, and to take the optimized measures to make deep excavations safety and economic and adjacent buildings keep good serviceability in urban areas with soft soil conditions.

  20. A research on the excavation, support, and environment control of large scale underground space

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Pil Chong; Kwon, Kwang Soo; Jeong, So Keul [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    With the growing necessity of the underground space due to the deficiency of above-ground space, the size and shape of underground structures tend to be complex and diverse. This complexity and variety force the development of new techniques for rock mass classification, excavation and supporting of underground space, monitoring and control of underground environment. All these techniques should be applied together to make the underground space comfortable. To achieve this, efforts have been made on 5 different areas; research on the underground space design and stability analysis, research on the techniques for excavation of rock by controlled blasting, research on the development of monitoring system to forecast the rock behaviour of underground space, research on the environment inspection system in closed space, and research on dynamic analysis of the airflow and environmental control in the large geos-spaces. The 5 main achievements are improvement of the existing structure analysis program(EXCRACK) to consider the deformation and failure characteristics of rock joints, development of new blasting design (SK-cut), prediction of ground vibration through the newly proposed wave propagation equation, development and In-Situ application of rock mass deformation monitoring system and data acquisition software, and trial manufacture of the environment inspection system in closed space. Should these techniques be applied to the development of underground space, prevention of industrial disaster, cut down of construction cost, domestication of monitoring system, improvement of tunnel stability, curtailment of royalty, upgrade of domestic technologies will be brought forth. (Abstract Truncated)

  1. On justification of efficient Energy-Force parameters of Hydraulic-excavator main mechanisms

    Science.gov (United States)

    Komissarov, Anatoliy; Lagunova, Yuliya; Shestakov, Viktor; Lukashuk, Olga

    2018-03-01

    The article formulates requirements for energy-efficient designs of the operational equipment of a hydraulic excavator (its boom, stick and bucket) and defines, for a mechanism of that equipment, a new term “performance characteristic”. The drives of main rotation mechanisms of the equipment are realized by hydraulic actuators (hydraulic cylinders) and transmission (leverage) mechanisms, with the actuators (the cylinders themselves, their pistons and piston rods) also acting as links of the leverage. Those drives are characterized by the complexity of translating mechanical-energy parameters of the actuators into energy parameters of the driven links (a boom, a stick and a bucket). Relations between those parameters depend as much on the types of mechanical characteristics of the hydraulic actuators as on the types of structural schematics of the transmission mechanisms. To assess how energy-force parameters of the driven links change when a typical operation is performed, it was proposed to calculate performance characteristics of the main mechanisms as represented by a set of values of transfer functions, i.e. by functional dependences between driven links and driving links (actuators). Another term “ideal performance characteristic” of a mechanism was introduced. Based on operation-emulating models for the main mechanisms of hydraulic excavators, analytical expressions were derived to calculate kinematic and force transfer functions of the main mechanisms.

  2. Dynamic simulation of cable shovel specific energy in oil sands excavation

    Energy Technology Data Exchange (ETDEWEB)

    Awuah-Offei, K. [Missouri-Rolla Univ., Rolla, MO (United States). School of Materials, Energy and Earth Resources; Frimpong, S. [Missouri-Rolla Univ., Rolla, MO (United States). Dept. of Mining Engineering, Mining and Nuclear Engineering; Askari-Nasab, H. [Alberta Univ., Edmonton, AB (Canada). School of Mining and Petroleum Engineering

    2005-07-01

    Oil sand excavation requires the use cable shovels which constitute one of the major costs in surface mining operations. Random occurrences of shales and limestones within the Athabasca oil sands formation result in varying shovel diggability and stress loading of the boom-crowd-dipper-teeth assembly which reduces digging efficiency. This inefficient use of cable shovels negatively affects the return on capital investment in these otherwise effective machines. In the Athabasca oil sands, varying stress loading has the potential to increase shovel downtime and increase maintenance costs. This paper presented a newly developed cable shovel simulator that uses shovel kinematics and dynamics, dynamic cutting resistance and payload models. It can model the specific energy needed to overcome the resistance to machine motion and material digging. The comprehensive model considers both machine motion and machine-formation interaction forces. It also provides a comprehensive theoretical assessment of shovel performance. The model is useful to mining engineers when examining both the machine operating parameters and material parameters that influence shovel performance. The study showed that bulk density is the most important material property influencing diggability. Operator preferences also influence the specific energy of excavation. 12 refs., 2 tabs., 6 figs.

  3. Model uncertainty of various settlement estimation methods in shallow tunnels excavation; case study: Qom subway tunnel

    Science.gov (United States)

    Khademian, Amir; Abdollahipour, Hamed; Bagherpour, Raheb; Faramarzi, Lohrasb

    2017-10-01

    In addition to the numerous planning and executive challenges, underground excavation in urban areas is always followed by certain destructive effects especially on the ground surface; ground settlement is the most important of these effects for which estimation there exist different empirical, analytical and numerical methods. Since geotechnical models are associated with considerable model uncertainty, this study characterized the model uncertainty of settlement estimation models through a systematic comparison between model predictions and past performance data derived from instrumentation. To do so, the amount of surface settlement induced by excavation of the Qom subway tunnel was estimated via empirical (Peck), analytical (Loganathan and Poulos) and numerical (FDM) methods; the resulting maximum settlement value of each model were 1.86, 2.02 and 1.52 cm, respectively. The comparison of these predicted amounts with the actual data from instrumentation was employed to specify the uncertainty of each model. The numerical model outcomes, with a relative error of 3.8%, best matched the reality and the analytical method, with a relative error of 27.8%, yielded the highest level of model uncertainty.

  4. Great Excavations: Tales of Early Southwestern Archaeology, 1888-1939, School of American Research Press, 1995

    Directory of Open Access Journals (Sweden)

    Stephen E. Nash

    1997-05-01

    Full Text Available Great Excavations: Tales of Early Southwestern Archaeology, 1 888-1939, is an "intentionally selective" account of eight major archaeological expeditions to the Southwest in the late 19th and early 20th centuries. It succeeds in achieving the goals set forth in the prologue. The reader is taken on an "armchair tour"  of early Southwestern excavations in the hope that the resulting "basic understanding of what the early archae­ologists did" will stimulate a desire to "learn more about the intriguing prehistory of the Southwest" (pp. xiii. As a student of the history of North American archaeology, I would be amiss to speak for Elion's "layperson" audience, but my suspicion is that her presentation will indeed stimulate those readers. As an archaeologist, I thoroughly enjoyed this book, and it may well be that Elliott's journalistic approach makes this book more enjoyable because she is able to remain above the level of detail that often burden archaeolo­gists' accounts of these expeditions. I must temper this statement by noting that Elliott's journalistic hyper­ bole and tendency to oversimplify complex research and analysis are at times discomforting.

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

    International Nuclear Information System (INIS)

    Holmberg, R.

    1983-09-01

    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

  6. Bucket wheel rehabilitation of ERC 1400-30/7 high-capacity excavators from lignite quarries

    Science.gov (United States)

    Vîlceanu, Fl; Iancu, C.

    2016-11-01

    The existence of bucket wheel equipment type ERC 1400-30/7 in lignite quarries with lifetime expired, or in the ultimate life period, together with high cost investments for their replacement, makes rational the efforts made to rehabilitation in order to extend their life. Rehabilitation involves checking operational safety based on relevant expertise of metal structures supporting effective resistance but also the replacement (or modernization) of subassemblies that can increase excavation process productivity, lowering energy consumption, reducing mechanical stresses. This paper proposes an analysis of constructive solution of using a part of the classical bucket wheel, on which are located 9 cutting cups and 9 chargers cups and adding a new part so that the new redesigned bucket-wheel will contain 18 cutting-chargers cups, compared to the classical model. On the CAD model of bucket wheel was performed a static and a dynamic FEA, the results being compared with the yield strength of the material of the entire structure, were checked mechanical stresses in the overall distribution map, and were verified the first 4 vibrating modes the structure compared to real loads. Thus was verified that the redesigned bucket-wheel can accomplish the proposed goals respectively increase excavation process productivity, lowering energy consumption and reducing mechanical stresses.

  7. Theoretical Investigations on the Influence of Artificially Altered Rock Mass Properties on Mechanical Excavation

    Science.gov (United States)

    Hartlieb, Philipp; Bock, Stefan

    2018-03-01

    This study presents a theoretical analysis of the influence of the rock mass rating on the cutting performance of roadheaders. Existing performance prediction models are assessed for their suitability for forecasting the influence of pre-damaging the rock mass with alternative methods like lasers or microwaves, prior to the mechanical excavation process. Finally, the RMCR model was chosen because it is the only reported model incorporating a range of rock mass properties into its calculations. The results show that even very tough rocks could be mechanically excavated if the occurrence, orientation and condition of joints are favourable for the cutting process. The calculated improvements in the cutting rate (m3/h) are up to 350% for the most favourable cases. In case of microwave irradiation of hard rocks with an UCS of 200 MPa, a reasonable improvement in the performance by 120% can be achieved with as little as an extra 0.7 kWh/m3 (= 1% more energy) compared to cutting only.

  8. Re-Excavation of Seti First Tomb, Kv17, Luxor, Egypt

    Directory of Open Access Journals (Sweden)

    Ayman HAMED

    2013-12-01

    Full Text Available This article is discussing technical challenges within engineering works made during re-excavation of the 174 m long tunnel which was cut into bedrock of desert shale known as 'Esna shale'. Recent historical events, during the last decade, explained much of the tunnel deformations and dirt filling inside tunnel space "Debris", caused by multiple water runoff attack to king's valley. The author is also discussing the challenging work under severe financial regime; using non conventional solutions adopted with extraordinary actions in using junk yard equipment. Seti I tomb, is considered as the deepest opening in the valley, not mentioning the risk in re-excavation the tomb, harsh atmospheric conditions inside the tunnel, measured and monitored by author, needed a serious ventilation system to serve workers during removal of dirt. Through that, an interesting mathematical relation between atmospheric variables has been emphasized. Design of steel supporting system serving an inclined deep tunnel with irregular circumference, under strict condition of reversibility, has been performed as a remarkable topic, to solve and apply in such archaeological site. Finally, the article is considered as a scientific pattern for application of geo-engineering in conservation of underground archaeological sites.

  9. A new technique in the excavation of ground-nest bee burrows (Hymenoptera: Apoidea

    Directory of Open Access Journals (Sweden)

    Diego Marinho

    Full Text Available ABSTRACT Bees have a diversified natural history, thus the methods applied to study such diversity are varied. When it comes to studies of nesting biology, bees which nest in pre-existing cavities have been reasonably well studied since researchers started using trap-nests. However, bees whose nests are built underground are poorly studied due to the difficulty of finding natural nesting areas and the absence of a method that facilitates bee nest excavation. The latter is evidenced by the lack of accurate descriptions in literature of how nests are excavated. In this study we tested cylindrical rubber refills of eraser pen as a new material to be used as a tracer of underground nest galleries in a natural nesting area of two species of Epicharis Klug, 1807 (Apidae. We compared this technique directly with plaster in powder form mixed with water and our results with other methodological studies describing alternative methods and materials. The rubber refill technique overcame the main issues presented by materials such as plaster, molten metal alloys and bioplastic, namely: death of the organisms by high temperatures and/or formation of plugs and materials unduly following the roots inside the galleries.

  10. A Basic Robotic Excavator (the Glenn Digger): Description, Design, and Initial Operation

    Science.gov (United States)

    Bauman, Steve; Newman, Paul; Izadnegahdar, Alain; Johnson, Kyle; Abel, Phillip

    2016-01-01

    This paper describes the design, commercial part selections, fabrication, assembly, installation, and initial operation of a two degree of freedom robotic excavator. Colloquially referred to as "the NASA Glenn Digger," it was designed specifically to be mounted onto, and to operate with, the then newly developed Centaur 2 robotic mobility base. The excavator, when mounted to Centaur 2, is designed to scoop loose regolith from the terrain, raise its loaded bucket up and dump the load into a hopper of at least a 1-m-height. The hopper represents the input to a machine that would process the raw material, such as to produce oxygen from lunar regolith as would be required for long-term lunar habitation. This equipment debuted at the annual Research and Technology Studies ("Desert RATS", Ref. 1) event held north of Flagstaff, Arizona, in September of 2010, when the Digger was successfully joined to Centaur 2 and the shoveling articulation was demonstrated. During 2011, the hardware was modified for added strength, strain gauges were added to measure loads, and the controls were improved in preparation for the 2011 Desert RATS event, where additional "field operations" experience was gained.

  11. The gravel sand transition in a disturbed catchment

    Science.gov (United States)

    Knighton, A. David

    1999-03-01

    More than 40 million cubic metres of mining waste were supplied to the Ringarooma River between 1875 and 1984, leading to successive phases of aggradation and degradation. The natural bed material is gravel but, given the volume of introduced load and the fact that much of the input was less than 5 mm in diameter, the size composition of the bed changed from gravel to sand during the phase of downstream progressive aggradation. A very sharp gravel-sand transition developed in which median grain size decreased from over 30 mm to under 3 mm in less than 500 m. With upstream supplies of mining debris becoming depleted first, degradation followed the same downstream progressive pattern as aggradation, causing the transition to migrate downstream. By 1984, the river could be regarded as a series of zones, each characterized by a particular bed condition: a natural cobble-gravel bed, unaffected by mining inputs (0-32 km); pre-disturbance bed re-exposed by degradation over 35-40 years (32-53 km); sandy substrate with a gravel armour produced by differential transport during degradation (53-65 km); sand dominated but with developing surface patches of coarser material (65-75 km); sandy bed reflecting the size composition of the original mining input (75-118 km). Although the gravel-sand transition itself is sharp, the transitional zone is lengthy (53-75 km). As degradation continues, the gravel-sand transition is expected to progress downstream but it has remained in a stable position for 12 years. Indeed, two major floods during the period released large quantities of sand from the sub-armour layer and newly-formed banks of mine tailings, causing fining both above and below the transition. Surface grain size is an adjustable component in the transitional zone as the river strives to recover from a major anthropogenic disturbance.

  12. Characterization of the emissions impacts of hybrid excavators with a portable emissions measurement system (PEMS)-based methodology.

    Science.gov (United States)

    Cao, Tanfeng; Russell, Robert L; Durbin, Thomas D; Cocker, David R; Burnette, Andrew; Calavita, Joseph; Maldonado, Hector; Johnson, Kent C

    2018-04-13

    Hybrid engine technology is a potentially important strategy for reduction of tailpipe greenhouse gas (GHG) emissions and other pollutants that is now being implemented for off-road construction equipment. The goal of this study was to evaluate the emissions and fuel consumption impacts of electric-hybrid excavators using a Portable Emissions Measurement System (PEMS)-based methodology. In this study, three hybrid and four conventional excavators were studied for both real world activity patterns and tailpipe emissions. Activity data was obtained using engine control module (ECM) and global positioning system (GPS) logged data, coupled with interviews, historical records, and video. This activity data was used to develop a test cycle with seven modes representing different types of excavator work. Emissions data were collected over this test cycle using a PEMS. The results indicated the HB215 hybrid excavator provided a significant reduction in tailpipe carbon dioxide (CO 2 ) emissions (from -13 to -26%), but increased diesel particulate matter (PM) (+26 to +27%) when compared to a similar model conventional excavator over the same duty cycle. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Design and construction of earth retaining walls with anchors employed in excavation works at Oi Nuclear Power Plant

    International Nuclear Information System (INIS)

    Saino, Susumu; Aoshima, Ken-ichiro; Kamide, Atsushi.

    1990-01-01

    In Oi Nuclear Power Station, Kansai Electric Power Co., Inc., No.3 and No.4 plants of each 1180 MWe output are additionally installed, neighboring existing No.1 and No.2 plants of each 1175 MWe output in operation. The start of operation is expected in December, 1991 in No.3 plant, and in February, 1993 in No.4 plant. The total quantity of earth excavated for this additional installation works is about 3.3 million m 3 . The main works are, subsequently to the preparation of the site, the excavation for the foundations of reactor buildings and others, and the construction of the foundations for the seawater system facilities for cooling condensers and reactor auxiliary machines, and the works were begun in May, 1987. The excavation by using anchors was carried out in seven places. The vertical excavation on large scale was carried out by using the earth retaining walls of concrete-sprayed anchor structure in drain pits. In this report, the outline of the geological features, the outline of the excavation works, the design of the earth retaining walls, the execution of concrete spraying, the planning and result of measurement are described. (K.I.)

  14. Optimally growing boundary layer disturbances in a convergent nozzle preceded by a circular pipe

    Science.gov (United States)

    Uzun, Ali; Davis, Timothy B.; Alvi, Farrukh S.; Hussaini, M. Yousuff

    2017-06-01

    We report the findings from a theoretical analysis of optimally growing disturbances in an initially turbulent boundary layer. The motivation behind this study originates from the desire to generate organized structures in an initially turbulent boundary layer via excitation by disturbances that are tailored to be preferentially amplified. Such optimally growing disturbances are of interest for implementation in an active flow control strategy that is investigated for effective jet noise control. Details of the optimal perturbation theory implemented in this study are discussed. The relevant stability equations are derived using both the standard decomposition and the triple decomposition. The chosen test case geometry contains a convergent nozzle, which generates a Mach 0.9 round jet, preceded by a circular pipe. Optimally growing disturbances are introduced at various stations within the circular pipe section to facilitate disturbance energy amplification upstream of the favorable pressure gradient zone within the convergent nozzle, which has a stabilizing effect on disturbance growth. Effects of temporal frequency, disturbance input and output plane locations as well as separation distance between output and input planes are investigated. The results indicate that optimally growing disturbances appear in the form of longitudinal counter-rotating vortex pairs, whose size can be on the order of several times the input plane mean boundary layer thickness. The azimuthal wavenumber, which represents the number of counter-rotating vortex pairs, is found to generally decrease with increasing separation distance. Compared to the standard decomposition, the triple decomposition analysis generally predicts relatively lower azimuthal wavenumbers and significantly reduced energy amplification ratios for the optimal disturbances.

  15. Historical photogrammetry: Bird's Paluxy River dinosaur chase sequence digitally reconstructed as it was prior to excavation 70 years ago.

    Science.gov (United States)

    Falkingham, Peter L; Bates, Karl T; Farlow, James O

    2014-01-01

    It is inevitable that some important specimens will become lost or damaged over time, conservation is therefore of vital importance. The Paluxy River dinosaur tracksite is among the most famous in the world. In 1940, Roland T. Bird described and excavated a portion of the site containing associated theropod and sauropod trackways. This excavated trackway was split up and housed in different institutions, and during the process a portion was lost or destroyed. We applied photogrammetric techniques to photographs taken by Bird over 70 years ago, before the trackway was removed, to digitally reconstruct the site as it was prior to excavation. The 3D digital model offers the opportunity to corroborate maps drawn by R.T. Bird when the tracksite was first described. More broadly, this work demonstrates the exciting potential for digitally recreating palaeontological, geological, or archaeological specimens that have been lost to science, but for which photographic documentation exists.

  16. The Origin of the ‘Chicago Method’ Excavation Techniques: Contributions of William Nickerson and Frederick Starr

    Directory of Open Access Journals (Sweden)

    David Browman

    2013-09-01

    Full Text Available What were the origins of the ‘Chicago method’ of scientific excavation? What is it and how did it get that name? Does its origin predate its popular employment at excavations in the USA during the 1930s and 1940s, and go back to institutional competition between Frederic Ward Putnam of the Field Museum and Frederick Starr of the University of Chicago? Or was it the result of the fieldwork of avocational archaeologist and one of Putnam’s first students, William Baker Nickerson, who implemented it as the basis of his fieldwork, and proved its efficacy, for many years before he retired in 1921? Nickerson’s detailed notes on the results of his thorough stratigraphic excavation techniques, used at many archaeological sites in Iowa, Illinois, Ohio and Minnesota, were passed on to the first University of Chicago field party doing archaeological work in Illinois, that consequently became the foundations of the later ‘Chicago method’.

  17. Loss of 'blue carbon' from coastal salt marshes following habitat disturbance.

    Directory of Open Access Journals (Sweden)

    Peter I Macreadie

    Full Text Available Increased recognition of the global importance of salt marshes as 'blue carbon' (C sinks has led to concern that salt marshes could release large amounts of stored C into the atmosphere (as CO2 if they continue undergoing disturbance, thereby accelerating climate change. Empirical evidence of C release following salt marsh habitat loss due to disturbance is rare, yet such information is essential for inclusion of salt marshes in greenhouse gas emission reduction and offset schemes. Here we investigated the stability of salt marsh (Spartinaalterniflora sediment C levels following seagrass (Thallasiatestudinum wrack accumulation; a form of disturbance common throughout the world that removes large areas of plant biomass in salt marshes. At our study site (St Joseph Bay, Florida, USA, we recorded 296 patches (7.5 ± 2.3 m(2 mean area ± SE of vegetation loss (aged 3-12 months in a salt marsh meadow the size of a soccer field (7 275 m(2. Within these disturbed patches, levels of organic C in the subsurface zone (1-5 cm depth were ~30% lower than the surrounding undisturbed meadow. Subsequent analyses showed that the decline in subsurface C levels in disturbed patches was due to loss of below-ground plant (salt marsh biomass, which otherwise forms the main component of the long-term 'refractory' C stock. We conclude that disturbance to salt marsh habitat due to wrack accumulation can cause significant release of below-ground C; which could shift salt marshes from C sinks to C sources, depending on the intensity and scale of disturbance. This mechanism of C release is likely to increase in the future due to sea level rise; which could increase wrack production due to increasing storminess, and will facilitate delivery of wrack into salt marsh zones due to higher and more frequent inundation.

  18. Harmonic disturbance location by applying Bayesian inference

    NARCIS (Netherlands)

    Ye, G.; Xiang, Y.; Cuk, V.; Cobben, J.F.G.

    2016-01-01

    Harmonic pollution is one of the most important power quality issues in electric power systems. Correct location of the main harmonic disturbance source is a key step to solve the problem. This paper presents a method to detect the location of harmonic disturbance source in low voltage network

  19. A Full Disturbance Model for Reaction Wheels

    NARCIS (Netherlands)

    Le, M.P.; Ellenbroek, Marcellinus Hermannus Maria; Seiler, R; van Put, P.; Cottaar, E.J.E.

    2014-01-01

    Reaction wheels are rotating devices used for the attitude control of spacecraft. However, reaction wheels also generate undesired disturbances in the form of vibrations, which may have an adverse effect on the pointing accuracy and stability of spacecraft (optical) payloads. A disturbance model for

  20. Nonunity gain minimal-disturbance measurement

    DEFF Research Database (Denmark)

    Sabuncu, Metin; Mišta, L.; Fiurášek, J.

    2007-01-01

    We propose and experimentally demonstrate an optimal nonunity gain Gaussian scheme for partial measurement of an unknown coherent state that causes minimal disturbance of the state. The information gain and the state disturbance are quantified by the noise added to the measurement outcomes...

  1. The Dimensionality of Body Image Disturbance.

    Science.gov (United States)

    Galgan, Richard J.; And Others

    1987-01-01

    Examined personality variables in 75 male and 75 female college students. Found two dimensions underlying body image disturbance variables, one loading on body image dissatisfaction and one loading on body image disturbance. Low negative correlation between two factors suggests that distortion and dissatisfaction are fairly distinct and that body…

  2. Instrumentation for Power System Disturbance Monitoring, Data ...

    African Journals Online (AJOL)

    In this paper, the level of instrumentation for power system disturbance monitoring, data acquisition and control in Nigerian Electric Power System; National Electric Power Authority (NEPA) is presented. The need for accurate power system disturbance monitoring is highlighted. A feature of an adequate monitoring, data ...

  3. Transience after disturbance: Obligate species recovery dynamics depend on disturbance duration.

    Science.gov (United States)

    Singer, Alexander; Johst, Karin

    2017-06-01

    After a disturbance event, population recovery becomes an important species response that drives ecosystem dynamics. Yet, it is unclear how interspecific interactions impact species recovery from a disturbance and which role the disturbance duration (pulse or press) plays. Here, we analytically derive conditions that govern the transient recovery dynamics from disturbance of a host and its obligately dependent partner in a two-species metapopulation model. We find that, after disturbance, species recovery dynamics depend on the species' role (i.e. host or obligately dependent species) as well as the duration of disturbance. Host recovery starts immediately after the disturbance. In contrast, for obligate species, recovery depends on disturbance duration. After press disturbance, which allows dynamics to equilibrate during disturbance, obligate species immediately start to recover. Yet, after pulse disturbance, obligate species continue declining although their hosts have already begun to increase. Effectively, obligate species recovery is delayed until a necessary host threshold occupancy is reached. Obligates' delayed recovery arises solely from interspecific interactions independent of dispersal limitations, which contests previous explanations. Delayed recovery exerts a two-fold negative effect, because populations continue declining to even smaller population sizes and the phase of increased risk from demographic stochastic extinction in small populations is prolonged. We argue that delayed recovery and its determinants -species interactions and disturbance duration - have to be considered in biodiversity management. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Disturbing, Disordered or Disturbed? Perspectives on the Definition of Problem Behavior in Educational Settings.

    Science.gov (United States)

    Wood, Frank H., Ed.; Lakin, K. Charlie, Ed.

    The book contains five papers presented at a 1979 topical conference on the definition of emotional disturbance and behavioral disorders in educational settings. The first paper, by F. Wood, is titled "Defining Disturbing, Disordered, and Disturbed Behavior." Topics covered include ambivalence about defining deviant behavior by special educators,…

  5. Sequential Subterranean Transport of Excavated Sand and Foraged Seeds in Nests of the Harvester Ant, Pogonomyrmex badius.

    Directory of Open Access Journals (Sweden)

    Walter R Tschinkel

    Full Text Available During their approximately annual nest relocations, Florida harvester ants (Pogonomyrmex badius excavate large and architecturally-distinct subterranean nests. Aspects of this process were studied by planting a harvester ant colony in the field in a soil column composed of layers of 12 different colors of sand. Quantifying the colors of excavated sand dumped on the surface by the ants revealed the progress of nest deepening to 2 m and enlargement to 8 L in volume. Most of the excavation was completed within about 2 weeks, but the nest was doubled in volume after a winter lull. After 7 months, we excavated the nest and mapped its structure, revealing colored sand deposited in non-host colored layers, especially in the upper 30 to 40 cm of the nest. In all, about 2.5% of the excavated sediment was deposited below ground, a fact of importance to sediment dating by optically-stimulated luminescence (OSL. Upward transport of excavated sand is carried out in stages, probably by different groups of ants, through deposition, re-transport, incorporation into the nest walls and floors and remobilization from these. This results in considerable mixing of sand from different depths, as indicated in the multiple sand colors even within single sand pellets brought to the surface. Just as sand is transported upward by stages, incoming seeds are transported downward to seed chambers. Foragers collect seeds and deposit them only in the topmost nest chambers from which a separate group of workers rapidly transports them downward in increments detectable as a "wave" of seeds that eventually ends in the seed chambers, 20 to 80 cm below the surface. The upward and downward transport is an example of task-partitioning in a series-parallel organization of work carried out by a highly redundant work force in which each worker usually completes only part of a multi-step process.

  6. Disturbance analysis in nuclear power plants

    International Nuclear Information System (INIS)

    Sillamaa, M.A.

    Disturbance analysis is any systematic procedure that helps an operator determine what has failed. This paper describes the typical information currently provided in CANDU power plants to help the operator respond to a disturbance. It presents a simplified model of how an operator could get into trouble, and briefly reviews development work on computerized disturbance analysis systems for nuclear power plants being done in various countries including Canada. Disturbance analysis systems promise to be useful tools in helping operators improve their response to complex situations. However, the originality and complexity of the work for a disturbance analysis system and the need to develop operator confidence and management support require a 'walk before you run' approach

  7. 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

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

    International Nuclear Information System (INIS)

    Samper, Javier; Molinero, Jorge; Changbing Yang; Guoxiang Zhang

    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

  9. Archaeogeophysical Studies in the Ruins of Kars-Ani (Turkey) in the 2009 Excavation Season

    Science.gov (United States)

    Hoskan, Nihan; Ahmet Yuksel, Fethi; Gorucu, Ziya; Coruhlu, Yasar

    2010-05-01

    The Ani ancient city, which is at 48 km distance to Kars (Turkey), is founded at the banks of the Arpacay River flowing in the vicinity of Turkey - Armenia border and is in the borders of Mevcut Ocakli Village. Recent studies show that the first settlement in Ani ancient city could be in the 5th millenium B.C.(Chalcolithic Period) and moreover, there were some buildings built in the Iron and Bronze Period. In the early 9th century, Ashot Msaker, who was Bagratuni dynasty (806-827), declared their first capital city at Bagaran, some 40 km south of Ani, and then transferred it to Kars in the year 929. In 961, King Ashot III (953-977) transferred the capital city from Kars to Ani. Ani expanded during the reign of King Smbat II (977-989). Recent research shows that by the early 11th century the population of Ani was over 100,000. After capture of Ashot, Ani surrendered to Byzantine controlled in 1045. A Greek governor was installed in the city. In 1064 a Seljuk Turkish army, headed by Sultan Alparslan, attacked and captured Ani. Then the Georgians captured Ani in 1124, 1161 and 1174. By the 14th century Ani was ruled by the Turkish dynasties, namely Jalayrids and the Kara Koyunlu. After the Persian Safavids ruled Ani, it became part of the Turkish Ottoman Empire in 1579. A small town remained within its walls until 1650 A.C. and it was completely abandoned by the middle of the 18th century. Examples of Sasani, Arabic, Armenian, and Seljuk architecture can be found among the Ani ruins. Ani is home to the first Turkish mosque built in Anatolia, namely Ebul Menucehr. The mosque was erected by the members of the Seljuk Dynasty in 1072. The first archaeological excavations were conducted at Ani in 1892. Since then, several archaeological excavations have been done in Ani. In the 2009 excavation season, magnetic methods were applied in Ani ruins to find the exact locations of the ruins. Magnetic Gradient Measurements were taken in front of Ebul Menucehr Mosque. After

  10. Feature Extraction for Digging Operation of Excavator Based on Data-Driven Skill-Based PID Controller

    Directory of Open Access Journals (Sweden)

    Kazushige Koiwai

    2017-11-01

    Full Text Available Improvement of the work efficiency is demanded by aging and reducing of the working population in the construction field, so that some automation technologies are applied to construction equipment, such as bulldozers and excavators. However, not only the automation technologies but also expert skills are necessary to improve the work efficiency. In this paper, the human skill evaluation is proposed by the data-driven skill-based PID controller. The proposed method is applied to the excavator digging operation. As the result, the difference between the novice operation and the skilled operation is extracted. Moreover, the numerical difference is clarified based on the result.

  11. Modelling and Analysis of the Excavation Phase by the Theory of Blocks Method of Tunnel 4 Kherrata Gorge, Algeria

    Science.gov (United States)

    Boukarm, Riadh; Houam, Abdelkader; Fredj, Mohammed; Boucif, Rima

    2017-12-01

    The aim of our work is to check the stability during excavation tunnel work in the rock mass of Kherrata, connecting the cities of Bejaia to Setif. The characterization methods through the Q system (method of Barton), RMR (Bieniawski classification) allowed us to conclude that the quality of rock mass is average in limestone, and poor in fractured limestone. Then modelling of excavation phase using the theory of blocks method (Software UNWEDGE) with the parameters from the recommendations of classification allowed us to check stability and to finally conclude that the use of geomechanical classification and the theory of blocks can be considered reliable in preliminary design.

  12. E16 Sandvika-Wøyen - Analysis of tunnel excavation, achieved contour quality and influence of applied initiation system.

    OpenAIRE

    Sklodowska, Anna Maria

    2016-01-01

    The drill and blast excavation method is the most commonly used method for tunnel construction in Norway. In D&B the results from blasting can be evaluated through several factors, such as pull percentage, vibration level and contour quality. The main goal of the thesis was to analyze excavation with a special focus on the quality of the achieved contour and the influence of the applied initiation system. The analysis was performed based on results from the Bjørnegård tunnel, which wa...

  13. Design aspects of the Alpha Repository. V. Suite selection and cost analysis of excavation/hauling systems

    International Nuclear Information System (INIS)

    Zeller, T.J.; Grams, W.H.

    1975-01-01

    The various types of haulage and excavation equipment that may be suitable for use in the development and excavation of the Alpha repository are described with discussion of the advantages, disadvantages, expected costs, availability, and special features of each. The various equipment suites are delineated, and the costs of mining and transportation of the salt are presented and discussed. Individual manufacturers contacted and equipment considered are listed. Most of the equipment is ''off-the-shelf''; however, some manufactuers were contacted that do custom work because of their expertise in salt mining equipment. The costs of custom equipment are comparable to those for standard equipment

  14. Recovery of lotic macroinvertebrate communities from disturbance

    Science.gov (United States)

    Wallace, J. Bruce

    1990-09-01

    Ecosystem disturbances produce changes in macrobenthic community structure (abundances, biomass, and production) that persist for a few weeks to many decades. Examples of disturbances with extremely long-term effects on benthic communities include contamination by persistent toxic agents, physical changes in habitats, and altered energy inputs. Stream size, retention, and local geomorphology may ameliorate the influence of disturbances on invertebrates. Disturbances can alter food webs and may select for favorable genotypes (e.g., insecticidal resistance). Introductions of pesticides into lotic ecosystems, which do not result in major physical changes within habitats, illustrate several factors that influence invertebrate recovery time from disturbance. These include: (1) magnitude of original contamination, toxicity, and extent of continued use; (2) spatial scale of the disturbance; (3) persistence of the pesticide; (4) timing of the contamination in relation to the life history stages of the organisms; (5) vagility of populations influenced by pesticides; and (6) position within the drainage network. The ability of macroinvertebrates to recolonize denuded stream habitats may vary greatly depending on regional life histories, dispersal abilities, and position within the stream network (e.g., headwaters vs larger rivers). Although downstream drift is the most frequently cited mechanism of invertebrate recolonization following disturbance in middle- and larger-order streams, evidence is presented that shows aerial recolonization to be potentially important in headwater streams. There is an apparent stochastic element operating for aerial recolonization, depending on the timing of disturbance and flight periods of various taxa. Available evidence indicates that recolonization of invertebrate taxa without an aerial adult stage requires longer periods of time than for those that possess winged, terrestrial adult stages (i.e., most insects). Innovative, manipulative

  15. Discriminating Natural Variation from Legacies of Disturbance in Semi-Arid Forests, Southwestern USA

    Science.gov (United States)

    Swetnam, T. L.; Lynch, A. M.; Falk, D. A.; Yool, S. R.; Guertin, D. P.

    2014-12-01

    Characterizing differences in existing vegetation driven by natural variation versus disturbance legacies could become a critical component of applied forest management practice with important implications for monitoring ecologic succession and eco-hydrological interactions within the critical zone. Here we characterize variations in aerial LiDAR derived forest structure at individual tree scale in Arizona and New Mexico. Differences in structure result from both topographic and climatological variations and from natural and human related disturbances. We chose a priori undisturbed and disturbed sites that included preservation, development, logging and wildfire as exemplars. We compare two topographic indices, the topographic position index (TPI) and topographic wetness index (TWI), to two local indicators of spatial association (LISA): the Getis-Ord Gi and Anselin's Moran I. We found TPI and TWI correlate well to positive z-scores (tall trees in tall neighborhoods) in undisturbed areas and that disturbed areas are clearly defined by negative z-scores, in some cases better than what is visible from traditional orthophotography and existing GIS maps. These LISA methods also serve as a robust technique for creating like-clustered stands, i.e. common stands used in forest inventory monitoring. This research provides a significant advancement in the ability to (1) quantity variation in forest structure across topographically complex landscapes, (2) identify and map previously unrecorded disturbance locations, and (3) quantify the different impacts of disturbance within the perimeter of a stand or event at ecologically relevant scale.

  16. Excavating a Silk Road City: the Medieval Citadel of Taraz, Kazakhstan

    Directory of Open Access Journals (Sweden)

    Giles Dawkes

    2013-10-01

    Full Text Available The city of Taraz, located near the southern border with Uzbekistan, is one of the most significant historic settlements in Kazakhstan, and two seasons of fieldwork in the central market-place have revealed a substantial depth of medieval stratigraphy. Despite frequent mentions in Arabic and Chinese written sources, both the form and evolution of this important Silk Road city remain poorly understood. Evidence for a series of successive medieval buildings, including a bathhouse and a Zoroastrian flame shrine, was found in the area of the former citadel. These excavations, undertaken as a joint initiative between the Centre for Applied Archaeology and Kazakh archaeologists, were the first for 50 years in the city and form part of a wider public outreach programme.

  17. Archaeology Through Computational Linguistics: Inscription Statistics Predict Excavation Sites of Indus Valley Artifacts.

    Science.gov (United States)

    Recchia, Gabriel L; Louwerse, Max M

    2016-11-01

    Computational techniques comparing co-occurrences of city names in texts allow the relative longitudes and latitudes of cities to be estimated algorithmically. However, these techniques have not been applied to estimate the provenance of artifacts with unknown origins. Here, we estimate the geographic origin of artifacts from the Indus Valley Civilization, applying methods commonly used in cognitive science to the Indus script. We show that these methods can accurately predict the relative locations of archeological sites on the basis of artifacts of known provenance, and we further apply these techniques to determine the most probable excavation sites of four sealings of unknown provenance. These findings suggest that inscription statistics reflect historical interactions among locations in the Indus Valley region, and they illustrate how computational methods can help localize inscribed archeological artifacts of unknown origin. The success of this method offers opportunities for the cognitive sciences in general and for computational anthropology specifically. Copyright © 2015 Cognitive Science Society, Inc.

  18. Study on the provenance of ancient porcelain excavated in Maojiawan ruin by WDXRF analysis

    International Nuclear Information System (INIS)

    Xie Guoxi

    2007-01-01

    In order to determine the provenance of two different kinds of ancient celadons which were excavated in Maojiawan ruin located in Beijing of China and named FLQ (imitated celadon) and WLNQ which is celadon outside and blue-white inside, ten components of each sample's body and glaze were measured by the wave length dispersive X-ray fluorescence (WDXRF) analysis. Multivariates statistical analysis was used to analyze and compare the experiment data with those of LQY (ancient celadon) made in Zhejiang and ancient Jingdezhen porcelain (JDZ) made in Jingdezhen. The results show that the two different kinds of ancient celadons have the same provenance as JDZ, that is, they were produced in Jingdezhen. (authors)

  19. Pilot-Scale Bio-Augmented Aerobic Composting of Excavated Foot-And-Mouth Disease Carcasses

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    Seonghoon Kim

    2017-03-01

    Full Text Available In the present work, we tested the validity of using novel, bio-augmented, aerobic composting with carcass-degrading microorganisms for the ex situ stabilization of carcasses at pilot scale with previously poorly decomposed carcasses excavated from a 3-year old burial site. The significantly decreased chemical oxygen demand (COD, 160,000 mg/kg to 40,000 mg/kg and inorganic nitrogen species (total nitrogen, 5000 mg/kg to 2000 mg/kg indicated effective bio-stabilization of carcasses by bio-augmented composting. The subsequent germination assays and the quantitative characterization of potentially pathogenic bacteria using NGS (next-generation sequencing showed that the burial–composting sequential system with the carcass-degrading microorganisms and mechanical agitation successfully reduced plant toxicity as well as microbial risk to human health, suggesting that the composting by-product is suitable for farming or/and landfill use(s.

  20. Demolition, construction and excavation wastes in Copenhagen. Los residuos de demolicion, construccion y excavacion en Copenhague

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    Hahn, N.J.; Lauridsen, P.S.

    1994-01-01

    Demolition Waste, Construction Waste and Excavation Waste will in a modern society represent a major part of the total amount of the industrial wastes. Implementation of the Regulation for Industrial Waste in Copenhagen has resulted insignificant changes in the transportation and processing of this type of waste was typically disposed of as mixed waste on landfill sites and open dumps. Today most of this waste is sorted at the source (see figure 1) and recycled namely as secondary raw materials. This change in the disposal of construction waste etc, is due to two main factors: implementation of the regulation of commercial wastes and a significant raise in the (governmental) waste tax on specially landfilling activities. (Author)