WorldWideScience

Sample records for backfilling

  1. Horizontal roof gap of backfill hydraulic support

    Institute of Scientific and Technical Information of China (English)

    张强; 张吉雄; 邰阳; 方坤; 殷伟

    2015-01-01

    For the backfill hydraulic support as the key equipment for achieving integration of backfilling and coal mining simultaneously in the practical process, its characteristics will directly influence the backfill body’s compression ratio. Horizontal roof gap, as a key parameter of backfilling characteristics, may impact the backfilling effect from the aspects of control of roof subsidence in advance, support stress, backfilling process and the support design. Firstly, the reason why horizontal roof gap exists was analyzed and its definition, causes and connotation were introduced, then adopting the Pro/E 3D simulation software, three typical 3D entity models of backfill hydraulic supports were built, based on the influence of horizontal roof gap on backfilling effect, and influence rules of four factors, i.e. support height, suspension height, suspension angle and tamping angle, were emphatically analyzed on horizontal roof gap. The results indicate that, the four factors all have significant impacts on horizontal roof gap, but show differences in influence trend and degree, showing negative linear correlation, positive linear correlation, positive semi-parabolic correlation and negative semi-parabolic correlation, respectively. Four legs type is the most adaptive to the four factors, while six legs (II) type has the poorest adaptability, and the horizontal roof gap is small under large support height, small suspension height, small suspension angle and large tamping angle situation. By means of optimizing structure components and their positional relation and suspension height of backfill scrape conveyor in the process of support design and through controlling working face deployment, roof subsidence in advance, mining height and backfilling during engineering application, the horizontal roof gap is optimized. The research results can be served as theoretical basis for support design and guidance for backfill support to have better performance in backfilling.

  2. Geotechnical considerations in mine backfilling in Australia

    Energy Technology Data Exchange (ETDEWEB)

    N. Sivakugan; R.M. Rankine; K.J. Rankine; K.S. Rankine [James Cook University, Townsville, Qld. (Australia). School of Engineering

    2006-07-01

    Mine backfilling can play a significant role in the overall operation of a mine operation. In the Australian mining industry, where safety is a prime consideration, hydraulic systems are the most common backfills deployed. Many accidents reported at hydraulic fill mines worldwide have mainly been attributed to a lack of understanding of their behaviour and barricade bricks. There are two basic types of backfilling strategies. The first, uncemented backfilling, does not make use of binding agents such as cement, and their characteristics can be studied using soil mechanics theories. A typical example of uncemented backfilling is the use of hydraulic fills that are placed in the form of slurry into the underground voids. The second category, cemented backfilling, makes use of a small percentage of binder such as Portland cement or a blend of Portland cement with another pozzolan such as fly ash, gypsum or blast furnace slag. This paper describes the findings from an extensive laboratory test programme carried out in Australia on more than 20 different hydraulic fills and several barricade bricks. A limited description of paste backfills is also provided, and the usefulness of numerical modelling as an investigative tool is highlighted. 21 refs., 10 figs., 1 tab.

  3. Colonization of compacted backfill materials by microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Lucht, L.M.; Stroes-Gascoyne, S.; Miller, S.H.; Hamon, C.J.; Dixon, D.A

    1997-11-01

    Experiments were carried out to investigate the occurrence of pore clogging in backfill by bacterial activity. Four differently prepared and treated backfill materials were used to determine the effects of the quality and preparation method of the backfill materials on the occurrence of pore clogging. The backfills were compacted in permeameters which were infused with either groundwater or sterile distilled water. A constant pressure was applied to increase the rate of saturation. Results showed different inflow rates for the four materials despite the use of the same packing method for each specimen, the same dry density for each backfill and indications of similar initial pore volumes. These differences were likely caused by the fact that the two slowest-flowing permeameters contained a mixture of Na-bentonite and illitic shale simulating a glacial lake clay. Hydraulic conductivities measured ranged from 5 x 10{sup -11} m/s to 5 x 10{sup -12} m/s for the backfills containing glacial lake clay and 4 x 10{sup -12} m/s to 9 s 10{sup -13} m/s for the backfills containing a mixture of Na-bentonite and illitic shale. Weekly samples of outflow from the permeameters were analyzed microbially. Aerobic heterotrophs were low initially but stabilized around 10{sup 6} to 10{sup 7} colony forming units (CFU)/mL after about one week. Anaerobic heterotrophs stabilized at around 10{sup 2} to 10{sup 3} CFU/mL. Sulphate-reducing bacteria (SRB) were measured by the most probable number (MPN) method. Results showed low initial numbers but they stabilized around 10{sup 4} MPN/mL after one to two months. No significant numbers of aerobic or anaerobic sulphur oxidizing bacteria were found. Enumeration of methanogens indicated that they were generally present in the permeameters that contained non-autoclaved backfill. Results are partially inconclusive because of the lack of confirmation of methane gas present in the headspace of part of the MPN culture tubes. Microbial pore clogging

  4. A Historical Review of WIPP Backfill Development

    Energy Technology Data Exchange (ETDEWEB)

    Brush, L.H.; Krumhansl, J.L.; Molecke, M.A.; Papenguth, H.W.

    1999-07-15

    Backfills have been part of Sandia National Laboratories' [Sandia's] Waste Isolation Pilot Plant [WIPP] designs for over twenty years. Historically, backfill research at Sandia has depended heavily on the changing mission of the WIPP facility. Early testing considered heat producing, high level, wastes. Bentonite/sand/salt mixtures were evaluated and studies focused on developing materials that would retard brine ingress, sorb radionuclides, and withstand elevated temperatures. The present-day backfill consists of pure MgO [magnesium oxide] in a pelletized form and is directed at treating the relatively low contamination level, non-heat producing, wastes actually being disposed of in the WIPP. It's introduction was motivated by the need to scavenging CO{sub 2} [carbon dioxide] from decaying organic components in the waste. However, other benefits, such as a substantial desiccating capacity, are also being evaluated. The MgO backfill also fulfills a statutory requirement for assurance measures beyond those needed to demonstrate compliance with the US Environmental Protection Agency [EPA] regulatory release limits. However, even without a backfill, the WIPP repository design still operates within EPA regulatory release limits.

  5. Performance of cemented coal gangue backfill

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qin-li; WANG Xin-min

    2007-01-01

    Possibility of cemented gangue backfill was studied with gangue of Suncun Coal Mine, Xinwen Coal Group, Shandong,and fly ash of nearby thermal power plant, in order to treat enormous coal gangue on a large scale and to recovery safety coal pillars.The results indicate that coal gangue is not an ideal aggregate for pipeline gravity flow backfill, but such disadvantages of gangue as bad fluidity and serious pipe wear can be overcome by addition of fly ash. It is approved that quality indexes such as strength and dewatering ratio and piping feature of slurry can satisfy requirement of cemented backfill if mass ratio of cement to fly ash to gangue higher middle and long term comprehensive strength.

  6. Implementation of Paste Backfill Mining Technology in Chinese Coal Mines

    OpenAIRE

    Qingliang Chang; Jianhang Chen; Huaqiang Zhou; Jianbiao Bai

    2014-01-01

    Implementation of clean mining technology at coal mines is crucial to protect the environment and maintain balance among energy resources, consumption, and ecology. After reviewing present coal clean mining technology, we introduce the technology principles and technological process of paste backfill mining in coal mines and discuss the components and features of backfill materials, the constitution of the backfill system, and the backfill process. Specific implementation of this technology a...

  7. Experimental Evaluation of Backfill in Scour Holes around Offshore Monopiles

    DEFF Research Database (Denmark)

    Sørensen, Søren Peder Hyldal; Ibsen, Lars Bo; Frigaard, Peter

    2010-01-01

    . Currently there is no knowledge concerning the relative density, and hereby also the strength and deformation properties of the backfilled soil material. The strength of the backfilled soil and the time scale of respective erosion and backfilling is of high importance when designing the steel structure...

  8. Numerical calculation of backfilling of scour holes

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Baykal, Cüneyt; Fuhrman, David R.;

    2014-01-01

    A fully-coupled hydrodynamic and morphologic CFD model is presented for simulating backfilling processes around structures. The hydrodynamic model is based on Reynolds-averaged Navier-Stokes equations, coupled with two-equation k-ω turbulence closure. The sediment transport model consists of sepa...

  9. Assessment of backfill design for KBS-3V repository

    Energy Technology Data Exchange (ETDEWEB)

    Keto, Paula (B+tech, Eurajoki (Finland)); Dixon, David (AECL, Harwell (United Kingdom)); Jonsson, Esther; Gunnarsson, David (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Boergesson, Lennart (Clay Technology AB, Lund (Sweden)); Hansen, Johanna (Posiva (Finland))

    2009-12-15

    Posiva and SKB initiated a joint programme BACLO (Backfilling and Closure of the Deep repository) in 2003 with the aim to develop methods and materials for backfilling of deposition tunnels. This report summarises the work done in the third and final phase of the BACLO programme. The main objective of this phase was to study how the various processes active during backfill installation and saturation as well as technical constraints affect its design basis. The work focused on the performance and technical feasibility of a block backfill concept, which calls for filling the majority of the tunnel volume with pre-compacted backfill blocks and the remaining volume with bentonite pellets. Several backfill composition alternatives were chosen for study and they consisted of clay materials with differing amounts of swelling minerals. A large body of information was gained on the effect of different processes on the performance of these backfill options, e.g. water inflow, piping, erosion, self-healing, homogenisation and interaction between backfill and buffer in various laboratory and small-scale field tests. More practical tests included e.g. studies how the blocks and pellets could be installed to the deposition tunnel. Based on the new information on the effect of the processes investigated and the estimated achievable block filling degree and backfill density, recommendations were made concerning material selection, backfill layout and technical issues. In addition, issues requiring further attention to verify the long-term performance of the proposed backfill concept are identified and listed

  10. Implementation of Paste Backfill Mining Technology in Chinese Coal Mines

    Directory of Open Access Journals (Sweden)

    Qingliang Chang

    2014-01-01

    Full Text Available Implementation of clean mining technology at coal mines is crucial to protect the environment and maintain balance among energy resources, consumption, and ecology. After reviewing present coal clean mining technology, we introduce the technology principles and technological process of paste backfill mining in coal mines and discuss the components and features of backfill materials, the constitution of the backfill system, and the backfill process. Specific implementation of this technology and its application are analyzed for paste backfill mining in Daizhuang Coal Mine; a practical implementation shows that paste backfill mining can improve the safety and excavation rate of coal mining, which can effectively resolve surface subsidence problems caused by underground mining activities, by utilizing solid waste such as coal gangues as a resource. Therefore, paste backfill mining is an effective clean coal mining technology, which has widespread application.

  11. Implementation of paste backfill mining technology in Chinese coal mines.

    Science.gov (United States)

    Chang, Qingliang; Chen, Jianhang; Zhou, Huaqiang; Bai, Jianbiao

    2014-01-01

    Implementation of clean mining technology at coal mines is crucial to protect the environment and maintain balance among energy resources, consumption, and ecology. After reviewing present coal clean mining technology, we introduce the technology principles and technological process of paste backfill mining in coal mines and discuss the components and features of backfill materials, the constitution of the backfill system, and the backfill process. Specific implementation of this technology and its application are analyzed for paste backfill mining in Daizhuang Coal Mine; a practical implementation shows that paste backfill mining can improve the safety and excavation rate of coal mining, which can effectively resolve surface subsidence problems caused by underground mining activities, by utilizing solid waste such as coal gangues as a resource. Therefore, paste backfill mining is an effective clean coal mining technology, which has widespread application.

  12. Tunnel backfill erosion by dilute water

    Energy Technology Data Exchange (ETDEWEB)

    Olin, M. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2014-03-15

    The goal was to estimate smectite release from tunnel backfill due to dilute groundwater pulse during post glacial conditions. The plan was to apply VTT's two different implementations (BESW{sub D} and BESW{sub S}) of well-known model of Neretnieks et al. (2009). It appeared difficult to produce repeatable results using this model in COMSOL 4.2 environment, therefore a semi-analytical approximate approach was applied, which enabled to take into account both different geometry and smectite content in tunnel backfill as compared to buffer case. The results are quite similar to buffer results due to the decreasing effect of smaller smectite content and the increasing effect of larger radius. (orig.)

  13. Some characteristics of potential backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, D.R.

    1983-05-01

    A backfill material is one of the multiple barriers that may be involved in the disposal of nuclear waste. Such backfill should be a desiccant with the hydrous product having acceptable stability; it should sorb any released radioisotopes, and it should reseal any breached site. The backfill must also have acceptable thermal conductivity. This report presents data on the rate of hydration and the nature of the product of reaction of some candidate backfill materials with water and with brine. Thermal conductivity data is reported for both the reactants and the products. Granular MgO at 150/sup 0/C completely hydrates in less than 10 hours. At 60/sup 0/C and 20/sup 0/C, such extensive hydration requires about 100 and 1000 hours, respectively. The product of the reaction is stable to more than 300/sup 0/C. A doped discalcium silicate was less reactive and the product contains less water of crystallization than the MgO. The reaction product of dicalcium silicate is cementous, but it has low thermal stability. Bentonite readily reacts with water and expands. The reaction product has the properties of vermiculite, which indicates that magnesium ions have diffused into the bentonite structure and are not simply adsorbed on the surface. If bentonite is emplaced in a saline environment, the properties of vermiculite, the reaction product, should also be considered. The thermal conductivity of MgO, discalcium silicate, and bentonite is primarily dependent on the porosity of the sample. A slight increase in thermal conductivity was found with increased temperature, in contrast to most rocks. If the conductive data for the different materials is equated to the same porosity, MgO has the superior thermal conductivity compared to bentonite or discalcium silicate.

  14. Hydraulic calculation of gravity transportation pipeline system for backfill slurry

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qin-li; HU Guan-yu; WANG Xin-min

    2008-01-01

    Taking cemented coal gangue pipeline transportation system in Suncun Coal Mine, Xinwen Mining Group, Shandong Province, China, as an example, the hydraulic calculation approaches and process about gravity pipeline transportation of backfill slurry were investigated. The results show that the backfill capability of the backfill system should be higher than 74.4m3/h according to the mining production and backfill times in the mine; the minimum velocity (critical velocity) and practical working velocity of the backfill slurry are 1.44 and 3.82m/s, respectively. Various formulae give the maximum ratio of total length to vertical height of pipeline (L/H ratio) of the backfill system of 5.4, and then the reliability and capability of the system can be evaluated.

  15. Backfilling of trenches exposed to waves

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Fredsøe, Jørgen

    1997-01-01

    This paper treats the numerical prediction of initial and long-term morphology of small pipeline trenches. For this purpose a refined flow and sediment transport description is applied such that the entire mathematical problem is formulated and solved on a curvilinear grid using a k - ε turbulence...... of a particle in waves and L the trench length, is investigated in detail, and an optimal KC-number for the backfilling rate is found. Coherent structures in the non-uniform unsteady trench-flow are shown to dominate the deposition rate when present. The importance of a detailed description of the flow...

  16. 30 CFR 816.105 - Backfilling and grading: Thick overburden.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Backfilling and grading: Thick overburden. 816...-SURFACE MINING ACTIVITIES § 816.105 Backfilling and grading: Thick overburden. (a) Definition. Thick... surrounding terrain. (b) Performance standards. Where thick overburden occurs within the permit area,...

  17. Strata movement controlling effect of waste and fly ash backfillings in fully mechanized coal mining with backfilling face

    Institute of Scientific and Technical Information of China (English)

    Zhang Jixiong; Zhang Qiang; Huang Yanli; Liu Jinwei; Zhou Nan; Zan Dongfeng

    2011-01-01

    A fully mechanized coal mining with backfilling (FMCMB) provides advantages of safety and efficiency for coal mining under buildings,railways,and water bodies.According to the field geological conditions,we analyzed the controlling effect of strata movement by the waste and fly ash backfilling in FMCMB face.Based on the key strata theory,we established the equivalent mining thickness model,and analyzed the action of the bulk factor of backfilling body to the equivalent mining thickness.In addition,we numerically simulated the controlling function of the strata movement by backfilling bodies with different strength.And the numerical simulation result show that the deformation of stratum and the subsidence of surface can be controlled by FMCMB.The result provides references to the effective execution of fully mechanized coal mining with solid waste backfilling in goal.

  18. Backfilling and closure of the deep repository. Assessment of backfill concepts

    Energy Technology Data Exchange (ETDEWEB)

    Gunnarsson, David; Boergesson, Lennart [Clay Technology AB, Lund (Sweden); Keto, Paula [Saanio Riekkola Oy (Finland); Tolppanen, Pasi [Jaakko Poeyry Infra (Finland); Hansen, Johanna [Posiva Oy, Helsinki (Finland)

    2004-06-01

    This report presents the results from work made in Phase 1 of the joint SKB-Posiva project 'Backfilling and Closure of the Deep Repository' aiming at selecting and developing materials and techniques for backfilling and closure of a KBS-3 type repository for spent nuclear fuel. The aim of phase 1, performed as a desk study, was to describe the potential of the suggested backfill concepts in terms of meeting SKB and Posiva requirements, select the most promising ones for further investigation, and to describe methods that can be used for determining the performance of the concepts. The backfilling concepts described in this report differ from each other with respect to backfill materials and installation techniques. The concepts studied are the following: Concept A: Compaction of a mixture of bentonite and crushed rock in the tunnel. Concept B: Compaction of natural clay with swelling ability in the tunnel. Concept C: Compaction of non-swelling soil type in the tunnel combined with application of pre-compacted bentonite blocks at the roof. Concept D: Placement of pre-compacted blocks; a number of materials are considered. Concept E: Combination of sections consisting of a) crushed rock compacted in the tunnel and b) pre-compacted bentonite blocks. The bentonite sections are installed regularly above every disposal hole. Concept F: Combination of sections consisting of a) crushed rock compacted in the tunnel and b) pre-compacted bentonite blocks. The distance between the bentonite sections is adapted to the local geology and hydrology.The assessment of the concepts is based on performance requirements set for the backfill in the deposition tunnels for providing a stable and safe environment for the bentonite buffer and canister for the repository service time. In order to do this, the backfill should follow certain guidelines, 'design criteria' concerning compressibility, hydraulic conductivity, swelling ability, long-term stability, effects on

  19. Application of paste backfill in underground coal fires

    Energy Technology Data Exchange (ETDEWEB)

    Drebenstedt, C.; Masniyom, M. [Technische Univ., Freiberg (Germany)

    2009-07-01

    Coal fires are common in most coalfields around the world, and most particularly in China. The main countries affected by coal fires include China, India, the United States, Australia, Indonesia and South Africa. The fires cause sinkholes; large-scale subsidence; air pollution in the form of greenhouse gases; global warming; loss of mining productivity; contamination of drinking water; damage of flora and fauna; and a high safety risk. Therefore, protecting the economically valuable coal resources and the environment is of significant national and international importance. This paper discussed the use of paste backfill in the Wuda Inner Mongolia coalfield to cool down the burning coal and cut off the air supply to prevent coal fires. The study investigated backfill materials and techniques suited for underground coal fires. The paper presented the results of laboratory tests that were conducted on physical, chemical and mechanical properties of different backfill materials and mixtures, with particular attention to materials generated as by-products and other cheaply available materials such as fly ash from power plants. The characteristics of backfill materials, grain size analysis, and chemical composition of backfill were also identified. It was concluded that backfilling voids enhance the stability of the mine, thereby improving safety for the workforce. 4 refs., 2 tabs., 4 figs.

  20. Closure of the Brewer Gold Mine by pit backfilling

    Energy Technology Data Exchange (ETDEWEB)

    Lewis-Russ, A.; Lupo, J.F. [Titan Environmental Corp., Englewood, CO (United States); Bronson, J.M. [Titan Environmental Corp., Tempe, AZ (United States)] [and others

    1996-12-31

    Brewer Gold Mine, located in north-central South Carolina, is implementing an innovative reclamation plan that includes backfilling the main Brewer open pit with mine waste. The primary goals of the closure are to reduce acid rock drainage and minimize or eliminate long-term operation and maintenance requirements by restoring the site property to approximate pre-mining topography. The plan calls for consolidation of approximately 200 acres of waste into approximately 20 hectares (50 acres). Much of the material to be backfilled into the pit, including spent heap leach material and waste rock, has acid-generating potential. Therefore, the backfill design integrated geochemical properties of the backfill materials with expected post-closure conditions. A prime consideration was the final position of the water table. Since mining at the site started in the early 1800`s, no records exist of the original groundwater levels. Therefore, the design incorporates a large anoxic limestone drain to control the final groundwater level. Additional amendments are to be placed in targeted areas of the backfill to maximize their utilization. A low-permeability cap system that includes a GEOSYNTHETIC clay liner has been designed to limit infiltration into the backfill.

  1. Status of Research on Magnesium Oxide Backfill

    Energy Technology Data Exchange (ETDEWEB)

    PAPENGUTH,HANS W.; KRUMHANSL,JAMES L.; BYNUM,R. VANN; WANG,YIFENG; KELLY,JOHN W.; ANDERSON,HOWARD; NOWAK,E. JAMES

    2000-07-31

    For the WIPP, chemical and physical characteristics of MgO suggest it to be the most beneficial backfill choice, particularly because it has the ability to buffer the aqueous chemical conditions to control actinide volubility. In the current experimental program, the authors are developing a technical basis for taking credit for the complete set of attributes of MgO in geochemical, hydrogeological, and geomechanical technical areas, resulting in an improved conceptual model for the WIPP such as the following. Water uptake by MgO will delay the development of mobile actinides and gas generation by microbes and corrosion. Reduced gas generation will reduce or even eliminate spallings releases. As MgO hydrates, it swells, reducing porosity and permeability, which will inhibit gas flow in the repository, in turn reducing spallings releases. Hydration will also result in a self-sealing mechanism by which water uptake and swelling of MgO adjacent to a groundwater seep cuts off further seepage. Reaction with some groundwaters will produce cementitious materials, which will help to cement waste particles or produce a cohesive solid mass. Larger particles are less likely to be entrained in a spallings release. If sufficient water eventually accumulates in a repository to support microbial gas generation, magnesium carbonate cements will form; also producing good cohesion and strength.

  2. Backfilling of deposition tunnels: Use of bentonite pellets

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David (Atomic Energy of Canada Limited (Canada)); Sanden, Torbjoern (Clay Technology AB (Sweden)); Jonsson, Esther (Swedish Nuclear Fuel and Waste Mangaement Co. (Sweden)); Hansen, Johanna (Posiva Oy (Finland))

    2011-02-15

    The state of knowledge related to use of bentonite pellets as part of backfill or other gap filling components in repository applications is reviewed. How the pellets interact with adjacent sealing materials and the surrounding rock mass is a critical aspect in determining backfill behaviour. The key features and processes that determine how the pellet component of the KBS-3V deposition tunnel backfill will behave are discussed and recommendations related to what additional information needs to be developed are provided. Experiences related to pellet material composition, size, shape, placement options and more importantly, the density to which they can be placed all indicate that there are significant limitations to the achievable as-placed density of bentonite pellet fill. Low as-placed density of the pellet fill component of the backfill is potentially problematic as the outermost regions of tunnel backfill will be the first region of the backfill to be contacted by water entering the tunnels. It is also through this region that initial water movement along the length of the deposition tunnels will occur. This will greatly influence the operations in a tunnel, especially with respect to situations where water is exiting the downstream face of still open deposition tunnels. Pellet-filled regions are also sensitive to groundwater salinity, susceptible to development of piping features and subsequent mechanical erosion by through flowing water, particularly in the period preceding deposition tunnel closure. A review of the experiences of various organisations considering use of bentonite-pellet materials as part of buffer or backfill barriers is provided in this document. From this information, potential options and limitations to use of pellets or pellet-granule mixtures in backfill are identified. Of particular importance is identification of the apparent upper-limits of dry density to which such materials can to be placed in the field. These bounds will

  3. On the risk of liquefaction of buffer and backfill

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, R. [Geodevelopment AB, Lund (Sweden)

    2000-10-01

    The necessary prerequisites for liquefaction of buffers and backfills in a KBS-3 repository exist but the stress conditions and intended densities practically eliminate the risk of liquefaction for single earthquakes with magnitudes up to M=8 and normal duration. For buffers rich in expandable minerals it would be possible to reduce the density at water saturation to 1,700 - 1,800 kg/m{sup 3} or even less without any significant risk of liquefaction, while the density at saturation of backfills with 10 - 15% expandable clay should not be reduced to less than about 1,900 kg/m{sup 3}. Since the proposed densities of both buffers and backfills will significantly exceed these minimum values it is concluded that there is no risk of liquefaction of the engineered soil barriers in a KBS-3 repository even for very significant earthquakes.

  4. Experimental and Numerical Study of Wave-Induced Backfilling Beneath Submarine Pipelines

    DEFF Research Database (Denmark)

    Bayraktar, Deniz; Ahmad, Joseph; Eltard-Larsen, Bjarke

    Through complementary experimental and numerical efforts, the present paper aims to make a significant contribution to the overall understanding of backfilling processes beneath submarine pipelines. For this purpose, we aim to simplify the experimental backfilling process to an elementary two...

  5. Use of Dilute Flowable Backfill for Corrosion Mitigation of Buried Pipe

    Science.gov (United States)

    2010-02-01

    Engineers Engineer Research & Development Center Construction Engineering Research Laboratory Flowable Backfill Design Specifications Mix Composition ...US Army Corps of Engineers Engineer Research & Development Center Construction Engineering Research Laboratory Use of Dilute Flowable Backfill for...1. REPORT DATE FEB 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Use of Dilute Flowable Backfill for

  6. 30 CFR 819.19 - Auger mining: Backfilling and grading.

    Science.gov (United States)

    2010-07-01

    ... of the highwall shall be stable and not pose a hazard to the public health and safety or to the... health and safety or to the environment. ... authority that the backfill, designed by a qualified registered professional engineer, has a minimum...

  7. 30 CFR 816.102 - Backfilling and grading: General requirements.

    Science.gov (United States)

    2010-07-01

    ..., acid- and toxic-forming materials, and combustible materials exposed, used, or produced during mining.... 816.102 Section 816.102 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT...-SURFACE MINING ACTIVITIES § 816.102 Backfilling and grading: General requirements. (a) Disturbed...

  8. 30 CFR 817.102 - Backfilling and grading: General requirements.

    Science.gov (United States)

    2010-07-01

    .... 817.102 Section 817.102 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT...-UNDERGROUND MINING ACTIVITIES § 817.102 Backfilling and grading: General requirements. (a) Disturbed areas... leaching of toxic materials. (d) Spoil may be placed on the area outside the mined-out surface area...

  9. The Buffer and Backfill Handbook. Part 2: Materials and techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Geodevelopment AB, Lund (Sweden)

    2001-12-01

    Improved technology and prospection yielding more pure and homogeneous raw materials for preparing buffers and backfills will ultimately outdate the clays and ballast materials described in the present part of the Handbook. It describes experimentally investigated materials of potential use in repositories but other, more suitable materials will replace them in the future. The Handbook will hence have to be reviewed regularly, making room for superior materials in future, upgraded Handbook versions. Buffer is the term for dense clay used for embedment of canisters with highly radioactive waste, while backfill is soil used for filling tunnels and shafts in repositories. Examples of soil materials of potential use as buffers and backfills in repositories of KBS-3 type are described in this part of the Handbook. They are: smectitic clay materials intended for preparation of buffers (canister-embedding clay) and used as clay component in artificially prepared tunnel and shaft backfills consisting of mixtures of clay and ballast. Ballast materials intended for backfilling of tunnels and shafts and used as components of artificially prepared backfills. Smectitic natural clay soils intended for use as buffers and backfills. Very fine-grained smectite clay used as grout for sealing rock fractures. In this part of the Handbook for Buffers and Backfills, description of various candidate materials will be made with respect to their mineral composition and physical properties, with respect to the groundwater chemistry that can be expected in a deep repository in Swedish bedrock. Chapter 3 deals with smectitic clay materials intended for embedment of heat-producing canisters with highly radioactive waste. Focus is on the nature of the buffer constituents, i. e. the smectite content, the non-expanding clay minerals colloidal and the accessory non-clay minerals as well as amorphous matter and organic substances. The dominant part of the chapter describes the occurrence and origin

  10. A New Mode of Coal Mining Under Buildings with Paste-Like Backfill Technology

    Institute of Scientific and Technical Information of China (English)

    崔建强; 孙恒虎; 黄玉诚

    2002-01-01

    The formation of the paste-like backfill technology was introduced briefly in this paper. From the actual cases of coal mines, a new mode of coal mining un der buildings with the technology was proposed. And its specificity was analyzed , and a further introduction to the full-sand-soil solidifying material was given. The main parts of the backfill system, such as the backfill preparation system, the pipeline transportation system, the backfill systems in fully-mechanized mining faces and the backfill process, were presented emphatically.

  11. Backfilling of KBS-3V deposition tunnels - possibilities and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Wimelius, Hans (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Pusch, Roland (Geodevelopment International AB, Lund (Sweden))

    2008-12-15

    By definition for the SKB repository concept, the backfill of KBS-3V deposition tunnels must be so designed that transport of dissolved matter is controlled by diffusion and not by advective water flow. This requires that the hydraulic conductivity of the backfill does not exceed about E-10 m/s. The backfilling materials also have to adequately resist compression caused by upward expansion of the buffer. It must also exert an effective pressure of at least 100 kPa on the rock in order to provide support to the rock and minimize spalling of the rock. These criteria are fulfilled by several approaches and options for backfill materials, placed and compacted layer wise or in the form of blocks of compacted clay powder. Based on the experience from comprehensive lab studies and considering practical issues, SKB has selected a concept where the major part of the backfill consists of stacked blocks that are surrounded by clay pellets. Using this concept a basis for a detailed evaluation, a study of three different techniques for placing the blocks has been undertaken. The three block placement techniques examined are the 'Block', 'Robot', and 'Module' methods. They involve different block sizes and techniques for handling and placing the blocks but the same way of preparing the foundation bed of the blocks and placing the pellet filling. The blasted tunnels have a varying cross section, caused by the orientation of the blast-holes. This requires that a varying fraction of blocks be installed in the backfilling along the blasted tunnel interval if sufficiently high density and low hydraulic conductivity is to be achieved. The efficiency of filling will depend on the type of clay used in the blocks. For example, using Friedland clay for block preparation, the filling efficiency must be 80% while it can be reduced to 60% if more smectite-rich clay is used. The use of a clay with high smectite content increases margins and is concluded to be

  12. Effect of Initial Backfill Temperature on the Deformation Behavior of Early Age Cemented Paste Backfill That Contains Sodium Silicate

    Directory of Open Access Journals (Sweden)

    Aixiang Wu

    2016-01-01

    Full Text Available Enhancing the knowledge on the deformation behavior of cemented paste backfill (CPB in terms of stress-strain relations and modulus of elasticity is significant for economic and safety reasons. In this paper, the effect of the initial backfill temperature on the CPB’s stress-strain behavior and modulus of elasticity is investigated. Results show that the stress-strain relationship and the modulus of elasticity behavior of CPB are significantly affected by the curing time and initial temperature of CPB. Additionally, the relationship between the modulus of elasticity and unconfined compressive strength (UCS and the degree of hydration was evaluated and discussed. The increase of UCS and hydration degree leads to an increase in the modulus of elasticity, which is not significantly affected by the initial temperature.

  13. Backfilling of KBS-3V deposition tunnels - possibilities and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Wimelius, Hans (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Pusch, Roland (Geodevelopment International AB, Lund (Sweden))

    2008-12-15

    By definition for the SKB repository concept, the backfill of KBS-3V deposition tunnels must be so designed that transport of dissolved matter is controlled by diffusion and not by advective water flow. This requires that the hydraulic conductivity of the backfill does not exceed about E-10 m/s. The backfilling materials also have to adequately resist compression caused by upward expansion of the buffer. It must also exert an effective pressure of at least 100 kPa on the rock in order to provide support to the rock and minimize spalling of the rock. These criteria are fulfilled by several approaches and options for backfill materials, placed and compacted layer wise or in the form of blocks of compacted clay powder. Based on the experience from comprehensive lab studies and considering practical issues, SKB has selected a concept where the major part of the backfill consists of stacked blocks that are surrounded by clay pellets. Using this concept a basis for a detailed evaluation, a study of three different techniques for placing the blocks has been undertaken. The three block placement techniques examined are the 'Block', 'Robot', and 'Module' methods. They involve different block sizes and techniques for handling and placing the blocks but the same way of preparing the foundation bed of the blocks and placing the pellet filling. The blasted tunnels have a varying cross section, caused by the orientation of the blast-holes. This requires that a varying fraction of blocks be installed in the backfilling along the blasted tunnel interval if sufficiently high density and low hydraulic conductivity is to be achieved. The efficiency of filling will depend on the type of clay used in the blocks. For example, using Friedland clay for block preparation, the filling efficiency must be 80% while it can be reduced to 60% if more smectite-rich clay is used. The use of a clay with high smectite content increases margins and is concluded to be

  14. Backfilling technology and strata behaviors in fully mechanized coal mining working face

    Institute of Scientific and Technical Information of China (English)

    Zhang Qiang; Zhang Jixiong; Huang Yanli; Ju Feng

    2012-01-01

    Based on the principle of fully mechanized backfilling and coal mining technology and combined with theXingtai Coal Mine conditions,we mainly optimized the coal mining equipment and adjusted the coal mining method in the Xingtai Coal Mine 7606 working face for implementation this technology,Firstly,we define the practical backfilling process as the "(from backfilling scraper conveyor's) head to tail backfilling,step by step swinging up of the tamping arm.gradual compacting,moving formed backfilling scraper conveyor when the second tamping arm cannot pass and connecting the immediate roof by back material push front material movement".Meanwhile,the stress changes of backfill body in coal mined out area was monitored by stress sensors,and the roof caving law was analyzed by monitoring the dynamic subsidence of -210 west roadway of this face.The site tests results show that using this new backfilling and coal mining integrated technology,the production capacity in the 7606 working face can reach to 283,000 ton a year,and 282,000 ton of solid materials (waste and fly ash) is backfilled,which meets the needs of high production and efficiency.The goaf was compactly backfilled with solid material and the strata behavior was quite desirable,with an actual maximum vertical stress of the backfill body of 5.5 MPa.Backfill body control the movement of overburden within a certain range,and there is no collapses of major areas in the overlying strata upon backfilled gob.The maximum subsidence and speed were 231 mm and 15.75 mm/d respectively,which proved the practical significance of this integrated technology.

  15. Radon emanation from backfilled mill tailings in underground uranium mine.

    Science.gov (United States)

    Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekananda; Patnaik, R Lokeswara; Sethy, Narendra Kumar

    2014-04-01

    Coarser mill tailings used as backfill to stabilize the stoped out areas in underground uranium mines is a potential source of radon contamination. This paper presents the quantitative assessment of radon emanation from the backfilled tailings in Jaduguda mine, India using a cylindrical accumulator. Some of the important parameters such as (226)Ra activity concentration, bulk density, bulk porosity, moisture content and radon emanation factor of the tailings affecting radon emanation were determined in the laboratory. The study revealed that the radon emanation rate of the tailings varied in the range of 0.12-7.03 Bq m(-2) s(-1) with geometric mean of 1.01 Bq m(-2) s(-1) and geometric standard deviation of 3.39. An increase in radon emanation rate was noticed up to a moisture saturation of 0.09 in the tailings, after which the emanation rate gradually started declining with saturation due to low diffusion coefficient of radon in the saturated tailings. Radon emanation factor of the tailings varied in the range of 0.08-0.23 with the mean value of 0.21. The emanation factor of the tailings with moisture saturation level over 0.09 was found to be about three times higher than that of the absolutely dry tailings. The empirical relationship obtained between (222)Rn emanation rate and (226)Ra activity concentration of the tailings indicated a significant positive linear correlation (r = 0.95, p radon emanation rate from the backfill material of similar nature.

  16. Effects of grouting, shotcreting and concrete leachates on backfill geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Luna, Miguel; Arcos, David; Duro, Lara [Enviros Consulting, Valldoreix, Barc elona (Spain)

    2007-11-15

    The use of concrete to seal open fractures (grouting) and to impermeabilise the deposition tunnels (shotcreting) has been envisaged in the construction of a high level nuclear waste (HLNW) repository according to SKB designs. Nevertheless, the geochemical effect of using concrete in the repository is not fully understood. Concrete degradation due to the interaction with groundwater can affect the performance of other repository barriers, such as the backfill material used for sealing the deposition tunnels. One of the main effects of concrete degradation is the generation of alkaline plumes. For this reason, SKB is currently planning to use a type of concrete whose degradation result in lower pH values than those developed with Ordinary Portland Cement (OPC). In order to assess the long-term geochemical effect of including low-pH concrete elements in a HLNW repository, we performed a 2D reactive-transport model of a backfilled deposition tunnel that intersects a hydraulic conductive fracture which has been partially grouted. An additional case has been modelled where part of the deposition tunnel walls were covered with a shotcrete layer. The modelling results predict the development of a high-alkalinity plume, larger in the case of considering a grouted fracture, accompanied by the precipitation of CSH-phases in the fracture. However, the effect on the backfill material is only significant if concrete is in contact with the backfill (shotcrete case). In order to conduct these models, and considering that at the beginning of the present work there was not a specific composition for such a low-pH concrete, its composition has been assumed in order to meet the expected geochemical evolution of concrete degradation according to SKB expectations. This is a pH of pore water of around 11 and the degradation of CSH phases resulting in a source for Ca and Si into the system. For this reason, jennite and tobermorite have been selected, although it is known that jennite is

  17. Mechanical analysis of roof stability under nonlinear compaction of solid backfill body

    Institute of Scientific and Technical Information of China (English)

    Li Meng⇑; Zhang Jixiong; Liu Zhan; Zhao Xu; Huang Peng

    2016-01-01

    Based on the compaction characteristic test and the nonlinear compaction deformation characteristics of backfill material, this paper applies the theory of nonlinear elastic foundation of thin plate to establish a mechanical model of backfill body and roof in solid dense backfill coal mining. This study critically anal-yses the deflection equation of the roof by the energy method, derives the conditions of roof breakage and combined with concrete engineering practice analyses, determines roof movement regularity and stabil-ity in solid dense backfill mining. Analysis of the engineering practice of the 13,120 backfill panel of Pingmei 12# mine shows the theoretical maximum of roof convergence in backfill mining to be 415 mm which is in significant agreement with the measured value. During the advancing process of solid backfill mining at the panel, the maximum tensile stress on the roof is less than its tensile strength which does not satisfy the conditions for roof breakage. Drilling results on the roof and ground pressure monitoring show that the integrity of roof is strong, which is consistent with the theoretical calculations described in this study. The results presented in the study provide a basis for further investigation into strata movement theory in solid dense backfill mining.

  18. 30 CFR 816.106 - Backfilling and grading: Previously mined areas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Backfilling and grading: Previously mined areas...-SURFACE MINING ACTIVITIES § 816.106 Backfilling and grading: Previously mined areas. (a) Remining... opertions where the volume of all reasonably available spoil is demonstrated in writing to the...

  19. 30 CFR 817.106 - Backfilling and grading: Previously mined areas.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Backfilling and grading: Previously mined areas...-UNDERGROUND MINING ACTIVITIES § 817.106 Backfilling and grading: Previously mined areas. (a) Remining... operations where the volume of all reasonably available spoil is demonstrated in writing to the...

  20. Flowable Backfill Materials from Bottom Ash for Underground Pipeline

    Directory of Open Access Journals (Sweden)

    Kyung-Joong Lee

    2014-04-01

    Full Text Available The purpose of this study was to investigate the relationship between strength and strain in manufacturing controlled low strength materials to recycle incineration bottom ash. Laboratory tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. The optimum mixing ratios were 25%–45% of in-situ soil, 30% of bottom ash, 10%–20% of fly ash, 0%–3% of crumb rubber, 3% of cement, and 22% of water. Each mixture satisfied the standard specifications: a minimum 20 cm of flowability and 127 kPa of unconfined compressive strength. The average secant modulus (E50 was (0.07–0.08 qu. The ranges of the internal friction angle and cohesion for mixtures were 36.5°–46.6° and 49.1–180 kPa, respectively. The pH of all of the mixtures was over 12, which is strongly alkaline. Small-scale chamber tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. Vertical deflection of 0.88–2.41 mm and horizontal deflection of 0.83–3.72 mm were measured during backfilling. The vertical and horizontal deflections of controlled low strength materials were smaller than that of sand backfill.

  1. Particle Flow Characteristics and Transportation Optimization of Superfine Unclassified Backfilling

    Directory of Open Access Journals (Sweden)

    Ke-ping Zhou

    2017-01-01

    Full Text Available In order to investigate the high volume fraction problem of the solid phase in superfine unclassified backfilling pipeline transportation, characteristic parameters were obtained by fitting to test data with an R–R particle size distribution function; then, a Euler dense-phase DPM (Discrete phase model model was established by applying solid–liquid two-phase flow theory and the kinetic theory of granular flow (KTGF. The collision and friction of particles were imported by the UDF (User-define function function, and the pipeline fluidization system, dominated by interphase drag forces, was analyzed. The best concentration and flow rate were finally obtained by comparing the results of the stress conditions, flow field characteristics, and the discrete phase distributions. It is revealed that reducing the concentration and flow rate could control pressure loss and pipe damage to a certain degree, while lower parameters show negative effects on the transportation integrity and backfilling strength. Indoor tests and field industrial tests verify the reliability of the results of the numerical simulations. Research shows that the model optimization method is versatile and practical for other, similar, complex flow field working conditions.

  2. Design and application of solid, dense backfill advanced mining technology with two pre-driving entries

    Institute of Scientific and Technical Information of China (English)

    Zhang Qiang; Zhang Jixiong; Guo Shuai; Gao Rui; Li Weikang

    2015-01-01

    New solid backfill mining technology provides unique technical advantages for‘three-under’ coal min-ing which refers to coal resources trapped under buildings, railways, and water bodies. This technology has a much higher recovery rate and can effectively control the surface subsidence. However, successful application of this technology depends heavily on geological conditions. To avoid the disadvantages asso-ciated with downward mining and overhead backfilling with this new technology, a new advanced solid backfill mining design with two pre-driving entries is proposed here to ensure the backfill effect. Taking Huayuan coal mine as an example, this paper tests the double gob-side entries retaining with no pillar left scheme and optimizes an integrated technology setup for backfill mining and gob-side entry retain-ing. Field applications show that the recovery rate increased from 40%for strip mining to 85%for backfill mining. Moreover, the new backfill technology allowed for better control over the surrounding rock deformation caused by the gob-side entry retaining effect and better control of ground subsidence as compared to strip mining.

  3. Research on U-steel yieldable support with backfill technology in rock roadway

    Institute of Scientific and Technical Information of China (English)

    LUO Yong; CHANG Ju-cai

    2009-01-01

    The loading on U-steel yieldable support cannot be organically combined with the law of strata behaviors from the surrounding rocks of roadway. In order to effectively solve the problem, U-steel yieldable support with backfill material and the performance requirements of backfill material were analyzed on the basis of structural mechanics. The mechanical properties of backfill material selected were tested in the laboratory, and the test results show that the ratio of the backfill material complies with the requirements of backfill technology; it can effectively optimize the relationship between the support and the surrounding rock, and the filling layer can avoid the partial stress concentration and fully improve the support performance. Compared with U-steel yieldable support with gangue filling, the filed application shows that the supporting result of U-steel yieldable support with backfill technology is satisfactory, the stress on U-steel yieldable support with backfill technology decreases greatly and distributes uniformly, convergence of the surrounding rock of roadway is decreased by more than 50%, and the surrounding rocks of roadway are controlled effectively.

  4. Research on U-steel yieldable support with backfill technology in rock roadway

    Energy Technology Data Exchange (ETDEWEB)

    Yong Luo; Ju-cai Chang [Huainan Mining Group Co. Ltd., Huainan (China). Postdoctoral Scientific Research Station

    2009-12-15

    The loading on U-steel yieldable support cannot be organically combined with the law of strata behaviors from the surrounding rocks of roadway. In order to effectively solve the problem, U-steel yieldable support with backfill material and the performance requirements of backfill material were analyzed on the basis of structural mechanics. The mechanical properties of backfill material selected were tested in the laboratory, and the test results show that the ratio of the backfill material complies with the requirements of backfill technology; it can effectively optimize the relationship between the support and the surrounding rock, and the filling layer can avoid the partial stress concentration and fully improve the support performance. Compared with U-steel yieldable support with gangue filling, the filed application shows that the supporting result of U-steel yieldable support with backfill technology is satisfactory, the stress on U-steel yieldable support with backfill technology decreases greatly and distributes uniformly, convergence of the surrounding rock of roadway is decreased by more than 50%, and the surrounding rocks of roadway are controlled effectively.

  5. Realizing of Optimization of Binder Backfill Material Under Certain Strength with Fuzzy Sets

    Institute of Scientific and Technical Information of China (English)

    崔明义; 胡华

    2001-01-01

    The main factors deciding the compressive strength of binder backfill body are tailing density and binder dosage in binder backfill materials. Based on the antecedent of certain pulp density, the method of increasing the tailing density and reducing the binder dosage, or the manner of cutting down the tailing density and gaining the binder dosage are taken to guarantee the strength of backfill body. The problem that should be solved is how to determine the tailing density and the binder dosage rationally. This paper tries to realize the correct selection of the tailing density and the binder dosage in computer with the method of fuzzy mathematics.

  6. Groundwater flow evaluation through backfilling materials of a surface coal mining site of Northeast Mexico

    Science.gov (United States)

    Gutierrez-Ojeda, C.; Martínez-Morales, M.; Ortíz-Flores, G.

    2013-05-01

    Surface coal mining at the Allende-Piedras Negras aquifer system requires the complete dewatering and removal of the aquifer. The aquifer contains several geologic layers of variable hydraulic conductivity. Backfilling material is composed of a mixture of permeable and impermeable layers and it was initially considered as impermeable. Exploratory drillings, pumping tests and a geophysical survey were performed in the backfilling materials and the surrounding unaltered materials in order to evaluate the natural groundwater flow modification due to the mining activities. Results of geophysical survey evidenced a saturated water table within the back filling material which was verified by exploratory drilling. Pumping tests showed that unaltered materials have a mean hydraulic conductivity of 34.5 m/day while the backfilling of 5.3 m/day. Although the mining activities reduce the hydraulic conductivity by almost an order of magnitude, it was corroborated the existence of a groundwater flow through the backfilling materials.

  7. Effects of bituminous layer as backfill material on mechanical behavior in tunnel model

    OpenAIRE

    Moriyoshi, Akihiro; Takano, Shin-ei; Urata, Hiroyuki; Suzuki, Tetsuya; Yoshida, Takaki

    2001-01-01

    This paper describes the effects of bituminous material as a backfill material on mechanical behavior in model tunnel in laboratory. It is known that load spreading and relaxation of bituminous material are good properties. Then if we use bituminous material as a backfill material of tunnel, the tunnel will have waterproof, good load spreading property. We used new bituminous material (Aquaphalt) which can solidify in water. We conducted relaxation test in tension for new bituminous mat...

  8. REQUIREMENT OF FLUIDITY OF HIGH WATER CONTENT MATERIALS FORTHE GETWAY-SIDE BACKFILLING TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    QiTaiyue; MaNianjie

    1996-01-01

    Through analyzing the effects of water consumption, diameter of solid particle, and flow velocity on the fluidity of high water content material slurry, the relationship among the fluidity, the isotropy of the slurry, and the pumping facilities applied in getway-side backfilling has been found. And the requirment of fluidity of high water content material for the design of getway-side backfilling technique is put forward in the paper.

  9. Design, production and initial state of the backfill and plug in deposition tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Boerjesson, Lennart; Gunnarsson, David; Johannesson, Lars-Erik; Jonsson, Esther

    2010-12-15

    The report is included in a set of Production reports, presenting how the KBS-3 repository is designed, produced and inspected. The set of reports is included in the safety report for the KBS-3 repository and repository facility. The report provides input on the initial state of the backfill and plug in deposition tunnels for the assessment of the long-term safety, SR-Site. The initial state refers to the properties of the engineered barriers once they have been finally placed in the KBS-3 repository and will not be further handled within the repository facility. In addition, the report provides input to the operational safety report, SR-Operation, on how the backfill and plug shall be handled and installed. The report presents the design premises and reference designs of the backfill and plug in deposition tunnels and verifies their conformity to the design premises. It also describes the production of the backfill from excavation and delivery of backfill material to installation in the deposition tunnel, and gives an outline of the installation of the plug. Finally, the initial states of the backfill and plug and their conformity to the reference designs and design premises are presented

  10. Mechanical interaction buffer/backfill. Finite element calculations of the upward swelling of the buffer against both dry and saturated backfill

    Energy Technology Data Exchange (ETDEWEB)

    Boergesson, Lennart (Clay Technology AB, Lund (Sweden)); Hernelind, Jan (5T-Engineering AB, Vaesteraas (Sweden))

    2009-10-15

    The mechanical interaction between the buffer material in the deposition hole and the backfill material in the deposition tunnel is an important process in the safety assessment since the primary function of the backfill is to keep the buffer in place and not allow it to expand too much and thereby loose too much of its density and barrier properties. In order to study the upwards swelling of the buffer and the subsequent density reduction a number of finite element calculations have been performed. The calculations have been done with the FE-program Abaqus with 3D-models of a deposition hole and the deposition tunnel. In order to refine the modelling only the two extreme cases of completely un-wetted (dry) and completely water saturated (wet) backfill have been modelled. For the wet case the influence of different factors has been studied while only one calculation of the dry case has been done. The calculated upwards swelling of the buffer varied between 2 and 15 cm for the different wet cases while it was about 10 cm for the dry case. In the wet reference case the E-modulus of the block and pellets fillings was 50 MPa and 3.24 MPa respectively, the friction angle between the buffer and the rock and canister was 8.7 deg and there were no swelling pressure from the backfill. There is a strong influence of the friction angle on both the upwards swelling and the canister heave. The friction is important for preventing especially canister displacements. The unrealistic case of no friction yielded strong unacceptable influence on the buffer with an upwards swelling of 15 cm and a strong heave of 5 cm of the canister. The influence of the backfill stiffness is as expected strong. Both buffer swelling and canister heave are twice as large at the E-modulus E = 25 MPa than at the E-modulus E = 100 MPa. The influence of the stiffness of the pellets filling is not strong since there are no pellets on the floor in the model used. The influence of the swelling pressure of the

  11. Use of fly ash in backfill at Kidd Creek Mines

    Energy Technology Data Exchange (ETDEWEB)

    Yu, T.R.; Counter, D.B. (Kidd Creek Mines Ltd., Timmins, ON (Canada))

    1988-01-01

    In an effort to increase productivity, the use of fly ash from thermal power plants as a binder for consolidated backfill was studied. From laboratory and underground tests for its cementitious properties and environmental effects, it was found that a portion of Portland cement could be replaced by the same amount of type C fly ash (produced from subbituminous coal or lignite) to produce an acceptable consolidated rockfill product for use at an Ontario mine. The environmental concerns in terms of dust control and emanation of radon gas were unfounded from measurements. The dust count was comparable to the use of Portland cement only, or with ground blast furnance slag, and the radiation readings were low, averaging one-seventh the regulation level. Since May 1984, a total of over 100,000 tonnes of fly ash has been consumed as a binder blended with Portland cement, producing over four million tonnes of consolidated rockfill. To date, the fill in the stopes has performed very satisfactorily, while yielding considerable cost savings. 9 refs.

  12. A simplified DEM numerical simulation of vibroflotation without backfill

    Science.gov (United States)

    Jiang, M. J.; Liu, W. W.; He, J.; Sun, Y.

    2015-09-01

    Vibroflotation is one of the deep vibratory compaction techniques for ground reinforcement. This method densities the soil and improves its mechanical properties, thus helps to protect people's lives and property from geological disasters. The macro reinforcement mechanisms of vibroflotation method have been investigated by numerical simulations, laboratory and in-situ experiments. However, little attention has been paid on its micro - mechanism, which is essential to fully understand the principle of the ground reinforcement. Discrete element method (DEM), based on discrete mechanics, is more powerful to solve large deformation and failure problems. This paper investigated the macro-micro mechanism of vibroflotation without backfill under two conditions, i.e., whether or not the ground water was considered, by incorporating inter-particle rolling resistance model in the DEM simulations. Conclusions obtained are as follows: The DEM simulations incorporating rolling resistance well replicate the mechanical response of the soil assemblages and are in line with practical observations. The void ratio of the granular soil fluctuates up and down in the process of vibroflotation, and finally reduces to a lower value. It is more efficient to densify the ground without water compared to the ground with water.

  13. Dessicant materials screening for backfill in a salt repository

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, D.R.

    1980-10-01

    Maintaining an anhydrous environment around nuclear waste stored in a salt repository is a concern which can be alleviated by using a desiccant material for backfilling. Such a desiccant should desiccate a brine yet be non deliquescent, the hydrated product should have moderate thermal stability, and the desiccant should have a high capacity and be readily available. From a literature search MgO and CaO were identified for detailed study. These oxides, and an intimate mixture of the two obtained by calcining dolomite, were used in experiments to further determine their suitability. They proved to be excellent desiccants with a high water capacity. The hydrates of both have moderate thermal stability and a high water content. Both MgO and CaO react in an alkaline chloride brine forming oxychloride compounds with different waters of crystallization. Some of these compounds are the Sorel Cements. CaO hydrates to Ca(OH)/sub 2/ which carbonates with CO/sub 2/ in air to form CaCO/sub 3/ and release the hydrated water. Thus the intimate mixture of CaO and MgO from calcined dolomite may serve as a desiccant and remove CO/sub 2/ from the repository atmosphere.

  14. Optimization of backfill pellet properties AASKAR DP2 - Laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Linus; Sanden, Torbjoern [Clay Technology AB, Lund (Sweden)

    2012-12-15

    Bentonite pellets are planned to be used as a part of the backfill in the Swedish spent nuclear fuel deep repository concept KBS-3. This report describes testing and evaluation of different backfill pellet candidates. The work completed included testing of both pellet material and pellet type. The materials tested were sourced from India (ASHA), Greece (IBECO, 2 products) and Wyoming USA (MX-80 clay). The majority of the tests were completed on the ASHA clay as well as the IBECO-RWC-BF products, with only limited testing of the others. The pellets tested were manufactured using both extrusion and roller compaction techniques and had different sizes and geometries. The following tests have been performed and are presented in this report: 1. General tests. Water content, bulk density and dry density have been determined for both the pellet filling and the individual pellets. The compressibility of the pellet filling was tested with CRS-tests and the strength of the individual pellets was tested with a special compression test. The water content varied from 11.3% to 18.7% and was highest for the extruded pellets. The dry density was somewhat higher for the roller-compacted pellets and their compressibility was lower. The strength of the individual pellets was generally higher for the extruded pellets. 2. Erosion. The pellet filling will be exposed to groundwater inflow when installed in the tunnel. This flow could possibly cause significant erosion on the pellet filling. Erosion tests have been performed with comparisons in erosion resistance made on the various material- and pellet-types. The influence of variations in water salinity and flow rates was also tested. The IBECO extruded 6- and 10- mm diameter rods and the compacted Posiva spec.-A pellet filling seem to have the lowest tendency to erode. It is also the IBECO extruded pellet filling that withstands variations in water salinity and flow rates best. 3. Water storing capacity. The pellet filling

  15. Vertical transportation system of solid material for backfilling coal mining technology

    Institute of Scientific and Technical Information of China (English)

    Ju Feng; Zhang Jixiong; Zhang Qiang

    2012-01-01

    For transportation of solid backfill material such as waste and fly ash from the surface to the bottom of the shaft in a fully mechanized backfilling coal backfilling coal mining technology,we developed a new vertical transportation system to transport this type of solid backfill material.Given the demands imposed on safely in feeding this material,we also investigated the structure and basic parameter of this system.For a mine in the Xingtai mining area the results show that:(1) a vertical transportation system should include three main parts,i.e.,a feeding borehole,a maintenance chamber and a storage silo; (2) we determined that 486 mm is a suitable diameter for bore holes,the diameter of the storage silo is 6 m and its height 30 m in this vertical transportation system; (3) a conical buffer was developed to absorb the impact during the feeding process.To ensure normal implementation of fully mechanized backfilling coal mining technology and the safety of underground personnel,we propose a series of security technologies for anti-blockage,storage silo cleaning.high pressure air release and aspiration.This vertical transporting system has been applied in one this particular mine,which has fed about 4 million tons solid material with a feeding depth of 350 m and safely exploited 3 million tons of coal.

  16. Effect of localized water uptake on backfill hydration and water movement in a backfilled tunnel: half-scale tests at Aespoe Bentonite Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D. [Atomic Energy of Canada Limited, Chalk River (Canada); Jonsson, E. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Hansen, J. [Posiva Oy, Olkiluoto (Finland); Hedin, M. [Aangpannefoereningen, Stockholm (Sweden); Ramqvist, G. [Eltekno AB, Figeholm (Sweden)

    2011-04-15

    The report describes the outcome of the work within the project 'SU508.20 Impact of water inflow in deposition tunnels'. Project decision SKB doc 1178871 Version 3.0. Two activity plans have been used for the field work: AP TD SU50820-09-019 and AP TD SU 50820-09-071. SKB and Posiva have been examining those processes that may have particularly strong effects on the evolution of a newly backfilled deposition tunnel in a KBS-3V repository. These assessments have involved the conduct of increasingly large and complex laboratory tests and simulations of a backfilled tunnel section. In this series of four tests, the effect of water inflow into a backfilled tunnel section via an intersecting fracture feature was evaluated. The tests included the monitoring of mock-ups where water entered via the simulated fractures as well as evaluation of what the effect of isolated tunnel sections caused by localized water inflow would have on subsequent evolution of these isolated sections. It was found that even a slowly seeping fracture can have a substantial effect on the backfill evolution as it will cause development of a gasket-like feature that effectively cuts of air and water movement from inner to outer regions of the backfilled tunnel. Water entering via these fractures will ultimately move out of the tunnel via a single discrete flow path, in a manner similar to what was observed in previous 1/2-scale and smaller simulations. If the low-rate of water inflow from fracture is the only source of water inflow to the tunnel this will result in hydraulic behaviour similar to that observed for a single inflow point in previous tests. The presence of a fracture feature will however result in a larger proportion of water uptake by the process of suction than might occur in a point inflow situation and hence a more uniform water distribution will be present in the pellet fill. This also results in a greater tendency for water to be absorbed into the adjacent block fill

  17. Study on Key Technology of Using Shell Sand as Backfill for Sea Reclamation

    Institute of Scientific and Technical Information of China (English)

    LI Neng-hui; QU Yi-rong; HE Wen-qin; CHEN Hui

    2005-01-01

    The results of a study on the key technology of using shell sand, a kind of sea sand, as backfill for sea reclamation are described briefly. Laboratory tests show that the physical and mechanical properties of shell sand are as good as normal quartz sand. Based on the chemical test and durability test of shell sand it could be concluded that the influence of corrosion of shell sand by acid rain and sea water might be ignored in the evaluation of the safety and durability of the engineering project. The results of field improvement tests show that the bearing capacity of shell sand backfill foundation is more than 200 kPa after vibroflotation improvement or dynamic compaction improvement. The shell sand is a good backfill material for sea reclamation.

  18. Overlying strata movement of recovering standing pillars with solid backfilling by physical simulation

    Institute of Scientific and Technical Information of China (English)

    An Baifu; Miao Xiexing; Zhang Jixiong; Ju Feng; Zhou Nan

    2016-01-01

    To analyze the overlying strata movement law of recovering room mining standing pillars with solid backfilling. Physical simulation experiments with sponge and wood as the backfilling simulation material were tested. The results show that: (i) The covering-rock mechanics of the overly strata comes from‘two-arch structures+hinged girder+bend beam”to‘backfilling material+hinged girder+bent beam”by increasing the fill ratio from 0%to 85%, the beginning of overlying strata movement appears later and the total duration of subsidence velocity increased from zero to the highest value increases. The trend of‘single polarization” of the subsidence velocity curves becomes noticeable and the velocity variation trend becomes stable. (ii) The equiponderate aeolian sand was added to improve the anti-pressure ability of the loess, and the corresponding ground processing&transportation system was designed.

  19. Valorization of mining waste and tailings through paste backfilling solution, Imiter operation, Morocco

    Institute of Scientific and Technical Information of China (English)

    Khaldoun Abdelhadi; Ouadif Latifa; Baba Khadija; Bahi Lahcen

    2016-01-01

    Mine waste and process tailings storage is one of important challenge for which mining operations are increasingly confronted. Treatment discharges of plants and main part of waste rock development are generally stored on surface areas. The volume and chemical characteristics of these materials generate serious problem for required storage spaces and mainly environmental degradation. Paste backfill (PBF) is one of ingenious solutions to minimize the quantity of tailings to store. PBF is basically defined as a combination of mine processing tailings, binder, and water mixing. The purpose of this paper is to present backfilling components characterization and formula verification for a waste valorization solu-tion through paste backfilling technology in Imiter operation. Obtained results and realized analysis demonstrate PBF conformity and adequacy with assigned underground functions. However the studied recipe can be more ameliorated to obtain an optimal mixture ensuring the required mechanical strength.

  20. A novel silica alumina-based backfill material composed of coal refuse and fly ash.

    Science.gov (United States)

    Yao, Yuan; Sun, Henghu

    2012-04-30

    In this paper, a systematic study was conducted to investigate a novel silica alumina-based backfill material composed of coal refuse and fly ash. The coal refuse and fly ash had different properties under various thermal activation temperatures (20 °C, 150 °C, 350 °C, 550 °C, 750 °C and 950 °C). It is known that a thermal activation temperature ranging from 20 °C to 950 °C significantly increases the flowability and pozzolanic properties of the coal refuse; however, the flowability of fly ash decreases when the activation temperature is higher than 550 °C because of a severe agglomeration phenomenon on its surface. An optimal design for this backfill material was determined to include an activated portion composed of 5% coal refuse at 750 °C and 15% fly ash at 20 °C. This combination yields the best performance with excellent flowability, a high compressive strength and a low bleeding rate. The microanalysis results corresponded well with the performance tests at different activation conditions. In the coal refuse, kaolinite peaks began to decrease because of their transformation into metakaolin at 550 °C. Chlorite peaks disappeared at 750 °C. Muscovite peaks decreased at 750 °C and disappeared at 950 °C. During this process, muscovite 2M(1) gradually dehydroxylated to muscovite HT. Furthermore, this paper examined the environmental acceptance and economic feasibility of this technology and found that this silica alumina-based backfill material composed of coal refuse and fly ash not only meets EPA requirements but also has several advantages in industry feasibility when compared with hydraulic backfill, rock backfill and paste backfill.

  1. Backfill for iliac-crest donor sites: a prospective, randomized study of coralline hydroxyapatite.

    Science.gov (United States)

    Bojescul, John A; Polly, David W; Kuklo, Timothy R; Allen, Thomas W; Wieand, Kay E

    2005-08-01

    We report on a prospective randomized study of coralline hydroxyapatite (CH) used as backfill for iliac-crest donor sites. Autogenous iliac-crest bone graft is routinely harvested for spinal fusion. Donor-site morbidity is underappreciated; the presumption is that donor sites regenerate. In this study, we assessed the biological viability of the backfill CH (Pro OsteonTM Implant 500 Hydroxyapatite Bone Void Filler; Interpore, Irvine, Calif) and compared donor-site morbidity after harvest. Twelve patients (11 men, 1 woman) were enrolled: 5 in the backfill group and 7 in the no-backfill group. As part of routine evaluations done preoperatively and 6 weeks, 3 months, 6 months, and 1 year postoperatively, plain radiographs and computed tomography (CT) scans were used to assess bone ingrowth, and technetium bone scans were used to assess biological activity. Postoperative pain analysis was also done. Ten patients (9 men, 1 woman) completed the study. Of the 4 completers in the backfill group, 3 (75%) showed bony ingrowth on plain radiographs and CT scans at 1 year; the fourth patient showed bony ingrowth only on plain radiographs. All 4 patients showed biological activity on bone scans and reported mild pain to no pain. Of the 6 completers in the no-backfill group, 1 (17%) showed bony ingrowth on plain radiographs and CT scans. No patient showed biological activity on bone scans at 1 year. CH aids in iliac-crest healing after bone-graft harvesting by acting as a biological osteoconductive matrix. Postoperative pain at the bone-graft site is potentially reduced. More studies of larger numbers of patients are needed to assess the true long-term benefits of this material in a clinical setting.

  2. Backfilling of a Scour Hole around a Pile in Waves and Current

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Petersen, Thor Ugelvig; Locatelli, Luca;

    2013-01-01

    This paper presents the results of an experimental investigation of the backfilling of scour holes around circular piles. Scour holes around a pile are generated either by a current or a wave. Subsequently, the flow climate is changed from current to wave, combined waves and current, or wave...... around the pile for the same wave (or combined waves and current) climate. The time scale of backfilling has been determined as a function of three parameters, namely, (1) the Keulegan-Carpenter number of the initial wave or current (which generates the initial scour hole); (2) that of the subsequent...

  3. UNDERGROUNG PLACEMENT OF COAL PROCESSING WASTE AND COAL COMBUSTION BY-PRODUCTS BASED PASTE BACKFILL FOR ENHANCED MINING ECONOMICS

    Energy Technology Data Exchange (ETDEWEB)

    Y.P. Chugh; D. Biswas; D. Deb

    2002-06-01

    This project has successfully demonstrated that the extraction ratio in a room-and-pillar panel at an Illinois mine can be increased from the current value of approximately 56% to about 64%, with backfilling done from the surface upon completion of all mining activities. This was achieved without significant ground control problems due to the increased extraction ratio. The mined-out areas were backfilled from the surface with gob, coal combustion by-products (CCBs), and fine coal processing waste (FCPW)-based paste backfill containing 65%-70% solids to minimize short-term and long-term surface deformations risk. This concept has the potential to increase mine productivity, reduce mining costs, manage large volumes of CCBs beneficially, and improve the miner's health, safety, and environment. Two injection holes were drilled over the demonstration panel to inject the paste backfill. Backfilling was started on August 11, 1999 through the first borehole. About 9,293 tons of paste backfill were injected through this borehole with a maximum flow distance of 300-ft underground. On September 27, 2000, backfilling operation was resumed through the second borehole with a mixture of F ash and FBC ash. A high-speed auger mixer (new technology) was used to mix solids with water. About 6,000 tons of paste backfill were injected underground through this hole. Underground backfilling using the ''Groutnet'' flow model was simulated. Studies indicate that grout flow over 300-foot distance is possible. Approximately 13,000 tons of grout may be pumped through a single hole. The effect of backfilling on the stability of the mine workings was analyzed using SIUPANEL.3D computer program and further verified using finite element analysis techniques. Stiffness of the backfill mix is most critical for enhancing the stability of mine workings. Mine openings do not have to be completely backfilled to enhance their stability. Backfill height of about 50% of the seam

  4. Evaluation of the effect of sodium silicate addition to mine backfill, Gelfill L Part 1

    Institute of Scientific and Technical Information of China (English)

    M. Kermani; F.P. Hassani; E. Aflaki; M. Benzaazoua; M. Nokken

    2015-01-01

    In this paper, the mechanical properties of sodium silicate-fortified backfill, called Gelfill, were investi-gated by conducting a series of laboratory experiments. Two configurations were tested, i.e. Gelfill and cemented hydraulic fill (CHF). The Gelfill has an alkali activator such as sodium silicate in its materials in addition to primary materials of mine backfill which are tailings, water and binders. Large numbers of samples of Gelfill and CHF with various mixture designs were cast and cured for over 28 d. The me-chanical properties of samples were investigated using uniaxial compression test, and the results were compared with those of reference samples made without sodium silicate. The test results indicated that the addition of an appropriate amount of an alkali activator such as sodium silicate can enhance the mechanical (uniaxial compressive strength) and physical (water retention) properties of backfill. The microstructure analysis conducted by mercury intrusion porosimetry (MIP) revealed that the addition of sodium silicate can modify the pore size distribution and total porosity of Gelfill, which can contribute to the better mechanical properties of Gelfill. It was also shown that the time and rate of drainage in the Gelfill specimens are less than those in CHF specimens made without sodium silicate. Finally, the study showed that the addition of sodium silicate can reduce the required setting time of mine backfill, which can contribute to increase mine production in accordance with the mine safety.

  5. Numerical simulation of wave-induced scour and backfilling processes beneath submarine pipelines

    DEFF Research Database (Denmark)

    Fuhrman, David R.; Baykal, Cüneyt; Sumer, B. Mutlu

    2014-01-01

    A fully-coupled hydrodynamic/morphodynamic numerical model is presented and utilized for the simulation of wave-induced scour and backfilling processes beneath submarine pipelines. The model is based on solutions to Reynolds-averaged Navier–Stokes equations, coupled with k−ω turbulence closure...

  6. Experimental and numerical study of wave-induced backfilling beneath submarine pipelines

    DEFF Research Database (Denmark)

    Bayraktar, Deniz; Ahmad, Joseph; Eltard-Larsen, Bjarke

    2016-01-01

    This paper presents results of complementary experimental and numerical studies involving wave-induced backfilling of current-generated scour holes beneath submarine pipelines. The laboratory experiments are conducted in a wave-plus-current flume, utilizing Laser Doppler Anemometry to measure...

  7. Fluid transport along gutta-percha backfills with and without sealer

    NARCIS (Netherlands)

    Wu, MK; van der Sluis, LWM; Wesselink, PR

    2004-01-01

    Objective. The use of heat may influence the sealing ability of sealer. The aim of this study was to compare the fluid transport along the gutta-percha backfill portion when different sealers were used or no sealer at all. Study design. Four groups consisting of the roots of maxillary and mandibular

  8. Buffer, backfill and closure process report for the safety assessment SR-Site

    Energy Technology Data Exchange (ETDEWEB)

    Sellin, Patrik (ed.)

    2010-11-15

    This report gives an account of how processes in buffer, deposition tunnel backfill and the closure important for the long-term evolution of a KBS-3 repository for spent nuclear fuel, will be documented in the safety assessment SR-Site

  9. Evaluation of the effect of sodium silicate addition to mine backfill, Gelfill − Part 1

    Directory of Open Access Journals (Sweden)

    M. Kermani

    2015-06-01

    Full Text Available In this paper, the mechanical properties of sodium silicate-fortified backfill, called Gelfill, were investigated by conducting a series of laboratory experiments. Two configurations were tested, i.e. Gelfill and cemented hydraulic fill (CHF. The Gelfill has an alkali activator such as sodium silicate in its materials in addition to primary materials of mine backfill which are tailings, water and binders. Large numbers of samples of Gelfill and CHF with various mixture designs were cast and cured for over 28 d. The mechanical properties of samples were investigated using uniaxial compression test, and the results were compared with those of reference samples made without sodium silicate. The test results indicated that the addition of an appropriate amount of an alkali activator such as sodium silicate can enhance the mechanical (uniaxial compressive strength and physical (water retention properties of backfill. The microstructure analysis conducted by mercury intrusion porosimetry (MIP revealed that the addition of sodium silicate can modify the pore size distribution and total porosity of Gelfill, which can contribute to the better mechanical properties of Gelfill. It was also shown that the time and rate of drainage in the Gelfill specimens are less than those in CHF specimens made without sodium silicate. Finally, the study showed that the addition of sodium silicate can reduce the required setting time of mine backfill, which can contribute to increase mine production in accordance with the mine safety.

  10. Efficacy of backfilling and other engineered barriers in a radioactive waste repository in salt

    Energy Technology Data Exchange (ETDEWEB)

    Claiborne, H.C.

    1982-09-01

    In the United States, investigation of potential host geologic formations was expanded in 1975 to include hard rocks. Potential groundwater intrusion is leading to very conservative and expensive waste package designs. Recent studies have concluded that incentives for engineered barriers and 1000-year canisters probably do not exist for reasonable breach scenarios. The assumption that multibarriers will significantly increase the safety margin is also questioned. Use of a bentonite backfill for surrounding a canister of exotic materials was developed in Sweden and is being considered in the US. The expectation that bentonite will remain essentially unchanged for hundreds of years for US repository designs may be unrealistic. In addition, thick bentonite backfills will increase the canister surface temperature and add much more water around the canister. The use of desiccant materials, such as CaO or MgO, for backfilling seems to be a better method of protecting the canister. An argument can also be made for not using backfill material in salt repositories since the 30-cm-thick space will provide for hole closure for many years and will promote heat transfer via natural convection. It is concluded that expensive safety systems are being considered for repository designs that do not necessarily increase the safety margin. It is recommended that the safety systems for waste repositories in different geologic media be addressed individually and that cost-benefit analyses be performed.

  11. Water saturation phase of the buffer and backfill in the KBS-3V concept. Special emphasis given to the influence of the backfill on the wetting of the buffer

    Energy Technology Data Exchange (ETDEWEB)

    Boergesson, Lennart; Faelth, Billy [Clay Technology AB, Lund (Sweden); Hernelind, Jan [5T Engineering AB, Vaesteraas (Sweden)

    2006-08-15

    The wetting and rate of saturation of the buffer and backfill materials in a KBS- V repository from the rock fractures and the rock matrix have been investigated by a large number of different finite element models and calculations. For most models the FE-code ABAQUS has been used but for investigation of the influence of trapped air in the backfill FE-code Code Bright was used. Both codes include completely coupled THM models, which have been used, but for some calculations it has been sufficient to limit the models to only use the hydraulic or thermohydraulic parts of the models. The following analyses have been made: 1. The influence of the backfill properties and wetting conditions on the water saturation phase of the buffer has been investigated with the old FEM-model used in earlier wetting calculations for SR-97. The old calculations have been updated regarding the influence of the backfill. The model is 2-dimensional with axial symmetry around the axis of the deposition hole. These calculations show that there is strong influence of wetting from the backfill if the rock is rather dry (K{sub rock} = 10{sup -13} m/s), while the influence is low if the rock is rather wet (K{sub rock} = 10{sup -12} m/s). At K{sub rock} = 10{sup -13} m/s the time to saturation decreases with a factor 2 in the absence of fractures and with a factor 1.5 with two fractures intersecting the hole when water is supplied from the backfill (30/70) compared to when no water is available. A completely dry rock yields very long time to saturation and of course decisive influence of the water supply from the backfill. If water is freely available at a water pressure of 5 MPa in the backfill it takes 250-500 years to reach full saturation of the buffer. If the water available in the backfill is limited to the initial amount (completely dry rock also around the tunnel and thus no addition of water from the rock in the tunnel) it will take several thousands years to reach some kind of

  12. Paste-like self-flowing transportation backfilling technology based on coal gangue

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-min; ZHAO Bin; ZHANG Chuan-shu; ZHANG Qin-li

    2009-01-01

    A paste-like self-flowing pipeline transportation backfilling technology with coal gangue as aggregate is proposed to remove the potential damage caused by coal gangue piles. As well, the difficult problems of recovering high quality safety coal pillars and deep mining of the Suncun Coal Mine (SCM), Xinwen Coal Group, Shandong are resolved. The physical-chemical properties of coal gangue, optimized proportion of materials, backfilling system and craft in the SCM were studied in the laboratory and then an industrial test was carried out on high quality coal pillars under a town. The results show that finely crushed kaolinized and fresh gangue with granularity less than 5 mm can be used as aggregate with fly ash to replace part of the cement and a compos-ite water reducer as an additive, accounting for 1.0%-1.5% of the total amount of cement and fly ash. The recommended proportion is I(cement):4(fly ash): 15(coal gangue), with a mass fraction of 72%-75%, theological paste-like properties and a strength of more than 0.7 MPa at 7 d. The sequence of adding cement, fly ash, water reducer and then coal gangue ensures that the suspended state of the slurry, reducing the wear and jam of pipelines. The working face is advancing continuously by the alternating craft of building block walls with coal gangue and backfilling mined-out gobs with paste-like slurry. The recovery rate is as high as 90% with a backfilling cost of 36.9 Yuan/t, good utilization of coal gangue and no subsidence on the surface. This technology provides a good theoretical basis and application experience for coal mines, cement backfilling with paste-like slurry.

  13. Colloids in the mortar backfill of a cementitious repository for radioactive waste.

    Science.gov (United States)

    Wieland, E; Spieler, P

    2001-01-01

    Colloids are present in groundwater aquifers and water-permeable engineered barrier systems and may facilitate the migration of radionuclides. A highly permeable mortar is foreseen to be used as backfill for the engineered barrier of the Swiss repository for low- and intermediate-level waste. The backfill is considered to be a chemical environment with some potential for colloid generation and, due to its high porosity, for colloid mobility. Colloid concentration measurements were carried out using an in-situ liquid particle counting system. The in-house developed counting system with three commercially available sensors allowed the detection of single particles and colloids at low concentrations in the size range 50-5000 nm. The counting system was tested using suspensions prepared from certified size standards. The concentrations of colloids with size range 50-1000 nm were measured in cement pore water, which was collected from a column filled with a highly permeable backfill mortar. The chemical composition of the pore water corresponded to a Ca(OH)2-controlled cement system. Colloid concentrations in the backfill pore water were found to be typically lower than approximately 0.1 ppm. The specific (geometric) surface areas of the colloid populations were in the range 240 m2 g(-1) to 770 m2 g(-1). The low colloid inventories observed in this study can be explained by the high ionic strength and Ca concentrations of the cement pore water. These conditions are favourable for colloid-colloid and colloid-backfill interactions and unfavourable for colloid-enhanced nuclide transport.

  14. Roadway backfill method to prevent geohazards induced by room and pillar mining: a case study in Changxing coal mine, China

    Science.gov (United States)

    Zhou, Nan; Li, Meng; Zhang, Jixiong; Gao, Rui

    2016-11-01

    Coal mines in the western areas of China experience low mining rates and induce many geohazards when using the room and pillar mining method. In this research, we proposed a roadway backfill method during longwall mining to target these problems. We tested the mechanical properties of the backfill materials to determine a reasonable ratio of backfill materials for the driving roadway during longwall mining. We also introduced the roadway layout and the backfill mining technique required for this method. Based on the effects of the abutment stress from a single roadway driving task, we designed the distance between roadways and a driving and filling sequence for multiple-roadway driving. By doing so, we found the movement characteristics of the strata with quadratic stabilization for backfill mining during roadway driving. Based on this research, the driving and filling sequence of the 3101 working face in Changxing coal mine was optimized to avoid the superimposed influence of mining-induced stress. According to the analysis of the surface monitoring data, the accumulated maximum subsidence is 15 mm and the maximum horizontal deformation is 0.8 mm m-1, which indicated that the ground basically had no obvious deformation after the implementation of the roadway backfill method at 3101 working face.

  15. Position-optimization on retained entry and backfilling wall in gob-side entry retaining techniques

    Institute of Scientific and Technical Information of China (English)

    Xiaowei Feng; Nong Zhang

    2015-01-01

    This study investigates the stability problem of gob-side entry retaining (GER) and backfilling wall which located under the key block B. Based on the combined research of elastic–plastic mechanics, structure mechanics and modern theory of mining-induced pressure, the caving characteristic and roof structure over the GER were analyzed, and the vertical force and the torque on retained entry roof were also derived as the position for the retained entry varies. On the basis of the specific geology in Huainan mining area, the results indicate that a relatively more stable position for retained entry neighbors the hinge point of block A and B, and it also located at a scope ranging from this point to the one-third length of block B in horizontal direction. As to appropriate position for backfilling wall, this study recommends partial-road-in backfilling method for GER. Field trial conducted at panel face 12418 of Xieqiao Mine demonstrates that the recommended width for original entry is 3.6 m and the preferred width proportion between original retained entry and original entry is 75%or so whereas the avoidable one is 88%or so. These findings provide qualitative references to the mines which share similar geology as what Huainan mining area characterized.

  16. shandong gold grand Mining company Backfilling Performance research%山东黄金盛大矿业公司尾砂性能研究

    Institute of Scientific and Technical Information of China (English)

    高干; 符勇

    2014-01-01

    through chemical and physical properties experiment of the iron ore backfilling, the sizes of backfilling materials are classified and the backfilling materials below 0.037 mm are removed. the results show that the backfilling materials classification is an ideal filling aggregate.%通过铁矿尾砂的物理化学性质实验,将尾砂中的细粒级进行分级,即把-0.037 mm以下的细粒级尾砂分级去除,结果表明分级尾砂是理想的充填骨料。

  17. Analysis on Filling Ratio and Shield Supporting Pressure for Overburden Movement Control in Coal Mining with Compacted Backfilling

    Directory of Open Access Journals (Sweden)

    Yanli Huang

    2016-12-01

    Full Text Available Since the weight of overburden is sustained by both the backfill body and the unmined solid coal in coal mining with compacted backfilling (CMCB panels, the stress and deformation characteristics of the surrounding rocks in coal mining are radically changed. The overburden movement control mechanism by coordinating with backfill body and shield in CMCB was studied systematically in this paper. Based on the analysis of deformational and structural characteristics of surrounding rock in CMCB panels, the methods of theoretical analysis, numerical simulation and engineering test are employed. The results show that the fracture of the main roof is mainly controlled by the filling ratio φ and is non-correlated to the shield supporting pressure p. However, p has a significant control effect on the deflection of roof within the shield canopy length, and adversely affects the filling ratio. With the increase of the filling ratio of the gob, the maximum sagging of the immediate and the main roofs, the peak front and the influence range of the abutment pressures are gradually reduced. Correspondingly, the stable period of internal pressure of backfill body in the gob is shortened. Engineering practice shows that the sagging of the gob roof, the distribution of the abutment pressure, the distribution of the internal pressure in the backfill body, and the ground surface sagging results obtained by the in-situ measurement are approximately corresponding to the theoretical analysis and numerical simulation results.

  18. The Buffer and Backfill Handbook. Part 3: Models for calculation of processes and behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Geodevelopment AB, Lund (Sweden)

    2003-01-15

    The present document collects conceptual and mathematical models that have been proposed for describing the performance of buffers and backfills and processes in them that are related to their function under repository conditions. As in the preceding parts the following types of sealing components are defined. By definition, the buffer shall be so composed that radionuclide transport in the clay-based barriers takes place by diffusion and not by water flow, which makes it important to predict the extent and rate of diffusive transport of such elements through the buffer. It depends strongly on the density and homogeneity of the buffer, which in turn depend on the maturation rate and the ultimate degree of homogeneity of the buffer. They are influenced by the temperature and temperature gradient that exist in the initial phase of water saturation, in which the hydraulic interaction with the near field rock is also important. Design of suitable buffer and backfills hence requires that their performance can be quantified, which requires that the various processes can be modeled conceptually and expressed in mathematical form. Based on the present knowledge this can only be made for some of the involved mechanisms and for coupled processes there is still a very limited number of mathematically expressed computational codes. The models referred to here are conceptual in the first place, defining the respective processes and material property parameters. The quick development of computational tools, numerical as well as analytical, makes it irrelevant to give detailed descriptions of them, while the various assumptions on which they are based - especially the conceptual models - have been considered in some detail. The models of practical use are only described in general terms and examples at the end of the respective chapter illustrate how they can be utilized. A very important fact is that transport and rheological processes in a repository are hardly ever of simple

  19. BEHAVIOUR OF BACKFILL MATERIALS FOR ELECTRICAL GROUNDING SYSTEMS UNDER HIGH VOLTAGE CONDITIONS

    Directory of Open Access Journals (Sweden)

    S. C. LIM

    2015-06-01

    Full Text Available Backfill materials like Bentonite and cement are effective in lowering grounding resistance of electrodes for a considerable period. During lightning, switching impulses and earth fault occurrences in medium and high voltage networks, the grounding system needs to handle extremely high currents either for a short duration or prolonged period respectively. This paper investigates the behaviour of bentonite, cement and sand under impulse and alternating high voltage (50Hz conditions. Fulguritic-formation was observed in all materials under alternating high voltage. The findings reveal that performance of grounding systems under high voltage conditions may significantly change from the outcomes anticipated at design stage.

  20. Deep repository - Engineered barrier system. Erosion and sealing processes in tunnel backfill materials investigated in laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sanden, Torbjoern; Boergesson, Lennart; Dueck, Ann; Goudarzi, Reza; Loennqvist, Margareta (Clay Technology AB, Lund (Sweden))

    2008-12-15

    SKB in Sweden and Posiva in Finland are developing and plan to implement similar disposal concepts for the final disposal of spent nuclear fuel. Co-operation and joint development work between Posiva and SKB with the overall objective to develop backfill concepts and techniques for sealing and closure of the repository have been going on for several years. The investigation described in this report is intended to acquire more knowledge regarding the behavior of some of the candidate backfilling materials. Blocks made of three different materials (Friedland clay, Asha 230 or a bentonite/ballast 30/70 mixture) as well as different bentonite pellets have been examined. The backfill materials will be exposed to an environment simulating that in a tunnel, with high relative humidity and water inflow from the rock. The processes and properties investigated are: 1. Erosion properties of blocks and pellets (Friedland blocks, MX-80 pellets, Cebogel QSE pellets, Minelco and Friedland granules). 2. Displacements of blocks after emplacement in a deposition drift (Blocks of Friedland, Asha 230 and Mixture 30/70). 3. The ability of these materials to seal a leaking in-situ cast plug cement/rock but also other fractures in the rock (MX-80 pellets). 4. The self healing ability after a piping scenario (Blocks of Friedland, Asha 230 Mixture 30/70 and also MX-80 pellets). 5. Swelling and cracking of the compacted backfill blocks caused by relative humidity. The erosion properties of Friedland blocks were also investigated in Phase 2 of the joint SKBPosiva project 'Backfilling and Closure of the Deep Repository, BACLO, which included laboratory scale experiments. In this phase of the project (3) some completing tests were performed with new blocks produced for different field tests. These blocks had a lower density than intended and this has an influence on the erosion properties measured. The erosion properties of MX-80 pellets were also investigated earlier in the project but

  1. A device for vacuum drying, inert gas backfilling and solder sealing of hermetic implant packages.

    Science.gov (United States)

    Schuettler, Martin; Huegle, Matthias; Ordonez, Juan S; Wilde, Juergen; Stieglitz, Thomas

    2010-01-01

    Modern implanted devices utilize microelectronics that have to be protected from the body fluids in order to maintain their functionality over decades. Moisture protection of implants is addressed by enclosing the electronic circuits into gas-tight packages. In this paper we describe a device that allows custom-built hermetic implant packages to be vacuum-dried (removing residual moisture from inside the package), backfilled with an inert gas at adjustable pressure and hermetically sealed employing a solder seal. A typical operation procedure of the device is presented.

  2. Mining pressure monitoring and analysis in fully mechanized backfilling coal mining face-A case study in Zhai Zhen Coal Mine

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qiang; ZHANG Ji-xiong; KANG Tao; SUN Qiang; LI Wei-kang

    2015-01-01

    Fully mechanized solid backfill mining (FMSBM) technology adopts dense backfill body to support the roof. Based on the distinguishing characteristics and mine pressure control principle in this technology, the basic principles and methods for mining pressure monitoring were analyzed and established. And the characteristics of overburden strata movement were analyzed by monitoring the support resistance of hydraulic support, the dynamic subsidence of immediate roof, the stress of backfill body, the front abutment pressure, and the mass ratio of cut coal to backfilled materials. On-site strata behavior measurements of 7403W solid backfilling working face in Zhai Zhen Coal Mine show that the backfill body can effectively support the overburden load, obviously control the overburden strata movement, and weaken the strata behaviors distinctly. Specific performances are as follows. The support resistance decreases obviously; the dynamic subsidence of immediate roof keeps consistent to the variation of backfill body stress, and tends to be stable after the face retreating to 120-150 m away from the cut. The peak value of front abutment pressure arises at 5-12 m before the operating face, and mass ratio is greater than the designed value of 1.15, which effectively ensures the control of strata movement. The research results are bases for intensively studying basic theories of solid backfill mining strata behaviors and its control, and provide theoretical guidance for engineering design in FMSBM.

  3. Modelling geochemical and microbial consumption of dissolved oxygen after backfilling a high level radiactive waste repository.

    Science.gov (United States)

    Yang, Changbing; Samper, Javier; Molinero, Jorge; Bonilla, Mercedes

    2007-08-15

    Dissolved oxygen (DO) left in the voids of buffer and backfill materials of a deep geological high level radioactive waste (HLW) repository could cause canister corrosion. Available data from laboratory and in situ experiments indicate that microbes play a substantial role in controlling redox conditions near a HLW repository. This paper presents the application of a coupled hydro-bio-geochemical model to evaluate geochemical and microbial consumption of DO in bentonite porewater after backfilling of a HLW repository designed according to the Swedish reference concept. In addition to geochemical reactions, the model accounts for dissolved organic carbon (DOC) respiration and methane oxidation. Parameters for microbial processes were derived from calibration of the REX in situ experiment carried out at the Aspö underground laboratory. The role of geochemical and microbial processes in consuming DO is evaluated for several scenarios. Numerical results show that both geochemical and microbial processes are relevant for DO consumption. However, the time needed to consume the DO trapped in the bentonite buffer decreases dramatically from several hundreds of years when only geochemical processes are considered to a few weeks when both geochemical reactions and microbially-mediated DOC respiration and methane oxidation are taken into account simultaneously.

  4. The Buffer and Backfill Handbook. Part 3: Models for calculation of processes and behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Geodevelopment AB, Lund (Sweden)

    2003-01-15

    The present document collects conceptual and mathematical models that have been proposed for describing the performance of buffers and backfills and processes in them that are related to their function under repository conditions. As in the preceding parts the following types of sealing components are defined. By definition, the buffer shall be so composed that radionuclide transport in the clay-based barriers takes place by diffusion and not by water flow, which makes it important to predict the extent and rate of diffusive transport of such elements through the buffer. It depends strongly on the density and homogeneity of the buffer, which in turn depend on the maturation rate and the ultimate degree of homogeneity of the buffer. They are influenced by the temperature and temperature gradient that exist in the initial phase of water saturation, in which the hydraulic interaction with the near field rock is also important. Design of suitable buffer and backfills hence requires that their performance can be quantified, which requires that the various processes can be modeled conceptually and expressed in mathematical form. Based on the present knowledge this can only be made for some of the involved mechanisms and for coupled processes there is still a very limited number of mathematically expressed computational codes. The models referred to here are conceptual in the first place, defining the respective processes and material property parameters. The quick development of computational tools, numerical as well as analytical, makes it irrelevant to give detailed descriptions of them, while the various assumptions on which they are based - especially the conceptual models - have been considered in some detail. The models of practical use are only described in general terms and examples at the end of the respective chapter illustrate how they can be utilized. A very important fact is that transport and rheological processes in a repository are hardly ever of simple

  5. Evaluation of Computational Method of High Reynolds Number Slurry Flow for Caverns Backfilling

    Energy Technology Data Exchange (ETDEWEB)

    Bettin, Giorgia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-05-01

    The abandonment of salt caverns used for brining or product storage poses a significant environmental and economic risk. Risk mitigation can in part be address ed by the process of backfilling which can improve the cavern geomechanical stability and reduce the risk o f fluid loss to the environment. This study evaluate s a currently available computational tool , Barracuda, to simulate such process es as slurry flow at high Reynolds number with high particle loading . Using Barracuda software, a parametric sequence of simu lations evaluated slurry flow at Re ynolds number up to 15000 and loading up to 25%. Li mitations come into the long time required to run these simulation s due in particular to the mesh size requirement at the jet nozzle. This study has found that slurry - jet width and centerline velocities are functions of Re ynold s number and volume fractio n The solid phase was found to spread less than the water - phase with a spreading rate smaller than 1 , dependent on the volume fraction. Particle size distribution does seem to have a large influence on the jet flow development. This study constitutes a first step to understand the behavior of highly loaded slurries and their ultimate application to cavern backfilling.

  6. Assessment of (222)Rn emanation from ore body and backfill tailings in low-grade underground uranium mine.

    Science.gov (United States)

    Mishra, Devi Prasad; Sahu, Patitapaban; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

    2014-02-01

    This paper presents a comparative study of (222)Rn emanation from the ore and backfill tailings in an underground uranium mine located at Jaduguda, India. The effects of surface area, porosity, (226)Ra and moisture contents on (222)Rn emanation rate were examined. The study revealed that the bulk porosity of backfill tailings is more than two orders of magnitude than that of the ore. The geometric mean radon emanation rates from the ore body and backfill tailings were found to be 10.01 × 10(-3) and 1.03 Bq m(-2) s(-1), respectively. Significant positive linear correlations between (222)Rn emanation rate and the (226)Ra content of ore and tailings were observed. For normalised (226)Ra content, the (222)Rn emanation rate from tailings was found to be 283 times higher than the ore due to higher bulk porosity and surface area. The relative radon emanation from the tailings with moisture fraction of 0.14 was found to be 2.4 times higher than the oven-dried tailings. The study suggested that the mill tailings used as a backfill material significantly contributes to radon emanation as compared to the ore body itself and the (226)Ra content and bulk porosity are the dominant factors for radon emanation into the mine atmosphere.

  7. 30 CFR 717.14 - Backfilling and grading of road cuts, mine entry area cuts, and other surface work areas.

    Science.gov (United States)

    2010-07-01

    ... to prevent leaching of toxic pollutants. Barren rock or similar materials excess to the mining... MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR INITIAL PROGRAM REGULATIONS UNDERGROUND MINING GENERAL PERFORMANCE STANDARDS § 717.14 Backfilling and grading of road cuts, mine entry area...

  8. Effect of Waste Brick as Mineral Admixture on the Mechanical Performance of Cemented Paste Backfill

    Science.gov (United States)

    Külekçi, Gökhan; Erçikdi, Bayram; Aliyazicioğlu, Şener

    2016-10-01

    This study presents the replacement and addition of granulated waste brick (WB) to ordinary Portland cement (OPC) in a cemented paste backfill (CPB) of sulphide tailings. The addition and OPC rate is about 15-45% and 7% in weight respectively. Pozzolanic activity tests indicated the fineness of WB samples being the major factor of pozzolanic activity instead of chemical composition. All CPB samples displayed the required strength and durability when WB was used as an additive to OPC. On the other hand, a binder dosage of >7wt % was needed to apply the required 28-day strength of ≥ 0.7 MPa when the OPC was replaced by 15-45 wt% WB samples. The durability of CPB samples is closely inter-related with the calcination temperatures and glass phase content of WB.

  9. Chemical modeling of backfill composed of quartz sand, lime and an Fe-phase

    Energy Technology Data Exchange (ETDEWEB)

    Meike, A.; Glassley, W.E.

    1997-01-01

    The area adjacent to the waste package is an important component of the engineered barrier system in a high level radioactive waste repository. The combination of lime, quartz sand, and a phase containing reduced iron is investigated whether it can achieve reduction of oxygen in the waste emplacement drift (thereby reducin corrosion rates) and increase the pH. The simulations conducted to date have examined the following backfill options: Fe metal only, Fe metal and lime, and iron metal/lime/quartz sand in equal volume ratios. Each option was simulated under two environments: limited and unlimited air exchange with the atmosphere. Results suggest that the most important variable during the process of chemical conditioning is the amount of air exchange that occurs in the emplacement drift. The desired chemical conditioing (both oxidation potential and pH) will be far less effective in an emplacement that experiences an unlimited exchange of air with the atmosphere.

  10. Improved recovery in highwall mining using backfill. ACARP Project C3052

    Energy Technology Data Exchange (ETDEWEB)

    Hume, R.G.; Searle, G.K. [BFP, Richmond, Vic. (Australia)

    1998-07-01

    In Australia, coal mines have generally not adopted filling to increase mining recovery. The aim of this project, entitled 'Improved recovery in highwall mining using backfill', was to examine the feasibility of using fill to improve recovery in highwall mining. Current fill practice was reviewed for metalliferous as well as coal mining, both here in Australia and overseas, for its applicability to highwall mining. Studies were then made at a conceptual level to determine whether fill could be economically used, to determine appropriate sources for fill and to trial key aspects of fill behaviour. A review of filling methods led to conceptual studies being undertaken on seven filling methods and these studies demonstrated that fill could be used to improve recovery. These studies were then further refined. Selected filling materials have been reviewed and laboratory tests have been made on these to assess their suitability. 40 refs., 5 figs., 2 tabs.

  11. Engineered Barrier System - Long-term Stability of Buffer and Backfill. Synthesis and extended abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Apted, Mick; Arthur, Randy [Monitor Scientific LLC, Denver, CO (United States); Savage, Dave [Quintessa Ltd., Nottingham (GB)] (eds.)

    2005-09-15

    SKI is preparing to review the license applications being developed by the Swedish Nuclear Fuel and Waste Management Company (SKB) for an encapsulation plant and a deep repository for the geological disposal of spent nuclear fuel. As part of its preparation, SKI is conducting a series of technical workshops on key aspects of the Engineered Barrier System (EBS) of the repository. This workshop concerns the longterm stability of the buffer and the backfill. Previous workshops have addressed the overall concept for long-term integrity of the EBS, the manufacturing, testing and QA of the EBS and the performance confirmation for the EBS. The goal of this work is to achieve a comprehensive overview of all aspects of SKB's EBS work prior to the handling of forthcoming license applications. The reports from the EBS workshops will be used as one important basis in future review work. The workshops involve the gathering of a sufficient number of independent experts in different subjects of relevance to the particular aspect of EBS. A workshop starts with presentations and discussions among these experts. Following this, SKB presents recent results and responds to questions as part of an informal hearing. Finally, the independent experts and the SKI staff examine the SKB responses from different viewpoints. This report aims to summarise the issues discussed at the buffer and backfill workshop and to extract the essential viewpoints that have been expressed. The report is not a comprehensive record of the discussions and individual statements made by workshop participants should be regarded as opinions rather than proven facts. This reports includes apart from the workshop synthesis, questions to SKB identified prior or during the workshop, and extended abstracts for introductory presentations.

  12. Porewater salinity and the development of swelling pressure in bentonite-based buffer and backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D.A. [Atomic Energy of Canada Limited (Canada)

    2000-06-01

    At the depths proposed for a nuclear fuel waste repository, it is likely that saline groundwater conditions will be encountered in the granitic rocks of Finland and Canada. The potential for saline groundwater to influence of the ability of bentonite-based buffer and backfilling materials to swell and thereby generate swelling pressure has been reviewed. Based on the data collected from existing literature, it would appear that porewater salinities as high as 100 g/l will not compromise the ability of confined, bentonite-based materials to develop a swelling pressure of at least 100 kPa on its confinement, provided the effective clay dry density (ECDD), exceeds approximately 0.9 Mg/m{sup 3}. At densities less than approximately 0.9 Mg/m{sup 3} the swelling pressure of bentonite-based materials may be reduced and become sensitive to salt concentration. The influence of porewater salinity on swelling pressure can be compared on the basis of the ECDD required to develop 100 kPa of swelling pressure. In order to generate 100 kPa of swelling pressure an ECDD of approximately 0.7 Mg/m{sup 3} is required to be present under fresh water or brackish porewater conditions. This density would need to be increased to approximately 0.9 Mg/m{sup 3} where the groundwater conditions were saline. The impact that groundwater salinity will have on density specifications for buffer and backfilling materials are discussed with reference to the nuclear fuel waste disposal concepts of Finland and Canada. (orig.)

  13. The solubility of nickel and its migration through the cementitious backfill of a geological disposal facility for nuclear waste.

    Science.gov (United States)

    Felipe-Sotelo, M; Hinchliff, J; Field, L P; Milodowski, A E; Holt, J D; Taylor, S E; Read, D

    2016-08-15

    This work describes the solubility of nickel under the alkaline conditions anticipated in the near field of a cementitious repository for intermediate level nuclear waste. The measured solubility of Ni in 95%-saturated Ca(OH)2 solution is similar to values obtained in water equilibrated with a bespoke cementitious backfill material, on the order of 5×10(-7)M. Solubility in 0.02M NaOH is one order of magnitude lower. For all solutions, the solubility limiting phase is Ni(OH)2; powder X-ray diffraction and scanning transmission electron microscopy indicate that differences in crystallinity are the likely cause of the lower solubility observed in NaOH. The presence of cellulose degradation products causes an increase in the solubility of Ni by approximately one order of magnitude. The organic compounds significantly increase the rate of Ni transport under advective conditions and show measurable diffusive transport through intact monoliths of the cementitious backfill material.

  14. Experimental studies on the inventory of cement-derived colloids in the pore water of a cementitious backfill material

    Energy Technology Data Exchange (ETDEWEB)

    Wieland, E

    2001-06-01

    The potential role of near-field colloids for the colloid-facilitated migration of radionuclides has stimulated investigations concerning the generation and presence of colloids in the near-field of a repository for low- and intermediate level waste (L/ILW). The highly gas permeable mortar (Nagra designation: mortar M1) is currently favoured as backfill material for the engineered barrier of the planned Swiss L/ILW repository. The cementitious backfill is considered to be a chemical environment with some potential for colloid generation. In a series of batch-style laboratory experiments the physico-chemical processes controlling the inventory of colloids in cement pore water of the backfill were assessed for chemical conditions prevailing in the initial stage of the cement degradation. In these experiments, backfill mortar M1 or quartz, respectively, which may be used as aggregate material for the backfill, were immersed in artificial cement pore water (a NaOH/KOH rich cement fluid). Colloid concentrations in the cement pore water were recorded as a function of time for different experimental settings. The results indicate that a colloid-colloid interaction process (coagulation) controlled the colloid inventory. The mass concentration of dispersed colloids was found to be typically lower than 0.02 ppm in undisturbed batch systems. An upper-bound value was estimated to be 0.1 ppm taking into account uncertainties on the measurements. To assess the potential for colloid generation in a dynamic system, colloid concentrations were determined in the pore water of a column filled with backfill mortar. The chemical conditions established in the mortar column corresponded to conditions observed in the second stage of the cement degradation (a Ca(OH){sub 2{sup -}} controlled cement system). In this dynamic system, the upper-bound value for the colloid mass concentration was estimated to be 0.1 ppm. Implications for radionuclide mobility were deduced taking into account the

  15. FY:15 Transport Properties of Run-of-Mine Salt Backfill ? Unconsolidated to Consolidated.

    Energy Technology Data Exchange (ETDEWEB)

    Dewers, Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Heath, Jason E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Leigh, Christi D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-28

    The nature of geologic disposal of nuclear waste in salt formations requires validated and verified two-phase flow models of transport of brine and gas through intact, damaged, and consolidating crushed salt. Such models exist in other realms of subsurface engineering for other lithologic classes (oil and gas, carbon sequestration etc. for clastics and carbonates) but have never been experimentally validated and parameterized for salt repository scenarios or performance assessment. Models for waste release scenarios in salt back-fill require phenomenological expressions for capillary pressure and relative permeability that are expected to change with degree of consolidation, and require experimental measurement to parameterize and validate. This report describes a preliminary assessment of the influence of consolidation (i.e. volume strain or porosity) on capillary entry pressure in two phase systems using mercury injection capillary pressure (MICP). This is to both determine the potential usefulness of the mercury intrusion porosimetry method, but also to enable a better experimental design for these tests. Salt consolidation experiments are performed using novel titanium oedometers, or uniaxial compression cells often used in soil mechanics, using sieved run-of-mine salt from the Waste Isolation Pilot Plant (WIPP) as starting material. Twelve tests are performed with various starting amounts of brine pore saturation, with axial stresses up to 6.2 MPa (~900 psi) and temperatures to 90°C. This corresponds to UFD Work Package 15SN08180211 milestone “FY:15 Transport Properties of Run-of-Mine Salt Backfill – Unconsolidated to Consolidated”. Samples exposed to uniaxial compression undergo time-dependent consolidation, or creep, to various degrees. Creep volume strain-time relations obey simple log-time behavior through the range of porosities (~50 to 2% as measured); creep strain rate increases with temperature and applied stress as expected. Mercury porosimetry

  16. Coupled effect of cement hydration and temperature on hydraulic behavior of cemented tailings backfill

    Institute of Scientific and Technical Information of China (English)

    WU Di; CAI Si-jing

    2015-01-01

    Cemented tailings backfill (CTB) is made by mixing cement, tailings and water together, thus cement hydration and water seepage flow are the two crucial factors affecting the quality of CTB. Cement hydration process can release significant amount of heat to raise the temperature of CTB and in turn increase the rate of cement hydration. Meanwhile, the progress of cement hydration consumes water and produces hydration products to change the pore structures within CTB, which further influences the hydraulic behavior of CTB. In order to understand the hydraulic behavior of CTB, a numerical model was developed by coupling the hydraulic, thermal and hydration equations. This model was then implemented into COMSOL Multiphysics to simulate the evolutions of temperature and water seepage flow within CTB versus curing time. The predicted outcomes were compared with correspondent experimental results, proving the validity and availability of this model. By taking advantage of the validated model, effects of various initial CTB and curing temperatures, cement content, and CTB's geometric shapes on the hydraulic behavior of CTB were demonstrated numerically. The presented conclusions can contribute to preparing more environmentally friendly CTB structures.

  17. THM modelling of buffer, backfill and other system components. Critical processes and scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, Mattias; Kristensson, Ola; Boergesson, Lennart; Dueck, Ann (Clay Technology AB, Lund (Sweden)); Hernelind, Jan (5T-Engineering AB, Vaesteraas (Sweden))

    2010-03-15

    A number of critical thermo-hydro-mechanical processes and scenarios for the buffer, tunnel backfill and other filling components in the repository have been identified. These processes and scenarios representing different aspects of the repository evolution have been pinpointed and modelled. In total, 22 cases have been modelled. Most cases have been analysed with finite element (FE) calculations, using primarily the two codes Abaqus and Code-Bright. For some cases analytical methods have been used either to supplement the FE calculations or due to that the scenario has a character that makes it unsuitable or very difficult to use the FE method. Material models and element models and choice of parameters as well as presumptions have been stated for all modelling cases. In addition, the results have been analysed and conclusions drawn for each case. The uncertainties have also been analysed. Besides the information given for all cases studied, the codes and material models have been described in a separate so called data report

  18. Buffer and backfill process report for the safety assessment SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Sellin, Patrik (comp.)

    2006-09-15

    This document compiles information on processes in the buffer and deposition tunnel backfill relevant for long-term safety of a KBS-repository. It supports the safety assessment SR-Can, which is a preparatory step for a safety assessment that will support the licence application for a final repository in Sweden. The purpose of the process reports is to document the scientific knowledge of the processes to a level required for an adequate treatment of the processes in the safety assessment. The documentation is not exhaustive from a scientific point of view, since such a treatment is neither necessary for the purposes of the safety assessment nor possible within the scope of an assessment. However, it must be sufficiently detailed to motivate, by arguments founded on scientific understanding, the treatment of each process in the safety assessment. The purpose is further to determine how to handle each process in the safety assessment at an appropriate degree of detail, and to demonstrate how uncertainties are taken care of, given the suggested handling.

  19. Investigation on hydraulic properties of compacted GMZ bentonite used as buffer/backfill material

    Directory of Open Access Journals (Sweden)

    Ye W. M.

    2016-01-01

    Full Text Available During the past decades, GMZ bentonite has been widely investigated for its use as buffer/backfill materials in China. Based on a comprehensive review of the former studies, achievements on experimental and theoretic works on the hydraulic aspects of compacted GMZ bentonite with consideration of temperature effects are presented in this paper. Water retention property of compacted GMZ bentonite depends on constraint conditions. Temperature effects on water-retention depend on constraint conditions and suction. The hysteresis behaviour is not obvious. Based on the test results, a revised water retention model was developed for considering the temperature effect. The saturated hydraulic conductivity of the densely compacted GMZ bentonite increases as dry density and temperature increases. A revised model, which considers temperature influence on water viscosity and the effective flow cross-sectional area of porous channels, for prediction of saturated hydraulic conductivity have been developed and verified. The unsaturated hydraulic conductivity of confined densely compacted GMZ bentonite samples decreases first and then increases with suction decrease from an initial value of 80 MPa to zero. With consideration of temperature effects and microstructure changes, a revised model for prediction of unsaturated hydraulic conductivity of compacted GMZ01 bentonite was proposed.

  20. A Numerical Model for Natural Backfill of Pipeline Trenches Subjected to Unidirectional/Oscillatory Flows

    Institute of Scientific and Technical Information of China (English)

    LIANG Dong-fang; CHENG Liang; Kervin YEOW

    2005-01-01

    A numerical model for the self-burial of a pipeline trench is developed. Morphological evolutions of a pipeline trench under steady-current or oscillatory-flow conditions are simulated with/without a pipeline inside the trench. The oscillatory flow in this study represents the action of waves. The two-dimensional Reynolds-averaged continuity and Navier-Stokes equations with the standard k-ε turbulence closure, as well as the sediment transport equations, are solved with the finite difference method in a curvilinear coordinate system. Both bed and suspended loads of sediment transport are included in the morphological model. Because of the lack of experimental data on the backfilling of pipeline trenches, the numerical model is firetly verified against three closely-relevant experiments available in literature. A detailed measurement of the channel migration phenomenon under steady currents is employed for the assessment of the integral performance of the model. The two experimental results from U-tube tests are used to validate the model's ability in predicting oscillatory flows. Different time-marching schemes are employed for the morphological computation under unidirectional and oscillatory conditions. It is found that vortex motions within the trench play an important role in the trench development.

  1. The Buffer and Backfill Handbook. Part 1: Definitions, basic relationships and laboratory methods

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Geodevelopment AB, Lund (Sweden)

    2002-04-01

    Part 1 of this Handbook is focused on description of fundamental issues of soil physical and chemical arts and on soil mechanical definitions and relationships. Part 2 comprises a material data basis including also preparation and field testing methods. Part 3 provides a collection of physical and mathematical models and examples of how they can and should be applied. The present document, which has been prepared by Geodevelopment AB in co-operation with Scandia Consult AB and Clay Technology AB, Sweden, and with TVO, Finland, makes up Part 1. Most of the data and information emanate from the work that Geodevelopment AB and Clay Technology AB have performed for SKB but a number of results from experiments made in and for other organizations have been included as well. A significant number of experimental procedures and ways of characterizing buffers and backfills are included. The experience from the comprehensive international Stripa Project, concerning both systematic material investigations in the laboratory and the full-scale field experiments, has contributed significantly to this report. However, similar and additional information gained from later work in SKB's Aespoe Hard Rock Laboratory and from NAGRA and also from other waste-isolation projects have helped to make this document of assumed international interest.

  2. SR-Site Data report. THM modelling of buffer, backfill and other system components

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, Mattias; Boergesson, Lennart; Kristensson, Ola (Clay Technology AB, Lund (Sweden))

    2010-03-15

    This report is a supplement to the SR-Site data report. Based on the issues raised in the Process reports concerning THM processes in buffer, backfill and other system components, 22 modelling tasks have been identified, representing different aspects of the repository evolution. The purpose of this data report is to provide parameter values for the materials included in these tasks. Two codes, Code{_}Bright and Abaqus, have been employed for the tasks. The data qualification has focused on the bentonite material for buffer, backfill and the seals for tunnel plugs and bore-holes. All these system components have been treated as if they were based on MX-80 bentonite. The sources of information and documentation of the data qualification for the parameters for MX-80 have been listed. A substantial part of the refinement, especially concerning parameters used for Code{_}Bright, is presented in the report. The data qualification has been performed through a motivated and transparent chain; from measurements, via evaluations, to parameter determinations. The measured data was selected to be as recent, traceable and independent as possible. The data sets from this process are thus regarded to be qualified. The conditions for which the data is supplied, the conceptual uncertainties, the spatial and temporal variability and correlations are briefly presented and discussed. A more detailed discussion concerning the data uncertainty due to precision, bias and representativity is presented for measurements of swelling pressure, hydraulic conductivity, shear strength, retention properties and thermal conductivity. The results from the data qualification are presented as a detailed evaluation of measured data. In order to strengthen the relevance of the parameter values and to confirm previously used relations, either newer or independent measurements have been taken into account in the parameter value evaluation. Previously used relations for swelling pressure, hydraulic

  3. Diffusion coefficient test of {sup 237}Np in bentonite backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Cui Anxi; Fan Zhiwen; Zhang Jinsheng; Gu Cunli [China Inst. for Radiation Protection, Shanxi (China); Mukai, M.; Maeda, T.; Matsumoto, J.; Tanaka, T.; Ogawa, H. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-03-01

    This paper describes the work on diffusion coefficient test of Np in bentonite backfill materials. Due to its very low permeability, diffusion is the dominant migration mechanics in bentonite. The bentonite comes from Inner Mongolia of China. {sup 237}Np was used as tracer. The special apparatus for diffusion test was setup, the diffusion coefficient of Np in pure bentonite and sand-bentonite mixture were tested. The tracer was introduced between two bentonite columns. After a specific contacting period, the bentonite columns were taken out and cut to very thin slices. The radioactivity in bentonite slices was analyzed to give the nuclide concentration versus distance curves. The diffusion coefficient could be estimated. The diffusion coefficient of pure bentonite at different density was tested. When the density of pure bentonite samples varied from 1.1, 1.3, 1.5 to 1.7 g/ml, their diffusion coefficient were 1.36 x 10{sup -13} m{sup 2}/s 1.16 x 10{sup -13}m{sup 2}/s, 1.07 x 10{sup -13} m{sup 2}/s and 8.26 x 10{sup -14} m{sup 2}/s respectively. The diffusion coefficient of Np in sand-bentonite mixture sample was 4.13 x 10{sup -13} m{sup 2}/s. To estimate the distribution coefficient (K{sub d}) value of Np in mixture sample by diffusion method, the diffusion coefficient of Br was measured./ The concluded K{sub d} value was 77ml/g for the sand-bentonite mixture. The K{sub d} value obtained by batch test methods was 30ml/g. The reason is related with the error of Br diffusion coefficient and solid-liquid ratio. (author)

  4. Design and construction of the backfilled pit cover system at Whistle Mine, Canada : a case study

    Energy Technology Data Exchange (ETDEWEB)

    Ayres, B.K.; O' Kane, M. [O' Kane Consultants Inc., Saskatoon, SK (Canada); Lanteigne, L. [Inco Ltd., Sudbury, ON (Canada)

    2005-07-01

    This paper describes the design and construction of an engineered cover system developed during the decommissioning of Inco's Whistle Mine in Sudbury, Ontario. The process involved the relocation of 6.4 million tonnes of acid-generating waste rock to the open pit from 2 adjacent stockpiles. The cover system, which works as a barrier to minimize the entry of atmospheric oxygen and water to the underlying material, was developed for backfilling the pit to reduce acid-rock drainage. The effectiveness of a range of cover systems was determined through geochemical modelling. Field trials were also conducted at the site to monitor the performance of the cover system and to estimate full-scale construction costs. A calibrated model of covered waste rock was developed using the VADOSE/W two-dimensional soil-atmosphere model and field data. Net percolation and oxygen infiltration through various cover system alternatives were predicted for site-specific climate conditions. The runoff management and final landform for the pit cover system was determined through erosion and landform evolution numerical modelling. The long-term performance of the pit cover system is affected by physical process such as erosion, slope instability, wet-dry cycles, freeze-thaw cycles, consolidation, extreme climate events and brush fires. Efforts were made to minimize the chemical processes that affect liner performance such as osmotic consolidation, dispersion, dissolution, acidic hydrolysis, mineralogical consolidation, sorption, salinization and oxidation. It was noted that the performance of the liner is also influenced by biological processes such as root penetration, burrowing animals, bioturbation, human intervention, bacteriological clogging and the establishment of vegetation. 12 refs., 2 tabs., 10 figs.

  5. Characterization of a backfill candidate material, IBECO-RWC-BF Baclo Project - Phase 3 Laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Johannesson, Lars-Erik; Sanden, Torbjoern; Dueck, Ann; Ohlsson, Lars (Clay Technology AB, Lund (Sweden))

    2010-01-15

    A backfill candidate material, IBECO-RWC-BF, which origin from Milos, Greece, has been investigated. The material was delivered both as granules and as pellets. The investigation described in this report aimed to characterize the material and evaluate if it can be used in a future repository. The following investigations have been done and are presented in this report: 1. Standard laboratory tests. Water content, liquid limit and swelling potential are examples on standard tests that have been performed. 2. Block manufacturing. The block compaction properties of the material have been determined. A first test was performed in laboratory but also tests in large scale have been performed. After finishing the test phase, 60 tons of blocks were manufactured at Hoeganaes Bjuf AB. The blocks will be used in large scale laboratory tests at Aespoe HRL. 3. Mechanical parameters. The compressibility of the material was investigated with oedometer tests (four tests) where the load was applied in steps after saturation. The evaluated oedometer modulus varied between 34.50 MPa. Tests were made to evaluate the elastic parameters of the material (E, nu). Altogether three tests were made on specimens with dry densities of about 1,710 kg/m3. The evaluated E-modulus and Poisson's ratio varied between 231-263 MPa and 0.16-0.19 respectively. The strength of the material, both the compressive strength and the tensile strength were measured on specimens compacted to different dry densities. The test results yielded a relation between density and the two types of strength. Furthermore, tests have been made in order to determine the compressibility of the unsaturated filling of pellets. Two tests were made where the pellets were loosely filled in a Proctor cylinder and then compressed at a constant rate of strain during continuously measurement of the applied load. 4. Swelling pressure and hydraulic conductivity. There is, as expected, a very clear influence of the dry density on the

  6. Characterization of a backfill candidate material, IBECO-RWC-BF Baclo Project - Phase 3 Laboratory tests

    Energy Technology Data Exchange (ETDEWEB)

    Johannesson, Lars-Erik; Sanden, Torbjoern; Dueck, Ann; Ohlsson, Lars (Clay Technology AB, Lund (Sweden))

    2010-01-15

    A backfill candidate material, IBECO-RWC-BF, which origin from Milos, Greece, has been investigated. The material was delivered both as granules and as pellets. The investigation described in this report aimed to characterize the material and evaluate if it can be used in a future repository. The following investigations have been done and are presented in this report: 1. Standard laboratory tests. Water content, liquid limit and swelling potential are examples on standard tests that have been performed. 2. Block manufacturing. The block compaction properties of the material have been determined. A first test was performed in laboratory but also tests in large scale have been performed. After finishing the test phase, 60 tons of blocks were manufactured at Hoeganaes Bjuf AB. The blocks will be used in large scale laboratory tests at Aespoe HRL. 3. Mechanical parameters. The compressibility of the material was investigated with oedometer tests (four tests) where the load was applied in steps after saturation. The evaluated oedometer modulus varied between 34.50 MPa. Tests were made to evaluate the elastic parameters of the material (E, nu). Altogether three tests were made on specimens with dry densities of about 1,710 kg/m3. The evaluated E-modulus and Poisson's ratio varied between 231-263 MPa and 0.16-0.19 respectively. The strength of the material, both the compressive strength and the tensile strength were measured on specimens compacted to different dry densities. The test results yielded a relation between density and the two types of strength. Furthermore, tests have been made in order to determine the compressibility of the unsaturated filling of pellets. Two tests were made where the pellets were loosely filled in a Proctor cylinder and then compressed at a constant rate of strain during continuously measurement of the applied load. 4. Swelling pressure and hydraulic conductivity. There is, as expected, a very clear influence of the dry density on the

  7. Deep repository - engineered barrier systems. Half scale tests to examine water uptake by bentonite pellets in a block-pellet backfill system

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, David (Atomic Energy of Canada Limited (AECL) (Canada)); Lundin, Cecilia (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Oertendahl, Ellinor (NCC (Sweden)); Hedin, Mikael (Aangpannefoereningen, Stockholm (Sweden)); Ramqvist, Gunnar (Eltekno AB (Sweden))

    2008-12-15

    In order to examine the behaviour of water entering a section of tunnel that had recently been backfilled using a combination of bentonite pellets and compacted, smectitic clay blocks, a series of large-scale tests have been completed. These tests, done at a scale of approximately 0.5 that of an emplacement tunnel were completed in a mock-up constructed in the Buffer Laboratory at SKB's Aespoe Hard Rock Laboratory. A total of 12 tests, undertaken under well controlled conditions were completed, examining the effects of inflow rate, inflow location and time on assemblies of blocks and pellets. Water was supplied to the assembly at rates ranging from 0.1 to 2.5 l/min and the time for water exit, the exit location, potential for erosion of backfill, the rate of water uptake and resistance of the assembly to water influx were all monitored for periods of 3 to 7 days. The testing time was selected to simulate a reasonable duration for unanticipated backfilling interruption. Longer durations were not necessary and risked both the stability of the system and the loss of the early stage conditions through progression of swelling and homogenization. Testing determined that initial water movement through backfill is largely controlled by the pellets. Water influx of up to 30 l/h at a single location was diverted by the pellets forming essentially horizontal flow channels (pipes) along the chamber wall - pellet interface. These piping features directed the majority of the incoming water around the backfill and towards the unconfined downstream face of the assembly. The time required for the water to exit the assembly was dependant on a combination of inflow rate and distance that it needed to travel. Water typically exited the face of the backfill at well-defined location(s) and once established, these features remained for the duration of the test. The exiting water typically carried only limited eroded material but could cause some disruption of the downstream face of

  8. Fat metaplasia and backfill are key intermediaries in the development of sacroiliac joint ankylosis in patients with ankylosing spondylitis

    DEFF Research Database (Denmark)

    Maksymowych, Walter P; Wichuk, Stephanie; Chiowchanwisawakit, Praveena

    2014-01-01

    bone in the sacroiliac (SI) joints and may reflect resolution of inflammation and tissue repair at sites of erosions. The purpose of this study was to test our hypothesis that SI joint ankylosis develops following repair of erosions and that tissue characterized by fat metaplasia is a key intermediary...... step in this pathway. METHODS: We used the Spondyloarthritis Research Consortium of Canada (SPARCC) SI structural lesion score (SSS) method to assess fat metaplasia, erosions, backfill, and ankylosis on MRIs of the SI joints in 147 patients with AS monitored for 2 years. Univariate and multivariate...

  9. Couple mechanics hydraulics and sorption properties of mixtures to evaluate buffer/backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Yi-Lin, Jan [Ching Yun Univ., Dept. of Civil Engineering, Taiwan (China); Shih-Chin, Tsaia [Fooyin Univ., Dept. of Industrial Safety and Hygiene, Taiwan (China); Yi-Lin, Jan; Chun-Nan, Hsu [National Tsing Hua Univ., Dept. of Nuclear Science, Taiwan (China)

    2005-07-01

    The technique of multi-barrier disposal systems of radwaste has been studying among the world. The buffer materials that retard the migration of nuclides and make the canisters stable play a very important role. To couple engineering and sorption properties to evaluate the buffer/backfill materials, synthetic groundwater (GW) and seawater(SW) were used as the liquid phases to simulate possible conditions for a deep geological disposal in an island. The R{sub d} value of Cs, I and Se (10{sup -4} M ) with respect to various composite ratios of bentonite/ laterite/ quartz sand mixtures were measured using batch sorption tests in GW and SW. De-ionic water (DIW) was used as the liquid phase for Atterberg limit tests, triaxial shear test s and hydraulic conductivity tests to acquire the engineering properties of those mixtures mention above. The Atterberg limit tests results showed that 7 samples are concluded inorganic clays of high plasticity and one is inorganic clays of medium plasticity. The samples with 30% quartz sand content indicate the higher shear strength than those with 50% quartz sand content and very low hydraulic conductivity for all samples are in the same order about 1{sup -10} m/s. The sorption of Cs on mixtures reveals that distribution coefficients (R{sub d}s) is higher in GW than those in SW. The Rd s of Cs are inverse proportion to plastic index (PI) in GW and SW as well as the R{sub d}s of Se. The sorption of Se on mixtures is affected significantly by composition of solid phase. However, the major affection for sorption of Se is solid phase and that of Cs is liquid phase. Very low sorption of I on all mixtures in GW and SW. Under these experimental conditions, these results reveal that more effective buffer material composition of 30% quartz sand content which PI are 40 to 60. Laterite is more effective sorbent for Cs and Se than Bentonite. (authors)

  10. Borehole Heat Exchanger Systems: Hydraulic Conductivity and Frost-Resistance of Backfill Materials

    Science.gov (United States)

    Anbergen, Hauke; Sass, Ingo

    2016-04-01

    Ground source heat pump (GSHP) systems are economic solutions for both, domestic heating energy supply, as well as underground thermal energy storage (UTES). Over the past decades the technology developed to complex, advanced and highly efficient systems. For an efficient operation of the most common type of UTES, borehole heat exchanger (BHE) systems, it is necessary to design the system for a wide range of carrier fluid temperatures. During heat extraction, a cooled carrier fluid is heated up by geothermal energy. This collected thermal energy is energetically used by the heat pump. Thereby the carrier fluid temperature must have a lower temperature than the surrounding underground in order to collect heat energy. The steeper the thermal gradient, the more energy is transferred to the carrier fluid. The heat injection case works vice versa. For fast and sufficient heat extraction, even over long periods of heating (winter), it might become necessary to run the BHE with fluid temperatures below 0°C. As the heat pump runs periodically, a cyclic freezing of the pore water and corresponding ice-lens growth in the nearfield of the BHE pipes becomes possible. These so called freeze-thaw-cycles (FTC) are a critical state for the backfill material, as the sealing effect eventually decreases. From a hydrogeological point of view the vertical sealing of the BHE needs to be secured at any time (e.g. VDI 4640-2, Draft 2015). The vertical hydraulic conductivity of the BHE is influenced not only by the permeability of the grouting material itself, but by the contact area between BHE pipes and grout. In order to assess the sealing capacity of grouting materials a laboratory testing procedure was developed that measures the vertical hydraulic conductivity of the system BHE pipe and grout. The key features of the procedure are: • assessment of the systeḿs hydraulic conductivity • assessment of the systeḿs hydraulic conductivity after simulation of freeze-thaw-cycle

  11. 分层填土作用在挡土墙上的主动土压力%Active Soil Pressure on Retaining Wall With Layered Backfills

    Institute of Scientific and Technical Information of China (English)

    杨雪强

    2001-01-01

    基于土的塑性极限分析理论,考虑墙后分层填土的滑动变形协调条件,探讨了分层填土作用在挡土墙上主动土压力的计算方法,得出了一些有益的结论.%Based on soil plasticity and limit analysis theory,together with sliding harmonious condition of layered backfills,calculating method of active soil pressure on retaining wall with layered backfills is proposed,and corresponding conclusions are also made in this paper.

  12. Research and application of schemes for constructing concrete pillars in large section finishing cut in backfill coal mining

    Institute of Scientific and Technical Information of China (English)

    Sun Qiang; Zhang Jixiong; Ju Feng; Li Linyue; Zhao Xu

    2015-01-01

    Based on the technology of controlling surrounding rock deformation by constructing concrete pillars in large section finishing cut in backfill coal mining, the characteristics of vertical stress on concrete pillars and main factors influencing pillar stability are analyzed. By building a Winkler elastic foundation mechanical model for the support system constituted of coal pillar, backfill body and concrete pillars, mechanical calculation on stability of concrete pillar is carried out to evaluate the pillar stability and safety. Seven numeral models in three schemes with different pillar sizes, inter-row distances and com-pression ratios at the stopes were analyzed through numerical simulation according to width reduction principle. The practice of finishing cut at III644 workface at Yangzhuang coal mine shows that:when the actual compression ratio is 86.5%, construction size inside the finishing cut is 2000 mm ? 2000 mm and the interval between concrete pillars is 2000 mm ? 2000 mm, the pillars can be stable with the maxi-mum movement of two sides of each pillar being only 83 mm and 54 mm, which achieves the expected effect.

  13. Initial field testing definition of subsurface sealing and backfilling tests in unsaturated tuff; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.A. [Sandia National Labs., Albuquerque, NM (United States); Case, J.B.; Tyburski, J.R. [I. T. Corp., Albuquerque, NM (United States)

    1993-05-01

    This report contains an initial definition of the field tests proposed for the Yucca Mountain Project repository sealing program. The tests are intended to resolve various performance and emplacement concerns. Examples of concerns to be addressed include achieving selected hydrologic and structural requirements for seals, removing portions of the shaft liner, excavating keyways, emplacing cementitious and earthen seals, reducing the impact of fines on the hydraulic conductivity of fractures, efficient grouting of fracture zones, sealing of exploratory boreholes, and controlling the flow of water by using engineered designs. Ten discrete tests are proposed to address these and other concerns. These tests are divided into two groups: Seal component tests and performance confirmation tests. The seal component tests are thorough small-scale in situ tests, the intermediate-scale borehole seal tests, the fracture grouting tests, the surface backfill tests, and the grouted rock mass tests. The seal system tests are the seepage control tests, the backfill tests, the bulkhead test in the Calico Hills unit, the large-scale shaft seal and shaft fill tests, and the remote borehole sealing tests. The tests are proposed to be performed in six discrete areas, including welded and non-welded environments, primarily located outside the potential repository area. The final selection of sealing tests will depend on the nature of the geologic and hydrologic conditions encountered during the development of the Exploratory Studies Facility and detailed numerical analyses. Tests are likely to be performed both before and after License Application.

  14. Sheetflow Effects and Canal Backfilling on Sediment Source and Transport in Everglades Freshwater Marshes: Analysis of Molecular Organic Biomarkers

    Science.gov (United States)

    Regier, P.; He, D.; Saunders, C.; Coronado-Molina, C.; Jara, B.; Jaffe, R.

    2014-12-01

    Historic freshwater sheetflow in the Florida Everglades distributed sediment to form a ridge-and-slough landscape. However, drainage along with reduction and obstruction of flow has resulted in degradation of this ridged topography. The DECOMP Physical Model is a landscape-scale project aiming to reestablish natural sheetflow to the central and southern Everglades by redesigning barriers to flow. To validate proof of concept that increased flow will rebuild ridge-slough microtopography, biomarker proxies were established for ridge and slough organic matter sources. In addition, partial and complete canal backfill options were assessed via sediment trap accumulation in each backfill treatment area. Flocculent matter (floc) and sediment samples were collected, solvent extracted, chromatographically separated, and analyzed on a GC/MS using internal standard for quantification. Four molecular organic biomarkers were evaluated: the aquatic proxy (Paq), highly-branched isoprenoids (C20 HBI), kaurenes and botyrococcenes. Paq, an aquatic proxy of mid to long-chain n-alkanes, was shown to clearly differentiate between ridge-derived and slough-derived organic matter with Paq values increasing along ridge-to-slough transects. Kaurenes indicated presence of ridge-derived organic matter while C20 HBI and botyrococcenes were indicative of periphyton-derived organic matter which is commonly more abundant in sloughs. Biomarker distributions during both low (present day) and high (managed) water flow through the DECOMP experimental parcel were determined and discussed comparatively.

  15. Characterisation of bentonites from Kutch, India and Milos, Greece - some candidate tunnel back-fill materials?

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Siv; Karnland, Ola (Clay Technology AB, Lund (Sweden))

    2009-12-15

    During the past decades comprehensive investigations have been made on bentonite clays in order to find optimal components of the multi-barrier system of repositories for radioactive waste. The present study gives a mineralogical characterisation of some selected bentonites, in order to supply some of the necessary background data on the bentonites for evaluating their potential as tunnel back-fill materials. Two bentonites from the island of Milos, Greece (Milos BF 04 and BF 08), and two bentonites from Kutch, India (Kutch BF 04 and BF 08) were analysed for their grain size distribution, cation exchange properties and chemical composition. The mineralogical composition was determined by X-ray diffraction analysis and evaluated quantitatively by use of the Siroquant software. Both the bulk bentonite and the <1mum fraction were analyzed when relevant. Prior to the chemical analyses the <1 mum fractions were converted to homo-ionic clays and purified by dialysis. The chemical data were used for calculating the structural formula of the smectites. Milos BF 04 contains ca. 10% particles >63 mum. The bentonite is distinguished by a high content of dolomite and calcite, which make up almost 25% of the bulk sample. The major accessory minerals are K-feldspars and plagioclase, whereas the content of sulphur-bearing minerals is very low (0.06% total S). Smectite makes up around 60% of the bulk sample, which has a CEC value of 73 meq/100 g. The pool of interlayer cations has a composition Mg>Ca>>Na>>K. The X-ray diffraction characteristics and the high potassium content (1.03% K{sub 2}O) of the <1 mum fraction suggest that the smectite is interstratified with ca. 10% illitic layers. Based on the charge distribution the smectite should be classified as montmorillonite and according to the structural formula, Mg predominates over Fe in the octahedral sheet. However, remnants of Mg-carbonates, if present, may be a source of error in the formula calculation. Milos BF 08 has a

  16. Coupling mechanism of roof and supporting wall in gob-side entry retaining in fully-mechanized mining with gangue backfilling

    Institute of Scientific and Technical Information of China (English)

    Ma Zhanguo; Gong Peng; Fan Jinquan; Geng Minmin; Zhang Guowei

    2011-01-01

    We analyzed the deformation characteristics of overlying stratum in backfilling with fully-mechanized and retaining roadways along the gob area coal mining technology,and established a mechanical model for the roof key stratum of retaining roadways along gob under the conditions of backfilling and fullymechanized coal mining technology.Using Winkler elastic foundation theory,we analyzed a part of the key stratum under the action of elastic foundation coupling problem,and derived deflection analytical expressions.Combined with specific conditions,we obtained the deflection curves for the roof key stratum of retaining roadways along gob under the conditions of backfilling and fully-mechanized coal mining technology.On this basis,we adopted the Coulomb's earth pressure theory to solve the problem of lateral pressure of the gangue filling area on the supporting wall beside the roadway and to provide the theoretical basis for reasonable selection of the distance between gangue concrete wall and roof and further discussion on the supporting stability of roadway.

  17. Effects of Fine Gangue on Strength, Resistivity, and Microscopic Properties of Cemented Coal Gangue Backfill for Coal Mining

    Directory of Open Access Journals (Sweden)

    Tingye Qi

    2015-01-01

    Full Text Available The cemented coal gangue backfill (CGB in coal mining is normally made of gangue (particle size of 0–15 mm, fly ash, cement, and water. In this study, the effects of the weight content (ranging from 20% to 60% of fine gangue (0–5 mm on the microscopic characteristics, resistivity, and compressive strength of CGB were investigated at 3 d and 28 d curing times, respectively. The test results indicate that the strengths of the CGB, regardless of the curing time, increased with fine gangue content changing from 20% up to 40%. Further increase in fine gangue introduced a decrease in the strength. Another observation is that, at 3 days, a general increasing trend of CGB resistivity was noted with fine gangue content. At 28 days, the resistivity of CGB decreased with increase in the fine gangue content. Correlations between the resistivity and compression strength of CGB show a concave pattern, which attribute to the various micromechanism influenced on the resistivity and strength of CGB with different fine gangue content. It indicates that using resistivity to derive strength of CGB is not appropriate.

  18. Uptake Mechanisms of Eu(III) on Hydroxyapatite: A Potential Permeable Reactive Barrier Backfill Material for Trapping Trivalent Minor Actinides.

    Science.gov (United States)

    Xu, Lin; Zheng, Tao; Yang, Shitong; Zhang, Linjuan; Wang, Jianqiang; Liu, Wei; Chen, Lanhua; Diwu, Juan; Chai, Zhifang; Wang, Shuao

    2016-04-05

    The permeable reactive barrier (PRB) technique has attracted an increasing level of attention for the in situ remediation of contaminated groundwater. In this study, the macroscopic uptake behaviors and microscopic speciation of Eu(III) on hydroxyapatite (HAP) were investigated by a combination of theoretical modeling, batch experiments, powder X-ray diffraction (PXRD) fitting, and X-ray absorption spectroscopy (XAS). The underlying removal mechanisms were identified to further assess the application potential of HAP as an effective PRB backfill material. The macroscopic analysis revealed that nearly all dissolved Eu(III) in solution was removed at pH 6.5 within an extremely short reaction time of 5 min. In addition, the thermodynamic calculations, desorption experiments, and PXRD and XAS analyses definitely confirmed the formation of the EuPO4·H2O(s) phase during the process of uptake of dissolved Eu(III) by HAP via the dissolution-precipitation mechanism. A detailed comparison of the present experimental findings and related HAP-metal systems suggests that the relative contribution of precipitation to the total Eu(III) removal increases as the P:Eu ratio decreases. The dosage of HAP-based PRB for the remediation of groundwater polluted by Eu(III) and analogous trivalent actinides [e.g., Am(III) and Cm(III)] should be strictly controlled depending on the dissolved Eu(III) concentration to obtain an optimal P:M (M represents Eu, Am, or Cm) ratio and treatment efficiency.

  19. 烧结法赤泥全尾砂胶结充填料%Paste backfilling material prepared with red mud from sintering process and unclassified tailings

    Institute of Scientific and Technical Information of China (English)

    黄迪; 倪文; 祝丽萍

    2012-01-01

    为了解决全尾砂、赤泥大量堆积产生的环境问题,实验采用烧结法赤泥、全尾砂等固体废弃物制备矿山充填料.结果表明:胶结剂的优化配比为赤泥49.2%+矿渣32.8%+熟料10%+石膏8%;充填料强度随着全尾砂掺量的增加而急剧下降;试块在水化初期即出现钙矾石、C-S-H凝胶,这些水化产物对早期强度的提高有很大帮助;差式扫描-热重分析表明试块在水化初期即可固结大量水.烧结法赤泥全尾砂胶结充填料具有早期强度高、固结水量大以及大量利用废料等特点,可满足目前矿山充填的需要.%To solve the problems of environmental pollution brought by the stockpiling of unclassified tailings and red mud, a mine backfilling material was prepared with red mud from sintering process, unclassified tailings and other solid wastes. The experimental results show that the optimal mass proportions of the cementing agent are red mud 49.2% , slag 32.8% , clinker aggregate 10% , and plaster 8% ; the strength of the backfilling material block reduces sharply with the increase of the unclassified tailings addition; the hydration products of cttringite and C-S-H gel generated in the test block at the early stage of hydration help for the early strength. Differential scanning calorimetry-thermo gravimetrie (DSC-TG) analysis shows that the test block concretes lots of water at the early stage. The prepared paste backfilling material has the characteristic of high early strength, large water concretion, high quantity wastes utilization, etc. , and it can meet the requirement of mine backfilling.

  20. 粉煤灰对矿渣胶结充填材料性能的影响%Influence of Fly Ash Performance of Slag Cemented Backfilling Materials

    Institute of Scientific and Technical Information of China (English)

    董璐; 高谦; 南世卿; 何环莎

    2012-01-01

    In view of the features of fly ash as abundant resources,low costs and improving the construction of mortar, the influence of fly ash on strength and liquidity of slag cemented materials is studied through experiments. The results show that the slag cemented backfilling materials with the lime and desulfurization gypsum as the activator, the compressive strength of backfilling body gradually declined with the adding amount of fly ash increasing. 1% of fly ash is added each time,the intensity decreased by 1. 82% at 7 d and by 1. 61% at 28 d on average. Meanwhile,the yield stress and viscosity of the backfilling is getting lower,which indicates that fly ash can largely improve the rheology of backfilling materials,and make high concentration of mortars conveying by gravity flow. Comprehensively considering the strength and the rheology, the optimal dosage of the fly ash ranges from 10% to 20%.%针对粉煤灰具有来源广、价格低廉和能改善砂浆施工性能的特点,研究了粉煤灰对矿渣胶结充填材料强度和流动性的影响.结果表明:在以石灰和脱硫石膏为激发剂制备的矿渣胶凝材料中,随着粉煤灰添加量的不断增大,充填体的抗压强度逐渐下降,每添加1%的粉煤灰,7d强度平均降低1.82%,28 d强度平均降低1.61%;但是充填料的屈服应力和塑形黏度却在不断降低,说明粉煤灰的添加能够很好地改善充填料浆的流变性,实现砂浆高浓度自流输送.综合考虑强度和流变性的影响效果,粉煤灰的最优掺量范围为10%~ 20%.

  1. Modeling coupled blast/structure interaction with Zapotec, benchmark calculations for the Conventional Weapon Effects Backfill (CONWEB) tests.

    Energy Technology Data Exchange (ETDEWEB)

    Bessette, Gregory Carl

    2004-09-01

    Modeling the response of buried reinforced concrete structures subjected to close-in detonations of conventional high explosives poses a challenge for a number of reasons. Foremost, there is the potential for coupled interaction between the blast and structure. Coupling enters the problem whenever the structure deformation affects the stress state in the neighboring soil, which in turn, affects the loading on the structure. Additional challenges for numerical modeling include handling disparate degrees of material deformation encountered in the structure and surrounding soil, modeling the structure details (e.g., modeling the concrete with embedded reinforcement, jointed connections, etc.), providing adequate mesh resolution, and characterizing the soil response under blast loading. There are numerous numerical approaches for modeling this class of problem (e.g., coupled finite element/smooth particle hydrodynamics, arbitrary Lagrange-Eulerian methods, etc.). The focus of this work will be the use of a coupled Euler-Lagrange (CEL) solution approach. In particular, the development and application of a CEL capability within the Zapotec code is described. Zapotec links two production codes, CTH and Pronto3D. CTH, an Eulerian shock physics code, performs the Eulerian portion of the calculation, while Pronto3D, an explicit finite element code, performs the Lagrangian portion. The two codes are run concurrently with the appropriate portions of a problem solved on their respective computational domains. Zapotec handles the coupling between the two domains. The application of the CEL methodology within Zapotec for modeling coupled blast/structure interaction will be investigated by a series of benchmark calculations. These benchmarks rely on data from the Conventional Weapons Effects Backfill (CONWEB) test series. In these tests, a 15.4-lb pipe-encased C-4 charge was detonated in soil at a 5-foot standoff from a buried test structure. The test structure was composed of a

  2. M4FT-16LL080303052-State of Knowledge for Colloid Facilitated Radionuclide Transport and Update on Actinide Diffusion in Bentonite Backfill

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences; Joseph, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences

    2016-08-16

    This progress report (Level 4 Milestone Number M4FT-16LL080303052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Crystalline Disposal R&D Activity Number FT-16LL080303051 and Crystalline International Collaborations Activity Number FT-16LL080303061. The focus of this research is the interaction of radionuclides with Engineered Barrier System (EBS) and host rock materials at various physico-chemical conditions relevant to subsurface repository environments. They include both chemical and physical processes such as solubility, sorption, and diffusion. The colloid-facilitated transport effort focused on preparation of a draft manuscript summarizing the state of knowledge and parameterization of colloid-facilitated transport mechanisms in support of reactive transport and performance assessment models for generic crystalline repositories. This draft manuscript is being submitted as a level 3 milestone with LANL as the primary author. LLNL’s contribution to that effort is summarized only briefly in the present report. A manuscript summarizing long-term U(VI) diffusion experiments through bentonite backfill material was recently accepted for publication; the contents of that manuscript are summarized in the present report. The Np(IV) diffusion experiments were started mid-year and are ongoing. The completion of these experiments is planned for early FY17. Our progress in quantifying Np(IV) diffusion in bentonite backfill is summarized in the present report. Our involvement with the NEA TDB project was summarized in a recent Argillite Disposal activity report. It is not included in this report.

  3. Laboratory determination of migration of Eu(III) in compacted bentonite-sand mixtures as buffer/backfill material for high-level waste disposal.

    Science.gov (United States)

    Zhou, Lang; Zhang, Huyuan; Yan, Ming; Chen, Hang; Zhang, Ming

    2013-12-01

    For the safety assessment of geological disposal of high-level radioactive waste (HLW), the migration of Eu(III) through compacted bentonite-sand mixtures was measured under expected repository conditions. Under the evaluated conditions, advection and dispersion is the dominant migration mechanism. The role of sorption on the retardation of migration was also evaluated. The hydraulic conductivities of compacted bentonite-sand mixtures were K=2.07×10(-10)-5.23×10(-10)cm/s, The sorption and diffusion of Eu(III) were examined using a flexible wall permeameter for a solute concentration of 2.0×10(-5)mol/l. The effective diffusion coefficients and apparent diffusion coefficients of Eu(III) in compacted bentonite-sand mixtures were in the range of 1.62×10(-12)-4.87×10(-12)m(2)/s, 1.44×10(-14)-9.41×10(-14)m(2)/s, respectively, which has a very important significance to forecast the relationship between migration length of Eu(III) in buffer/backfill material and time and provide a reference for the design of buffer/backfill material for HLW disposal in China.

  4. 山东煤炭工业充填开采研究与实践%Research and practice on backfill mining in Shandong coal industry

    Institute of Scientific and Technical Information of China (English)

    乔乃琛

    2015-01-01

    为了推进煤炭工业绿色发展、煤炭清洁高效利用,促进煤炭工业循环可持续发展,分析、研究了山东省煤炭行业实施充填开采的必要性和可行性,通过多种途径转变煤炭生产方式,优化、引导、规范和扶持煤炭企业实施充填开采。%In order to promoting green development of coal industry,efficient utilization of clean coal mining and sustainable development of coal industry circle,the authors introduced and studied necessity and feasibility of backfill mining in Shandong coal industry,furthermore,ac-cording to various channels to change coal production mode,and also optimized,guided,stand-ardized and supported implement backfill mining for coal enterprises.

  5. M4FT-16LL080303052-State of Knowledge for Colloid Facilitated Radionuclide Transport and Update on Actinide Diffusion in Bentonite Backfill

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences; Joseph, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences

    2016-08-16

    This progress report (Level 4 Milestone Number M4FT-16LL080303052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Crystalline Disposal R&D Activity Number FT-16LL080303051 and Crystalline International Collaborations Activity Number FT-16LL080303061. The focus of this research is the interaction of radionuclides with Engineered Barrier System (EBS) and host rock materials at various physico-chemical conditions relevant to subsurface repository environments. They include both chemical and physical processes such as solubility, sorption, and diffusion. The colloid facilitated transport effort focused on preparation of a draft manuscript summarizing the state of knowledge and parameterization of colloid facilitated transport mechanisms in support of reactive transport and performance assessment models for generic crystalline repositories. This draft manuscript is being submitted as a level 3 milestone with LANL as the primary author. LLNL’s contribution to that effort is summarized only briefly in the present report. A manuscript summarizing longterm U(VI) diffusion experiments through bentonite backfill material was recently accepted for publication; the contents of that manuscript are summarized in the present report. The Np(IV) diffusion experiments were started mid-year and are ongoing. The completion of these experiments is planned for early FY17. Our progress in quantifying Np(IV) diffusion in bentonite backfill is summarized in the present report. Our involvement with the NEA TDB project was summarized in a recent Argillite Disposal activity report. It is not included in this report.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-06-15

    therefore divided into seven sampling groups, each with similar properties. The properties of one sampling group (i.e. KBU10002 + KBU10008) resembled those of the groundwater, while others (i.e. KBU10004 + KBU10006, KBU10005, and KFA01-KFA04) differed, for example, in microbial composition, salinity, sulphate content, and the concentrations of calcium, potassium, magnesium, sodium, and many dissolved metals, actinides, and lanthanides. One sampling group comprised sampling points that seemed to be in contact with tunnel air (KBU10003 + KBU10007). Another sampling group comprised sampling points, near the canisters in the buffer (KB513-614), with very little pore water with high pH and a high salt content. One sampling point in the backfill, which had not been reached by the groundwater as of May 2007 (KBU10001), now yielded pore water with properties resembling those of groundwater. The gas composition in the sampling groups was uniform in that the proportion of nitrogen in the extracted gas was increasing while the oxygen content was decreasing with time. ATP analyses demonstrated that the biomass in the Prototype was higher than in the surrounding groundwater. The microbiological results indicated that aerobic microbes, such as methane-oxidizing bacteria and culturable heterotrophic bacteria, thrived in the aerobic Prototype environment. The chemical data indicated differences between the sampling groups: concentrations of sodium and potassium were higher in the Prototype pore water than in the groundwater outside it, while calcium was lower than in the groundwater. Obviously, cation exchange occurs in the montmorillonite interlayers. At sampling points containing active microbes, copper, rubidium, vanadium, and uranium were enriched up to 225 times the groundwater levels; microbes are possibly responsible for dissolving these substances by excreting compound-specific ligands. Overall, the observations presented here strongly support our hypothesis that oxygen will be

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-15

    chemistry. The in 2007 improved sampling and analysis protocols worked very well. Also, the molecular methods that were tested for the first time in the Prototype showed promising potential. IPR 08-01 revealed that many of the hydrochemical sampling points differ quite remarkably from each other. The 16 sampling points were therefore divided into seven sampling groups with similar properties. The properties of one sampling group (i.e., KBU10002+8) resembled those of the groundwater, while others (i.e., KBU10004+6, KBU10005, and KFA01-04) differed, for example, in microbial composition, salinity, sulphate content, pH, and the concentrations of calcium, potassium, magnesium, sodium, and many dissolved metals, actinides, and lanthanides. One sampling group contained sampling points that seemed to be in contact with tunnel air (KBU10003+7). Another sampling group contained sampling points near the canisters in the buffer (KB513-614) with very little pore water with high pH and a high salt content. One sampling point in the backfill, which had not been reached by the groundwater as of May 2007 (KBU10001), now consisted of pore water with properties resembling those of groundwater. The gas composition in the sampling groups was uniform in that the proportion of nitrogen in the extracted gas was increasing and the oxygen content decreasing with time. In most sampling groups, the oxygen content in the pore water had decreased from 3-7% as of May 2007 to 0.6-4% in 2009. This can also be compared with the proportion of oxygen in the gas phase in 2005, which was 10-18%. Hydrogen, methane, helium, and carbon dioxide concentrations varied, especially in the sampling groups with extractable pore water. ATP analyses demonstrated that the biomass in the Prototype repository is high compared to the surrounding groundwater. The microbiological results indicated that aerobic microbes, such as MOB and CHAB, thrived in the aerobic Prototype environment

  8. Ore Dilution Prediction of Ore Drawing below Backfilling of Waste Rock Layer and Particle Flow Numerical Analysis%回填废石层下放矿损贫预测及颗粒流数值分析

    Institute of Scientific and Technical Information of China (English)

    刘增辉; 高谦; 李欣; 李俊华

    2011-01-01

    When open-air is transferred to underground mining, the backfilling of waste rock layer has a certain impact on ore loss and dilution in the ore drawing process. There are three main factors of ore loss and dilution below backfilling of waste rock layer, backfilling thickness, and particle size of waste rock layer and its non-uniformal level Through reprocesslng the experimental data from different tests ,the paper summed up the mathematical model of ore loss and dilution rate below the backfilling of waste rock layer. Combining with transition from open-pit to underground mining in stope Ⅲ of Sijiaying iron mine,the non-uniformity and particle size of the backfilling of waste rock layer are designed. Through the orthogonal experimental method of particle flow numerical simulation,the relationship of such four factors as ore dilution ratio λ,backfilling thickness h, particle diameter d, particle non-uniformity K of waste rock layer with the ore loss rate is set up,which provides a reference for the rational design of backfilling layer in similar conditions.%露天转地下开采,回填废石层在放矿过程中对矿石的损失和贫化有一定的影响.回填废石层下放矿损贫的主要影响因素有回填层厚度、废石的粒径和非均匀度3个方面,对不同试验者的实验数据重新处理,总结出了回填废石层下放矿贫化率和损失率的数学模型,并结合司家营铁矿Ⅲ采场的露天转地下工程进行了回填废石粒径与非均匀度的设计.通过颗粒流数值正交试验方法,分别从绝对因素和相对因素回归建立了贫化率λ、回填层厚度h、回填层粒径d、回填层粒径非均匀度K4个因素和损失率之间的关系,为类似条件下的回填层合理设计提供参考.

  9. Influence of pressure conditions and back-filling materials on the durability of bore-hole ground loops; Lebensdauer von Erdwaermesonden in Bezug auf Druckverhaeltnisse und Hinterfuellung

    Energy Technology Data Exchange (ETDEWEB)

    Rohner, R. [E. Rohner, Arnegg (Switzerland); Rybach, L.; Salton, M. [Swiss Federal Institute of Technology (ETHZ), Institut fuer Geophysik, Zuerich (Switzerland)

    2001-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) discusses the influence of the relatively high pressures found in ground loops at depths of more than 200 metres and the effects caused by overloading the ground loops. The latter can cause the back-filling between the ground loop and the surrounding rock to freeze. The report describes tests carried out on 70-metre and 265-metre deep test bore-hole installations. The results of investigations into the influence of such pressure conditions on the materials of the ground loop and their service life are presented. The results are also compared with simulations using the FRACTure and EED calculation programmes. Details are given on the bore-holes with respect to their geology and construction. The report concludes that bore-hole ground loops can be considered as being very robust components with a long service life, provided they are designed and installed according to accepted professional standards.

  10. 土工袋技术在市政沟槽回填中的应用研究%Application of soilbags to urban trench backfill

    Institute of Scientific and Technical Information of China (English)

    刘斯宏; 高军军; 王子健; 王柳江; 胡晓平

    2014-01-01

    市政工程中管线埋入地下采用的基本流程是先开挖沟槽,将开挖的原土作为渣土处理,待管线在沟槽中安放后再用二灰土石填埋沟槽,经夯实后铺设沥青或混凝土路面。为了有效利用沟槽开挖土、减少二灰土石用量,建议采用土工袋技术处理,即将沟槽开挖土装入土工编织袋后回填至沟槽中。阐述了土工袋技术原理,并依托南京市雨污分流工程,对用土工袋回填的沟槽进行了平板载荷试验、落锤式挠度检测和路面振动测试,评价土工袋沟槽的回填效果。结果表明:土工袋在提高沟槽承载力、减少沉降变形、削弱交通振动干扰等方面具有明显效果。土工袋避免弃土外运,减少了扬尘污染,不失为一种绿色、环保、经济的工程新技术。%The basic way to bury pipelines into ground in the municipal projects is:excavating a trench firstly, and throwing away the excavated soils as wastes; backfilling the expensive lime-ash soil into the trench after the pipelines are placed properly; tamping foundation and laying asphalt or concrete pavements. In consideration of recycling the excavated soils and reducing the use of lime-ash soil, soilbag technique is suggested in urban trench backfills so as to cut down the project costs. The mechanism of soilbag technique is briefly elucidated herein; and several field tests such as plate loading test, falling-weight deflection and vibration response measurements are then carried out respectively to evaluate the benefits of a soilbag-trench, with the strong support of the Rain and Sewage Diversion Project in Nanjing. The test results show that soilbag technique performances superbly in improving the bearing capacity of subgrade, decreasing the settlement of roadbed as well as in reducing and isolating the traffic-induced vibrations, compared with the common backfill scheme. It is also proved that backfilling the trench with soilbags is a

  11. Strength evolution and deformation behaviour of cemented paste backfill at early ages:Effect of curing stress, filling strategy and drainage

    Institute of Scientific and Technical Information of China (English)

    Ghirian Alireza; Fall Mamadou⇑

    2016-01-01

    In this study, a pressure cell apparatus is developed to investigate the early age evolution of the strength and deformation behaviour of cemented paste backfill (CPB) when subjected to various loading condi-tions under different curing scenarios. The different curing scenarios that are simulated include: (1) drained and undrained conditions, (2) different filling rates, (3) different filling sequences, and (4) differ-ent curing stresses. The findings show that drainage, curing stress, curing time and filling rate influence the mechanical and deformation behaviours of CPB materials. The coupled effects of consolidation, drai-nage and suction contribute to the strength development of drained CPB subjected to curing stress. On the other hand, particle rearrangement caused by the applied pressure and suction development due to self-desiccation plays a significant role in the strength gain of undrained CPB cured under stress. Furthermore, curing stress induces slightly faster rate of cement hydration, which can contribute to strength acquisition.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-06-15

    therefore divided into seven sampling groups, each with similar properties. The properties of one sampling group (i.e. KBU10002 + KBU10008) resembled those of the groundwater, while others (i.e. KBU10004 + KBU10006, KBU10005, and KFA01-KFA04) differed, for example, in microbial composition, salinity, sulphate content, and the concentrations of calcium, potassium, magnesium, sodium, and many dissolved metals, actinides, and lanthanides. One sampling group comprised sampling points that seemed to be in contact with tunnel air (KBU10003 + KBU10007). Another sampling group comprised sampling points, near the canisters in the buffer (KB513-614), with very little pore water with high pH and a high salt content. One sampling point in the backfill, which had not been reached by the groundwater as of May 2007 (KBU10001), now yielded pore water with properties resembling those of groundwater. The gas composition in the sampling groups was uniform in that the proportion of nitrogen in the extracted gas was increasing while the oxygen content was decreasing with time. ATP analyses demonstrated that the biomass in the Prototype was higher than in the surrounding groundwater. The microbiological results indicated that aerobic microbes, such as methane-oxidizing bacteria and culturable heterotrophic bacteria, thrived in the aerobic Prototype environment. The chemical data indicated differences between the sampling groups: concentrations of sodium and potassium were higher in the Prototype pore water than in the groundwater outside it, while calcium was lower than in the groundwater. Obviously, cation exchange occurs in the montmorillonite interlayers. At sampling points containing active microbes, copper, rubidium, vanadium, and uranium were enriched up to 225 times the groundwater levels; microbes are possibly responsible for dissolving these substances by excreting compound-specific ligands. Overall, the observations presented here strongly support our hypothesis that oxygen will be

  13. Determination of internal pressure and the backfill gas composition of nuclear fuel rods; Determinacion de la presion interna y la composicion del gas de llenado de barras de combustible nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Garcia C, M.A.; Cota S, G.; Merlo S, L.; Fernandez T, F. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    An important consideration in the nuclear fuel manufacturing is the measurement of the helium atmosphere pressure and its composition analysis inside the nuclear fuel rod. In this work it is presented a system used to measure the internal pressure and to determine the backfill gas composition of fuel rods. The system is composed of an expansion chamber provided of a seals system to assure that when rod is drilled, the gas stays contained inside the expansion chamber. The system is connected to a pressure measurement digital system: Baratron MKS 310-AHS-1000. Range 1000 mm Hg from which the pressure readings are taken when this is stabilized in all the system. After a gas sample is sent toward a Perkin Elmer gas chromatograph, model 8410 with thermal conductivity detector to get the corresponding chromatogram and doing the necessary calculations for obtaining the backfill gas composition of the rod in matter. (Author)

  14. Discussion on counter-digging and backfill methods of low filling soil roadbed%谈低填方土质路基工程反挖回填施工方法

    Institute of Scientific and Technical Information of China (English)

    赵伟

    2012-01-01

    Combining with roadbed counter-digging and backfill engineering at contraction section of national highway line No. 208 reconstruction project, this thesis introduces counter-digging and backfill methods of low filling soil roadbed, and summarizes some technological points, which has laid a foundation for the application of counter-digging method in roadbed engineering.%结合国道208线改建工程某合同段路基反挖回填工程施工实例,介绍了低填方土质路基反挖回填施工方法,并总结了一些技术要点,为推广该施工方法在路基工程中的应用奠定了基础。

  15. Treatment Technology on Roof Fall and Landslide of Backfilled Tunnel in Goaf%采空区回填体隧道冒顶塌方处理技术

    Institute of Scientific and Technical Information of China (English)

    谈东亚

    2014-01-01

    Based on the example of treatment on backfilled landslide in goaf encountered in Wusong Tunnel construction in Tongling,according to the characteristics of goaf backfilling roof fall and landslide,from the safety angle,measures are used to deal with the landslide,like temporary reinforcement of the sound section with circumferential vertical steel support,ad-vanced support with cuff shed pipe,grouting reinforcement with cement water glass,reservation core soil excavation,backfill-ing of light weight concrete,arch replacement technology,so as to provide references for similar projects in the future.%以铜陵市五松隧道在施工中遇到的采空区回填体塌方处理为例,针对采空区回填体导致冒顶塌方的特点,从安全顺利的角度,通过临时环向竖向钢支撑加固未塌方段、套管法超前管棚超前预支护、水泥水玻璃注浆加固、预留核心土法开挖支护、回填轻质混凝土、换拱等技术,安全顺利地处理完该塌方,为今后类似工程提供一定的参考。

  16. Analysis of Impacts on Earthquake Response of Intake Tower by Backfill Concrete on Tower Back%塔背回填混凝土对进水塔地震响应的影响分析

    Institute of Scientific and Technical Information of China (English)

    李锋

    2015-01-01

    塔背回填混凝土将岸塔式进水塔和山岩连成一体,提高了进水塔整体刚度,有效改善了塔体在地震情况下的拉应力幅值,对进水塔结构的抗震设计非常关键。以某水电站的岸塔式进水塔为例,针对不同高度塔背回填混凝土的塔体模型进行三维有限元静动力计算,以分析回填混凝土对进水塔地震响应的影响。%The backfill concrete on the tower back integrates the intake tower and the mountain rockmass, increasing the overall rigidity of the intake tower and effectively improving the tensile stress range value of the tower body in earthquake condition.This is very important for the aseismic design of the intake tower structure.With the case of the intake tower of one hydropower station, the static and dynamic calculations in 3D finite element method are performed to the tower models with the backfill concrete on the tower back at different heights so as to analyze the impacts on the earthquake response of the intake tower by the backfill concrete on the tower back.

  17. 核子密度仪在阿曼管沟回填中的应用%Use of nuclear density gauge for testing trench backfilling in Oman

    Institute of Scientific and Technical Information of China (English)

    邓兆勋; 刘光然

    2011-01-01

    针对国际工程——阿曼马斯喀特污水管网工程点多、面广、管沟回填速度快、检测频率高等特点,阐述了核子密度仪的工作原理,依据英国BS标准进行校正的方法及针对阿曼政府对辐射源的管理所采取的防护措施,保证了工程质量和施工的顺利进行。%Considering Oman Muscat waste water collection network project——an international construction project which has many engineering aspects,requirement of quick backfilling and fast detection,high test frequencies,this article explains the working principle of the nuclear density gauge,according to the British BS standard method of correction and focusing on the management of the government of Oman to the radiation protection measures taken to ensure the engineering quality and construction to proceed smoothly.

  18. Research and Development of a New Silica-Alumina Based Cementitious Material Largely Using Coal Refuse for Mine Backfill, Mine Sealing and Waste Disposal Stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Henghu Sun; Yuan Yao

    2012-06-29

    Coal refuse and coal combustion byproducts as industrial solid waste stockpiles have become great threats to the environment. To activate coal refuse is one practical solution to recycle this huge amount of solid waste as substitute for Ordinary Portland Cement (OPC). The central goal of this project is to investigate and develop a new silica-alumina based cementitious material largely using coal refuse as a constituent that will be ideal for durable construction, mine backfill, mine sealing and waste disposal stabilization applications. This new material is an environment-friendly alternative to Ordinary Portland Cement. The main constituents of the new material are coal refuse and other coal wastes including coal sludge and coal combustion products (CCPs). Compared with conventional cement production, successful development of this new technology could potentially save energy and reduce greenhouse gas emissions, recycle vast amount of coal wastes, and significantly reduce production cost. A systematic research has been conducted to seek for an optimal solution for enhancing pozzolanic reactivity of the relatively inert solid waste-coal refuse in order to improve the utilization efficiency and economic benefit as a construction and building material.

  19. RESEARCH ON ACTIVE EARTH PRESSURE BEHIND RIGID RETAINING WALL FROM CLAYEY BACKFILL CONSIDERING SOIL ARCHING EFFECTS%考虑土拱效应的黏性填土挡土墙主动土压力研究

    Institute of Scientific and Technical Information of China (English)

    涂兵雄; 贾金青

    2012-01-01

    Analytical expressions for the active earth pressure ratio and active earth pressure are derived, against on a rigid retaining wall from clayey backfill undergoing horizontal translation) considering the soil arching effects and the influence of soil-wall friction angle, wall adhesion and cohesion of backfill. The results show that the active earth pressure ratio and active earth pressure are related to soil-wall friction angle, depth of the point and the internal friction angle, cohesion, unit weight of the backfill. The theoretical comparisons between the analytical expressions proposed for active earth pressure ratio and active earth pressure and the existing classical theory, the previous research results show great agreement with each other, so as to verity the correctness of the results in this paper.%以墙后填土为黏性土的刚性挡土墙为研究对象,考虑挡土墙后的土拱效应,以及墙土摩擦角、墙土黏结力、墙后填土黏聚力的影响,推导挡土墙在平动模式下的主动土压力系数和主动土压力解析解.结果表明,考虑土拱效应的主动土压力系数和主动土压力均与墙土摩擦角、计算点深度以及墙后填土的内摩擦角、黏聚力及重度有关.通过将求解的主动土压力系数和主动土压力与现有经典理论解及前人理论研究成果对比,发现结果完全吻合,验证该研究结果的正确性.

  20. 赤泥膏体和似膏体全尾砂胶结充填料研究%Research on Whole- tailings Paste and Paste -like Backfilling Material with Red Mud

    Institute of Scientific and Technical Information of China (English)

    祝丽萍; 倪文; 黄迪; 黄晓燕; 王中杰

    2011-01-01

    实验以赤泥、水淬高炉矿渣、脱硫石膏、全尾砂和少量水泥熟料制备出一种新型的膏体和似膏体全尾砂胶结充填材料,通过对体系质量浓度的考察,得出了质量浓度(水胶比)一坍落度、坍落度一强度关系曲线。膏体全尾砂胶结充填料的合适的质量浓度为79.4%~81.9%,所制备的试块60d强度达到4~6MPa;似膏体胶结充填料的合适的质量浓度为78.0%左右,所制备的试块60d强度为4MPa左右。通过SEM分析表明,该充填料固化后形成絮状和团簇状的胶体以及针棒状的石膏和钙矾石,它们团聚交织在一起形成小仙人球状的结构填充在尾砂颗粒%A new paste and paste -like backfilling material was prepared with red mud,quenched blast furnace slag, desulphuri- zation gypsum,wholetailings and a little cement clinker. With the different concentration of the slurry, the relationship between mass concentration and slump as well as the relation of slump and strength were obtained. The results of the experiment indicated that the appropriate concentration of the cemented whole - tailings backfilling paste was 79.4% - 81.9% and its compres sive strength of 60 days was 4 to 6 MPa ; the appropriate concen tration of the cemented paste - like backfilling was 78.0% and its compressive strength of 60 days reached about 4 MPa. By scanning electron microscope ( SEM ) , flocculence - shaped and cluster - shaped C - S - H as well as the needle - like gypsum and ettringite were observed. They reunited together to form somesmall cactiballs and the cactiballs filled up the gap between the tailings,which enhance the connection between the phase and the matrix phase. The backfilling material reported in this paper also has some excellent properties, such as good working performance,low cost and high strength.

  1. Modeling of Coupled Thermo-Hydro-Mechanical Processes with Links to Geochemistry Associated with Bentonite-Backfilled Repository Tunnels in Clay Formations

    Science.gov (United States)

    Rutqvist, Jonny; Zheng, Liange; Chen, Fei; Liu, Hui-Hai; Birkholzer, Jens

    2014-01-01

    This paper presents simulation results related to coupled thermal-hydraulic-mechanical (THM) processes in engineered barrier systems (EBS) and clay host rock, in one case considering a possible link to geochemistry. This study is part of the US DOE Office of Nuclear Energy's used fuel disposition campaign, to investigate current modeling capabilities and to identify issues and knowledge gaps associated with coupled THMC processes and EBS-rock interactions associated with repositories hosted in clay rock. In this study, we simulated a generic repository case assuming an EBS design with waste emplacement in horizontal tunnels that are back-filled with bentonite-based swelling clay as a protective buffer and heat load, derived for one type of US reactor spent fuel. We adopted the Barcelona basic model (BBM) for modeling of the geomechanical behavior of the bentonite, using properties corresponding to the FEBEX bentonite, and we used clay host rock properties derived from the Opalinus clay at Mont Terri, Switzerland. We present results related to EBS host-rock interactions and geomechanical performance in general, as well as studies related to peak temperature, buffer resaturation and thermally induced pressurization of host rock pore water, and swelling pressure change owing to variation of chemical composition in the EBS. Our initial THM modeling results show strong THM-driven interactions between the bentonite buffer and the low-permeability host rock. The resaturation of the buffer is delayed as a result of the low rock permeability, and the fluid pressure in the host rock is strongly coupled with the temperature changes, which under certain circumstances could result in a significant increase in pore pressure. Moreover, using the BBM, the bentonite buffer was found to have a rather complex geomechanical behavior that eventually leads to a slightly nonuniform density distribution. Nevertheless, the simulation shows that the swelling of the buffer is functioning to

  2. Study on Wear Mechanism of Paste Backfilling Pipeline in Deep Mining%深井开采膏体充填管线磨损机理研究

    Institute of Scientific and Technical Information of China (English)

    吴顺江; 容宇

    2012-01-01

    会泽铅锌矿开采深度超过1000m,属深井开采.主要采用膏体充填处理采空区,由于长时间膏体料浆摩擦管壁,管线磨损严重甚至磨穿管壁,导致部分浆液外淤,管道卸压会导致堵管事故的发生,堵管次数随着管线的磨蚀呈上升趋势.通过研究发现,影响管线磨损的因素包括固体颗粒粒级组成、形状、浆体的性质、粘度、流速及管材质量等.在充填过程中,通过对提高膏体浓度、增加管线输送阻力和改变尾砂粒级组成等进行分析,结合现场实验,提出了合理解决管线磨损和延长管线寿命的一系列措施,取得了较好的效果.%The mining depth of Huize lead &zinc ore deposit is more than 1 000 m, it belongs to deep mining. The goaf is mainly treated by paste backfilling; the tube wall has been severe worn, even wore out, due to the friction of pipe wall by paste slurry for a long time, which give rise to external silting of partial slurry, so that pressure relief of pipeline can generate pipe blockage, the times of pipe blockage showed an increasing tendency following with the abrasion of pipeline. The research results showed that the influencing factor of pipeline abrasion includes: the particle size compositions of solid particle, shape, the property, viscosity, flow velocity of slurry and tube quality, etc. According to the analysis of paste concentration increasing, pipeline transport resistance increasing and changing of tailings' size fraction composition, etc. And combining with the field experiment, a series measures is proposed to rationally solve the problems of pipeline abrasion and lengthen the service life of pipeline, and good effect is obtained.

  3. 对坦墙墙后土体第二破裂面的研究%Research on The Second Failure Surface of Backfill Behind Retaining Wall With Gentle Back Surface

    Institute of Scientific and Technical Information of China (English)

    杨雪强; 范瑛

    2001-01-01

    Based on soil plasticity and limit analysis theory,the second failure surface of backfill behind retaining wall with gentle back surface are studied from two view points of maximum active soil pressure and minimum resistive overturning safety factor,and it is further considered that the minimum resistive overturning safety factor is the best approach to studying the failure mechanism of backfill under complex back surface conditions of retaining structures.%基于土的塑性极限分析理论,从挡土墙最小抗倾覆安全系数和挡土墙背上的最大主动土压力两个角度,分别研究了坦墙后土体中第二破裂面的位置,认为在复杂的挡土结构墙背条件下,用最小抗倾覆安全系数来研究挡土墙后土体的破坏机制较为合理。

  4. Effects of Superplasticizer on Transport Properties of Backfill Slurry Contained Bittern%高效减水剂对含盐卤充填料浆输送特性的影响

    Institute of Scientific and Technical Information of China (English)

    王昆; 杨鹏; 吕文生; 刘杰; 张浩

    2016-01-01

    With the special geological and hydrological conditions of Sanshandao gold mine,there were large amounts of bittern ions in backfill mixing water according to the test results,which has an adverse effect in slurry gravity transportation. The possibility of using superplasticizer to improve slurry transportation properties was explored in this paper to realize high concentration gravity transportation. The backfill slurry was prepared with using classified tailings,backfill water,cement and adding different kinds and amounts of superplasticizer. The slurry settling and bleeding rates were tested by standing in the measuring cylinder. And the rheological properties were tested by using R/S-SST rheometer. The influence law of superplastici-zer on slurry settling and rheological properties were revealed by comparative analysis. The results showed:The slurry mixed with 0. 5‰ naphthalene superplasticizer suffered the largest decline in bleeding rates. And it provided an effective way of re-ducing stope dewatering pressure;The slurries with 0. 5‰ naphthalene superplasticizer admixture under high cement-tailings ratio condition and 0. 5‰polycarboxylene superplasticizer admixture under low cement-tailings ratio condition suffered the lar-gest decline in settling rates;The rheological property of backfill slurry contained bittern can be represented as Bingham flow pattern. The best transport efficiency could be achieved by mixing 0. 5‰ polycarboxylene superplasticizer when the slurry vis-cosity and yield stress both showed relatively low values. In conclusion,the suspension of backfill slurry contained bittern could be enhanced by superplasticizer. And the slurry viscosity and yield stress were both effectively reduced. Thus the pipe wall ab-rasion was decreased.%三山岛金矿地质水文条件特殊,测得充填用水中富含盐卤离子,对料浆自流输送造成不利影响。本研究探索使用高效减水剂改善含盐卤料浆的输送特性,以实现

  5. Study on Preparation, Microstructure and Solidifying Mechanism of Backfill Materials from Mud Solidification%泥浆固化充填材料的制备、微结构及其固化机理的研究

    Institute of Scientific and Technical Information of China (English)

    彭美勋; 蒋建宏; 王正红; 申少华

    2011-01-01

    应用复合胶凝剂制备红壤土泥浆充填材料,利用正交实验方法研究了胶凝剂组分对充填体强度的影响,并运用扫描电镜和X射线衍射技术探讨了固化机理.泥浆固化体早期(3d和7d)强度高,后期(28 d)强度稳定增长.其中硫铝酸盐熟料、石灰和硬石膏的总加量对固化体各龄期强度的影响最为显著;水玻璃与烧碱的加量对固化体的早期强度增长有益,但对后期强度有一定的负面影响;矿渣和硅灰对固化体后期抗压强度有明显贡献.对粘土进行离子交换,并在水化过程不同阶段生成C-S-H凝胶与高结晶水含量的钙矾石是复合胶凝剂的固化机理.%Backfill materials were prepared for mud using complex gel agents. The effects of the components on the strength of the backfill materials were studied with orthogonal experiment methods and the solidification mechanism of the backfill materials were discussed by SEM and XRD technologies. The mud solidification specimens exhibited high compressive strength at early period (3d and 7 d) that developed stably at later period (28 d). The content of sulphoaluminate cement clinker, lime and anhydrite significantly affected the compressive strength at every period, and the content of water glass and caustic soda were beneficial to improve the compressive strength at early period but negative to that at later period somewhat. The slag and silica fume obviously contributed to the development of the compressive strength. The solidification mechanisms of the complex gel agents were proposed based on the ion exchange with the mud and the generation of the C-S-H gelatin and ettringite containing high content of crystal water.

  6. 高瓦斯矿井高水材料充填墩柱沿空留巷技术%Gateway Retained Along Goaf Technology with Pier Pillar Backfilled with High Water Material in High Gassy Mine

    Institute of Scientific and Technical Information of China (English)

    史国跃

    2014-01-01

    In order to improve a high timber consumption,high labor intensity,complicated construction and low support strength of the timber pack gateway retained along the goaf,a high water material was applied to backfill the pier pillar for the gateway retained along the goaf technology in Gaohe Mine and the industrial trial was conducted in No. E1302 air return gateway.The results showed that the max convergence between the roof and floor of the timber pack gateway retained along the goaf was 286 mm,the max convergence between the roof and floor of the gateway retained along the goaf with the pier pillar backfilled with the high water material was 188 mm and the max deformation value of the pier pillar was 65 mm.The construction technology of the gateway retained along the goaf with the pier pillar backfilled with the high water material was simple.The compressive strength of the pier pillar was high and could control the deformation of the surrounding rock.Meanwhile,the ventilation cross section enlarged of the mine roadway would be favorable for the ventilation gas discharging and could prevent the gas accident occurred in the mine.%为了改善木垛沿空留巷木料消耗量大、劳动强度高、施工复杂、支护强度较低的问题,高河煤矿采用了高水材料充填墩柱沿空留巷技术,并在E1302回风巷进行了工业性试验。结果表明:木垛沿空留巷顶底板最大移近量为286 mm,采用高水材料充填墩柱沿空留巷技术顶底板最大移近量为188 mm,墩柱最大变形量为65 mm,高水材料充填墩柱沿空留巷技术施工工艺简单、墩柱抗压强度大,可有效控制围岩变形,同时增大巷道通风断面有利于风排瓦斯,防止矿井发生瓦斯事故。

  7. 超高水材料覆岩离层及冒落裂隙带注浆充填技术%Grouting Backfill Technology with Super High Water Material for Overburden Bed-separation and Falling Fractured Zone

    Institute of Scientific and Technical Information of China (English)

    王成真; 冯光明

    2011-01-01

    In order to the problems occurred by the great amount pressurized flowing water in the bed-separation after the traditional grouting and subsidence control technology conducted in the overburden bed-separation, in combination with the basic performances of the super water material, based on the key strata theory of the strata control as the guide, the grouting backfill technology with the super water material was provided for the overburden strata bed-separation and falling fractured zone.The technology would fully fill with the super water material in the bed-separation space, the space between the falling rocks of the falling zone and the cracks of the fractured zone.After the grouting material solidified, the filled material could control the activities of the overburden strata.The previous practical results of the overburden strata grouting and the application of the grouting and backfill technology to an imaginary coal mining face showed that the grouting and backfill with the super water material in the overburden strata bed-separation and falling fractured zone would have a subsidence reduction rate between 80% ~ 90% and would have a high production and high efficient coal mining in seam under the buildings,railway line and water body.%为了解决传统覆岩离层注浆减沉技术实施后离层区内大量承压可流动水体所带来的问题,结合超高水材料基本性能,以岩层控制的关键层理论为指导,提出了超高水材料覆岩离层及冒落裂隙带注浆充填技术.该技术将超高水材料浆液充满关键层下的离层空间、冒落带垮落矸石间缝隙以及裂缝带裂隙,凝固后的充填体控制上覆岩活动.根据以往覆岩离层注浆实践结果及超高水材料注浆充填技术在假想工作面的应用可知:超高水材料覆岩离层及冒落裂隙带注浆充填的减沉率在80%~90%,有助实现"三下"压煤开采的高产高效.

  8. Experimental Study on Optimization of Phosphogypsum Plaster Mix Proportion for Backfill Strength%磷石膏膏体充填材料强度优化配比试验研究

    Institute of Scientific and Technical Information of China (English)

    张小瑞; 赵国彦; 李地元; 孙智慧

    2015-01-01

    为研究贵州开磷矿业总公司采用磷石膏和黄磷渣胶结充填采空区的可行性,在实验室测试了磷石膏及黄磷渣的主要物理化学性质,制备了不同浓度不同配比的充填料浆,并测试其坍落度、泌水率和不同龄期的单轴抗压强度。采用正交试验设计优化磷石膏膏体配比,并采用Mathematica对强度数据进行拟合,得出本次试验的最优结果为:磷石膏膏体充填料的最优质量比为黄磷渣∶磷石膏=1∶4,添加CaO质量为5%,磷石膏膏体质量浓度为67%~68%。在该配比条件下,磷石膏膏体充填体28 d单轴抗压强度为2.15~3.42 MPa,可满足矿山安全生产需求,并显著降低料浆泌水率。%In order to probe into the feasibility of backfilling the mined⁃out area with cemented mixture of phosphogypsum and yellow phosphorus slag for Guizhou Kaiyang Phosphorous Mine Bureau, backfill material with different slurry concentration and different proportioning were prepared based on the laboratory tests on the physical and mechanical properties of phosphogypsum and yellow phosphorus slag, for which the slump, bleeding rate and uniaxial compressive strength were also tested. Afterwards, orthogonal regression method was adopted to optimize the proportion of phosphogypsum plaster in the design and Mathematica was then used for strength data fit, leading to the optimized proportions of phosphogypsum plaster as backfill material as follows: the ratio of yellow phosphorus slag to phosphogypsum at 1∶4, addition of CaO in quantities of 5%, mass concentration of phosphogypsum plaster at 67%~68%. With such proportioning, the phosphogypsum plaster has a uniaxial compressive strength of 2.15~3.42 MPa after 28 days of aging with bleeding rate notably reduced, which can meet the safety requirement for mining production.

  9. Explore the Problems of Municipal Water Supply Pipeline Trench Excavation and Backfill%市政给水管道沟槽开挖及回填问题的研究

    Institute of Scientific and Technical Information of China (English)

    覃永和

    2014-01-01

    随着城市化进程的加快,城市给水管网改造工程也在不断的增多。本文主要就市政给水管网改造工程中的给水管道沟槽开挖及回填问题进行了研究,以提高给水管网改造工程的质量。%With the speeding up of urbanization, the reconstr-uction project of urban water supply pipeline network has in-creased. This article mainly carries on the exploration of the water supply pipe trench excavation and backfil problems in the municipal water supply pipeline network reconstruction en-gineering, in order to improve the quality of the water supply pipe network project.

  10. Environmental assessment of the reuse of municipal solid waste incineration bottom ash in quarry backfilling; Evaluation environnementale de la valorisation de machefers d'incineration d'ordures menageres en remplissage de carriere

    Energy Technology Data Exchange (ETDEWEB)

    Brons-Laot, G.

    2002-10-15

    The leaching behaviour of three different MSWI bottom ashes-based materials containing hydraulic binders is assessed in the conditions specified by the quarry backfilling application. An adapted approach methodology is applied: - physical, mineralogical and chemical characterizations of materials, - use of parametric tests to determine the effect of main scenarios factors on the release, - chemical modelling based on mineralogical and experimental leaching data with geochemical calculation codes, - chemical reaction / transport coupled modelling. The main results demonstrate that: - the batch and dynamic tests allow to obtain enough data to model and to predict the long term behaviour, - the chemical modelling of the solid / liquid equilibrium permits the determination of the chemical reactions involved and the prediction of pollutants solubilization in different chemical contexts, - the new materials (source term) present a low environmental impact in the conditions specified by the considered scenarios. (author)

  11. Development of On-line Monitoring System of Paste Backfill in the Goaf%采空区膏状充填体在线监测系统研制

    Institute of Scientific and Technical Information of China (English)

    张新国; 江宁; 江霞; 江兴元

    2011-01-01

    Gangue gream-body filling is the main technological means of realizing green mine and the best technology to solve the problem of mine under water body, building and rail, and on karst water body and to control surface subsidence, which used the surface movement observation to evaluate the filling effect in the past,but cycle is often longer,cost is higher and amount of labour is larger using the mood of surface movement observation. To this point, developed the on-line monitoring system of paste backfill in the goaf, based on the KJ216 monitoring system of plank pressure. Comprehensively evaluated the filling effect through long-term monitoring of long-term stress, deformation and hydration degree of paste backfill in the goaf. The practice showed that the system worked well on site.%作为实现“绿色开采”的主要技术手段和当前解决“三下一上”压煤问题,控制地表沉陷效果最好的矸石膏体充填开采技术,其充填效果评价过去一直采用的是地表岩移观测的方式,但是采用地表岩移观测的方式周期往往较长、费用较高、劳动量大.为此,基于K(J216顶板压力在线监测系统,研制了采空区膏状充填体在线监测系统.对采空区膏状充填体长期受力、变形和水化程度进行长期监测,综合评价充填效果.实践证明该系统现场应用效果良好.

  12. Study on Roadway Reinforcement Technique by Retractable Circular Support and Backfilling Grouting%可缩性圆形支架壁后充填注浆加固技术研究

    Institute of Scientific and Technical Information of China (English)

    李书民; 孙小岩; 张丰

    2011-01-01

    By analyzing the failure of traditional support by 36 U-shaped steel and wire mesh in the track dip in Changcun coal mine, it can be concluded that anchoring property is the primary cause for the low anchorage force and the poor effect of anchoring. Through analyzing the cross section of roadway and roadway reinforcement theory by backfilling grouting, roadway reinforcement technique by retractable circular support and backfilling grouting is put into effect This industrial practice demonstrates that this technique can solve the matter of deformation failure of soft rock roadway and can be used in other roadways with the similar situation in Changcun coal mine.%通过对常村煤矿轨道下山采用锚网(索)+ 36U型钢等常规支护形式失败的原因进行分析,得出巷道可锚性差是造成锚杆锚固力低和锚固效果差的主要因素;同时对巷道断面的选择和壁后充填注浆加固机理的分析,提出采用可缩性圆形支架壁后充填注浆加固技术.实践证明,采用可缩性圆形支架壁后充填注浆加固技术可有效解决软岩巷道变形的难题,为常村煤矿类似的巷道提供了一个有效的支护新途径.

  13. 平移变位模式下黏性土非极限主动土压力%Non-limit active earth pressure of cohesive backfill under translation mode

    Institute of Scientific and Technical Information of China (English)

    陈奕柏; 柯才桐; 曹雄; 高洪波

    2014-01-01

    针对经典朗肯与库仑土压力理论不能计算非极限土压力的事实。根据土体渐进破坏机理,结合已有文献对准主动状态下土体摩擦角、黏聚力发挥值与墙体位移关系的研究,采用水平层分析法,通过建立水平微元体基本受力平衡方程,推导出非极限状态下黏性土主动土压力分布的一阶微分方程式。在此基础上给出了土压力合力及其作用点位置计算式,相应简化条件下,所提公式能够简化为朗肯、库仑主动土压力公式。算例分析结果表明:理论计算值与实测值基本吻合,获得了平移变位模式下黏性土非极限土压力随位移变化的规律,对实际工程挡土墙的设计计算具有一定的参考价值。%The classic Rankine and Coulomb earth pressure theory can not be used to calculate the non-limit earth pressure.Based on the progressive rupture mechanism,and combined with the existing research on the relationships between the mobilized friction angle,cohesion force and the displacement of rigid retaining wall under inter-mediate active state,the horizontal slices analysis method is used to de-duce the first-order differential equations of the active earth pressure distribution of cohesive backfill un-der unlimited state by establishing the basic force equilibrium equations of horizontal element.Based on this,the formula of the earth pressure resultant force and its action point are given,which can be simpli-fied to Rankine’s and Coulomb’s earth pressure formula under corresponding simplified conditions.The result of example analysis show that the calculated and measured earth pressure match with each other, the change regulation of non-limit earth pressure of cohesive backfill under translation mode is obtained, and which can be used for the design of retaining wall in practical engineering.

  14. 全尾砂胶结充填作用机理实验及数值模拟研究%Experimental and numerical simulative study on mechanism for cemented backfill of unclassified tailings

    Institute of Scientific and Technical Information of China (English)

    吴姗; 王东旭; 郭利杰

    2014-01-01

    采用钢筒实验,得到了岩柱被不同配比的全尾砂胶结充填料包围受压时的强度特征曲线,根据曲线特征将受压过程分为了三个阶段,充填体配比为1∶6时,其单轴抗压强度增大了42.9%,表明充填体与围岩共同作用,可显著提高岩柱的抗压强度。以某铁矿采用充填法开采为例,采用FLAC数值模拟,当空场在充填30%~65%时,空场底板应力及矿柱的竖向应力集中区域均变小,充填体施压于围岩,对围岩起柔性支护的作用。研究结果表明,充填体对围岩的支护类型为被动支护,可有效限制围岩继续变形作用,使采场处于稳定状态。%With steel tube experiments ,compressive strength characteristic curves of rock pillars surrounded by different proportions of unclassified tailings backfill material were obtained ,which divided compression process into three stages .As filling body ratio of 1 ∶ 6 ,the uniaxial compressive strength increased by 42 .9% ,indicating that filling body and rock together ,can significantly increase the compressive strength of rock pillar .To one Iron Mine used to fill mining method example ,through the FLAC numerical simulation ,when the empty field in filling 30% to 65% ,stresses of empty field plate and the vertical stress concentration areas of pillar are smaller ,and backfill pressure on surrounding rock which could flexible supporting the surrounding rock .The results show that the type of supporting filling body is passive support ,which can effectively limit the continued deformation of surrounding rock and make stope at a stable state .

  15. 风积砂质高浓度胶凝充填材料性能与粉煤灰掺量关系分析%RELATIONSHIP BETWEEN ENGINEERING PERFORMANCE AND MIX PROPORTION OF FLY ASH FOR CEMENTED AND HIGH CONCENTRATION BACKFILL MATERIAL WITH WIND-BLOWN SAND AS AGGREGATE

    Institute of Scientific and Technical Information of China (English)

    王晓东

    2016-01-01

    In coal mining with backfill,backfill material dominates the benefit,efficiency and effect.In order to get the characteristics varying pattern of cemented and high concentration backfill material with wind-blown sand as aggregate,fly ash is selected as variables to test and analyze the characteristics varying pattern of backfill material with the mix proportion of fly ash.The results show that,as the mix proportion of fly ash increases in a proper range in backfill material,the compressive strength increases,the bleeding rate decreases in general,the layered degree declines by linear pattern,the coagulation time grows up by exponential pattern,and the slump is growing consecutively.But,with the higher mix proportion of fly ash,the compressive strength and slump will drop comparatively.When the mix proportion of fly ash is in proper range,the fly ash optimizes the particle size gradient of backfill material,and makes water and cement distribution uniform in backfill material.As a result,the strength characteristic and rheological performance can be improved.However,some characteristics will degenerate with higher mix proportion of fly ash.%充填材料是决定煤炭充填开采效益、效率、效果的最主要因素.为了掌握风积砂质高浓度胶凝充填材料的性能变化规律,本文以粉煤灰的质量掺入比作为变量,试验研究和理论分析了粉煤灰对该充填材料性能的影响规律.结果表明,粉煤灰的适量添加可以提高充填材料的强度,大掺量导致强度相对降低;泌水率随着粉煤灰掺量的增大总体上呈减小趋势,较大掺量试样泌水速率相对较低;分层度随着粉煤灰掺量的增大线性降低;凝结时间随着粉煤灰掺量增大呈现指数增大;坍落度总体上随粉煤灰掺量的升高而增大,但大掺量会使其出现相对降低.分析认为,适量粉煤灰的掺入,使风积砂质高浓度胶凝充填材料的颗粒粒度、水分分布和水泥分散均匀,而使材

  16. Study on the Comprehensive Technology of Presupporting of Roof and Walls in Tailings Back-fill Mining%尾砂充填采矿法采场预控顶护帮综合技术研究

    Institute of Scientific and Technical Information of China (English)

    毛市龙; 杨鹏; 蔡嗣经; 赵海云

    2001-01-01

    To increase the mining capacity of Hedong Gold Mine,study was made on a new mining method at the mine,that was tailings back-fill mining with roof presupporting and sublevel open stoping.The new method adopted roof presupporting,deep and medium hole blasting,LHD ore removal and tailings filling.One-time blasting of deep and medium holes was applied for the cut-through raise and smooth surface blasting was used for the stope periphery and upper wall to ensure the stope safety.To ensure a smooth test,comprehensive technical measures for roof and wall supporting were taken.%为提高河东金矿的采矿生产能力,我们在河东金矿进行了新的采矿方法——预控顶分段空场尾砂充填采矿方法的研究。该采矿方法采用采场预控顶技术,中深孔爆破,铲运机出矿,尾砂充填。采场切割井用中深孔一次爆破技术,采场周边及上盘则采用光面爆破技术,确保采场稳定。为确保试验顺利进行,在采场进行了综合的护顶和护帮技术措施。

  17. Preparation of Whole-tailings Paste Backfilling Material with High Steel Slag Content and None Clinker Aggregate%高掺量钢渣无熟料体系制备全尾砂胶结充填料

    Institute of Scientific and Technical Information of China (English)

    胡文; 倪文; 张静文

    2012-01-01

    Using steel slag and tailings as the main filling material,this paper determined the optimized ingredient of the backfilling materials by analyzing the strength characteristics and mortar fluidity. X-ray diffraction analysis ( XRD) and scanning electron microscopy ( SEM) were used to observe microstructure and hydration products. The experiments result indicated that mortar fluidity can of artesian cemented filling and the 28 d compressive strength is 3. 73 MPa which can satisfy the requirement of compressive strength for mine filling when the content of steel slag, desulphogypsum, and slag is 63%,12%,and 25%.%以钢渣和尾砂为主要充填材料,综合分析料浆流动性能和胶结充填体强度,确定胶结充填料的优化配比,并通过X射线衍射(XRD)和扫描电镜(SEM)微观分析观察其微观结构和水化产物.试验结果表明,当钢渣掺量为63%、脱硫石膏掺量为12%、矿渣掺量为25%时,料浆流动性能满足自流型胶结充填的流动性要求,充填体28 d抗压强度为3.73 MPa,满足矿山充填强度要求.

  18. 强夯+CFG桩复合地基在较厚回填土中的应用%Application of dynamic compaction and CFG pile composite foundation in the treatment of thick backfill

    Institute of Scientific and Technical Information of China (English)

    郑宇; 王天勇; 杨铮; 金灿国; 王建华; 张相勇; 董素芹

    2013-01-01

    The design and construction method of dynamic compaction plus cement fly-ash grave ( CFG) pile were introduced to enhance the bearing capacity of foundation and control foundation settlement in thick backfill by an engineering example. The standard penetration test and static loading test were carried out to topsoil compacted by dynamic compaction, and the bearing capacity of the composite foundation processed by dynamic compaction and CFG was detected by static loading test of single pile composite foundation and vertical compression static loading test of single pile. The results show that the bearing capacity and deformation of composite foundation are acceptable and can meet the requirement of related codes. Moreover, the engineering example shows this method can shorten the construction period and is economic, convenient and safe.%通过工程实例,介绍了在较厚回填土中采用强夯+ CFG桩复合地基进行地基处理以提高地基承载力及控制沉降的设计及施工方法.强夯后对表层土进行标准贯入试验及静力载荷试验,打入CFG桩后对复合地基承载力进行单桩复合地基静载荷试验与单桩竖向抗压静载荷试验检测,结果表明地基承载力与变形均满足规范要求.工程实例表明采用此方法可节约造价、缩短工期且安全可靠.

  19. 薄煤层泵送矸石充填开采矿压显现规律研究%Research on Strata Behavior in the Process of Gangue Backfill by Filling Pump in Thin Coal Seam

    Institute of Scientific and Technical Information of China (English)

    林惠立; 李洪; 刘庆龙

    2012-01-01

    为有力地配合北宿煤矿薄煤层泵送矸石充填开采工业性试验,更好的为今后薄煤层充填开采提供可靠依据,在C1661充填开采工作面进行了矿压观测,C1661充填开采工作面与1863采用全部垮落法开采工作面相比,顶底板移近量增大11.4%,单体支柱末阻力增大54.8%,液压切顶支架末阻力增加8.8%,支架活柱缩量增大5.7%,支护强度基本相等,来压强度减小28%,周期来压步距增大27.3%,初次来压步距增大12%。%In order to coordinate with industrial test of gangue backfill by filling pump in thin coal seam in Beisu Coal Mine, and provide a more reliable basis for fill mining in thin coal seam in the future, strata control observation was conducted in C1661 working face. And com- pared with 1863 face which was mined by caving method, convergence between roof and floor increased by 11.4%, terminal resistance of sin- gle prop increased by 54.8%, terminal resistance of hydraulic support increased by 8.8%, expansion amount of hydraulic support increased by 5.7%, ground pressure strength decreased by 5.7%, periodic weighting length increased by 27.3%, first weighting interval increased by 12%, and the strength of support was basically the same.

  20. Energy storage and heat transfer characteristics of ground heat exchanger with phase change backfill materials%相变材料回填地埋管换热器蓄能传热特性

    Institute of Scientific and Technical Information of China (English)

    杨卫波; 孙露露; 吴晅

    2014-01-01

    points for the application of GSHP. In this paper, a new type of GHE with phase change backfill materials was presented to change its thermal response characteristics and heat transfer performance. Theoretically, the thermal interference radius of soil can be reduced by the phase change of phase change materials (PCM), and the energy storage performance of GHE can be improved due to the release of phase change latent heat. In order to further investigate the influences of solid-liquid phase change of phase change backfill materials on energy storage and heat transfer performance of GHE, a quasi-three dimensional heat transfer model with phase change was developed for the vertical U-bend GHE, which couples the one-dimensional fluid heat transfer in vertical direction with the two-dimensional soil transient heat transfer in level. The model was discreted by the control volume method and solved by the apparent heat capacity method. Based on the numerical solution of the model, the influences of solid-liquid phase change of PCM on energy storage performance of GHE and thermal response characteristics of soil temperature around GHE were analyzed for winter and summer mode respectively. The effects of phase change temperature and phase change latent heat of PCM on the thermal diffusivity and energy storage characteristics of GHE were discussed. The results indicate that under same conditions, the soil temperature variations trend is slow down and the thermal interference region is reduced due to the heat extraction and release during the phase change of PCM. The heat exchange performance of GHE can be evidently improved by backfilling materials with low and high phase change temperature for summer and winter respectively. At the same time, the energy storage performance can be enhanced by grouting the materials with large latent heat. The study is significant for releasing the thermal interference region of soil and improving the energy storage and heat transfer performance of

  1. Research on the Optimal Roof-contacted Filling Ratio of Upward Drift Stoping with Backfill%上向进路充填采矿法最佳充填接顶率研究

    Institute of Scientific and Technical Information of China (English)

    刘发平; 陈宪龙

    2015-01-01

    In the process of upward drift stoping with backfill in Baixiangshan iron mine,the roof-contacted effect is not perfect,the roof-contacted filling ratio of the mine is researched.The MIDAS /GTS finite element software is applied to analyze the stress condition of the first-step approach stope cemented pillars that have different roof-contacted filling ratio when the second-step approach stope are conducted. Besides that,the security and stability of the cemented pillars are evaluated,and the different roof-con-tacted filling ratios are analyzed in depth so as to determine the optimal roof-contacted filling ratio.when the second-step approach stope are conducted,the tensile safety coefficient of the first-step approach stope cemented pillars with 80%roof-contacted filling ratio is 2.03,the compressive strength factor of safety is 1.28,the synthesized safety coefficient is 1.60.The above research results can provide a brand-new di-rection for the other mines to improve the roof-contacted filling ratio scientifically.%为解决白象山铁矿在上向进路充填采矿过程中充填接顶效果不理想的问题,对该矿山的充填接顶率进行了研究。运用 MIDAS /GTS 有限元软件模拟分析二步进路采场开采时,一步进路采场不同充填接顶率胶结矿柱受力状况,并对胶结矿柱安全稳定性进行评价,对不同充填接顶率进行分析,从而确定最佳充填接顶率。当二步进路采场开采时,一步进路采场80%充填接顶率胶结矿柱抗拉安全系数为2.03,抗压安全系数为1.28,综合安全系数为1.6,为该矿上向进路充填法的最佳充填接顶率。该研究为其他矿山科学提高充填接顶率提供了一种全新的指导方向。

  2. Research on Backfilling Friction Stir Spot Welding of LY12 Al Alloy%LY12铝合金回填式搅拌摩擦点焊工艺研究

    Institute of Scientific and Technical Information of China (English)

    王朗; 王敏; 郭立杰

    2013-01-01

    采用回填式搅拌摩擦点焊对1mm厚的LY12铝合金薄板进行焊接,研究单参数对接头拉剪力的影响.结果表明,在其他条件不变时,套下压时间影响接头U型区域的宽度,套下压时间为3.2s时,接头的拉剪力达到最大值;其他参数对U型区域深度产生影响;回填时间为0.4s、旋转速度为1500r/min、下压深度为1.1mm、焊接压力为23 MPa时接头的拉剪力均达到最大值.正交试验工艺优化结果表明,最佳的工艺参数组合为:套下压时间为3.6s、回填时间为0.9s、旋转速度为2400r/min、下压深度为1.1mm、压力为24 MPa.对最佳参数组合下的接头进行金相分析,发现接头区域分为三个部分:混合区、热影响区和母材.%The backfilling friction stir spot welding to weld 1 mm-thick LY12 aluminum alloy plate was adopted, and the single parameter on the effect of joint's shear load was investigated. The results show that when other conditions remain unchange, pressure time affect the width of the joint area. When pressure time is 3.2 s, joint's shear load reach maximum; other parameters affect the depth of the joint area; when refilling time is 0.4 s, rotating speed is 1500 r/min, depth is 1.1 mm, pressure is 23MPa, joint's shear load reaches maximum. After the optimization of process parameters, the orthogonal test results show that the best process parameter combination is pressure time 3.6s, refilling time 0.9s, rotating speed 2400 r/m, depth 1.1 mm, pressure 24 MPa. The metallographic analysis of the welded joint at the best parameters found that the joint area is divided into three parts: mixed zone, heat affected zone and mother material.

  3. Erosion and deposition by supercritical density flows during channel avulsion and backfilling: Field examples from coarse-grained deepwater channel-levée complexes (Sandino Forearc Basin, southern Central America)

    Science.gov (United States)

    Lang, Jörg; Brandes, Christian; Winsemann, Jutta

    2017-03-01

    Erosion and deposition by supercritical density flows can strongly impact the facies distribution and architecture of submarine fans. Field examples from coarse-grained channel-levée complexes from the Sandino Forearc Basin (southern Central America) show that cyclic-step and antidune deposits represent common sedimentary facies of these depositional systems and relate to the different stages of avulsion, bypass, levée construction and channel backfilling. During channel avulsion, large-scale scour-fill complexes (18 to 29 m deep, 18 to 25 m wide, 60 to > 120 m long) were incised by supercritical density flows. The multi-storey infill of the large-scale scour-fill complexes comprises amalgamated massive, normally coarse-tail graded or widely spaced subhorizontally stratified conglomerates and pebbly sandstones, interpreted as deposits of the hydraulic-jump zone of cyclic steps. The large-scale scour-fill complexes can be distinguished from small-scale channel fills based on the preservation of a steep upper margin and a coarse-grained infill comprising mainly amalgamated hydraulic-jump zone deposits. Channel fills include repeated successions deposited by cyclic steps with superimposed antidunes. The deposits of the hydraulic-jump zone of cyclic steps comprise regularly spaced scours (0.2 to 2.6 m deep, 0.8 to 23 m long) infilled by intraclast-rich conglomerates or pebbly sandstones, displaying normal coarse-tail grading or backsets. These deposits are laterally and vertically associated with subhorizontally stratified, low-angle cross-stratified or sinusoidally stratified sandstones and pebbly sandstones, which were deposited by antidunes on the stoss side of the cyclic steps during flow re-acceleration. The field examples indicate that so-called spaced stratified deposits may commonly represent antidune deposits with varying stratification styles controlled by the aggradation rate, grain-size distribution and amalgamation. The deposits of small-scale cyclic

  4. 充填采煤面收作眼围岩变形控制技术研究%Study on surrounding rock deformation control of finishing cut in backfilling mining face

    Institute of Scientific and Technical Information of China (English)

    李猛; 张吉雄; 巨峰; 刘世伟; 曹远威

    2016-01-01

    To solve support dismantling problems caused by big cross-section finishing cut and to con-trol strata movement in solid backfilling mining face,this paper has adopted the theoretical analysis and FLAC3D numerical simulation method to study laws of surrounding rock deformation and failure mechanism of finishing cut. Then the comprehensive support technology of anchor (rope) mesh rein-forcement, temporary support of“#” type wooden cogs filled with grouting and permanent support of finishing cut grouting have been put forward. In addition,the supporting parameters of concrete pier consisting of wooden cogs has been optimized. The results have shown that when the reasonable spac-ing of concrete pier is 2 000 mm, the pier bearing capacity can satisfy the requirement of temporary support. The technology has been applied in Yangzhuang coal mine of Huaibei Coal Mining Group, and the accumulated sink value about 80 m above the working face has been only 60 mm, which has indi-cated that surrounding rock deformation control of finishing cut is well controlled.%为解决充填采煤面收作眼断面大、难支护及撤架困难等难题,采用理论分析和FLAC3D数值模拟方法研究了收作眼围岩变形破坏规律,提出了滑架通道锚(索)网加强支护、“井”字型木垛封闭灌浆的临时支护和收作眼空间注浆永久支护相结合的围岩控制技术方法,优化设计了“井”字型木垛形成的混凝土墩柱支护参数。结果表明:混凝土墩柱间排距均为2000 mm时,墩柱承载能力可满足临时支护的要求。该技术在淮北矿业集团杨庄煤矿进行了应用,通过监测工作面上方垂距约为80 m的巷道变形,其巷道累积下沉量仅为60 mm,表明收作眼围岩变形控制效果显著。

  5. 煤矿膏体充填材料性能随龄期变化的试验研究%Experimental study on the changes of coal paste backfilling material performance during hydration process

    Institute of Scientific and Technical Information of China (English)

    戚庭野; 冯国瑞; 郭育霞; 张玉江; 任昂; 康立勋; 郭军

    2015-01-01

    Coal paste backfilling material (CPBM) is composed of coal gangue, flyash, ordinary port-land cement and tap water. In order to identify the properties of each raw material, the mineral composi-tion, chemical composition of coal gangue flyash have been analyzed;the compressive strength, porosi-ty and electrical resistivity have been studied at different curing times. The samples taken from curing time of 7 d, 14 d and 28 d, have been evaluated for their mineral composition and microstructure. The law of CPBM property with increasing curing time has been analyzed, and the correlation among the compressive strength, porosity, resistivity and hydrating process has also been deeply discussed. The results indicate that firstly, with the curing time increasing, compressive strength and electrical resistiv-ity are increasing, while porosity and small pore content are reducing. Secondly, hydrated and poz-zolanic reaction occur in the change of CPBM property, with calcium hydroxide, C-S-H gel and ettring-ite being the reaction products. The calcium hydroxide crystal is only found at the curing time of 7 d, not at 14 d and 28 d, and the types and quantities of ettringite crystal at 28 d are more than at 7 d and 14 d. The crystal structure of 28 d presented more slender with the curing time increasing. Thirdly, the hy-drated and pozzolanic reaction are the two primary reasons causing the change of performance of CPBM strength with the change of curing time. Moreover,there is some interrelation between the per-formances.%煤矿膏体充填材料(CPBM)由煤矸石、粉煤灰、水泥和水为原料混合而成。为了了解各原料的性质,对煤矸石和粉煤灰的矿物组成、化学成分进行了分析,对固定配比CPBM在不同龄期的抗压强度、孔隙率和电阻率性能进行了研究,测定和观测7,14和28 d的矿物成分和微观结构;针对抗压强度、孔隙率、电阻率和水化过程之间存在的相关性进行了

  6. 西石门矿地下尾矿库安全回填项目环境影响及对策%Impacts of Backfilling Mine Tailings on Environment and a New Approach to Reduce Adverse Impacts of Xishimen Mine

    Institute of Scientific and Technical Information of China (English)

    钱金平

    2001-01-01

    The disposal of tailings is a key technical core for mining. Xishimen mine is adopting advanced technology for treating subterranean tailings by secondary concentration and dehydration. The treated tailings of mine could then be safely backfilled into underground, facilitating reducing adverse environmental impacts of mining.%介绍了西石门铁矿尾矿安全回填工程的基本情况,分析了地下尾矿库的库体安全性及环境影响并提出了相关对策。结论认为,西石门矿采用地下尾矿库技术,最大程度地减少了地面尾矿库对环境产生的不良影响,有利于尾矿库区的生态恢复。

  7. 露天坑回填土石混合体的渗流特性及颗粒元数值分析%PERMEABILITY CHARACTERISTICS OF ROCK AND SOIL AGGREGATE OF BACKFILLING OPEN-PIT AND PARTICLE ELEMENT NUMERICAL ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    高谦; 刘增辉; 李欣; 李俊华

    2009-01-01

    Combining with the backfilling(RSA) engineering in stope III of Sijiaying open-pit to underground iron mining of Hebei Iron and Steel Group Mining Co.,Ltd.,the permeability of rock and soil aggregate(RSA) is studied systematically by laboratory test,in-situ experiment and numerical simulation. The results show that there is an approximation linear relationship between the permeability coefficient of RSA and its non-uniform degree,and the permeability coefficient of RSA is directly proportional to the void ratio. The permeability of RSA can be reduced effectively by controlling the gradation of particle size of waste rock backfilled and reducing the average particle size and non-uniformity reasonably. The influence order to the seepage discharge of RSA is determined by particle element numerical orthogonal tests. The relationship formulas of the effects of four factors(thickness of back-packing,head pressure,porosity,particle diameter) on the seepage are obtained by quadratic stepwise regression analysis,and it can provide a calculation tool for impermeability of RSA.%针对土石混合体的渗透性,结合唐钢司家营铁矿III采场露天转井下的回填土石混合体工程,采用室内试验、现场试验和数值模拟的方法对其进行系统地研究,得出土石混合体的渗透系数与其非均匀度近似存在线性关系,渗透系数与混合土的孔隙比成正比;合理控制回填废石的粒径级配,降低平均粒径与非均匀度,可有效降低回填土石混合体的渗透性.通过颗粒元数值正交试验确定对土石混合体的渗流量影响顺序,并二次逐步回归出回填层厚度,水头压力,孔隙率,平均粒径对渗流量的关系式,为土石混合体防渗抗渗提供计算工具.

  8. 软基地段明洞不均匀沉降后的回填安全性及加固措施研究%Study on Backfilling Safety and Reinforcement Technology of Open-cut Tunnel with Differential Settlement in Soft Ground

    Institute of Scientific and Technical Information of China (English)

    程正明

    2012-01-01

    Stress-structure model is used to study the backfilling safety and reinforcement technology of the open-cut sec- tion of Xiang' an sub-sea tunnel with differential settlement in soft ground. The study results show that the predicted val- ue of the differential settlement of the open-cut tunnel is 80 mm, and the minima safety coefficient is 2. l 1. Although the structural safety coefficient meets the requirements, the differential settlement may induce cracks, dislocations and water seepage, which has serious effects on the operation function and durability of the tunnel. Countermeasures, including re- inforcing the arch feet by large-diameter root piles, reinforcing the invert by TSS steel pipe grouting, crack sealing by grouting, and backfilling symmetrically and layer by layer, are proposed. The monitoring results show that the predicted settlement coincides well with the measured settlement, the reinforcement has achieved good effect, and the displace- ment has been brought under effective control.%为分析厦门翔安海底隧道软基地段明洞不均匀沉降后的回填安全性和加固措施,采用荷载一结构模型进行研究。综合研究结论如下:1)填土后明洞差异沉降预测值为80mm,最小安全系数为2.11,虽然结构安全系数满足要求,但不均匀沉降将导致裂缝、错台及渗水,严重影响隧道使用功能和耐久性;2)提出采用大孔径树根桩加固明洞衬砌两侧拱脚,TSS钢花管注浆加固仰拱中央,灌浆封闭裂缝,分层对称填土的综合处理方案;3)经现场监测验证,预测沉降规律与实测吻合较好,加固措施成效良好,变形得到治理。

  9. 30 CFR 715.14 - Backfilling and grading.

    Science.gov (United States)

    2010-07-01

    ... configuration and the outslopes of the plateau shall not exceed 1v:2h, except where engineering data... used to meet the requirements of paragraph (j) of this section. (f) Definition of thin and thick... protect against upward migration of salts, exposure by erosion, to provide an adequate depth for...

  10. Load Bearing and Deformation Characteristics of Granular Spoils under Unconfined Compressive Loading for Coal Mine Backfill

    Directory of Open Access Journals (Sweden)

    Guodong Li

    2016-01-01

    Full Text Available The load bearing capacity and deformation response of granular spoils under uniaxial compression are numerically and experimentally investigated, aiming to shed light on the performance of back filled waste spoils while controlling ground subsidence after coal extraction. In numerical study, the particles are assembled in PFC commercial code in light of the digitized real shape of spoils with image technique, which is proved to be consistent with the physical test. The results from numerical and laboratory experiments showed that the complete compressive process of spoils tended to have spatial and temporal characteristics. The load-strain curves of investigated specimens could be divided into three stages (stage I, rearranging stage; stage II, breaking stage; stage III, consolidating stage and three zones (I, rearranging zone; II, interlocking zone; III, consolidated zone from outside to inside. During stage I, the load increasing rate of smaller spoils is relatively low, but it increases faster than larger ones in stages II and III. In addition, spoils with Talbot’s gradation are greater than single gradations. The magnitude of the density in consolidated zone is maximum, indicating that it is the main part holding the overlying strata weight.

  11. Selection of Backfill Materials for the Disposal of High Level Radioactive

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    2.5SelectionofBackfillMaterialsfortheDisposalofHighLevelRadioactiveWasteZhaoXin;GaoYuan;ThangYingjie;WeiLiansheng;LinZhangjiI...

  12. Geochemical studies of backfill aggregates, lake sediment cores and the Hueco Bolson Aquifer

    Science.gov (United States)

    Thapalia, Anita

    This dissertation comprises of three different researches that focuses on the application of geochemistry from aggregates, lake sediment cores and Hueco Bolson Aquifer. Each study is independent and presented in the publication format. The first chapter is already published and the second chapter is in revision phase. Overall, three studies measure the large scale (field) as well as bench scale (lab) water-rock interactions influenced by the climatic and anthropogenic factors spans from the field of environmental geology to civil engineering. The first chapter of this dissertation addresses the chemical evaluation of coarse aggregates from six different quarries in Texas. The goal of this work is to find out the best geochemical methods for assessing the corrosion potential of coarse aggregates prior to their use in mechanically stabilized earth walls. Electrochemical parameters help to define the corrosion potential of aggregates following two different leaching protocols. Testing the coarse and fine aggregates demonstrate the chemical difference due to size-related kinetic leaching effects. Field fines also show different chemistry than the bulk rock indicating the weathering impact on carbonate rocks. The second chapter investigates zinc (Zn) isotopic signatures from eight lake sediment cores collected both from pristine lakes and those impacted by urban anthropogenic contamination. Zinc from the natural weathering of rocks and anthropogenic atmospheric pollutants are transported to these lakes and the signatures are recorded in the sediments. Isotopic analysis of core samples provides the signature of anthropogenic contamination sources. Dated sediment core and isotopic analysis can identify Zn inputs that are correlated to the landuse and population change of the watersheds. Comparison of isotopic data from both pristine and urban lake sediment core also serves as an analog in other lake sediment cores in the world. The third chapter studies on Hueco Bolson Aquifer that an important sources of water in the El Paso/Cd. Juraez metroplex. To delineate the boundary between fresh and brackish water from the northern Hueco Bolson Aquifer, we utilize an integrative geochemical, geophysical, and sedimentological approach. The goal of this study is to use geophysical well-log analysis and the water chemical analysis for identifying the changes in the quality of the groundwater. A detailed microgravity survey is utilized to explore the subsurface geological structures that control the conduits and/or barriers of groundwater flow. A detailed geochemical analysis of aquifer samples provide salinity of groundwater that will complement to the subsurface structures obtained from the geophysical study. This fundamental research in developing methods from an integrated approach to estimate aquifer quality can be used as an analog for similar studies in other arid regions.

  13. Draft Test Plan for Brine Migration Experimental Studies in Run-of-Mine Salt Backfill

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Amy B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stauffer, Philip H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reed, Donald T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boukhalfa, Hakim [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Robinson, Bruce Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-02

    The primary objective of the experimental effort described here is to aid in understanding the complex nature of liquid, vapor, and solid transport occurring around heated nuclear waste in bedded salt. In order to gain confidence in the predictive capability of numerical models, experimental validation must be performed to ensure that (a) hydrological and physiochemical parameters and (b) processes are correctly simulated. The experiments proposed here are designed to study aspects of the system that have not been satisfactorily quantified in prior work. In addition to exploring the complex coupled physical processes in support of numerical model validation, lessons learned from these experiments will facilitate preparations for larger-scale experiments that may utilize similar instrumentation techniques.

  14. Mineralogical, chemical and physical study of potential buffer and backfill materials from ABM. Test Package 1

    Energy Technology Data Exchange (ETDEWEB)

    Kumpulainen, S.; Kiviranta, L. (B and Tech Oy, Helsinki (Finland))

    2011-07-15

    In the ABM experiment, three test packages with centre steel heaters surrounded by stacks of compacted bentonite rings of various clay materials were placed in boreholes in Aespoe tunnel. The first parcel was saturated with Aespoe groundwater and the heater was turned on simultaneously with the start of saturation. This parcel was excavated 30 months after its installation. Chemical, mineralogical and physical properties of the MX-80, Dep-CaN, Asha and Friedland clay samples from the ABM parcel 1 were analysed and compared to reference samples. Chemical analyses (ICP-AES, C, CO{sub 3}, S, water soluble SO{sub 4}, Fe2+/Fe3+), exchangeable cation analyses, mineralogical analyses (XRD, FTIR) and selective extractions were used to determine changes in the chemistry and mineralogy of ABM materials. Swelling pressure and hydraulic conductivity measurements were performed both for extracted samples and for ground and recompacted samples. Major changes in exchangeable cation composition were observed in all samples originating from equilibration with Aespoe groundwater and interactions with equilibrated waters from neighbouring block materials. Some minor changes in chemical composition were observed as well. Increases in soluble sulphate content in the vicinity of the heater were thought to result from precipitation of sulphate salts. Decreases in sodium content and increases in calcium content were ascribed to changes in exchangeable cations. Interaction with iron was observed to occur only in the close vicinity (first few mm) of the heater. No significantly measureable change in mineralogical composition was seen in any of the studied materials. Extracted Dep-CaN samples showed a slight decrease in swelling pressure. However, when the material was ground, compacted and measured again the swelling pressure was fully recovered. No related change in hydraulic conductivities was observed. (orig.)

  15. Cemented backfilling technology with unclassified tailings based on vertical sand silo

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A new technology characterized by rapidly non-mechanical settlement of unclassified tailings was developed based on a large number of tests,and dynamic settlement and continual slurry preparation without hardening in vertical sand silo were eventually realized by the addition of an effective flocculating agent (NPA).The results show that the sedimentation velocity of interface between unclassified tailings and water after the addition of NPA increases by 10-20 times,the sedimentation mass fraction of unclassified tailings at the bottom of vertical sand silo is up to 64%,the solid particle content of waste water meets the national standard,and the side influences of NPA can be removed by the addition of fly ash.The industrial test result shows that the system,the addition manner and the equipments are rational,and the vertical sand silo is used efficiently.This developed system is simple with large throughput,and the processing cost is 2.2 yuan(RMB)/m3,only 10%-20% of that by mechanical settlement.

  16. Laboratory Study on the Use of Tire Shreds and Rubber-Sand in Backfilled and Reinforced Soil Applications

    OpenAIRE

    Bernal, Andres; Lovell, C. W.; Salgado, Rodrigo

    1996-01-01

    Millions of scrap tires are discarded annually in the United States, the bulk of which are currently landfilled or stockpiled. This consumes valuable landfill space, or, if improperly disposed, creates a fire hazard and provides a prolific breeding ground for rats and mosquitoes. The use of tire shreds as lightweight fill material can sharply reduce the tire disposal problem. The present study, based on laboratory testing and numerical modeling examines the feasibility of incorporating tire s...

  17. Comparative Study of Segment Backfill Materials and Segment Attitude%管片壁后填充材料与管片姿态对比研究

    Institute of Scientific and Technical Information of China (English)

    陈建斌

    2016-01-01

    以神华神东补连塔煤矿二号辅运平硐工程为基础,在混凝土管片壁后分别填充混凝土、豆粒石、单液浆、双液浆等四种材料后,对管片的沉降和扭转进行了对比研究。结果表明填充材料为混凝土时管片的姿态控制最佳。%Based on the second subsidiary transport adit project of Shenhua Shendong Bulianta coal mine,this paper stud-ies the segment settlement and torsion after the concrete segments are filled with concrete,pea gravel,single-liquid grou-ting,double-liquid grouting respectively.The results show that the controlling of segment attitude is the best when filled by the concrete.

  18. 关于管道沟槽回填处理的体会%On the experience in backfill treatment of pipeline trench

    Institute of Scientific and Technical Information of China (English)

    王峰

    2010-01-01

    通过工程实例,提出管道沟槽回填的方案,阐述了施工中的材料要求、施工方式、检测方法、对回填的质量控制措施,以期指导市政排水管道建设工程,保证施工质量.

  19. Electrophoretically active sol-gel processes to backfill, seal, and/or densify porous, flawed, and/or cracked coatings on electrically conductive material

    Science.gov (United States)

    Panitz, Janda K.; Reed, Scott T.; Ashley, Carol S.; Neiser, Richard A.; Moffatt, William C.

    1999-01-01

    Electrophoretically active sol-gel processes to fill, seal, and/or density porous, flawed, and/or cracked coatings on electrically conductive substrates. Such coatings may be dielectrics, ceramics, or semiconductors and, by the present invention, may have deposited onto and into them sol-gel ceramic precursor compounds which are subsequently converted to sol-gel ceramics to yield composite materials with various tailored properties.

  20. Electrophoretically active sol-gel processes to backfill, seal, and/or densify porous, flawed, and/or cracked coatings on electrically conductive material

    Energy Technology Data Exchange (ETDEWEB)

    Panitz, J.K.; Reed, S.T.; Ashley, C.S.; Neiser, R.A.; Moffatt, W.C.

    1999-07-20

    Electrophoretically active sol-gel processes to fill, seal, and/or density porous, flawed, and/or cracked coatings on electrically conductive substrates. Such coatings may be dielectrics, ceramics, or semiconductors and, by the present invention, may have deposited onto and into them sol-gel ceramic precursor compounds which are subsequently converted to sol-gel ceramics to yield composite materials with various tailored properties. 6 figs.

  1. 无砂大孔混凝土在台背回填中的应用%The Application of the Non-sand-and-Big-Hole Concrete to Road Backfill

    Institute of Scientific and Technical Information of China (English)

    狄宝才; 曲义萍

    2007-01-01

    以西林河大桥为工程背景,对无砂大孔混凝土的配合比进行了设计,对无砂大孔混凝土的密度、强度、透水性等三方面路用性能进行了试验研究,提出了行之有效的施工方案,并对无砂大孔混凝土在台背回填中的综合效益进行了分析.

  2. 磷石膏基胶结材固结磷尾矿性能及浸出特征%Properties and leaching characteristics of cemented phosphate tailings backfill with phosphogypsum-based cementation material

    Institute of Scientific and Technical Information of China (English)

    黄绪泉; 赵小蓉; 唐次来; 冯思源; 杜奕锦; 陈伯宇

    2016-01-01

    以磷石膏基材料代替水泥作为磷尾矿充填胶结材,研究了磷尾矿固结浆体和硬化体性能、浸出液污染特性和固结机理.结果表明,在同样条件下,磷石膏基材料固结磷尾矿浆体比水泥泌水量要小、浆体流动性能更优;磷石膏基材料胶结磷尾矿硬化体除3d抗压强度略低外,其他龄期的强度是水泥的1.21~1.95倍.3d之后,磷石膏基材料和水泥胶结尾矿硬化体浸出液总磷含量基本相近,但pH明显远低于水泥,总磷也低于污水综合排放标准限值,对环境危害低.硬化体SEM和XRD分析发现,磷石膏基材料水化生成的水化硅酸钙凝胶、针状钙矾石晶体和磷尾矿中白云石、含磷矿物生成的透钙磷石等,是整个磷尾矿固结硬化体具有较高强度、较低总磷含量和pH值主要原因.该研究表明,磷石膏基材料固化磷尾矿比水泥更有应用前景.%Cementation mechanism and properties,which include the cementation slurry and a hardened specimen,along with the contamination properties of liquid leaching of phosphate tailings cementation with a phosphogypsum-based material (PM),as opposed to cement,were investigated in this study.The results showed that the bleeding quantity of a phosphate tailing cementation slurry with PM was smaller,and that the slurry fluidity with PM was better than that with cement under the same conditions.The compressive strength of the phosphate tailing hardened specimen with PM with different hydration age was 1.21 to 1.95 times higher than that with cement,except for a 3 day hydration.After a 3 day hydration period,the total phosphorus in the liquid leaching of hardened specimens with PM and cement was similar,but the pH with PM was far lower than that with cement.The total phosphorus in liquid leaching with PM was below the integrated wastewater discharge standard of China,which implied that the liquid leaching of hardened specimens with PM was safe to the environment.SEM and XRD analyses revealed that the main compositions of cemented phosphorus tailing included hydrated calcium silicate gels and acicular ettringite crystals,which were generated from the hydration of PM,dolomite,and brushite crystals,all of which contributed to higher compressive strength,lower total phosphorus,and pH.This finding suggests that PM is a more promising material for phosphate tailings cementation than cement.

  3. Study on application of argil fly-ash concrete to highway-bridge abutment-backfill%陶粒粉煤灰混凝土在桥涵台背回填中的应用研究

    Institute of Scientific and Technical Information of China (English)

    葛折圣; 黄晓明; 张肖宁; 高俊合

    2006-01-01

    通过材料性能试验、土工离心模型试验和数值计算,研究陶粒粉煤灰混凝土的物理力学性能及其在桥涵台背回填的应用效果.首先,通过材料性能试验研究不同配合比的陶粒粉煤灰混凝土的物理力学性能;其次,通过土工离心模型试验和数值计算研究陶粒粉煤灰混凝土用作桥涵台背回填材料时,作用于台背的土压力和回填体的变形特性.研究发现:陶粒粉煤灰混凝土具有轻质、高强度、高模量和易施工等诸多优点;陶粒粉煤灰混凝土回填体作用于台背的土压力明显小于常规回填材料;回填区和地基的沉降变形亦明显小于其他材料.结果表明:陶粒粉煤灰混凝土作为台背回填材料具有明显的优越性,是一种值得推荐的桥涵台背回填材料.

  4. Application of Backfill and Water Shutoff Technology in Annular Space of Freezing Pipe and Quality Control%冻结管环形空间充填堵水技术应用与质量控制

    Institute of Scientific and Technical Information of China (English)

    王楷

    2014-01-01

    大海则矿井区域属于白垩系和侏罗系煤系地层,含水软岩抗压强度较低,煤矿立井采用全深冻结法施工.文章结合工程实际介绍了冻结管环形空间充填堵水技术在西部含水软岩地层中应用的必要性和实施概况.同时,提出了若干项技术措施及性质要点来对实施质量进行控制,保证井筒建设与生产的安全.整个泥浆置换工序实施顺利,达到预期效果.

  5. 石灰浆对膏体充填料浆性能的影响研究%Study on the Influence from Lime Mortar to Property of Backfill Paste Filling Slurry

    Institute of Scientific and Technical Information of China (English)

    黄吉荣; 胡万宏; 容宇

    2010-01-01

    介绍了对现有膏体充填工艺所进行的取消石灰浆作添加剂的可行性实验研究.研究了不同浓度、不同石灰添加量对各龄期单轴抗压强度的影响.认为添加石灰对于提高试块3d强度具有较显著的作用,但28d强度大大降低;石灰添加量为6.4%时,28d强度仅为不添加的50%左右,认为取消石灰作为膏体添加剂具有积极意义.

  6. Steel slag-based cementing agent for tailings backfilling of iron mine%铁矿山尾矿回填用钢渣基胶结剂的研究

    Institute of Scientific and Technical Information of China (English)

    周超; 李媛; 常立忠; 范鼎东; 王佳

    2016-01-01

    本研究以转炉钢渣为主要成分,寻求针对铁矿山尾矿浆的胶结剂;从钢渣的固化机理人手,选择水泥熟料、元明粉、纯碱等为激发剂.经过优化实验发现,当胶结剂组成为钢渣63.16%、水泥熟料24%、元明粉6%、纯碱2%、烧碱1.5%、硫酸铝3.3%和三乙醇胺0.04%时,钢渣基胶结剂和铁尾矿混合后的3d、7d和28d的抗压强度分别能达到0.65MPa、1.03MPa和1.58MPa,达到铁矿山矿洞尾矿回填的要求.

  7. FCC化学填充材料充填技术在高冒区中的应用%FCC Chemistry Packing Material Backfill Technology in Gao Maoqu Application

    Institute of Scientific and Technical Information of China (English)

    倪国峰

    2010-01-01

    杜儿坪煤矿二采区对生产运输以及行人带来安全隐患,影响巷道的长期使用及整个工程进度,为了保证安全,快速高效防止瓦斯的积聚以及煤层的脱落,决定采用FCC化学填充材料进行填充治理.

  8. 40 CFR 144.81 - Does this subpart apply to me?

    Science.gov (United States)

    2010-07-01

    ... fresh water; (8) Sand backfill and other backfill wells used to inject a mixture of water and sand, mill... gas production) used to inject fluids into a non-oil or gas producing zone to reduce or eliminate... geothermal energy for heating, aquaculture and production of electric power; (12) Wells used for...

  9. Geochemical assessment of nuclear waste isolation. Report of activities during fiscal year 1982

    Energy Technology Data Exchange (ETDEWEB)

    1983-07-01

    The status of the following investigations is reported: canister/overpack-backfill chemical interactions and mechanisms; backfill and near-field host rock chemical interactions mechanisms; far-field host rock geochemical interactions; verification and improvement of predictive algorithms for radionuclide migration; and geologic systems as analogues for long-term radioactive waste isolation.

  10. Environmental Assessment, Wing Infrastructure Development Outlook (WINDO) Implementation Plan (FY 04-06). Volume 2, Beale Air Force Base, California

    Science.gov (United States)

    2005-08-01

    from the scour hole around the control tower and backfill with a “ flowable ” material. An engineering backfill such as low-strength material might be...aquifer or well capacity, water quality, surrounding geologic composition , and recharge rate. Floodplains are areas of low-level ground present along

  11. Application of Open-cut and Back-fill Method in Karst Ground of Highway and Its Applicable Conditions%明挖回填法在处治公路路基岩溶地基中的应用及其适用条件

    Institute of Scientific and Technical Information of China (English)

    曾重庆

    2005-01-01

    如何合理选择路基岩溶的处治方案对于保证工程质量、控制工程投资和施工工期具有重要的现实意义.岩溶地基的非开挖法处治方案已广为工程建设者所接受,对明挖回填方案似乎为工程界部分人员所忽视.介绍了明挖回填方案对路基岩溶的处治效果及其适用条件.

  12. The repair of ground cover of Bolivia-Brazil gas pipeline near Paraguay River crossing, in a swamp soft soil region, using geo synthetics reinforced backfilling; Reparo da cobertura do gasoduto Bolivia-Brasil junto ao Rio Paraguai, em trecho com solo mole, utilizando aterro reforcado com geosinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Cesar Augusto; Jorge, Kemal Vieira; Bechuate Filho, Pedro [TBG - Transportadora Brasileira Gasoduto Bolivia Brasil S.A., Campo Grande, MS (Brazil). Gerencia Regional Centro Oeste (CRGO); Teixeira, Sidnei H.C. [Geohydrotech Engenharia S.C. Ltda., Braganca Paulista, SP (Brazil)

    2005-07-01

    TBG - Transportadora Gasoduto Bolivia-Brasil S.A, executes routine maintenance works at the Gas Pipeline Right of Way, seeking its integrity. In the wetlands of Pantanal, near the Paraguay river crossing, the organic-alluvial soil was submitted to the process of subsidence. This process, associated with the river water flow erosion, shrank the soil volume and diminished or extinguished the pipeline land cover. The pipeline was exposed to the environment, and submitted to tension stresses and the risk of low cycle fatigue during the floods. The cathodic protection system also had to be evaluated, specially in the drought. To mitigate the problem, the embankment technique was adopted using sandy soil, reinforced with polyester geo-webs and with woven polipropene geo-textiles. The solution also used geo-webs with soil-cement as protection elements against the degradation of the geo-textiles blankets. Some monitoring works are associated with those interventions: monitoring of cathodic protection; topographical verification of horizontal and vertical displacements of the pipeline; levels of land covering, and rainfalls and flood measurement. The base of the embankment was built with hydraulic transported soil, and at the end consistently supported the gas pipeline. (author)

  13. 台湾36英寸海上管线项目中的预开沟、预扫床及回填作业%Pre-trenching, Pre-Sweeping and Backfilling for the 36" Offshore Pipeline Project in Taiwan

    Institute of Scientific and Technical Information of China (English)

    爱德华; 王曦

    2003-01-01

    本文主要讨论耙吸挖泥船在管线开沟工程中的优点.台湾36英寸海上管线项目表明了耙吸船这种特殊类型设备的多用性.在这个项目的三种不同场合下,耙吸挖泥船证明了她的各种能力.首先,耙吸船使用专用深水疏浚设备克服了大水深的困难;其次,未预料到的泥土问题,如泥土回流到新开挖沟槽内的问题;第三是由冲刷现象引起的自由跨度(freespans)问题,都藉由耙吸船使用高压冲水方式得以解决.因而,该耙吸挖泥船使项目避免了因预料不到的问题而必须调用昂贵的专用设备以及大的施工期延误.

  14. Experimental Study on the Mechanical Properties of Paste-like Fill Material

    Institute of Scientific and Technical Information of China (English)

    HUANG Yu-cheng; SUN Heng-hu

    2004-01-01

    The experiments, which include the complete stress-strain curves, triaxial compressive loading history and the main factors affecting the compressive strength of the material, were made to research the mechanical properties of paste-like fill material. The results show that the material still has a relatively high load-bearing capacity after yielding. From the view of the backfill strength, the suitable content of the fine particles in the aggregates is 20%, the curing temperature of backfill slurry is about 20 centigrade degrees or higher. The backfill strength can reach 2.5-3.6 MPa when the binder dosage is 5%-8%. It can meet the needs for mining with backfill.

  15. Evaluation of low-pH cement degradation in tunnel plugs and bottom plate systems in the frame of SR-Site

    Energy Technology Data Exchange (ETDEWEB)

    Grandia, Fidel; Galindez, Juan-Manuel; Molinero, Jorge; Arcos, David (Amphos XXI Consulting S.L., Barcelona (Spain))

    2010-09-15

    Low-pH concrete plugs are going to be used during the backfilling of depositional tunnels of the high-level nuclear waste repository. The stability of these plugs, however, is thought to be affected by water-concrete interaction that may lead to cement degradation and dissolution. Alkaline plumes derived from such a degradation could jeopardize the chemical stability of the clay material in the backfill due to the enhanced dissolution kinetics under high-pH solutions. In this study, the cement durability of concrete plugs to be used in the repository is numerically evaluated by performing reactive transport simulations based on the geochemical degradation of the cement compounds, mainly calcium silicate hydrates (CSH). The implementation of degradation process into the geochemical model is based on a solid solution approach for CSH alteration. The numerical model also takes into account the dependency of transport properties (e.g. molecular diffusion coefficient) with the changes in porosity due to mineral precipitation-dissolution. The simulations predict that the effect of low-pH concrete alteration on the stability of backfill materials would be low. The main process governing geochemistry in the backfill-concrete boundary would be the quick loss of porosity due to ettringite precipitation. The very high molar volume of this mineral enhances the rate of clogging. The ettringite formation is mainly driven by the high sulphate concentration in the backfill porewater, which in turn is controlled by the equilibrium with gypsum in the backfill. The release and diffusion of calcium (from CSH replacement) and Al (from katoite dissolution) from concrete causes ettringite precipitation at the concrete-backfill boundary. The loss of porosity dramatically reduces solute diffusion and, consequently, the backfill-concrete system remains almost invariably for hundreds of years

  16. Final Environmental Assessment for the Bridge Replacement and Scour Protection Measures at Avon Park Air Force Range, Florida

    Science.gov (United States)

    2012-03-01

    Scour protection measures would consist of backfill soil overlaid with geotextile plastic and then aggregate (broken concrete). The backfill soil...canal is scouring underneath these footers. The scour protection methods would include placement of fill and plastic geotextile overlaid with...back the earthen berm of Kissimmee Road. The riprap, geotextile and concrete aggregate would be placed at the interface between the canal floor

  17. Mechanics of granular-frictional-visco-plastic fluids in civil and mining engineering

    Science.gov (United States)

    Alehossein, H.; Qin, Z.

    2013-10-01

    The shear stress generated in mine backfill slurries and fresh concrete contains both velocity gradient dependent and frictional terms, categorised as frictional viscous plastic fluids. This paper discusses application of the developed analytical solution for flow rate as a function of pressure and pressure gradient in discs, pipes and cones for such frictional Bingham-Herschel-Bulkley fluids. This paper discusses application of this continuum fluid model to industrial materials like mine and mineral slurries, backfills and fresh concrete tests.

  18. Large Crater Repair at Silver Flag Exercise Site, Tyndall Air Force Base, Florida

    Science.gov (United States)

    2015-08-01

    for blending and placing rapid-setting cementitious backfill and capping material for large craters. ERDC/GSL TR-15-27 7 After completion of the...Caterpillar 279C Compact Track Loader Caterpillar 279C Compact Track Loaders (CTLs), or skid steers, are high- flow, rubber -tracked machines with quick...preparing the natural subgrade and crushed stone backfill. The plate compactor used was a Wacker WP 1550W (Figure 16), which has a 6.0-hp motor capable of

  19. Preliminary conceptual designs for advanced packages for the geologic disposal of spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Westerman, R.E.

    1979-04-01

    The present study assumes that the spent fuel will be disposed of in mined repositories in continental geologic formations, and that the post-emplacement control of the radioactive species will be accomplished independently by both the natural barrier, i.e., the geosphere, and the engineered barrier system, i.e., the package components consisting of the stabilizer, the canister, and the overpack; and the barrier components external to the package consisting of the hole sleeve and the backfill medium. The present document provides an overview of the nature of the spent fuel waste; the general approach to waste containment, using the defense-in-depth philosophy; material options, both metallic and nonmetallic, for the components of the engineered barrier system; a set of strawman criteria to guide the development of package/engineered barrier systems; and four preliminary concepts representing differing approaches to the solution of the containment problem. These concepts use: a corrosion-resistant meta canister in a special backfill (2 barriers); a mild steel canister in a corrosion-resistant metallic or nonmetallic hole sleeve, surrounded by a special backfill (2 barriers); a corrosion-resistant canister and a corrosion-resistant overpack (or hole sleeve) in a special backfill (3 barriers); and a mild steel canister in a massive corrosion-resistant bore sleeve surrounded by a polymer layer and a special backfill (3 barriers). The lack of definitive performance requirements makes it impossible to evaluate these concepts on a functional basis at the present time.

  20. Movement and deformation laws of the overlying strata in paste filling stope

    Institute of Scientific and Technical Information of China (English)

    Xu Ying; Chang Qingliang; Zhou Huaqiang; Cao Zhong; Li Xiushan; ChenJianhang

    2011-01-01

    We combined the similar simulation with numerical simulation to analyze the movement and deformation features of overlying strata caused by paste backfill mining,study the movement and deformation laws of the overlying strata in paste backfill mining,structural movement of the stope strata as well as the stope stress distribution laws.Furthermore,authors also explored the key factors to the movement and deformation of the overlying strata in paste backfill mining.The results indicate that a caving zone existed in the bending zone only in the overlying strata of the paste backfill mining.Compared with the roof caving mining,the degree of stress concentration and area of influence in the paste filling stope were apparently smaller.And the degree of destruction and area of the overlying strata decreased prominently.Also,there was no apparent strata behavior in the working face.Lastly,the filling ratio was the key to control the movement and deformation of the overlying strata.Combined with a specific engineering example,the author proved the reliability of the simulation results and provided a theoretical basis for the further extension of the paste backfill mining.

  1. Neon as a Buffer Gas for a Mercury-Ion Clock

    Science.gov (United States)

    Prestage, John; Chung, Sang

    2008-01-01

    A developmental miniature mercury-ion clock has stability comparable to that of a hydrogen-maser clock. The ion-handling components are housed in a sealed vacuum tube, wherein a getter pump is used to maintain the partial vacuum, and the evacuated tube is backfilled with mercury vapor in a buffer gas. Neon was determined to be the best choice for the buffer gas: The pressure-induced frequency pulling by neon was found to be only about two-fifths of that of helium. Furthermore, because neon diffuses through solids much more slowly than does helium, the operational lifetime of a tube backfilled with neon could be considerably longer than that of a tube backfilled with helium.

  2. Impact assessment of shallow land burial for low-level waste: modelling of the water flow and transport of radionuclides in the near-field

    Energy Technology Data Exchange (ETDEWEB)

    Walravens, J.; Volckaert, G.

    1996-09-18

    The Belgian concept for disposal of low-level waste consists of storage of waste drums into a concrete vault backfilled with a cementitious grout. The vault is placed above the water table and will be covered with a multilayer cap of clay, gravel, and sandy materials. The SCK/CEN is charged with the long-term performance assessment of the disposal site. The main processes and parameters determining the radioactivity release from the site are identified. The principal processes are the infiltration through the top cover and the sorption of waste on the backfill. The release of radionuclides from the site was modelled with the PORFLOW numerical code.

  3. Loads on Entrance Platforms for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Frigaard, Peter; Andersen, Thomas Lykke; Ramirez, Jorge Robert Rodriguez;

    2010-01-01

    The present paper gives an overview of the performed large scale tests in GWK, Hannover for studying wave run-up generated forces on wind turbine entrance platforms. The run-up height and velocity was measured by use of high speed video recordings supplemented by some wave gauges mounted...... at the pile. Hereafter, the run-up generated impact forces were measured on two types of grates and a solid plate. The pressure distribution was also measured for the solid plate. In addition to this the wave generated backfilling of an initial scour hole and the strength of the backfilling soil was studied...

  4. Scour properties of mono bucket foundation

    DEFF Research Database (Denmark)

    Stroescu, Ionut Emanuel; Frigaard, Peter Bak

    2016-01-01

    Field experience proved that the Mono Bucket Foundations (MBFs) have good response against scour development. Moreover, the ratio between large diameter (bucket lid) and the small diameter (shaft tower) is the driving parameter for the process of erosion/backfill, like scour protection diameter...... in the case of scour protected monopiles. However, the structural design to reduce the scour development for MBFs is still open to optimization. The influences of parameters that generate backfill and scour, the transfer load webs and the misalignment with seabed, have not been systematically studied until...

  5. Soil-Structure Interaction for Non-Slender, Large-Diameter Offshore Monopiles

    DEFF Research Database (Denmark)

    Sørensen, Søren Peder Hyldal

    conducted. The initial part of p-y curves for non-slender piles has been investigated by means of numerical modelling. The general behaviour of eccentrically loaded non-slender piles has been investigated by physical modelling. These tests have been conducted in the pressure tank at Aalborg University....... Hence, the application of an overburden pressure is possible. The timescale of the backfill process and the compaction of soil material backfilled around piles in storm conditions have been investigated by means of large-scale physical modelling....

  6. Peacekeeper Quantity-Distance Verification Program and Addendum.

    Science.gov (United States)

    1984-06-01

    Early Time Break Up 6-1 6.2 Surface Spallation 6-3 6.3 Fragment Launch Characteristics 6-9 6.4 Test Predictions 6-14 7.0 FRAGMENT SCALING METHODOLOGY 7-1...backfill, the lower portion of the 6-inch diameter columns was drilled into the native soil and backfilled with colored sand. Two-foot-long sections of...structural break up, attention was focused on three major areas: * early time break up response, surface spallation phenomena and fragment launch

  7. Soil-Structure Interaction for Non-Slender, Large-Diameter Offshore Monopiles

    DEFF Research Database (Denmark)

    Sørensen, Søren Peder Hyldal

    . The monopile foundation concept has been employed as the foundation for the majority of the currently installed offshore wind turbines. Therefore, this PhD thesis concerns the soil-pile interaction for non-slender, large-diameter offshore piles. A combination of numerical and physical modelling has been....... Hence, the application of an overburden pressure is possible. The timescale of the backfill process and the compaction of soil material backfilled around piles in storm conditions have been investigated by means of large-scale physical modelling....

  8. Dissertation Citations in Organismal Biology at Southern Illinois University at Carbondale: Implications for Collection Development

    Science.gov (United States)

    Nabe, Jonathan; Imre, Andrea

    2008-01-01

    We report on a citation analysis of Ph.D. dissertations in plant biology and zoology at Southern Illinois University Carbondale, undertaken to test the common assumption that scientists favor current research to such an extent that journal backfiles can be de-emphasized in academic library collections. Results demonstrate otherwise. The study is…

  9. Tailings management

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-05-01

    Careful planning and water management is essential to the proper management of conventional tailings impoundments. Alternatives, like dry stacking and tailings backfill are becoming more widely used. Effective closure is important, especially if acid rock drainage (ARD) is to be avoided. 11 refs., 3 photos.

  10. 7th international conference on acid rock drainage

    Energy Technology Data Exchange (ETDEWEB)

    Barnhisel, R.I. (ed.)

    2006-07-01

    This meeting also serves as the 23rd annual meeting of the American Society of Mining and Reclamation. The papers discussed various aspects of acid mine drainage including its impact, sustainability issues, case studies, lessons learned, characterization, closure/land use issues, emerging technologies, forestry/ecology, abandoned mine lands, modelling, pit lakes/backfill, soils and overburden, and treatment.

  11. 77 FR 46107 - Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Husky 1-North Dry...

    Science.gov (United States)

    2012-08-02

    ... backfill, and to cap overburden with a combination of low-seleniferous material and liner material. Agrium... practices designed to reduce, eliminate, or mitigate these impacts as described above. Suitable soil or... contaminants by vegetation, loss of soil and mineral resources; changes to air quality; loss of wildlife...

  12. 76 FR 32081 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

    Science.gov (United States)

    2011-06-03

    .... Liquids were allowed to drain off as solids settled. Trenches were then backfilled with soil obtained...-five foot long trench to have a synthetic liner. The permit also required leachate collection... native soil. As waste settled and no longer generated collectable quantities of leachate, the...

  13. Joining of beryllium by braze welding technique: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Banaim, P.; Abramov, E. [Ben-Gurion Univ. of the Negev, Beersheba (Israel); Zalkind, S.; Eden, S.

    1998-01-01

    Within the framework of some applications, there is a need to join beryllium parts to each other. Gas Tungsten Arc Braze Welds were made in beryllium using 0.3 mm commercially Aluminum (1100) shim preplaced at the joint. The welds exhibited a tendency to form microcracks in the Fusion Zone and Heat Affected Zone. All the microcracks were backfilled with Aluminum. (author)

  14. Stress field evolution law of mining environment reconstructing structure with change of filling height

    Institute of Scientific and Technical Information of China (English)

    CHEN Qing-fa; ZHOU Ke-ping; WANG Li-li

    2010-01-01

    For improving global stability of mining environment reconstructing structure,the stress field evolution law of the structure with the filling height change of low-grade backfill was studied by ADINA finite element analysis code.Three kinds of filling schemes were designed and calculated,in which the filling heights were 2,4,and 7 m,separately.The results show that there are some rules in the stress field with the increase of the filling height as follows:(1)the maximum value of tension stress of the roof decreases gradually,and stress conditions are improved gradually;(2)the tension stress status in the vertical pillar is transformed into the compressive stress status,and the carrying capacity is improved gradually; however,when the filling height is beyond 2.8 m,the carrying capacity of the vertical pillar grows very slowly,so,there is little significance to continue to fill the low-grade backfill;(3)the bottom pillar suffers the squeezing action from the vertical pillars at first and then the gravity action of the low-grade backfill,and the maximum value of tension stress of the bottom pillar firstly increases and then decreases.Considering the economic factor,security and other factors,the low-grade backfill has the most reasonable height(2.8 m)in the scope of all filling height.

  15. Rational design and construction of temporary steel tower bases; Karitetto kiso sekkei seko no gorika ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Ikemoto, M. [Kansai Electric Power Co. Inc., Osaka (Japan)

    2000-01-10

    Current design and construction of temporary steel tower bases are equivalent to those for permanent facilities, and removal of the whole base concrete requires a great deal of labor and cost. The newly developed rational liner plate type base uses no concrete, and uses liner plates in place of adhesive and frictional parts of previous base floor plates. The workability of back-filling using sandbags is very excellent. Use of improved soil material as back-filling mortar of liner plates shows a favorable separability. The whole base is reusable because of no damage of each component member. Unlike concrete bases, the liner plate base produces no waste materials due to removal. The steel-base anchor type base can reduce both excavating and back-filling soil by using earth anchors, and reduce excavating soil as much as possible by allotting lifting force to each earth anchor. Reduction of both excavating and back-filling soil makes the removing work of bases simple. Cost reduction of 30-40% was attained by each newly developed base as compared with costs of conventional bases. (NEDO)

  16. Micro- and nanopatterning of functional organic monolayers on oxide-free silicon by laser-induced photothermal desorption.

    Science.gov (United States)

    Scheres, Luc; Klingebiel, Benjamin; ter Maat, Jurjen; Giesbers, Marcel; de Jong, Hans; Hartmann, Nils; Zuilhof, Han

    2010-09-06

    The photothermal laser patterning of functional organic monolayers, prepared on oxide-free hydrogen-terminated silicon, and subsequent backfilling of the laser-written lines with a second organic monolayer that differs in its terminal functionality, is described. Since the thermal monolayer decomposition process is highly nonlinear in the applied laser power density, subwavelength patterning of the organic monolayers is feasible. After photothermal laser patterning of hexadecenyl monolayers, the lines freed up by the laser are backfilled with functional acid fluoride monolayers. Coupling of cysteamine to the acid fluoride groups and subsequent attachment of Au nanoparticles allows easy characterization of the functional lines by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Depending on the laser power and writing speed, functional lines with widths between 1.1 μm and 250 nm can be created. In addition, trifluoroethyl-terminated (TFE) monolayers are also patterned. Subsequently, the decomposed lines are backfilled with a nonfunctional hexadecenyl monolayer, the TFE stripes are converted into thiol stripes, and then finally covered with Au nanoparticles. By reducing the lateral distance between the laser lines, Au-nanoparticle stripes with widths close to 100 nm are obtained. Finally, in view of the great potential of this type of monolayer in the field of biosensing, the ease of fabricating biofunctional patterns is demonstrated by covalent binding of fluorescently labeled oligo-DNA to acid-fluoride-backfilled laser lines, which--as shown by fluorescence microscopy--is accessible for hybridization.

  17. Physical and numerical modelling of earth pressure on anchored sheet pile walls in sand

    DEFF Research Database (Denmark)

    Krogsbøll, Anette Susanne; Fuglsang, Leif D

    2006-01-01

    The influence of wall flexibility on earth pressure, bending moments and failure modes is studied. Numerical models are compared to results from model tests carried out in a geotechnical centrifuge. The back-fill is dry sand and failure is introduced by allowing the wall to rotate around the anchor...

  18. Physical and numerical modelling of earth pressure on anchored sheet pile walls in sand

    DEFF Research Database (Denmark)

    Krogsbøll, Anette Susanne; Fuglsang, Leif D

    The influence of wall flexibility on earth pressure, bending moments and failure modes is studied. Numerical models are compared to results from model tests carried out in a geotechnical centrifuge. The back-fill is dry sand and failure is introduced by allowing the wall to rotate around the anchor...

  19. 40 CFR 144.26 - Inventory requirements.

    Science.gov (United States)

    2010-07-01

    ... other backfill wells ; (B) Radioactive waste disposal wells that are not Class I wells (40 CFR 146.5 (e)(11)) (C) Geothermal energy recovery wells ; (D) Brine return flow wells ; (E) Wells used in... administered programs the information need not be submitted if a complete permit application is...

  20. JSTOR: A Non-Profit Working To Redefine Access to the Scholarly Journal.

    Science.gov (United States)

    Chepesiuk, Ron

    1997-01-01

    As costs of subscriptions to scholarly journals rise, libraries struggle to house their collections. Journal Storage (JSTOR) is building a reliable and comprehensive archive of important literature, filling the gaps in existing collections of backfiles, fostering preservation, increasing access, finding ways to reduce storage and care costs, and…

  1. Digital Format for Depositary Part of Scientific Publications' Collection

    Science.gov (United States)

    Zemskov, Andrei; Evstigneeva, Galina

    As a rule, any large library has so called depositary part of collection. Specific circulation of these publications is not high, but preservation, conservation and provision of access to given collection need permanent efforts. The paper presents evaluation of expenses and centralized systems efficiency. These systems (e.g. JSTOR, Backfiles for Future) are publicly accessible collections of full text versions of scientific periodicals.

  2. Field Measurements and Pullout Tests of Reinforced Earth Retaining Wall

    Institute of Scientific and Technical Information of China (English)

    陈群; 何昌荣; 朱分清

    2004-01-01

    In this paper, field measurements and pullout tests of a new type of reinforced earth retaining wall, which is reinforced by trapezoid concrete blocks connected by steel bar, are described. Field measurements included settlements of the earth fill, tensile forces in the ties and earth pressures on the facing panels during the construction and at completion. Based on the measurements, the following statements can be made: ( 1 ) the tensile forces in the ties increased with the height of backfill above the tie and there is a tensile force crest in most ties; (2) at completion, the measured earth pressures along the wall face were between the values of the active earth pressures and the pressures at rest; (3) larger settlements occurred near the face of the wall where a zone of drainage sand and gravel was not compacted properly and smaller settlements occurred in the well-compacted backfill. The results of field pullout tests indicated that the magnitudes of pullout resistances as well as tensile forces induced in the ties were strongly influenced by the relative displacements between the ties and the backfill, and pullout resistances increased with the height of backfill above the ties and the length of ties.

  3. THERMALLY CONDUCTIVE CEMENTITIOUS GROUTS FOR GEOTHERMAL HEAT PUMPS. PROGRESS REPORT BY 1998

    Energy Technology Data Exchange (ETDEWEB)

    ALLAN,M.L.; PHILIPPACOPOULOS,A.J.

    1998-11-01

    Research commenced in FY 97 to determine the suitability of superplasticized cement-sand grouts for backfilling vertical boreholes used with geothermal heat pump (GHP) systems. The overall objectives were to develop, evaluate and demonstrate cementitious grouts that could reduce the required bore length and improve the performance of GHPs. This report summarizes the accomplishments in FY 98.

  4. Mitigation of Traffic-Induced Ground Vibration by Inclined Wave Barriers

    DEFF Research Database (Denmark)

    Andersen, Lars; Augustesen, Anders Hust

    2009-01-01

    Double sheet pile walls can be used as wave barriers in order to mitigate ground vibrations from railways. The present analysis concerns the efficiency of such barriers, especially with regard to the influence of the barrier inclination and the backfill between the walls. Thus, the screening...

  5. Model for the Evolving Bed Surface around an Offshore Monopile

    DEFF Research Database (Denmark)

    Hartvig, Peres Akrawi

    2012-01-01

    This paper presents a model for the bed surface around an offshore monopile. The model has been designed from measured laboratory bed surfaces and is shown to reproduce these satisfactorily for both scouring and backfilling. The local rate of the bed elevation is assumed to satisfy a certain gene...

  6. Method to Predict Long Time Span of Scour Around Offshore Wind Turbine Foundations

    DEFF Research Database (Denmark)

    Dixen, Martin; Lohmann, Iris P.; Christensen, Erik Damgaard

    2012-01-01

    tables have been made based on full 3D numerical simulations of the flow and sediment transport for fixed configurations of the scour hole. When changing the governing parameters which are causing the scour development around the structure, the erosion rate or backfilling rate can be calculated from...

  7. A review of recent advances in numerical modelling of local scour problems

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu

    2014-01-01

    A review is presented of recent advances in numerical modelling of local scour problems. The review is organized in five sections: Highlights of numerical modelling of local scour; Influence of turbulence on scour; Backfilling of scour holes; Scour around complex structures; and Scour protection ...

  8. A Reality Check on Hedge Funds Returns

    NARCIS (Netherlands)

    Sluis, van der Pieter Jelle; Posthuma, Nolke

    2003-01-01

    In this article we examine the backfill bias or instant history bias for hedge funds using additional information from the Tass database. This is information about the exact date a hedge fund starts to reporting to Tass. Using this information we are able to reveal the length of the instant historie

  9. Highly conductive and stretchable polymer composites based on graphene/MWCNT network.

    Science.gov (United States)

    Chen, Mengting; Tao, Tao; Zhang, Ling; Gao, Wei; Li, Chunzhong

    2013-02-25

    We have manufactured a highly conductive and stretchable composite by backfilling a preformed graphene/MWCNT aerogel with poly(dimethylsiloxane) (PDMS). The electrical conductivity of our product can reach 2.8 S cm(-1) with only 1.3 wt% graphene/MWCNT loading, and remains constant after 100 times repeated stretching by 20% and 5000 times bending.

  10. In Situ Corrosion and Heat Loss Assessment of Two Nonstandard Underground Heat Distribution System Piping Designs: Supplement-Appendices for Final Report on Project F07-AR01

    Science.gov (United States)

    2011-06-01

    temperature, photos, outer jacket condition, notes on any wear or abrasion or other damage, properties and character of backfill soil immediately in...CIS Abbreviation Key Asp = Asphalt CIS = Close Interval Survey Con = Concrete LT = Left Turn MH = Manhole (Fort Carson nomenclature) N = North

  11. Tracking Trends: Students' Information Use in the Social Sciences and Humanities, 1995-2008

    Science.gov (United States)

    Smyth, Joanne B.

    2011-01-01

    This study uses citation analysis to examine students' dissertations and theses in history, psychology, and education, noting changes in research practices since the introduction of electronic journals and other online sources. Some findings challenge earlier studies, showing that students are making greater use of journal backfiles and that this…

  12. DoD Corrosion Prevention and Control. Current Program Status

    Science.gov (United States)

    2009-02-03

    Lightweight Fiber Reinforced (Thermoset) Polymer Composite Bridge Decks joint $425 $425 $850 9.9 $8.4 Dilute Flowable Backfill Validation for...Degradation of Composite Structures Degradation Effects of and Design Solutions for Composite Structures Joined to Metallic Structures Corrosion Impacts of

  13. Concept for Underground Disposal of Nuclear Waste

    Science.gov (United States)

    Bowyer, J. M.

    1987-01-01

    Packaged waste placed in empty oil-shale mines. Concept for disposal of nuclear waste economically synergistic with earlier proposal concerning backfilling of oil-shale mines. New disposal concept superior to earlier schemes for disposal in hard-rock and salt mines because less uncertainty about ability of oil-shale mine to contain waste safely for millenium.

  14. The Practicalities of Document Conversion.

    Science.gov (United States)

    Galbraith, Ian

    1993-01-01

    Describes steps involved in the conversion of source documents to scanned digital image format. Topics addressed include document preparation, including photographs and oversized material; indexing procedures, including automatic indexing possibilities; scanning documents, including resolution and throughput; quality control; backfile conversion;…

  15. 40 CFR 247.3 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... backfill material in place of concrete, compacted soils, or sand. Foam-in-place insulation is rigid... presence of polyhydroxyl compounds with the addition of cell stabilizers, blowing agents, and appropriate... composed principally of polymerized styrene resin processed to form a homogenous rigid mass of...

  16. Study on gob-side entry retaining in fully-mechanized longwall with top-coal caving and its application

    Institute of Scientific and Technical Information of China (English)

    Su Hai; Bai Jianbiao; Yan Shuai; Chen Yong; Zhang Zizheng

    2015-01-01

    Based on the engineering background of gob-side entry retaining in fully-mechanized longwall with top coal caving (GER-FLTC) on N2105 working face of Yuwu coal mine, by adopting the methods of theoret-ical analysis and numerical calculation, the control techniques of surrounding rocks in GER-FLTC working face are studied in this paper. The two main difficulties of stability of surrounding rocks at gob-side retained entry in fully-mechanized longwall working face are the stability control of top coal and control of large deformation of GER-FLTC working face. Interaction mechanical model between roofing and road-side backfilling in GER-FLTC is established and the equations for the calculation of roof-cutting resistance of roadside backfilling are derived. Results of numerical calculation show that the damage zones of top coal can be categorized into the delaminating zone of top coal above the backfilling, tensile damage zone of top coal above the retained roadway and shear damage zone of the upper rib of the solid coal. Stability control of top coal is the critical part to success of GER-FLTC. With consideration of large deformation of surrounding rocks of gob-side retained entry in fully-mechanized longwall, the support technique of‘roofing control and wall strengthening’ is proposed where high strength and highly prestressed anchor rods and diagonal tensile anchor cables support are used for top coal, high strength and highly pre-stressed yielding anchor rod support is used for solid coal and roadside prestressed load-carrying back-filling is constructed by high-water material, in order to maintain the integrity of the top coal, transfer load, high resistance yielding load-carrying of solid coal, roof-cutting of roadside backfilling and support, and to achieve GER-FLTC. Results from this study are successfully applied in engineering practice.

  17. The Effects of High Salinity Groundwater on the Performance of Clay Barriers

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David [Quintessa Ltd., Nottingham (United Kingdom)

    2005-07-01

    Potential changes in groundwater chemistry during the operational or post-closure periods of the Swedish repository for spent fuel could affect the performance of both the bentonite buffer and repository backfill. For example, the up-coning of saline groundwater could lead to decreased swelling pressures in both the bentonite buffer and tunnel backfills, and could also induce 'piping'. SKB is considering these issues as part of its 'SR-Can' safety assessment. This report reviews evidence for the behaviour of swelling clays in groundwaters of varying salinity with special relevance to the SKB programme. Smectite clays can absorb water into clay inter-layers with the most important parameters being: the surface density of charge of the clay; the charge and solvation behaviour of the inter-layer ions; and the electrolyte concentration or activity of water. Two categories of swelling are generally observed: innercrystalline swelling caused by the hydration of the exchangeable cations in the dry clay; and osmotic swelling, resulting from concentration gradients in ion concentrations between clay surfaces and pore water. Several models exist to interpret and predict the swelling behaviour of clays. SKB currently prefer an interpretation of clay swelling pressure where clay particles are viewed as 'macro-ions' and the entire clay-water system can be considered as a 'polyelectrolyte'. SKB use the term 'Donnan exclusion' to estimate the amount of introduced ions into the clay and hence the amount of reduced swelling pressure due to contact with a saline solution. Donnan exclusion is the process whereby the migration of anions through the narrow aqueous film surrounding clay platelets is restricted due to the repulsion by the negative charge of the clay platelets. SKB's experimental work shows that: There is an exponential relation between swelling pressure and mean basal interlamellar spacing of the clay. Ions from the

  18. Seismic pressure effect on retaining walls; Presiones generadas por sismo en muros de retencion

    Energy Technology Data Exchange (ETDEWEB)

    Bonola, Isaac; Aviles, Javier [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico)

    2006-04-15

    Retaining walls are auxiliary works used in different hydraulic structures. In seismically active areas, the dynamic pressures generated by the backfill must be appropriately evaluated at the design stage. Currently, a number of methods for estimating the seismic response of this type of works are available; however, most of them are simplified and not all the parameters involved have been examined. In this paper, a hybrid boundary and finite element method is presented for gravity walls in which the backfill can be represented by a horizontally layered medium. The effect of lateral extension of the backfill can be included in the model by introducing a vertical boundary coupling the movement of the backfill with that of the surrounding soil. The wave propagation analysis in the layered medium is carried out for both horizontal and vertical harmonic excitation; the latter excitation may cause important responses under certain situations. To illustrate the applicability of the proposed method, results for two numerical examples are presented: one for dry backfill and other for saturated backfill, considering in both cases the variations of dynamic properties of the soil with the depth. [Spanish] Los muros de retencion son estructuras auxiliares utilizadas en distintas obras hidraulicas. En zonas sismicas, las presiones dinamicas generadas por el relleno deben evaluarse adecuadamente en la etapa de diseno. Actualmente existen numerosos metodos para estimar la respuesta sismica de este tipo de estructuras; sin embargo, la mayoria de ellos son simplificados y no todos los parametros involucrados han sido examinados. En este trabajo se presenta un metodo hibrido de frontera y elemento finito para muros de gravedad en el que el relleno puede representarse por un medio estratificado horizontalmente. En el modelo puede incluirse el efecto de la extension lateral del relleno, introduciendo una frontera vertical que acopla el movimiento del relleno con el del suelo

  19. Thermo-Mechanical Behavior of Bentonite Buffer in a Deep Geological HLW Repository

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, S.; Cho, W. J.; Lee, J. O

    2008-08-15

    This work aims to investigate the influence of bentonite buffer and backfill, which will role as important engineered barriers, on the thermo-mechanical behaviors of a disposal system at a deep underground HLW repository. It will contribute to the disposal system development and performance assessment of the system. In this study, three-dimensional computer simulations were carried out with a consideration of the thermal and mechanical characteristics of the buffer and backfill for the investigation of the behavior of buffer and backfill under different disposal conditions. The understanding of the near field response to the variation of buffer and backfill properties will contribute to the development of an adequate buffer and backfill design in disposal conditions as well as the selection of a disposal site. The following conclusions could be drawn from the three-dimensional thermo-mechanical coupling analysis for investigating the possible influence of the bentonite buffer on the thermo-mechanical behavior around an underground repository, which is located at several hundred meters deep underground. o The bentonite swelling pressure can influence on the mechanical behavior of canister. Further detailed modeling is required in the future. o It is required to consider the water content and density of bentonite as important design parameters, because it was found that those influence the thermo-mechanical behavior of near field significantly. o A horizontal deposition hole and multi-level repository can results different maximum temperatures, stress concentration, and the required time for the maximum temperatures of canister, buffer, and rock compared to those of vertical deposition hole and single level repository. o Even though, the same laboratory results were used for driving the parameters for the plastic models used in the modeling, the mechanical behaviors were different. It is, therefore, required to use adequate plastic models for buffer and backfill

  20. Utilization of SRS pond ash in controlled low strength material. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Langton, C.A.; Rajendran, N.

    1995-12-01

    Design mixes for Controlled Low Strength Material (CLSM) were developed which incorporate pond ashes (fly ashes) from the A-Area Ash Pile, the old F-Area Ash Basin and the D-Area Ash Basin. CLSM is a pumpable, flowable, excavatable backfill used in a variety of construction applications at SRS. Results indicate that CLSM which meets all of the SRS design specifications for backfill, can be made with the A-, D-, and F-Area pond ashes. Formulations for the design mixes are provided in this report. Use of the pond ashes may result in a cost savings for CLSM used at SRS and will utilize a by-product waste material, thereby decreasing the amount of material requiring disposal.

  1. Numerical Simulation of Heat Transfer Characteristics of Horizontal Ground Heat Exchanger in Frozen Soil Layer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A simplified numerical model of heat transfer characteristics of horizontal ground heat exchanger (GHE) in the frozen soil layer is presented and the steady-state distribution of temperature field is simulated. Numerical results show that the frozen depth mainly depends on the soil's moisture content and ambient temperature. The heat transfer loss of horizontal GHE tends to grow with the increase of the soil's moisture content and the decrease of ambient temperature. Backfilled materials with optimal thermal conductivity can reduce the thermal loss effectively in the frozen soil. The applicability of the Chinese national standard "Technical Code for Ground Source Heat Pump (GB 50366-2005)" is verified. For a ground source heat pump project, the feasible layout of horizontal GHE should be determined based on the integration of the soil's structure, backfilled materials,weather data, and economic analysis.

  2. Scour Development around Bucket Foundations

    DEFF Research Database (Denmark)

    Stroescu, Ionut Emanuel; Frigaard, Peter Bak; Fejerskov, Morten

    2015-01-01

    The design without scour protection is a sensitive topic to most offshore developers, especially in the North Sea. However, newer research show that this concept is realistic if exists extended comprehension of the scour and backfill phenomena. The present paper shows comparative results for mono......The design without scour protection is a sensitive topic to most offshore developers, especially in the North Sea. However, newer research show that this concept is realistic if exists extended comprehension of the scour and backfill phenomena. The present paper shows comparative results...... for monopile and Bucket Foundation; using experimental analysis and real scour surveys around offshore installed Bucket Foundations. The main finding reflect that Bucket Foundation is a candidate for design without scour protection behaving like scour protected monopoles, in a variety of environmental...

  3. Mobility and survival of sulphate-reducing bacteria in compacted and fully water saturated bentonite - microstructural aspects

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, R. [Geodevelopment AB, Lund (Sweden)

    1999-12-01

    Sulphate-reducing bacteria will not be able to enter MX-80 buffer clay with the intended bulk density, i.e. 1900-2100 kg/m{sup 3}. Nor will they be able to survive and migrate in such environment. The only circumstances under which sulphate-reducing bacteria can enter, survive and migrate in engineered soil barriers in a KBS-3-type repository are those prevailing in backfills with lower MX-80 contents than about 10 % or in more smectite-rich, poorly compacted backfills saturated with electrolyte-rich pore water with Ca as dominating cation. In the phase of hydration and expansion of canister-embedding buffer, bacteria can enter the initially very soft clay gel at the rock/buffer contact to a depth of about a centimeter.

  4. Joint DOE/NRC field study of tracer migration in the unsaturated zone

    Energy Technology Data Exchange (ETDEWEB)

    Nyhan, J.; Polzer, W.; Essington, E.; Cokal, E.; Lane, L.; Lopez, E.; Stallings, E.; Walker, R.

    1986-03-01

    The results of a joint DOE/NRC field experiment to evaluate leaching and transport of solutes in a sandy silt backfill used for shallow land burial operations at Los Alamos are presented for steady-state and unsteady-state flow conditions. The migration of iodide, bromide, and lithium through the backfill material is studied as functions of depth and time and they are compared with one another. The bromide and iodide tracer data are used to estimate the diffusion coefficient, the tortuosity factor, and dispersivity. These values are used to calculate effective dispersion coefficients for subsequent analyses of the retardation factor and the distribution coefficient for lithium using least squares procedures. The results of the tracer migration study are discussed relative to challenges facing the waste management community, and chemical transport modeling opportunities are presented for a modeling workshop to be held in FY86.

  5. Standard test method for laboratory evaluation of magnesium sacrificial anode test specimens for underground applications

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1997-01-01

    1.1 This test method covers a laboratory procedure that measures the two fundamental performance properties of magnesium sacrificial anode test specimens operating in a saturated calcium sulfate, saturated magnesium hydroxide environment. The two fundamental properties are electrode (oxidation potential) and ampere hours (Ah) obtained per unit mass of specimen consumed. Magnesium anodes installed underground are usually surrounded by a backfill material that typically consists of 75 % gypsum (CaSO4·2H2O), 20 % bentonite clay, and 5 % sodium sulfate (Na2SO4). The calcium sulfate, magnesium hydroxide test electrolyte simulates the long term environment around an anode installed in the gypsum-bentonite-sodium sulfate backfill. 1.2 This test method is intended to be used for quality assurance by anode manufacturers or anode users. However, long term field performance properties may not be identical to property measurements obtained using this laboratory test. Note 1—Refer to Terminology G 15 for terms used ...

  6. Assessing materials (''Getters'') to immobilize or retard the transport of technetium through the engineered barrier system at the potential Yucca Mountain nuclear waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Viani, B E

    1999-03-15

    Current performance assessment calculations show that technetium (Tc) and neptunium (Np) will deliver the major fraction of the radiation dose to the accessible environment from the potential Yucca Mountain nuclear waste repository. Therefore, materials that can immobilize or delay the transport of Tc or Np (getters) are being considered for addition to either the waste-package or the backfill adjacent to the waste-package. Of the two radionuclides, Tc presents the greater challenge in identifying a suitable getter material. This report identifies several materials that warrant further consideration for immobilizing and/or sorbing Tc as additives to the backfill, and recommends active carbon and an inorganic oxide for initial testing. Other materials, such as zero valent iron, might be useful as getters if they were placed in the waste package itself, a subject that merits further investigation.

  7. Underground void filling by cemented mill tailings

    Institute of Scientific and Technical Information of China (English)

    Choudhary Bhanwar Singh; Kumar Santosh

    2013-01-01

    Underground mining always create voids. These voids can cause subsidence of surface. So it is always a demand to fill the void in such a manner that the effect of underground mining can be minimized. Void filling using mill tailings especially in metal mining is one of the best techniques. The tailings produced in milling process have traditionally been disposed in tailing ponds creating a waste disposal and environ-mental problems in terms of land degradation, air and water pollution, etc. This disposal practice is more acute in the metal milling industry where the fine grinding, required for value liberation, results in the production of very fine tailings in large percentage. This paper includes discussions on the effectiveness of different paste mixes with varying cement contents in paste backfilling operations. The results revealed that material composition and use of super plasticizer strongly influenced the strength of cemented backfill.

  8. Direct methods of soil-structure interaction analysis for earthquake loadings(II)

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Chung Bang; Lee, S. R.; Kim, J. M.; Park, K. L.; Oh, S. B.; Choi, J. S.; Kim, Y. S. [Korea Advanced Institute of Science Technology, Daejeon (Korea, Republic of)

    1994-07-15

    In this study, methods for 3-D soil-structure interaction analysis have been studied. They are 3-D axisymmetric analysis method, 3-D axisymmetric finite element method incorporating infinite elements, and 3-D boundary element methods. The computer code, named as 'KIESSI - PF', has been developed which is based on the 3-D axisymmetric finite element method coupled with infinite element method. It is able to simulate forced vibration test results of a soil-structure interaction system. The Hualien FVT post-correlation analysis before backfill and the blind prediction analysis after backfill have been carried out using the developed computer code 'KIESSI - PF'.

  9. Oil shale mining cost analysis. Volume I. Surface retorting process. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Resnick, B.S.; English, L.M.; Metz, R.D.; Lewis, A.G.

    1981-01-01

    An Oil Shale Mining Economic Model (OSMEM) was developed and executed for mining scenarios representative of commercially feasible mining operations. Mining systems were evaluated for candidate sites in the Piceance Creek Basin. Mining methods selected included: (1) room-and-pillar; (2) chamber-and-pillar, with spent shale backfilling; (3) sublevel stopping; and (4) sublevel stopping, with spent shale backfilling. Mines were designed to extract oil shale resources to support a 50,000 barrels-per-day surface processing facility. Costs developed for each mining scenario included all capital and operating expenses associated with the underground mining methods. Parametric and sensitivity analyses were performed to determine the sensitivity of mining cost to changes in capital cost, operating cost, return on investment, and cost escalation.

  10. An in vitro model to investigate filling of lateral canals.

    Science.gov (United States)

    Venturi, Mauro; Di Lenarda, Roberto; Prati, Carlo; Breschi, Lorenzo

    2005-12-01

    Aims of this work were to examine lateral canals in extracted teeth, to propose a new technique to produce artificial lateral canals, and to compare two obturation techniques. Cleared roots were examined to record measure and shape of lateral canals. Artificial lateral canals were prepared on human demineralized teeth before final clearing. Specimens were divided in two groups: canals of group 1 were filled with Schilder's technique, canals of group 2 were filled with vertical compaction with apical backfilling. Stereomicroscopic analysis of lateral canal filling revealed lower filling rates in apical canals compared to coronal ones and higher filling rates with "vertical compaction with apical backfilling" compared to Schilder's group. The tested procedure appears to be a reliable technique to obtain standardized lateral canals and to compare filling procedures.

  11. Characteristics of thermally-enhanced bentonite grouts for geothermal heat exchanger in South Korea

    Institute of Scientific and Technical Information of China (English)

    Chulho; LEE; Kangja; LEE; Hangseok; CHOI; Hyo-Pum; CHOI

    2010-01-01

    The thermal conductivity and viscosity of bentonite grouts have been evaluated and compared each other to determine the suitability of these materials for backfilling vertical boreholes of ground heat exchangers.Seven bentonite grouts from different product sources were considered in this paper.Two additives,silica sand and graphite were added in bentonite grouts to enhance thermal performance.The bentonite grouts indicate that both the thermal conductivity and the viscosity increase with the content of silica sand and graphite.Therefore,it is recommended to select cautiously the amount of silica sand and graphite considering not only thermal conductivity but also viscosity for the optimum condition of backfilling.Finally,the effect of salinity in the pore water on the change of swelling potential of the bentonite-based grouts has been quantitatively evaluated to show the feasibility of bentonite grouts in the coastal area.

  12. Mechanism of Geogrid Reinforced Soil at Bridge Approach

    Institute of Scientific and Technical Information of China (English)

    FENG Guangle; LUO Rong; CHEN Congxin

    2007-01-01

    Using Geogrid-Reinforced Soil (GRS) we studied the working mechanism and design method of GRS at bridge approach with high backfill by field experiment. In a highway section where the height of backfill is 13.5 meters, geogrids were used at two bridge approaches to address the bumping problems. Some soil pressure cells were used to measure the normal and lateral soil pressure at different locations in the roadbed. The experimental results indicate that geogrids in geogrid-reinforced soil (GRS) could produce an uplift force, the closer the location to the abutment, the larger the uplift force, and the reduction of measured soil pressures compared with theoretical values was the largest at the bottom of roadbed, less at the top than at the bottom, and the least in the mid-height of roadbed than at the bottom. These findings are different from those of the traditional greogrid-reinforced subgrade design method.

  13. Particle-scale Analysis of Key Technologies on Cut-and-over Tunnel in Slope Engineering

    Directory of Open Access Journals (Sweden)

    J.H. Yang

    2014-08-01

    Full Text Available When the shallow tunnel is constructed on the slope terrain in the mountains, there are the potential risks such as landslide induced by cutting the slope and the non-compacted backfill material during the construction of the cut-andcover tunnel. In order to solve these problems, based on a practical engineering, the optimized construction plans of the cut-and-cover tunnel were analyzed by particle flow code (PFC, the key parts of the open-cut construction were identified, and the anti-slide piles countermeasures were proposed. Furthermore, the grouting reinforcement process for the non-compacted backfill material around the shallow tunnel was simulated by PFC, and the variation characteristics of the porosity and grouting pressure were revealed as well. The results are of great value to the similar engineering.

  14. Tumor necrosis factor inhibitor therapy but not standard therapy is associated with resolution of erosion in the sacroiliac joints of patients with axial spondyloarthritis

    DEFF Research Database (Denmark)

    Pedersen, Susanne J; Wichuk, Stephanie; Chiowchanwisawakit, Praveena

    2014-01-01

    INTRODUCTION: Radiography is an unreliable and insensitive tool for the assessment of structural lesions in the sacroiliac joints (SIJ). Magnetic resonance imaging (MRI) detects a wider spectrum of structural lesions but has undergone minimal validation in prospective studies. The Spondyloarthritis...... Research Consortium of Canada (SPARCC) MRI Sacroiliac Joint (SIJ) Structural Score (SSS) assesses a spectrum of structural lesions (erosion, fat metaplasia, backfill, ankylosis) and its potential to discriminate between therapies requires evaluation. METHODS: The SSS score assesses five consecutive coronal...... slices through the cartilaginous portion of the joint on T1-weighted sequences starting from the transitional slice between cartilaginous and ligamentous portions of the joint. Lesions are scored dichotomously (present/absent) in SIJ quadrants (fat metaplasia, erosion) or halves (backfill, ankylosis...

  15. Research program to study the gamma radiation effects in Spanish bentonites; Programa de investigacion para estudiar los efectos de la radiacion gamma en bentonitas calcicas espanolas

    Energy Technology Data Exchange (ETDEWEB)

    Dies, J.; Tarrasa, F. [Universidad Politecnica de Catalunya (Spain); Cuevas de las, C.; Miralles, L.; Pueyo, J. J. [Universidad de Barcelona (Spain)

    2000-07-01

    The engineering barrier of a radioactive waste underground disposal facility, placed in a granitic host rock, will consist of a backfill of compacted bentonite blocks. At first, this material will be subjected to a gamma radiation field, from the waste canister, and heat from the spent fuel inside the canister. Moreover, any groundwater that reaches the repository will saturate the bentonite. For these reasons the performance of the engineered barrier must be carefully assessed in laboratory experiments. (Author)

  16. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed.

  17. Use of engineered soils and other site modifications for low-level radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    The U.S. Nuclear Regulatory Commission requires that low-level radioactive waste (LLW) disposal facilities be designed to minimize contact between waste and infiltrating water through the use of site design features. The purpose of this investigation is to identify engineered barriers and evaluate their ability to enhance the long-term performance of an LLW disposal facility. Previously used barriers such as concrete overpacks, vaults, backfill, and engineered soil covers, are evaluated as well as state-of-the-art barriers, including an engineered sorptive soil layer underlying a facility and an advanced design soil cover incorporating a double-capillary layer. The purpose of this investigation is also to provide information in incorporating or excluding specific engineered barriers as part of new disposal facility designs. Evaluations are performed using performance assessment modeling techniques. A generic reference disposal facility design is used as a baseline for comparing the improvements in long-term performance offered by designs incorporating engineered barriers in generic and humid environments. These evaluations simulate water infiltration through the facility, waste leaching, radionuclide transport through the facility, and decay and ingrowth. They also calculate a maximum (peak annual) dose for each disposal system design. A relative dose reduction factor is calculated for each design evaluated. The results of this investigation are presented for concrete overpacks, concrete vaults, sorptive backfill, sorptive engineered soil underlying the facility, and sloped engineered soil covers using a single-capillary barrier and a double-capillary barrier. Designs using combinations of barriers are also evaluated. These designs include a vault plus overpacks, sorptive backfill plus overpacks, and overpack with vault plus sorptive backfill, underlying sorptive soil, and engineered soil cover.

  18. Role of Soil Hysteresis in Impedance Testing as Applied to Buried Arches

    Science.gov (United States)

    1990-02-01

    information . I Add the individual listed to your distribution list. [] Delete the cited organization/individual. El Change of address. NAME: ORGANIZATION...arch structure shows that the backfill soil hysteretic behavoir is a dominant factor in explaining the absence of resonance in arch tests. ~ n0...TECHNICAL INFORMATION CENTER ATTN: ASMS 2CYS ATTN: DTIC/FDAB ATTN: MYE STRATEGIC AND THEATER NUCLEAR FORCES WEAPONS LABORATORY ATTN: DR E SEVIN ATTN

  19. Molecular Determinants Fundamental to Axon Regeneration After SCI

    Science.gov (United States)

    2010-07-01

    cord, thereby contributing to fai led functiona l resw rat ion. Previous work has demonstra ted that some brainstern neurons J in the adult zebra fish ...completeness of the transection and amount of additional tissue loss. Once we have chosen our approach we can start injuring fish and backfill...device. We can freely use this device and have started practicing. In parallel to the above, we have optimized histological steps such as fish

  20. Temperature reduction of A301 type low temperature ammonia synthesis catalyst%A301型低温氨合成催化剂的升温还原

    Institute of Scientific and Technical Information of China (English)

    王志峰; 郭新法

    2014-01-01

    介绍了中煤化工公司的A301型低温氨合成催化剂的装填、升温还原要点、控制方案及还原时的注意事项。%This paper introduces backfill, temperature reduction point, control scheme and matters need attention of A301 type low temperature synthesis catalyst in National Coal Chemical Company.

  1. Condition Assessment Survey (CAS) Program. Deficiency standards and inspections methods manual: Volume 1, 0.01 Foundations and footings

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    General information is presented for asset determinant factor/CAS repair codes/CAS cost factors; guide sheet tool & material listing; testing methods; inspection frequency; standard system design life tables; system work breakdown structure; and general system/material data. Deficiency standards and inspection methods are given for footings - spread/strip/grade beams; foundation walls; foundation dampproofing/waterproofing; excavation/backfill/ and piles & caissons.

  2. Implementation of the Barcelona Basic Model into TOUGH-FLAC for simulations of the geomechanical behavior of unsaturated soils

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, J.; Ijiri, Y.; Yamamoto, H.

    2010-06-01

    This paper presents the implementation of the Barcelona Basic Model (BBM) into the TOUGH-FLAC simulator analyzing the geomechanical behavior of unsaturated soils. We implemented the BBM into TOUGH-FLAC by (1) extending an existing FLAC{sup 3D} module for the Modified Cam-Clay (MCC) model in FLAC{sup 3D} and (2) adding computational routines for suction-dependent strain and net stress (i.e., total stress minus gas pressure) for unsaturated soils. We implemented a thermo-elasto-plastic version of the BBM, wherein the soil strength depends on both suction and temperature. The implementation of the BBM into TOUGH-FLAC was verified and tested against several published numerical model simulations and laboratory experiments involving the coupled thermal-hydrological-mechanical (THM) behavior of unsaturated soils. The simulation tests included modeling the mechanical behavior of bentonite-sand mixtures, which are being considered as back-fill and buffer materials for geological disposal of spent nuclear fuel. We also tested and demonstrated the use of the BBM and TOUGH-FLAC for a problem involving the coupled THM processes within a bentonite-backfilled nuclear waste emplacement tunnel. The simulation results indicated complex geomechanical behavior of the bentonite backfill, including a nonuniform distribution of buffer porosity and density that could not be captured in an alternative, simplified, linear-elastic swelling model. As a result of the work presented in this paper, TOUGH-FLAC with BBM is now fully operational and ready to be applied to problems associated with nuclear waste disposal in bentonite-backfilled tunnels, as well as other scientific and engineering problems related to the mechanical behavior of unsaturated soils.

  3. Expected environments in high-level nuclear waste and spent fuel repositories in salt

    Energy Technology Data Exchange (ETDEWEB)

    Claiborne, H.C.; Rickertsen, L.D., Graham, R.F.

    1980-08-01

    The purpose of this report is to describe the expected environments associated with high-level waste (HLW) and spent fuel (SF) repositories in salt formations. These environments include the thermal, fluid, pressure, brine chemistry, and radiation fields predicted for the repository conceptual designs. In this study, it is assumed that the repository will be a room and pillar mine in a rock-salt formation, with the disposal horizon located approx. 2000 ft (610 m) below the surface of the earth. Canistered waste packages containing HLW in a solid matrix or SF elements are emplaced in vertical holes in the floor of the rooms. The emplacement holes are backfilled with crushed salt or other material and sealed at some later time. Sensitivity studies are presented to show the effect of changing the areal heat load, the canister heat load, the barrier material and thickness, ventilation of the storage room, and adding a second row to the emplacement configuration. The calculated thermal environment is used as input for brine migration calculations. The vapor and gas pressure will gradually attain the lithostatic pressure in a sealed repository. In the unlikely event that an emplacement hole will become sealed in relatively early years, the vapor space pressure was calculated for three scenarios (i.e., no hole closure - no backfill, no hole closure - backfill, and hole closure - no backfill). It was assumed that the gas in the system consisted of air and water vapor in equilibrium with brine. A computer code (REPRESS) was developed assuming that these changes occur slowly (equilibrium conditions). The brine chemical environment is outlined in terms of brine chemistry, corrosion, and compositions. The nuclear radiation environment emphasized in this report is the stored energy that can be released as a result of radiation damage or crystal dislocations within crystal lattices.

  4. CATSIUS CLAY PROJECT: Calculation and testing of behaviour of unsaturated clay as barrier in radioactive waste repositories: stage 3: validation exercises at a large in situ scale

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, E. E.; Alcoverro, J.

    1999-07-01

    Stage 3 of CATSIUS CLAY Project: Validation Exercises at a Large in situ Scale includes two Benchmarks: Benchmark 3.1: In situ Hydration of Boom Clay Pellets (BACCHUS 2) and Benchmark 3.2: FEBEX Mock-up Test. The BACCHUS 2 in situ test was performed in the HADES underground laboratory (Mol, Belgium) to demonstrate and optimize an installation procedure for a clay based material and to study its hydration process. After drilling a vertical shaft (540 mm in diameter, 3.0 m in length) in the host Boom clay, a central filter (90 mm in diameter) was placed, the remaining space was filled with a mixture of clay pellets and clay powder and the assembly was sealed at the upper end by a resin plug (0.20 m in thickness) over which concrete was poured. The test was instrumented so that it could be used as a validation experiment. Total stress, pore water pressure and water content measurements were performed both in the backfill material and in the surrounding clay massif. Once the installation was complete, the natural hydration of the backfill material began (day 0). To accelerate the hydration process, on day 516 water was injected through the central filter. On day 624, after the saturation of the backfill was reached, the hydraulic circuit was closed and the undrained response of the system backfill-host clay was monitored until an overall steady state was reached. Partners were asked to provide predictions for the evolution of the pore water pressure and total pressure of various points where appropriate sensors are installed. This benchmark addresses the Hydro-Mechanical response of an unsaturated low density clay barrier under natural and artificial hydration. (Author)

  5. Deep Trenching Protection of Subsea Pipeline Crossing Channel%跨航道海底管道的深挖沟保护

    Institute of Scientific and Technical Information of China (English)

    杜喜军; 赵杰

    2015-01-01

    深挖沟填埋是对跨航道海底管道保护最常用也是最经济有效的方法.在制定深挖沟施工方案时需要重点考虑几个关键参数,包括土壤剪切强度、海底管道抗弯曲强度、挖沟机械设备的能力、挖沟回填的工程量等.挖沟后调查能够检测并及时反馈挖沟效果,是保证挖沟质量的关键.深挖沟后的沟槽回填是一项必不可少的工作.通过具体工程案例,分析了跨航道海底管道4 m深挖沟的影响因素,根据施工现场的实际情况制定了合理的挖沟方案,顺利完成跨航道海底管道的深挖沟掩埋工作.%Deep trenching and backfilling is the most common and the most economical method to protect subsea pipeline crossing channel. During deep trenching construction, there are several key parameters that is important, including shear strength of soil, bending strength of subsea pipeline, trenching equipment, quantity of backfilling etc. Trenching survey is able to detect and feedback the trench depth timely and it is the key to ensure the quality of trenching. Backfilling is an essential task. Through a specific Project, it analyzes the main factors affecting 4 meters depth trenching of subsea pipeline crossing channel, makes a reasonable trenching program based on the actual situation, and completes the task of trenching and backfilling successfully.

  6. The Reverse Approach for Monopile Scour

    DEFF Research Database (Denmark)

    Hartvig, Peres Akrawi

    2012-01-01

    The present paper deals with the theoretical and numerical modeling of scouring and backfilling around an offshore monopile. Based on existing relations for the bed load and the bed update, and a new model for the sediment pickup, it demonstrates the possibility of computing the mean bed shear st...... stress if the bed and bed update is estimated. The present concepts may be useful for developing methods for scour forecasting....

  7. Treatment and final disposal of nuclear waste. Programme for encapsulation, deep geological disposal, and research, development and demonstration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    Programs for RD and D concerning disposal of radioactive waste are presented. Main topics include: Design, testing and manufacture of canisters for the spent fuels; Design of equipment for deposition of waste canisters; Material and process for backfilling rock caverns; Evaluation of accuracy and validation of methods for safety analyses; Development of methods for defining scenarios for the safety analyses. 471 refs, 67 figs, 21 tabs.

  8. Treatment and disposal of radioactive wastes from nuclear power plants. Program for encapsulation, deep geologic deposition and research, development and demonstration; Kaernkraftavfallets behandling och slutfoervaring. Program foer inkapsling, geologisk djupfoervaring samt forskning, utveckling och demonstration

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    Programs for RD and D concerning disposal of radioactive waste are presented. Main topics include: Design, testing and manufacture of canisters for the spent fuels; Design of equipment for deposition of waste canisters; Material and process for backfilling rock caverns; Evaluation of accuracy and validation of methods for safety analyses; Development of methods for defining scenarios for the safety analyses. 471 refs, 67 figs, 21 tabs.

  9. Sustainable Use of Tepetate Composite in Earthen Structure

    OpenAIRE

    López-Lara, T.; Juan Bosco Hernandez-Zaragoza; Jaime Horta; Eduardo Rojas Gonzalez; Carlos Lopez-Cajun; Gerson Ramirez

    2013-01-01

    One of the best indicators for construction sustainability is the use of earthy local materials which are completely recyclables and savers of energy during their life cycle. Tepetate is an underestimated earth-natural material, vast and economic, used only in a compacted form in backfills for layers of low resistance in pavements and platforms of buildings. This volcanic soil, named in different ways in several countries, is found in the central region of Mexico. Its resistance as compacted ...

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

    OpenAIRE

    Qiu Jin; Li Fei

    2015-01-01

    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 monitori...

  11. The influence of sintering time on the properties of PM duplex stainless steel

    OpenAIRE

    Z. Brytan; L.A. Dobrzański; M. Actis Grande; Rosso, M.

    2009-01-01

    Purpose: The purpose of this paper is to analyse the effect of sintering time on the pore morphology, microstructural changes, tensile properties and corrosion resistance of vacuum sintered duplex stainless steel.Design/methodology/approach: In presented study PM duplex stainless steels were obtained through mixing base ferritic stainless steel powder with controlled addition of elemental alloying powders and then sintered in a vacuum furnace with argon backfilling at 1250°C for different tim...

  12. Neuroanatomy of pars intercerebralis neurons with special reference to their connections with neurons immunoreactive for pigment-dispersing factor in the blow fly Protophormia terraenovae.

    Science.gov (United States)

    Yasuyama, Kouji; Hase, Hiroaki; Shiga, Sakiko

    2015-10-01

    Input regions of pars intercerebralis (PI) neurons are examined by confocal and electron microscopies with special reference to their connections with neurons immunoreactive for pigment-dispersing factor (PDF) in the blow fly, Protophormia terraenovae. PI neurons are a prerequisite for ovarian development under long-day conditions. Backfills from the cardiac recurrent nerve after severance of the posterior lateral tracts labeled thin fibers derived from the PI neurons in the superior medial protocerebrum. These PI fibers were mainly synapsin-negative and postsynaptic to unknown varicose profiles containing dense-core vesicles. Backfilled fibers in the periesophageal neuropils, derived from the PI neurons or neurons with somata in the subesophageal zone, were varicose and some were synapsin-positive. Electron microscopy revealed the presence of both presynaptic and postsynaptic sites in backfilled fibers in the periesophageal neuropils. Many PDF-immunoreactive varicosities were found in the superior medial and lateral protocerebrum and double-labeling showed that 60-88 % of PDF-immunoreactive varicosities were also synapsin-immunoreactive. Double-labeling with the backfills and PDF immunocytochemistry showed that the PI fibers and PDF-immunoreactive varicosities were located close to each other in the superior medial protocerebrum. Results of triple-labeling of PI neurons, PDF-immunoreactive neurons and synapsin-immunoreactive terminals demonstrated that the synapsin-positive PDF-immunoreactive varicosities contacted the PI fibers. These data suggest that PI neurons receive synaptic contacts from PDF-immunoreactive fibers, which are derived from circadian clock neurons, of small ventral lateral neurons (previously called OL2) or posterior dorsal (PD) neurons with somata in the pars lateralis.

  13. Screening evaluation of radionuclide groundwater concentrations for the end state basement fill model Zion Nuclear Power Station decommissioning project

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan T.

    2014-06-09

    ZionSolutions is in the process of decommissioning the Zion Nuclear Power Plant. The site contains two reactor Containment Buildings, a Fuel Building, an Auxiliary Building, and a Turbine Building that may be contaminated. The current decommissioning plan involves removing all above grade structures to a depth of 3 feet below grade. The remaining underground structures will be backfilled with clean material. The final selection of fill material has not been made.

  14. Clasificación morfológica de los rellenos en el trasdós de bóvedas de fábrica

    Directory of Open Access Journals (Sweden)

    Ramos, A.

    2013-12-01

    Full Text Available This paper proposes a classification of the different type of backfill (granular, stiff or masonry backup at the extrados of vaults of historical masonry buildings scattered throughout the Iberian Peninsula. This study, in the mainframe of a broader research program, highlights the structural significance, rather disregarded in literature, of the backfill regarding the structural stability of such constructions. Furthermore, the most common patterns of the arrangement of masonry backup and backfill, as well as some structural considerations, are depicted to illustrate how to evaluate their structural contribution.En este artículo se establece una clasificación de los diferentes tipos de rellenos (rígidos o cementados, granulares firmes o sueltos y aligerados situados en el trasdós de bóvedas y que han podido datarse en diferentes construcciones históricas en el ámbito geográfico de la Península Ibérica. Estos rellenos, tal y como pretende demostrar el estudio más amplio y del que se extrae el presente artículo, tienen una importancia vital para la estabilidad estructural de estas construcciones. Además de la clasificación, se establecen los patrones tipo con los que se encuentran estos rellenos y se introducen algunas de las consideraciones estructurales que deben tenerse en cuenta si se consideran estructuralmente.

  15. Geoelectric monitoring of bentonite barrier resaturation in the Aespoeprototype repository. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wieczorek, Klaus; Komischke, Michael; Miehe, Ruediger; Moog, Helge

    2014-10-15

    In 1994, SKB started constructing the ''Prototype Repository'', a full-scale replica of a part of a future KBS-3 repository in crystalline rock, at the AespoeHard Rock Laboratory. Six emplacement boreholes were planned and constructed in two tunnel sections until end of 1999. The international EC co-funded Prototype Repository project was started in 2000 (contract FIKW-CT-2000-00055). The project partners were SKB (Sweden), POSIVA (Finland), ENRESA (Spain), GRS (Germany), BGR (Germany), UWC (UK), and JNC (Japan). Between 2000 and 2003 the complete Prototype Repository was equipped and instrumented, and monitoring was started. In February 2004 the EC funding expired. The Prototype Repository project was continued with national funding of the project partners. In 2011, dismantling of Section II was started in a three-year project. Backfill, buffer and canisters as well as part of the instrumentation were retrieved, and numerous laboratory investigations on buffer and backfill samples were performed. GRS' part in the Prototype Repository was the monitoring of backfill and buffer resaturation using geoelectric tomography. The measurements were completed in 2013.

  16. Prospects for coupled modelling

    Energy Technology Data Exchange (ETDEWEB)

    Savage, D.

    2012-07-01

    Clay-based buffer and tunnel backfill materials are important barriers in the KBS- 3 repository concept for final disposal of spent nuclear fuel in Finland. Significant changes can be expected to occur to the properties and behaviour of buffer and backfill, especially during re-saturation and through the thermal period. Reactions will occur in response to thermal and chemical gradients, induced by the thermal output of the spent fuel and at interfaces between different barrier materials, such as cement/clay, steel/clay etc. Processes of ion exchange, mineral dissolution and precipitation, and swelling can lead to significant re-distribution of mass and evolution of physical properties so that reliable predictive modelling of future behaviour and properties must be made. This report evaluates the current status of modelling of buffer and backfill evolution and tries to assess the potential future capabilities in the short- to medium-term (5-10 years) in a number of technical areas: (1) Non-isothermal (T-H-M-C-B) modelling and the potential for cementation, (2) The consistency of models, (3) Swelling pressure, (4) Cement-bentonite interactions, (5) Iron-bentonite interactions, (6) Mechanical (shear) behavior, and (7) Bentonite erosion.

  17. Redox-filled Carbon-Fiber Microelectrodes for Single-Cell Exocytosis

    Science.gov (United States)

    Cox, Jonathan T.; Gunderson, Christopher G.; Zhang, Bo

    2014-01-01

    Carbon-fiber microelectrodes (CFEs) are the primary electroanalytical tool in single-cell exocytosis and in-vivo studies. Here we report a new study on the kinetic properties of electrolyte-filled CFEs in single-cell measurements and demonstrate that the addition of outer sphere redox species, such as Fe(CN)63− and Ru(NH3)63+, in the backfill electrolyte solution can greatly enhance the kinetic response of CFEs. We show that at 750 mV, a voltage normally applied for detection of dopamine, the presence of fast outer sphere redox species in the backfilling solution significantly enhances the kinetic response of CFEs toward fast dopamine detection at single PC12 cells. Moreover, we also demonstrate that the use of Fe(CN)63− in the backfilling solution has enabled direct measurement of dopamine at applied voltages as low as 200 mV. This kinetic enhancement is believed to be due to faster electron-transfer kinetics on the coupling pole as compared to the sluggish reduction of oxygen. We anticipate that such redox-filled CFE ultramicroelectrodes will find many useful applications in single cell exocytosis and in-vivo sensing. PMID:24833889

  18. Nuclear waste package materials testing report: basaltic and tuffaceous environments

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, D.J.; Coles, D.G.; Hodges, F.N.; McVay, G.L.; Westerman, R.E.

    1983-03-01

    The disposal of high-level nuclear wastes in underground repositories in the continental United States requires the development of a waste package that will contain radionuclides for a time period commensurate with performance criteria, which may be up to 1000 years. This report addresses materials testing in support of a waste package for a basalt (Hanford, Washington) or a tuff (Nevada Test Site) repository. The materials investigated in this testing effort were: sodium and calcium bentonites and mixtures with sand or basalt as a backfill; iron and titanium-based alloys as structural barriers; and borosilicate waste glass PNL 76-68 as a waste form. The testing also incorporated site-specific rock media and ground waters: Reference Umtanum Entablature-1 basalt and reference basalt ground water, Bullfrog tuff and NTS J-13 well water. The results of the testing are discussed in four major categories: Backfill Materials: emphasizing water migration, radionuclide migration, physical property and long-term stability studies. Structural Barriers: emphasizing uniform corrosion, irradiation-corrosion, and environmental-mechanical testing. Waste Form Release Characteristics: emphasizing ground water, sample surface area/solution volume ratio, and gamma radiolysis effects. Component Compatibility: emphasizing solution/rock, glass/rock, glass/structural barrier, and glass/backfill interaction tests. This area also includes sensitivity testing to determine primary parameters to be studied, and the results of systems tests where more than two waste package components were combined during a single test.

  19. Long-Term Modeling of Coupled Processes in a Generic Salt Repository for Heat-Generating Nuclear Waste: Analysis of the Impacts of Halite Solubility Constraints

    Science.gov (United States)

    Blanco Martin, L.; Rutqvist, J.; Battistelli, A.; Birkholzer, J. T.

    2015-12-01

    Rock salt is a potential medium for the underground disposal of nuclear waste because it has several assets, such as its ability to creep and heal fractures and its water and gas tightness in the undisturbed state. In this research, we focus on disposal of heat-generating nuclear waste and we consider a generic salt repository with in-drift emplacement of waste packages and crushed salt backfill. As the natural salt creeps, the crushed salt backfill gets progressively compacted and an engineered barrier system is subsequently created [1]. The safety requirements for such a repository impose that long time scales be considered, during which the integrity of the natural and engineered barriers have to be demonstrated. In order to evaluate this long-term integrity, we perform numerical modeling based on state-of-the-art knowledge. Here, we analyze the impacts of halite dissolution and precipitation within the backfill and the host rock. For this purpose, we use an enhanced equation-of-state module of TOUGH2 that properly includes temperature-dependent solubility constraints [2]. We perform coupled thermal-hydraulic-mechanical modeling and we investigate the influence of the mentioned impacts. The TOUGH-FLAC simulator, adapted for large strains and creep, is used [3]. In order to quantify the importance of salt dissolution and precipitation on the effective porosity, permeability, pore pressure, temperature and stress field, we compare numerical results that include or disregard fluids of variable salinity. The sensitivity of the results to some parameters, such as the initial saturation within the backfill, is also addressed. References: [1] Bechthold, W. et al. Backfilling and Sealing of Underground Repositories for Radioactive Waste in Salt (BAMBUS II Project). Report EUR20621 EN: European Atomic Energy Community, 2004. [2] Battistelli A. Improving the treatment of saline brines in EWASG for the simulation of hydrothermal systems. Proceedings, TOUGH Symposium 2012

  20. Prototype repository: A full scale experiment at Äspö HRL

    Science.gov (United States)

    Johannesson, Lars-Erik; Börgesson, Lennart; Goudarzi, Reza; Sandén, Torbjörn; Gunnarsson, David; Svemar, Christer

    At Äspö Hard Rock Laboratory a full scale test of the Swedish concept for disposal of nuclear waste (KBS-3V) is in progress. The Prototype Repository project consists of two sections. The installation of the first section was made during summer and autumn 2001 and the second section during spring and summer 2003. Section 1 consists of four full-scale deposition holes, copper canisters equipped with electrical heaters, bentonite buffer consisting of blocks and pellets and a deposition tunnel backfilled with a mixture of bentonite and crushed rock, ending with a concrete plug. Section 2 consists of two full-scale deposition holes with a backfilled tunnel section and ends also with a concrete plug. Altogether 84 large bentonite blocks, with a total weight of about 130 tons, were installed and more than 2000 tons of backfill material were mixed and compacted in situ. Earlier developed techniques for both manufacturing and installing the buffer and the backfill were used in the project. Measurements and data from the installation allow calculations of the expected density in the buffer and in different parts of the backfill. The bentonite buffer in deposition holes 1, 3, 5 and 6, the backfill and the surrounding rock are instrumented with gauges for measuring temperature, water pressure, total pressure, relative humidity, resistivity, canister displacement and rock stresses. The instruments are connected to data acquisition systems by cables protected by tubes. These tubes are led through the rock in watertight lead-throughs to a nearby tunnel where the data acquisition systems are situated. More than 1100 transducers have been installed in the rock, buffer and the backfill. The technique for protecting the transducers from high water and swelling pressure was developed in this and preceding projects and furthermore different designs of transducers are used for the same type of measurement in order to compare their behaviour. The deposition holes have different water

  1. WATER DIVERSION MODEL

    Energy Technology Data Exchange (ETDEWEB)

    J.B. Case

    1999-12-21

    The distribution of seepage in the proposed repository will be highly variable due in part to variations in the spatial distribution of percolations. The performance of the drip shield and the backfill system may divert the water flux around the waste packages to the invert. Diversion will occur along the drift surface, within the backfill, at the drip shield, and at the Waste Package (WP) surface, even after the drip shield and WP have been breached by corrosion. The purpose and objective of this Analysis and Modeling Report (AMR) are to develop a conceptual model and constitutive properties for bounding the volume and rate of seepage water that flows around the drip shield (CRWMS M&O 1999c). This analysis model is to be compatible with the selected repository conceptual design (Wilkins and Heath, 1999) and will be used to evaluate the performance of the Engineered Barrier System (EBS), and to provide input to the EBS Water Distribution and Removal Model. This model supports the Engineered Barrier System (EBS) postclosure performance assessment for the Site Recommendation (SR). This document characterizes the hydrological constitutive properties of the backfill and invert materials (Section 6.2) and a third material that represents a mixture of the two. These include the Overton Sand which is selected as a backfill (Section 5.2), crushed tuff which is selected as the invert (Section 5.1), and a combined material (Sections 5.9 and 5.10) which has retention and hydraulic conductivity properties intermediate to the selected materials for the backfill and the invert. The properties include the grain size distribution, the dry bulk density and porosity, the moisture retention, the intrinsic permeability, the relative permeability, and the material thermal properties. The van Genuchten relationships with curve fit parameters are used to define the basic retention relationship of moisture potential to volumetric moisture content, and the basic relationship of unsaturated

  2. General strategy, clay based disposal concepts and integration (GSI)

    Energy Technology Data Exchange (ETDEWEB)

    Keto, P.; Gunnarsson, G.; Johannesson, L.E.; Hansen, J.; Emmerich, K.; Kemper, G.; Nuesch, R.; Schuhmann, R.; Koniger, F.; Schlager, St.; Gruner, M.; Hofmann, M.; Nuesch, R.; Kobayashi, I.; Toida, M.; Sasakura, T.; Bernier, F.; Li, X.L.; Ileana Denisa, Nistor; Neculai, DoruMiron; Tudor, Sajin; Abdelkrim, Azzouz; Ilie, Siminiceanu; Viswanadham, B.V.S.; Rajesh, S.; Sengupta, S.S.; Panturu, E.; Radulescu, R.; Jinescu, C.; Panturu Razvann, Ioan; Autio, J.; Sanden, T.; Borgesson, L.; Svensson, D.; Eng, A.; Sellin, P.; Dixon, D.A.; Martino, J.B.; Vignal, B.; Fujita, T.; Wei-Hsing, Huang; Wen-Chuan, Chen; Shu-Rong, Yang; Dmitriev, S.; Prozorov, L.; Litinsky, Y.; Tkachenko, A.; Guskov, A.; Sanden, T.; Borgesson, L.; Camp, S.; Gourc, J.P.; Ple, O.; Kaelin, J.L.; Marchiol, A.; Round, C.; Johannesson, L.E.; Nilsson, U.; Adamcova, R.; Frankovska, J.; Durmekova, T.; Haasova, Z.; Gatabin, C.; Guyot, J.L.; Resnikow, S.; Karnland, O.; Nilsson, U.; Weber, H.; Wersin, P.; Gray, M.N.; Dixon, D.A.; Poulesquen, A.; Radwan, J.; Poinssot, C.; Ferry, C.; Weber, H.P.; Plotze, M

    2007-07-01

    This session gathers 20 articles (posters) dealing with: the assessment of backfill materials and methods for deposition tunnels; HTV-1: a semi technical scale testing of a multi-layer hydraulic shaft sealing system; the development of water content adjust method by mixing powdered-ice and chilled bentonite: application to the construction of bentonite engineered barriers by shot-clay method; repository design issues related to the thermal impact induced by heat emitting radioactive waste; pillared clays, using Romanian montmorillonite; the simulation of differential settlements of clay based engineered barrier systems in a geo-centrifuge; the critical issues regarding clay behaviour in the KBS-3H repository design; an alternative buffer material experiment; assessing the performance of a swelling clay tunnel seal and issues identified in the course of its operation; the activation of a Ca-bentonite as buffer material; a large diameter borehole type repository in the clays for radioactive waste long term storage; the erosion of backfill materials during the installation phase; the behaviour of the clay cover of a site for very low level nuclear waste: field flexion tests; the laboratory tests made on three different backfill candidates for the Swedish KBS- 3V concept; the engineering geological clay research for radioactive waste repository in Slovakia; the ESDRED project, module 1 - Design, fabrication, assembly, handling and packaging of buffer rings; the laboratory experiments on the sealing ability of bentonite pellets; the screening of bentonite resources for use as an engineered barrier component in deep geologic repositories; the assessment of the radionuclide release from the near-field environment of a spent nuclear fuel geological repository; and the emplacement tests with granular bentonite.

  3. Systems study on engineered barriers: barrier performance analysis

    Energy Technology Data Exchange (ETDEWEB)

    Stula, R.T.; Albert, T.E.; Kirstein, B.E.; Lester, D.H.

    1980-09-01

    A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been modified and applied to several package designs. The objective of the study was to develop information to be used in programmatic decision making concerning engineered barrier package design and development. The assessment model, BARIER, was developed in previous tasks of the System Study on Engineered Barriers (SSEB). The new version discussed in this report contains a refined and expanded corrosion rate data base which includes pitting, crack growth, and graphitization as well as bulk corrosion. Corrosion rates for oxic and anoxic conditions at each of the two temperature ranges are supplied. Other improvements include a rigorous treatment of radionuclide release after package failure which includes resistance of damaged barriers and backfill, refined temperature calculations that account for convection and radiation, a subroutine to calculate nuclear gamma radiation field at each barrier surface, refined stress calculations with reduced conservatism and various coding improvements to improve running time and core usage. This report also contains discussion of alternative scenarios to the assumed flooded repository as well as the impact of water exclusion backfills. The model was used to assess post repository closure performance for several designs which were all variation of basic designs from the Spent Unreprocessed Fuel (SURF) program. Many designs were found to delay the onset of leaching by at least a few hundreds of years in all geologic media. Long delay times for radionuclide release were found for packages with a few inches of sorption backfill. Release of uranium, plutonium, and americium was assessed.

  4. An evaluation of repository-induced disturbances for a KBS-3 type repository

    Energy Technology Data Exchange (ETDEWEB)

    Savage, D.; McLeod, R.; McEwen, T. [QuantiSci, Melton Mowbray (United Kingdom)

    1998-03-01

    This report considers the potential physical and chemical perturbations caused by the excavation, operation and backfilling and sealing of a KBS-3 type repository for spent fuel in Sweden. Parts of the underground excavations are likely to remain open to the atmosphere for up to several decades. Time-dependent changes to the chemical environment and the properties of the geological formation will be occurring as well as the initial disturbance of construction and subsequent changes after backfilling. In addition, this report also discusses issues that arise from the co-disposal of spent fuel and intermediate level waste. The processes which are likely to act during each stage of a repository from construction through to backfilling and sealing have been reviewed and the degree to which these processes are understood and represented within the performance assessment is discussed. The areas of particular interest are: The coupling of thermal, hydrogeological and mechanical processes with particular reference to the development of the near-field; Understanding the transient process of re-saturation with particular reference to the buffer material surrounding the waste canisters, including chemical changes to the material; The impact of accidental events during the construction and operational phases of work and their possible consequence on the long term performance of the repository; Chemical issues relating to the co-disposal of spent fuel and intermediate level wastes within a single facility. When consideration of transient processes and coupling is discussed, it is apparent that numerical tools and a complete understanding to provide quantitative information is lacking. The importance of the engineered barrier system within the performance assessment for spent fuel disposal is recognised and the emphasis is placed on the understanding of the coupled processes in the evolution in the near-field of the geosphere 45 refs, 4 fig, 2 tabs

  5. Closure and Sealing Design Calculation

    Energy Technology Data Exchange (ETDEWEB)

    T. Lahnalampi; J. Case

    2005-08-26

    The purpose of the ''Closure and Sealing Design Calculation'' is to illustrate closure and sealing methods for sealing shafts, ramps, and identify boreholes that require sealing in order to limit the potential of water infiltration. In addition, this calculation will provide a description of the magma that can reduce the consequences of an igneous event intersecting the repository. This calculation will also include a listing of the project requirements related to closure and sealing. The scope of this calculation is to: summarize applicable project requirements and codes relating to backfilling nonemplacement openings, removal of uncommitted materials from the subsurface, installation of drip shields, and erecting monuments; compile an inventory of boreholes that are found in the area of the subsurface repository; describe the magma bulkhead feature and location; and include figures for the proposed shaft and ramp seals. The objective of this calculation is to: categorize the boreholes for sealing by depth and proximity to the subsurface repository; develop drawing figures which show the location and geometry for the magma bulkhead; include the shaft seal figures and a proposed construction sequence; and include the ramp seal figure and a proposed construction sequence. The intent of this closure and sealing calculation is to support the License Application by providing a description of the closure and sealing methods for the Safety Analysis Report. The closure and sealing calculation will also provide input for Post Closure Activities by describing the location of the magma bulkhead. This calculation is limited to describing the final configuration of the sealing and backfill systems for the underground area. The methods and procedures used to place the backfill and remove uncommitted materials (such as concrete) from the repository and detailed design of the magma bulkhead will be the subject of separate analyses or calculations. Post

  6. Mineralogy and sealing properties of various bentonites and smectite-rich clay materials

    Energy Technology Data Exchange (ETDEWEB)

    Karnland, Ola; Olsson, Siv; Nilsson, Ulf (Clay Technology AB (SE))

    2006-12-15

    The present work includes a coherent study of Wyoming bentonite with respect to the most relevant properties for use in a repository, and a parallel study of other potential buffer and tunnel backfilling materials. The reason for this is twofold; to quantify the effect of mineralogical variations on the various important sealing properties of bentonite, and to verify that there are alternative potential sources of bentonite. The latter is motivated by the fact that Sweden alone plans to deposit at least 6,000 copper canisters which include approximately 130,000 metric tones bentonite buffer material and several times more as tunnel backfill material. Different types of sealing clay materials may also be relevant to use, since the demands on the clay will be different at the various locations in a repository. Alternative sources of bentonite would consequently be valuable in order to secure quality, supply, and price. Important aspects on buffer and tunnel backfilling materials may be summarized as: Original sealing properties. Hazardous substances in any respect. Short-term effects of ground-water chemistry. Long-term stability, i.e. effects of temperature and ground-water chemistry. Availability. Costs. The focus in this study is on the first three items. The long-term stability is indirectly considered in that mineralogical composition is determined. The availability is only considered in such a way that most of the analyzed materials represent huge clay formations, which contain much more material than needed for a repository. The cost aspects have not been included, mainly because the present day price is not relevant due to the time frame of the construction of a repository

  7. Yucca Mountain Waste Package Closure System

    Energy Technology Data Exchange (ETDEWEB)

    shelton-davis; Colleen Shelton-Davis; Greg Housley

    2005-10-01

    The current disposal path for high-level waste is to place the material into secure waste packages that are inserted into a repository. The Idaho National Laboratory has been tasked with the development, design, and demonstration of the waste package closure system for the repository project. The closure system design includes welding three lids and a purge port cap, four methods of nondestructive examination, and evacuation and backfill of the waste package, all performed in a remote environment. A demonstration of the closure system will be performed with a full-scale waste package.

  8. Yucca Mountain Waste Package Closure System

    Energy Technology Data Exchange (ETDEWEB)

    Herschel Smartt; Arthur Watkins; David Pace; Rodney Bitsoi; Eric Larsen; Timothy McJunkin; Charles Tolle

    2006-04-01

    The current disposal path for high-level waste is to place the material into secure waste packages that are inserted into a repository. The Idaho National Laboratory has been tasked with the development, design, and demonstration of the waste package closure system for the repository project. The closure system design includes welding three lids and a purge port cap, four methods of nondestructive examination, and evacuation and backfill of the waste package, all performed in a remote environment. A demonstration of the closure system will be performed with a full-scale waste package.

  9. Long term investigation of thermal behaviour of 110 kV underground transmission lines in the Belgrade area

    Energy Technology Data Exchange (ETDEWEB)

    Sredojevic, M.R.; Naumov, R.M.; Popovic, D.P. [Nikola Tesla Electrical Engineering Inst., Belgrade (Yugoslavia); Simic, M.D. [Electrical Utility Co., Belgrade (Yugoslavia)

    1997-12-31

    The paper describes the procedure for applying a special cable backfill material, developed and manufactured at the Institute ``Nikola Tesla`` for the thermal stabilisation and reduction of hot spot cable operating temperature, on specific hot spots of 110 kV underground transmission lines in the Belgrade area. The results presented in this paper are an important contribution to the proof of the justification and necessity of defining and introducing in practice new procedures for the thermal stabilisation and reduction of operating temperature of existing, as well as of new, underground transmission cable lines to be built. (author)

  10. Guide for surface coal mine reclamation plans

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-11-15

    The purpose of the guide is to provide a framework for Nova Scotia's coal mining community to consult during reclamation planning and environmental assessment. The guide describe the best management practices for application to surface mine reclamation. Principles of reclamation, standard submission requirements for a reclamation plan, planning for reclamation, landscape design, and revegetation, and methods for site preparation, monitoring, and maintenance are discussed. Backfilling, flooded excavation management, and other options are outlined. The reclamation plan must consider decommissioning of equipment and infrastructure, water retention and treatment ponds, acid rock drainage control and monitoring, site monitoring, watercourse management, and public safety. A glossary is included.

  11. Non-equilibrium Green's function calculation for GaN-based terahertz-quantum cascade laser structures

    Science.gov (United States)

    Yasuda, H.; Kubis, T.; Hosako, I.; Hirakawa, K.

    2012-04-01

    We theoretically investigated GaN-based resonant phonon terahertz-quantum cascade laser (QCL) structures for possible high-temperature operation by using the non-equilibrium Green's function method. It was found that the GaN-based THz-QCL structures do not necessarily have a gain sufficient for lasing, even though the thermal backfilling and the thermally activated phonon scattering are effectively suppressed. The main reason for this is the broadening of the subband levels caused by a very strong interaction between electrons and longitudinal optical (LO) phonons in GaN.

  12. Optimization of ground source heat pumps related to soil and groundwater conditions as well as grouting material; Optimierung von Waermepumpen in Bezug auf Boden- und Grundwasserverhaeltnisse sowie Verpressmaterial

    Energy Technology Data Exchange (ETDEWEB)

    Katzenbach, R.; Clauss, F.; Waberseck, T. [Technische Univ. Darmstadt (Germany). Inst. und Versuchsanstalt fuer Geotechnik; Sass, J. [Technische Univ. Darmstadt (Germany). Inst. fuer Angewandte Geowissenschaften, Fachgebiet Ingenieurgeologie

    2006-07-01

    The capacity and the performance of ground source heat pumps and seasonal thermal storage systems with borehole heat exchangers depend on the conditions of the encountered subsoil and the groundwater and furthermore on the thermal properties of the grouting material used for conclusive backfilling of the annular space after installing the heat exchanger pipes in the borehole. Intensive investigations are carried out at the Technische Universitaet Darmstadt with the aim of an economical optimisation of the dimensioning of ground source heat pumps and seasonal thermal storage systems. (orig.)

  13. Remote monitoring within the framework of rock burst prevention. Fernueberwachung in der Gebirgsschlagverhuetung

    Energy Technology Data Exchange (ETDEWEB)

    Hahnekamp, H.G.; Koenig, W.; Kuzia, M.

    1991-12-12

    The DMT Institute for Rock Control and Backfilling of Cavities has developed a technically simple remote monitoring system for use within the framwork of rock burst prevention. With this system coal faces can be continuously monitored even under difficult underground conditions without serious operating problems. For the monitoring the variables measured underground, viz. rock pressure, rock movement and deformation of test boreholes, are transmitted via the telecommunication network of the colliery to a computer on the surface, where they are evaluated online with regard to recognition of a rock burst hazard. Display of the actual monitoring situation on the computer screen permits immediate initiation of safety measures in the event of danger. (orig.).

  14. Roughness’s shapes comparative analysis of some reinforced earth elements under monotonous loading

    Directory of Open Access Journals (Sweden)

    Mohamed Khemissa

    2015-09-01

    Full Text Available This paper presents and analyzes the experimental and numerical results of a series of pullout tests under monotonous loading performed on five steel strips presenting various forms of roughness (smooth, ribbed, punched, W-shaped, chain and embedded in the same dry sand massif constituting the backfill. The pullout tests were conducted by means of a small-scale model and the calculations carried out by using a finite elements computer program. Obtained results show a good agreement between the experimental and numerical data. They show in addition that the rough strips are more advantageous than the smooth strip. Among the rough strips considered, chain is most relevant.

  15. Direct methods of soil-structure interaction analysis for earthquake loadings (IV)

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, J. B.; Kim, D. S.; Choi, J. S.; Kwon, K. C.; Kim, Y. J.; Lee, H. J.; Kim, S. B.; Kim, D. K. [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1996-07-15

    Methodologies of SSI analysis for earthquake loadings have been reviewed. Based on the finite element method incorporating infinite element technique for the unbounded exterior region, a computer program for the nonlinear seismic analysis named as 'KIESSI-QK' has been developed. The computer program has been verified using a free-field site-response problem. The Hualien FVT stochastic finite element analysis after backfill and the blind prediction of earthquake responses have been carried out utilizing the developed computer program. The earthquake response analysis for the LSST structure has also been performed and compared with the measured data.

  16. Recommended values for the distribution coefficient (Kd) to be used in dose assessments for decommissioning the Zion Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan T.

    2014-06-09

    ZionSolutions is in the process of decommissioning the Zion Nuclear Power Plant. The site contains two reactor Containment Buildings, a Fuel Building, an Auxiliary Building, and a Turbine Building that may be contaminated. The current decommissioning plan involves removing all above grade structures to a depth of 3 feet below grade. The remaining underground structures will be backfilled. The remaining underground structures will contain low amounts of residual licensed radioactive material. An important component of the decommissioning process is the demonstration that any remaining activity will not cause a hypothetical individual to receive a dose in excess of 25 mrem/y as specified in 10CFR20 SubpartE.

  17. Recommended values for the distribution coefficient (Kd) to be used in dose assessments for decommissioning the Zion Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-09-24

    ZionSolutions is in the process of decommissioning the Zion Nuclear Power Plant. The site contains two reactor Containment Buildings, a Fuel Building, an Auxiliary Building, and a Turbine Building that may be contaminated. The current decommissioning plan involves removing all above grade structures to a depth of 3 feet below grade. The remaining underground structures will be backfilled. The remaining underground structures will contain low amounts of residual licensed radioactive material. An important component of the decommissioning process is the demonstration that any remaining activity will not cause a hypothetical individual to receive a dose in excess of 25 mrem/y as specified in 10CFR20 SubpartE.

  18. Engineered Materials Characterization Report for the Yucca Mountain Site Characterization Project, Volume 3, Revision 1, Corrosion Data and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    McCright, R D

    1998-04-01

    The Engineered Materials Characterization Report (EMCR) serves as a source of information on the properties of materials proposed as elements in the engineered barrier system (EBS) for the Yucca Mountain nuclear waste repository. Volume 3 covered the corrosion data and modeling efforts. The present report is a revision to Volume 3 and updates information on the corrosion (and other degradation modes) behavior of candidate materials for the various components of the EBS. It also includes work on the performance modeling of these materials. Work is reported on metallic barriers, basket materials, packing/backfill/invert materials, and non-metallic materials.

  19. Design and proof of function of a closure system for an HLW-repository in rock salt. Results of the preliminary safety analysis for the Gorleben site (VSG)

    Energy Technology Data Exchange (ETDEWEB)

    Mueller-Hoeppe, Nina; Breustedt, Michael; Engelhardt, Hans-Joachim; Wolf, Johanna [DBE Technology GmbH, Peine (Germany); Buhmann, Dieter; Czaikowski, Oliver; Herbert, Horst-Juergen; Wieczorek, Klaus; Xie, Mingliang [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH, Braunschweig (Germany)

    2015-07-01

    Within the preliminary safety analysis for the Gorleben site (VSG), a closure system was designed in order to complement the containment providing rock zone (CRZ) by sealing and backfilling measures. The design procedure as well as the technical proof of function was mainly performed according to standard procedures in civil engineering. In the context of VSG, rough individual technical proofs of several measures were carried out. Meanwhile, this gap has been closed by subsequent investigations. Altogether the results of all the individual technical proofs of function indicate that safe containment of radioactive waste is a realistic possibility at the Gorleben site.

  20. Sediment Transport

    DEFF Research Database (Denmark)

    Liu, Zhou

    Flow and sediment transport are important in relation to several engineering topics, e.g. erosion around structures, backfilling of dredged channels and nearshore morphological change. The purpose of the present book is to describe both the basic hydrodynamics and the basic sediment transport...... mechanics. Chapter 1 deals with fundamentals in fluid mechanics with emphasis on bed shear stress by currents, while chapter 3 discusses wave boundary layer theory. They are both written with a view to sediment transport. Sediment transport in rivers, cross-shore and longshore are dealt with in chapters 2...

  1. Performance assessment of sealing systems. Conceptual and integrated modelling of plugs and seals

    Energy Technology Data Exchange (ETDEWEB)

    Ruebel, Andre; Buhmann, Dieter; Kindlein, Jonathan; Lauke, Thomas

    2016-08-15

    The long-time isolation of radionuclides from the biosphere is the goal of the storage of radioactive waste in deep geological repositories. For repositories in rock salt, this goal is achieved on the one hand by the impermeable undisturbed part of the salt host rock formation and on the other hand by crushed salt, which is used to backfill the mine openings in the emplacement areas and galleries created during the construction of the repository. The crushed salt backfill is compacted over time and achieves a sufficiently high hydraulic resistance to avoid inflow of brines into the emplacement areas of the repository in the long-term. Plugs and seals must additionally provide their sealing function during the early post closure phase, until the compaction of the backfill is adequate and the permeability of the backfill is sufficiently low. To assess the future development of the waste repository, an adequate knowledge of the material behaviour is necessary and related mathematical models must be developed to be able to perform predictions on the long-term safety of the repository. An integrated performance assessment model was formulated that describes the long-term behaviour of a sealing built from salt concrete. The average permeability of the sealing changes with time after its emplacement from various processes of which two were regarded in a constitutive model: first, the healing of the EDZ in the host rock around the sealing, and second, the corrosion of the salt concrete material resulting from brine attack. Empirical parameter model functions were defined for both processes to reflect the actual behaviour. The mathematical model was implemented in the integrated performance assessment model LOPOS which is used by GRS as near-field model for repositories in salt. Deterministic and probabilistic calculations were performed with realistic parameters showing how the permeability of the sealing decreases during the first 2 000 years due to the healing of the EDZ

  2. STM in poslovne baze podatkov v Slovenij

    Directory of Open Access Journals (Sweden)

    Sam Brooks

    2003-01-01

    Full Text Available Through a detailed view of STM and business journals available in Slovenia, this article depicts the value of particular databases and the impact of a tremendous influx of information into the country in recent years. The two most comprehensive databases that are available from EBSCO, the world’s largest intermediary between publishers and libraries, are explored. EBSCO’s company strategies with regard to its academic databases are described. The article examines which databases are strongest in each discipline,and covers issues such as the availability of journals most-cited, full text formats,peer-review status, embargo periods, backfiles, and other important facets.

  3. The layer by layer selective laser synthesis of ruby

    Directory of Open Access Journals (Sweden)

    Vlasova M.

    2010-01-01

    Full Text Available In the work, features of the layer-by-layer selective laser synthesis (SLS of ruby from an Al2O3-Cr2O3 mixture are considered depending on the irradiation power, the laser beam traverse speed, the height and amount of the backfill of powder layers. It has been established that, under irradiation, a track consisting of polycrystalline textured ruby forms. The morphology of the surface of the track and its crystalline structure are determined by the irradiation conditions.

  4. Fabrication of high fidelity, high index three-dimensional photonic crystals using a templating approach

    Science.gov (United States)

    Xu, Yongan

    In this dissertation, we demonstrate the fabrication of high fidelity 3D photonic crystal through polymer template fabrication, backfilling and template removal to obtain high index inversed inorganic photonic crystals (PCs). Along the line, we study the photoresist chemistry to minimize the shrinkage, backfilling strategies for complete infiltration, and template removal at high and low temperatures to minimize crack-formation. Using multibeam interference lithography (MBIL), we fabricate diamond-like photonic structures from commercially available photoresist, SU-8, epoxy functionalized polyhedral oligomeric silsesquioxane (POSS), and narrowly distributed poly(glycidyl methacrylate)s (PGMA). The 3D structure from PGMA shows the lowest shrinkage in the [111] direction, 18%, compared to those fabricated from the SU-8 (41%) and POSS (48%) materials under the same conditions. To fabricate a photonic crystal with large and complete photonic bandgap, it often requires backfilling of high index inorganic materials into a 3D polymer template. We have studied different backfilling methods to create three different types of high index, inorganic 3D photonic crystals. Using SU-8 structures as templates, we systematically study the electrodeposition technique to create inversed 3D titania crystals. We find that 3D SU-8 template is completely infiltrated with titania sol-gel through a two-stage process: a conformal coating of a thin layer of films occurs at the early electrodeposition stage (simulated photonic bandgaps (PBGs) and the SEM observation, further supporting the complete filling by the wet chemistry. Since both PGMA and SU-8 decompose at a temperature above 400°C, leading to the formation of defects and cracks, a highly thermal and mechanical stable template is desired for PC fabrication. We fabricate the 3D POSS structures by MBIL, which can be converted to crack-free silica-like templates over the entire sample area (˜5 mm in diameter) by either thermal

  5. Latex-modified grouts for in-situ stabilization of buried transuranic/mixed waste

    Energy Technology Data Exchange (ETDEWEB)

    Allan, M.L.

    1996-06-01

    The Department of Applied Science at Brookhaven national Laboratory was requested to investigate latex-modified grouts for in-situ stabilization of buried TRU/mixed waste for INEL. The waste exists in shallow trenches that were backfilled with soil. The objective was to formulate latex-modified grouts for use with the jet grouting technique to enable in-situ stabilization of buried waste. The stabilized waste was either to be left in place or retrieved for further processing. Grouting prior to retrieval reduces the potential release of contaminants. Rheological properties of latex-modified grouts were investigated and compared with those of conventional neat cement grouts used for jet grouting.

  6. Buffer protection in the installation phase

    Energy Technology Data Exchange (ETDEWEB)

    Wimelius, Hans (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Pusch, Roland (Geodevelopment International AB, Lund (Sweden))

    2008-12-15

    The research and development of the design and construction of the SKB's repository for final disposal of spent reactor fuel is conducted along several paths ('lines'). Issues concerning the bedrock are dealt with in the 'rock line' and those related to buffer and backfill in deposition holes and tunnels are considered in the 'buffer line' and 'backfill line', respectively. These lines also deal with sub-activities that are coupled to several other lines. One of them includes development of techniques for protecting buffer blocks from moisture and water in the installation phase. Techniques and methods for placement and removal of the 'buffer protection sheet' are dealt with in the 'buffer line'. The removal is, however, considered as being part of the backfilling sequence. Since the performance of the sheet is of fundamental importance to the placement and function of the buffer it deserves particular attention. Thus, the removal of the rubber sheet that serves to protect the buffer blocks in the installation phase may be difficult and can cause significant problems that may require retrieval of already placed canister, buffer and backfill. These matters are in focus in the present report. Arrangements for protecting already placed buffer blocks from moist air and water have been tested in earlier large-scale experiments, i.e. the Prototype Repository project at Aespoe but the experience from them has called for more effective protection of the clay blocks as described in the present report. Focus is on the construction of foundation components at the bottom of the deposition holes required for establishing a tight seal between rock and buffer blocks, and on the protection sheet and arrangements for limiting water pressure on it. Special attention is paid to the drainage of the space between rock and protection sheet that is necessary for avoiding failure of the sheet and to systems for achieving

  7. Application of rock mechanics to cut-and-fill mining. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-15

    The conference on application of rock mechanics to cut-and-fill mining was held June 1-3, 1980, at the University of Luleaa, Luleaa, Sweden. Basic rock mechanics investigations of interest involving improving the support characteristics of backfilling by adding cement, compacting, and water removal have been entered individually into EDB. The papers also cover measurements of the support capability of such fills and the application of deformation measurements and calculations using finite element computer codes to the mining of particular ore bodies, including changes in the calculations as the mining progressed. (LTN)

  8. Application of rock mechanics to cut-and-fill mining. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-15

    The conference on application of rock mechanics to cut-and-fill mining was held June 1-3, 1980, at the University of Luleaa, Sweden. The papers in this volume deal almost entirely with the Naesliden project in Sweden. Stress measurements were made on the rock mass before and during mining and complex computer codes using the finite element method developed to calculate the strains and their changes as mining developed. Major problems involved the effects of joints and the mechanical properties of the hydraulic backfill and in corporating these items in the calculations. Most papers were entered individually into EDB. (LTN)

  9. In the heart of rock; Au coeur de la roche

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-01

    This educational document gives a presentation of the Andra underground research laboratory of Bure (Haute-Marne and Meuse, France) devoted to the study of the underground disposal of radioactive wastes. The document is presented in the form of a comics. It describes the geological setting of the laboratory, located in the eastern edge of the Paris basin, the properties of the Callovian-Oxfordian clay layer, the digging of the boreholes and galleries, the mine-by test and its instrumentation, the backfilling and sealing of the galleries and the reversibility of the burial of radioactive waste containers. (J.S.)

  10. Friction stir welding tool and process for welding dissimilar materials

    Science.gov (United States)

    Hovanski, Yuri; Grant, Glenn J; Jana, Saumyadeep; Mattlin, Karl F

    2013-05-07

    A friction stir welding tool and process for lap welding dissimilar materials are detailed. The invention includes a cutter scribe that penetrates and extrudes a first material of a lap weld stack to a preselected depth and further cuts a second material to provide a beneficial geometry defined by a plurality of mechanically interlocking features. The tool backfills the interlocking features generating a lap weld across the length of the interface between the dissimilar materials that enhances the shear strength of the lap weld.

  11. Selected problems relating to the dynamics of block-type foundations for machines

    Directory of Open Access Journals (Sweden)

    Marek Zombroń

    2014-07-01

    Full Text Available Atypical but real practical problems relating to the dynamics of block-type foundations for machines are considered using the deterministic approach and assuming that the determined parameters are random variables. A foundation model in the form of an undeformable solid on which another undeformable solid modelling a machine is mounted via viscoelastic constraints was adopted. The dynamic load was defined by a harmonically varying signal and by a series of short duration signals. The vibration of the system was investigated for the case when stratified ground (groundwater occurred within the side backfill was present. Calculation results illustrating the theoretical analyses are presented.

  12. Method of identifying defective particle coatings

    Science.gov (United States)

    Cohen, Mark E.; Whiting, Carlton D.

    1986-01-01

    A method for identifying coated particles having defective coatings desig to retain therewithin a build-up of gaseous materials including: (a) Pulling a vacuum on the particles; (b) Backfilling the particles at atmospheric pressure with a liquid capable of wetting the exterior surface of the coated particles, said liquid being a compound which includes an element having an atomic number higher than the highest atomic number of any element in the composition which forms the exterior surface of the particle coating; (c) Drying the particles; and (d) Radiographing the particles. By television monitoring, examination of the radiographs is substantially enhanced.

  13. Conventional drivage of gate roads with bolted supports. Indication of performance potential; Konventionelle Auffahrung von Floezstrecken mit Ankerausbau. Aufzeigen von Leistungspotenzialen

    Energy Technology Data Exchange (ETDEWEB)

    Beimdieck, J. [RAG Anthrazit Ibbenbueren GmbH, Ibbenbueren (Germany). Bereich Bergbau; Stoettner, M.T. [RAG Anthrazit Ibbenbueren GmbH, Ibbenbueren (Germany). Bereich Stab

    2008-06-19

    The road drivages at the Ibbenbueren mine are highly standardised. Drivage is carried out exclusively by drilling and shortfiring. A three-layer combined support - bolting, arches and backfilling with concrete - is used. Alternatives were sought in order to achieve a further increase in performance and reduce costs. Meanwhile the mine is driving 2 roadways by blasting and with only bolted supports. The equipment and process optimisations of the old standard were utilised with considerable increases in performance. The article describes the initial experience required. (orig.)

  14. Comparing the Thixotropic and Lightly Solidified Hardening Behavior of a Dredged Marine Clay

    OpenAIRE

    2014-01-01

    When a soil is disturbed upon remolding, it may lose part or all of its strength. As time passes, the structural arrangement of the soil particles would be restored to a stable form and the soil would regain hardness under constant volume and water content. The process is known as “thixotropic hardening”. On another note, dredged marine soils of the fine-grained type can be reused as a backfill material instead of being disposed to the open sea. The rest period required for the re...

  15. Coal-Mac, Inc. Phoenix No. 1 mine provides wildlife haven. 2007 Wildlife West Virginia Award

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, A.

    2007-07-15

    Coal Mac, Inc.'s Harless Wood Industrial Park off Holden 22 Mines Road in Logan Country, West Virginia is an award-winning reclamation site in the mountains frequented by geese, wild turkey, deer and black bears. Orchard grass and rye is a temporary cover for the timothy, clover and other seedlings. The area was mined several years ago. Some 40,000-50,000 tons of coal per month are surfaced mined with the current permit that takes in 1,500-2,000 acres. After removing the coal, valleys are backfilled as part of the mining and reclamation plan. 10 photos.

  16. Direct methods of soil-structure interaction analysis for earthquake loadings (V)

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, J. B.; Choi, J. S.; Lee, J. J.; Park, D. U. [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-07-15

    Methodologies of SSI analysis for earthquake loadings have been reviewed. Based on the finite method incorporating infinite element technique for the unbounded exterior region, a computer program for the nonlinear seismic analysis named as 'KIESSI' has been developed. The computer program has been verified using a free-field site-response problem. Post-correlation analysis for the Hualien FVT after backfill and the blind prediction of earthquake responses have been carried out utilizing the developed computer program. The earthquake response analyses for three LSST structures (Hualien, Lotung and Tepsco structure) have also been performed and compared with the measured data.

  17. Problems of the protection of bioresources development ofthe Bovanenkovo gas condensate field

    Directory of Open Access Journals (Sweden)

    Vladimir Dmitrievich Bogdanov

    2012-12-01

    Full Text Available The data on the fish fauna and fish food resources in the Bovanenkovo gas field are presented. The estimation of fishery and fishery potential of water bodies, hydrobiological characteristics of water bodies in the studied area are given. It is shown that the arrangement of the gas field leads to overfishing BGKM fish and change the state of aquatic ecosystems associated with the violation of runoff, backfilling flood waters, crossing streams communications, water diversion, pollution, sand mining. Thehydrobionts reaction to anthropogenic influence in the area of the gas field developmentis identified and recommendations to reduce the impact on aquatic ecosystems in the period of construction are given

  18. Direct methods of soil-structure interaction analysis for earthquake loadings (III)

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, J. B.; Lee, S. R.; Kim, J. M.; Park, K. R.; Choi, J. S.; Oh, S. B. [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1995-06-15

    In this study, direct methods for seismic analysis of soil-structure interaction system have been studied. A computer program 'KIESSI-QK' has been developed based on the finite element technique coupled with infinite element formulation. A substructuring method isolating the displacement solution of near field soil region was adopted. The computer program developed was verified using a free-field site response problem. The post-correlation analysis for the forced vibration tests after backfill of the Hualien LSST project has been carried out. The seismic analyses for the Hualien and Lotung LSST structures have been also performed utilizing the developed computer program 'KIESSI-QK'.

  19. Evaluation of Interface Shear Strength Properties of Geogrid Reinforced Foamed Recycled Glass Using a Large-Scale Direct Shear Testing Apparatus

    Directory of Open Access Journals (Sweden)

    Arul Arulrajah

    2015-01-01

    Full Text Available The interface shear strength properties of geogrid reinforced recycled foamed glass (FG were determined using a large-scale direct shear test (DST apparatus. Triaxial geogrid was used as a geogrid reinforcement. The geogrid increases the confinement of FG particles during shear; consequently the geogrid reinforced FG exhibits smaller vertical displacement and dilatancy ratio than FG at the same normal stress. The failure envelope of geogrid reinforced FG, at peak and critical states, coincides and yields a unique linear line possibly attributed to the crushing of FG particles and the rearrangement of crushed FG after peak shear state. The interface shear strength coefficient α is approximately constant at 0.9. This value can be used as the interface parameter for designing a reinforced embankment and mechanically stabilized earth (MSE wall when FG is used as a lightweight backfill and triaxial geogrid is used as an extensible earth reinforcement. This research will enable FG, recently assessed as suitable for lightweight backfills, to be used together with geogrids in a sustainable manner as a lightweight MSE wall. The geogrid carries tensile forces, while FG reduces bearing stresses imposed on the in situ soil. The use of geogrid reinforced FG is thus significant from engineering, economical, and environmental perspectives.

  20. A sensitivity analysis of the WIPP disposal room model: Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Labreche, D.A.; Beikmann, M.A. [RE/SPEC, Inc., Albuquerque, NM (United States); Osnes, J.D. [RE/SPEC, Inc., Rapid City, SD (United States); Butcher, B.M. [Sandia National Labs., Albuquerque, NM (United States)

    1995-07-01

    The WIPP Disposal Room Model (DRM) is a numerical model with three major components constitutive models of TRU waste, crushed salt backfill, and intact halite -- and several secondary components, including air gap elements, slidelines, and assumptions on symmetry and geometry. A sensitivity analysis of the Disposal Room Model was initiated on two of the three major components (waste and backfill models) and on several secondary components as a group. The immediate goal of this component sensitivity analysis (Phase I) was to sort (rank) model parameters in terms of their relative importance to model response so that a Monte Carlo analysis on a reduced set of DRM parameters could be performed under Phase II. The goal of the Phase II analysis will be to develop a probabilistic definition of a disposal room porosity surface (porosity, gas volume, time) that could be used in WIPP Performance Assessment analyses. This report documents a literature survey which quantifies the relative importance of the secondary room components to room closure, a differential analysis of the creep consolidation model and definition of a follow-up Monte Carlo analysis of the model, and an analysis and refitting of the waste component data on which a volumetric plasticity model of TRU drum waste is based. A summary, evaluation of progress, and recommendations for future work conclude the report.

  1. Experimental Study on the Microstructure Evolution of Mixed Disposal Paste in Surface Subsidence Areas

    Directory of Open Access Journals (Sweden)

    Wei Sun

    2016-05-01

    Full Text Available The integrated disposal of surface subsidence pits and surface solid waste can be realized by backfilling a surface subsidence area with a paste made from the solid wastes of mines, such as tailings and waste rock. The microstructures of these wastes determine the macroscopic properties of a paste backfill. This paper presents an experimental study on the internal structure evolution of pasty fluid mixed with different waste rock concentrations (10%, 30%, and 50% and cement dosages (1% and 2% under damage. To this end, a real-time computed tomography (CT scan is conducted using medical CT and a small loading device. Results show that UCS (uniaxial compressive strength increases when the amount of cement increases. Given a constant amount of cement, UCS increases first and then decreases as waste rock content increases. UCS is maximized at 551 kPa when the waste rock content is 30%. The paste body is a typical medium used to investigate initial damage, which mainly consists of microholes, pores, and microcracks. The initial damages also exhibit a high degree of random inhomogeneity. After loading, cracks are initiated and expand gradually from the original damage location until the overall damages are generated. The mesostructure evolution model of the paste body is divided into six categories, and this mesostructure is reasonable when the waste rock content is 30%.

  2. Interaction analysis of back-to-back mechanically stabilized earth walls

    Directory of Open Access Journals (Sweden)

    Sadok Benmebarek

    2016-10-01

    Full Text Available Back-to-back mechanically stabilized earth walls (BBMSEWs are encountered in bridge approaches, ramp ways, rockfall protection systems, earth dams, levees and noise barriers. However, available design guidelines for BBMSEWs are limited and not applicable to numerical modeling when back-to-back walls interact with each other. The objective of this paper is to investigate, using PLAXIS code, the effects of the reduction in the distance between BBMSEW, the reinforcement length, the quality of backfill material and the connection of reinforcements in the middle, when the back-to-back walls are close. The results indicate that each of the BBMSEWs behaves independently if the width of the embankment between mechanically stabilized earth walls is greater than that of the active zone. This is in good agreement with the result of FHWA design guideline. However, the results show that the FHWA design guideline underestimates the lateral earth pressure when back-to-back walls interact with each other. Moreover, for closer BBMSEWs, FHWA design guideline strongly overestimates the maximum tensile force in the reinforcement. The investigation of the quality of backfill material shows that the minor increase in embankment cohesion can lead to significant reductions in both the lateral earth pressure and the maximum tensile force in geosynthetic. When the distance between the two earth walls is close to zero, the connection of reinforcement between back-to-back walls significantly improves the factor of safety.

  3. Effect of transport-pathway simplifications on projected releases of radionuclides from a nuclear waste repository (Sweden)

    Science.gov (United States)

    Selroos, Jan-Olof; Painter, Scott L.

    2012-12-01

    The Swedish Nuclear Fuel and Waste Management Company has recently submitted an application for a license to construct a final repository for spent nuclear fuel, at approximately 500 m depth in crystalline bedrock. Migration pathways through the geosphere barrier are geometrically complex, with segments in fractured rock, deformation zones, backfilled tunnels, and near-surface soils. Several simplifications of these complex migration pathways were used in the assessments of repository performance that supported the license application. Specifically, in the geosphere transport calculations, radionuclide transport in soils and tunnels was neglected, and deformation zones were assumed to have transport characteristics of fractured rock. The effects of these simplifications on the projected performance of the geosphere barrier system are addressed. Geosphere performance is shown to be sensitive to how transport characteristics of deformation zones are conceptualized and incorporated into the model. Incorporation of advective groundwater travel time within backfilled tunnels reduces radiological dose from non-sorbing radionuclides such as I-129, while sorption in near-surface soils reduces radiological doses from sorbing radionuclides such as Ra-226. These results help quantify the degree to which geosphere performance was pessimistically assessed, and provide some guidance on how future studies to reduce uncertainty in geosphere performance may be focused.

  4. Dual-sided microstructured semiconductor neutron detectors (DSMSNDs)

    Energy Technology Data Exchange (ETDEWEB)

    Fronk, Ryan G., E-mail: rfronk@ksu.edu [Mechanical and Nuclear Engineering Department, Kansas State University, Manhattan, KS 66506, United States (United States); Bellinger, Steven L.; Henson, Luke C. [Radiation Detection Technologies, Inc., Manhattan, KS 66502 (United States); Ochs, Taylor R.; Smith, Colten T.; Kenneth Shultis, J.; McGregor, Douglas S. [Mechanical and Nuclear Engineering Department, Kansas State University, Manhattan, KS 66506, United States (United States)

    2015-12-21

    Microstructured semiconductor neutron detectors (MSNDs) have in recent years received much interest as high-efficiency replacements for thin-film-coated thermal neutron detectors. The basic device structure of the MSND involves micro-sized trenches that are etched into a vertically-oriented pvn-junction diode that are backfilled with a neutron converting material. Neutrons absorbed within the converting material induce fission of the parent nucleus, producing a pair of energetic charged-particle reaction products that can be counted by the diode. The MSND deep-etched microstructures produce good neutron-absorption and reaction-product counting efficiencies, offering a 10× improvement in intrinsic thermal neutron detection efficiency over thin-film-coated devices. Performance of present-day MSNDs are nearing theoretical limits; streaming paths between the conversion-material backfilled trenches, allow a considerable fraction of neutrons to pass undetected through the device. Dual-sided microstructured semiconductor neutron detectors (DSMSNDs) have been developed that utilize a complementary second set of trenches on the back-side of the device to count streaming neutrons. DSMSND devices are theoretically capable of greater than 80% intrinsic thermal neutron detection efficiency for a 1-mm thick device. The first such prototype DSMSNDs, presented here, have achieved 29.48±0.29% nearly 2× better than MSNDs with similar microstructure dimensions.

  5. Development of Aquaphalt, ordinary-temperature and underwater-hardening new material, and its characteristics. ; New material for the water and earthquake proofing of underground structures. Joon shichu kokagata shinzairyo Aquafalt no kaihatsu to tokusei. ; Chichu kozobutsu no bosuiyo, genshin prime yo shin zairyo

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, M.; Idota, Y.; Kouchi, K. (Okumura Corp., Tokyo (Japan))

    1990-10-09

    Shield technique is widely applied to the works of underground structures these days. Materials of cement system used for back-filling injection parts in the shield technique has the tendency to cause cracks; however, there has been a request for the development of a material which plays a role of cushion against ground subsidence. Now, a composite material (called Aquaphalt) which satisfies earthquake and water proofing features was developed, and this report introduces the results of the material {prime} s characteristic tests. Cement and highly water absorptive polymer are mixed in asphalt emulsion, the main component, in this new composite material. The material gelatinizes in 5 - 10 seconds after mixture, and hardens gradually in about 10 hours. As a result of indoor experiments, it was confirmed that the material has favorable water resistance and flexibility. It was also confirmed that the material attains initial strength, which is demanded in shield tunnel works, with the help of a hardening accelerator. Moreover, simulations of tunnel back-filling injection were carried out, and it was testified that this material is applicable with conventional installations. 3 refs., 8 figs., 3 tabs.

  6. Three-dimensional helical computed tomographic evaluation of three obturation techniques: In vitro study

    Directory of Open Access Journals (Sweden)

    M Chokkalingam

    2011-01-01

    Full Text Available Aim: The purpose of this study was to evaluate the adequacy of three obturation techniques namely lateral condensation, EQ Fil (backfill obturation and thermafil (core carrier obturation techniques using three-dimensional (3D helical computed tomography (CT by volume rendering method. Materials and Methods: Thirty freshly extracted teeth were randomly divided into three groups of 10 teeth each. Biomechanical preparation was done in all the teeth using rotary instruments. All three sets of teeth were placed in helical CT slice scanner and were imaged before obturation. The three sets were then obturated by following methods: Group I: lateral condensation, Group II: EQ Fil (backfill and Group III: thermafil (core carrier obturation.Volume of the pulp chamber and gutta-percha after obturation were calculated using volume rendering technique and adequacy of the obturation techniques were calculated. Statistical Analysis Used: One-way ANOVA and Multiple-Range Tukey Test by Tukey-HSD procedure Results: Mean change in lateral condensation (0.005±0.002 was significantly higher than that of thermafil obturation (0.002±0.001 [P<0.05]. Conclusions: Conventional lateral condensation technique showed maximal inadequacy of obturation and thermafil obturation technique showed the least inadequacy of obturation when the volume of the specimens were calculated and reconstructed

  7. Anticipated Degradation Modes of Metallic Engineered Barriers for High-Level Nuclear Waste Repositories

    Science.gov (United States)

    Rodríguez, Martín A.

    2014-03-01

    Metallic engineered barriers must provide a period of absolute containment to high-level radioactive waste in geological repositories. Candidate materials include copper alloys, carbon steels, stainless steels, nickel alloys, and titanium alloys. The national programs of nuclear waste management have to identify and assess the anticipated degradation modes of the selected materials in the corresponding repository environment, which evolves in time. Commonly assessed degradation modes include general corrosion, localized corrosion, stress-corrosion cracking, hydrogen-assisted cracking, and microbiologically influenced corrosion. Laboratory testing and modeling in metallurgical and environmental conditions of similar and higher aggressiveness than those expected in service conditions are used to evaluate the corrosion resistance of the materials. This review focuses on the anticipated degradation modes of the selected or reference materials as corrosion-resistant barriers in nuclear repositories. These degradation modes depend not only on the selected alloy but also on the near-field environment. The evolution of the near-field environment varies for saturated and unsaturated repositories considering backfilled and unbackfilled conditions. In saturated repositories, localized corrosion and stress-corrosion cracking may occur in the initial aerobic stage, while general corrosion and hydrogen-assisted cracking are the main degradation modes in the anaerobic stage. Unsaturated repositories would provide an oxidizing environment during the entire repository lifetime. Microbiologically influenced corrosion may be avoided or minimized by selecting an appropriate backfill material. Radiation effects are negligible provided that a thick-walled container or an inner shielding container is used.

  8. Permeability to brine of crushed salt rock for waste isolation, considering long-term pressure variation of overlying strata and dissolution processes. Final report; Durchlaessigkeitsverhalten von Steinsalzversatz gegenueber Laugen unter Beruecksichtigung von zeitlich veraenderlichen Ueberlagerungsdruecken und Loesungsvorgaengen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, H. [Battelle Ingenieurtechnik GmbH, Eschborn (Germany); Conen, O. [Technische Univ. Darmstadt (Germany); Haefner, F.; Bruck, J. v. der [Technische Univ. Bergakademie Freiberg (Germany)

    1999-07-01

    It cannot be excluded that there will be ingress of brines to underground isolation plants for nuclear and chemical toxic wastes. The transport mechanisms in the waste repository are much determined by the perviousness of the backfilling and the sealing material used after waste emplacement in salt rock mine shafts. The critical quantity is the permeability, both for inflow of brine into the bedded waste areas, and for contaminated brine squeeze-out mechanisms. The project research work was to establish the mass transfer parameters for calculating the transport mechanisms in backfilled and sealed shafts. Using near-reality simulation of conditions, the time-dependent influence of pressure variations of overlying strata, humidity and salt/brine interactions on the permeability was examined and quantified. (orig./CB) [German] In Endlagern fuer nukleare und chemotoxische Abfaelle im Salinar kann der Zutritt von Laugen nicht prinzipiell ausgeschlossen werden. Die Transportvorgaenge innerhalb des Endlagers werden wesentlich von der Durchlaessigkeit der Versatzmaterialien und der Verschluesse bestimmt. Die bestimmende Groesse, sowohl fuer den Laugenzufluss in die Einlagerungsbereiche als auch fuer das Auspressen kontaminierter Lauge aus dem Endlager, ist dabei die Permeabilitaet. Ziel der hier vorgestellten Arbeiten war es, Stofftransportparameter fuer die Berechnung von Ausbreitungsvorgaengen in den verfuellten Bereichen eines salinaren Endlagers bereitzustellen. Unter Simulation realitaetsnaher Bedingungen wurde der Einfluss von zeitabhaengigem Ueberlagerungsdruck (Gebirgsdruck), Feuchte und die Wechselwirkung von Salz/Lauge auf das Durchlaessigkeitsverhalten untersucht und quantifiziert. (orig.)

  9. Steady-State Creep of Rock Salt: Improved Approaches for Lab Determination and Modelling

    Science.gov (United States)

    Günther, R.-M.; Salzer, K.; Popp, T.; Lüdeling, C.

    2015-11-01

    Actual problems in geotechnical design, e.g., of underground openings for radioactive waste repositories or high-pressure gas storages, require sophisticated constitutive models and consistent parameters for rock salt that facilitate reliable prognosis of stress-dependent deformation and associated damage. Predictions have to comprise the active mining phase with open excavations as well as the long-term development of the backfilled mine or repository. While convergence-induced damage occurs mostly in the vicinity of openings, the long-term behaviour of the backfilled system is dominated by the damage-free steady-state creep. However, because in experiments the time necessary to reach truly stationary creep rates can range from few days to years, depending mainly on temperature and stress, an innovative but simple creep testing approach is suggested to obtain more reliable results: A series of multi-step tests with loading and unloading cycles allows a more reliable estimate of stationary creep rate in a reasonable time. For modelling, we use the advanced strain-hardening approach of Günther-Salzer, which comprehensively describes all relevant deformation properties of rock salt such as creep and damage-induced rock failure within the scope of an unified creep ansatz. The capability of the combination of improved creep testing procedures and accompanied modelling is demonstrated by recalculating multi-step creep tests at different loading and temperature conditions. Thus reliable extrapolations relevant to in-situ creep rates (10^{-9} to 10^{-13} s^{-1}) become possible.

  10. Numerical Simulation of Hysteretic Live Load Effect in a Soil-Steel Bridge

    Directory of Open Access Journals (Sweden)

    Sobótka Maciej

    2014-03-01

    Full Text Available The paper presents numerical simulation of hysteretic live load effect in a soil-steel bridge. The effect was originally identified experimentally by Machelski [1], [2]. The truck was crossing the bridge one way and the other in the full-scale test performed. At the same time, displacements and stress in the shell were measured. The major conclusion from the research was that the measured quantities formed hysteretic loops. A numerical simulation of that effect is addressed in the present work. The analysis was performed using Flac finite difference code. The methodology of solving the mechanical problems implemented in Flac enables us to solve the problem concerning a sequence of load and non-linear mechanical behaviour of the structure. The numerical model incorporates linear elastic constitutive relations for the soil backfill, for the steel shell and the sheet piles, being a flexible substructure for the shell. Contact zone between the shell and the soil backfill is assumed to reflect elastic-plastic constitutive model. Maximum shear stress in contact zone is limited by the Coulomb condition. The plastic flow rule is described by dilation angle ψ = 0. The obtained results of numerical analysis are in fair agreement with the experimental evidence. The primary finding from the performed simulation is that the slip in the interface can be considered an explanation of the hysteresis occurrence in the charts of displacement and stress in the shell.

  11. Neuronal responses to water flow in the marine slug tritonia diomedea

    Directory of Open Access Journals (Sweden)

    Jeffrey Blackwell

    2005-07-01

    Full Text Available The marine slug Tritonia diomedea must rely on its ability to touch and smell in order to navigate because it is blind. The primary factor that influences its crawling direction is the direction of water flow (caused by tides in nature. The sensory cells that detect flow and determine flow direction have not been identified. The lateral branch of Cerebral Nerve 2 (latCeN2 has been identified as the nerve that carries sensory axons to the brain from the flow receptors inthe oral tentacles. Backfilling this nerve to the brain resulted in the labeling of a number of cells located throughout the brain. Most of the labeled cells are concentrated in the cerebral ganglion where the nerve enters the brain. The medial and lateral branches of CeN2 were backfilled for comparison of the pattern of cells from each nerve. A map of the cells innervated by latCeN2 reveals the location of the stained cells. Extracellular recording from latCeN2 revealed its involvement in the detection of water flow and orientation. The nerve becomes active in response to water flow stimulation. Intracellular recordings of the electrical activity of these cells in a live animal will be the next step to determine if these cells are the flow receptors.

  12. Neuronal Responses to Water Flow in the Marine Slug Tritonia diomedea

    Directory of Open Access Journals (Sweden)

    James A. Murray

    2005-01-01

    Full Text Available The marine slug Tritonia diomedea mustrely on its ability to touch and smell in order to navigate because it is blind. The primaryfactor that influences its crawling direction is the direction of water flow (caused bytides in nature. The sensory cells that detect flow and determine flow directionhave not been identified. The lateral branch of Cerebral Nerve 2 (latCeN2 has beenidentified as the nerve that carries sensory axons to the brain from the flow receptors inthe oral tentacles. Backfilling this nerve to the brain resulted in the labeling of a numberof cells located throughout the brain. Most of the labeled cells are concentrated in the cerebral ganglion where the nerve enters thebrain. The medial and lateral branches of CeN2 were backfilled for comparison of thepattern of cells from each nerve. A map of the cells innervated by latCeN2 reveals thelocation of the stained cells. Extracellular recording from latCeN2 revealed itsinvolvement in the detection of water flow and orientation. The nerve becomes activein response to water flow stimulation. Intracellular recordings of the electricalactivity of these cells in a live animal will be the next step to determine if these cells arethe flow receptors.

  13. SPRAYED CLAY TECHNOLOGY FOR THE DEEP REPOSITORY OF HIGH-LEVEL RADIOACTIVE WASTE

    Directory of Open Access Journals (Sweden)

    Lucie Hausmannová

    2012-07-01

    Full Text Available The sealing barrier will play very important role in the Czech disposal concept of high level radioactive waste. It follows Swedish SKB3 design where granitic rock environment will host the repository. Swelling clay based materials as the most favorable for sealing purposes were selected. Such clays must fulfill certain requirements (e.g. on swelling properties, hydraulic conductivity or plasticity and must be stable for thousands of years. Better sealing behavior is obtained when the clay is compacted. Technology of the seal construction can vary according to its target dry density. Very high dry density is needed for buffer (sealing around entire canister with radioactive waste. Less strict requirements are on material backfilling the access galleries. It allows compaction to lower dry density than in case of buffer. One of potential technology for backfilling is to compact clay layers in most of the gallery profile by common compaction machines (rollers etc. and to spray clay into the uppermost part afterwards. The paper introduces the research works on sprayed clay technology performed at the Centre of Experimental Geotechnics of the Czech Technical University in Prague. Large scale in situ demonstration of filling of short drift in the Josef Gallery is also mentioned.

  14. Behavior of granular rubber waste tire reinforced soil for application in geosynthetic reinforced soil wall

    Directory of Open Access Journals (Sweden)

    G. G. D. RAMIREZ

    Full Text Available AbstractLarge quantities of waste tires are released to the environment in an undesirable way. The potential use of this waste material in geotechnical applications can contribute to reducing the tire disposal problem and to improve strength and deformation characteristics of soils. This paper presents a laboratory study on the effect of granular rubber waste tire on the physical properties of a clayey soil. Compaction tests using standard effort and consolidated-drained triaxial tests were run on soil and mixtures. The results conveyed an improvement in the cohesion and the angle of internal friction the clayey soil-granular rubber mixture, depending on the level of confining stress. These mixtures can be used like backfill material in soil retaining walls replacing the clayey soil due to its better strength and shear behavior and low unit weight. A numerical simulation was conducted for geosynthetic reinforced soil wall using the clayey soil and mixture like backfill material to analyzing the influence in this structure.

  15. Retrieval options study

    Energy Technology Data Exchange (ETDEWEB)

    1980-03-01

    This Retrieval Options Study is part of the systems analysis activities of the Office of Nuclear Waste Isolation to develop the scientific and technological bases for radioactive waste repositories in various geologic media. The study considers two waste forms, high level waste and spent fuel, and defines various classes of waste retrieval and recovery. A methodology and data base are developed which allow the relative evaluation of retrieval and recovery costs and the following technical criteria: safety; technical feasibility; ease of retrieval; probable intact retrieval time; safeguards; monitoring; criticality; and licensability. A total of 505 repository options are defined and the cost and technical criteria evaluated utilizing a combination of facts and engineering judgments. The repositories evaluated are selected combinations of the following parameters: Geologic Media (salt, granite, basalt, shale); Retrieval Time after Emplacement (5 and 25 years); Emplacement Design (nominal hole, large hole, carbon steel canister, corrosion resistant canister, backfill in hole, nominal sleeves, thick wall sleeves); Emplacement Configuration (single vertical, multiple vertical, single horizontal, multiple horizontal, vaults; Thermal Considerations; (normal design, reduced density, once-through ventilation, recirculated ventilation); Room Backfill; (none, run-of-mine, early, 5 year delay, 25 year delay, decommissioned); and Rate of Retrieval; (same as emplacement, variably slower depending on repository/canister condition).

  16. Sponge-Templated Macroporous Graphene Network for Piezoelectric ZnO Nanogenerator.

    Science.gov (United States)

    Li, Xinda; Chen, Yi; Kumar, Amit; Mahmoud, Ahmed; Nychka, John A; Chung, Hyun-Joong

    2015-09-23

    We report a simple approach to fabricate zinc oxide (ZnO) nanowire based electricity generators on three-dimensional (3D) graphene networks by utilizing a commercial polyurethane (PU) sponge as a structural template. Here, a 3D network of graphene oxide is deposited from solution on the template and then is chemically reduced. Following steps of ZnO nanowire growth, polydimethylsiloxane (PDMS) backfilling and electrode lamination completes the fabrication processes. When compared to conventional generators with 2D planar geometry, the sponge template provides a 3D structure that has a potential to increase power density per unit area. The modified one-pot ZnO synthesis method allows the whole process to be inexpensive and environmentally benign. The nanogenerator yields an open circuit voltage of ∼0.5 V and short circuit current density of ∼2 μA/cm(2), while the output was found to be consistent after ∼3000 cycles. Finite element analysis of stress distribution showed that external stress is concentrated to deform ZnO nanowires by orders of magnitude compared to surrounding PU and PDMS, in agreement with our experiment. It is shown that the backfilled PDMS plays a crucial role for the stress concentration, which leads to an efficient electricity generation.

  17. Interaction analysis of back-to-back mechanically stabilized earth walls

    Institute of Scientific and Technical Information of China (English)

    Sadok Benmebarek; Samir Attallaoui; Naïma Benmebarek

    2016-01-01

    Back-to-back mechanically stabilized earth walls (BBMSEWs) are encountered in bridge approaches, ramp ways, rockfall protection systems, earth dams, levees and noise barriers. However, available design guidelines for BBMSEWs are limited and not applicable to numerical modeling when back-to-back walls interact with each other. The objective of this paper is to investigate, using PLAXIS code, the effects of the reduction in the distance between BBMSEW, the reinforcement length, the quality of backfill material and the connection of reinforcements in the middle, when the back-to-back walls are close. The results indicate that each of the BBMSEWs behaves independently if the width of the embankment between mechanically stabilized earth walls is greater than that of the active zone. This is in good agreement with the result of FHWA design guideline. However, the results show that the FHWA design guideline un-derestimates the lateral earth pressure when back-to-back walls interact with each other. Moreover, for closer BBMSEWs, FHWA design guideline strongly overestimates the maximum tensile force in the reinforcement. The investigation of the quality of backfill material shows that the minor increase in embankment cohesion can lead to significant reductions in both the lateral earth pressure and the maximum tensile force in geosynthetic. When the distance between the two earth walls is close to zero, the connection of reinforcement between back-to-back walls significantly improves the factor of safety.

  18. Influence of EPS Geofoam Buffers on the Static Behavior of Cantilever Earth-Retaining Walls

    Directory of Open Access Journals (Sweden)

    Özgür L. Ertuğrul

    2012-03-01

    Full Text Available In this study, the effect of expanded polystyrene (EPS buffers on lateral stresses and deflections of model retaining walls with various flexibility values were investigated. For this purpose, 0.7 m high model walls were instrumented and 1-g model tests were performed in laboratory environment. In the first group of tests, the wall models retain only granular cohesionless backfill whereas in the second and third group of tests, EPS deformable buffers of two different thicknesses were installed between the wall and granular backfill. Tests were repeated for four different wall thicknesses and results were discussed comparatively. As wall flexibility increases, there is a decrease in the load reduction pattern of the buffer. On the other hand, utilization of geofoam buffers with flexible cantilever walls still provides substantial decrease in wall thrust and deflections thus leading to more economical retaining structure design. The lateral earth pressure coefficients determined through model tests were compared to those calculated from Coulomb's theory for active lateral earth stresses. A graph is provided for the estimation of lateral earth pressure coefficients for various combinations of wall flexibilities and buffer characteristics.

  19. Thermodynamic coupling of heat and matter flows in near-field regions of nuclear waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Carnahan, C.L.

    1983-11-01

    In near-field regions of nuclear waste repositories, thermodynamically coupled flows of heat and matter can occur in addition to the independent flows in the presence of gradients of temperature, hydraulic potential, and composition. The following coupled effects can occur: thermal osmosis, thermal diffusion, chemical osmosis, thermal filtration, diffusion thermal effect, ultrafiltration, and coupled diffusion. Flows of heat and matter associated with these effects can modify the flows predictable from the direct effects, which are expressed by Fourier's law, Darcy's law, and Fick's law. The coupled effects can be treated quantitatively together with the direct effects by the methods of the thermodynamics of irreversible processes. The extent of departure of fully coupled flows from predictions based only on consideration of direct effects depends on the strengths of the gradients driving flows, and may be significant at early times in backfills and in near-field geologic environments of repositories. Approximate calculations using data from the literature and reasonable assumptions of repository conditions indicate that thermal-osmotic and chemical-osmotic flows of water in semipermeable backfills may exceed Darcian flows by two to three orders of magnitude, while flows of solutes may be reduced greatly by ultrafiltration and chemical osmosis, relative to the flows predicted by advection and diffusion alone. In permeable materials, thermal diffusion may contribute to solute flows to a smaller, but still significant, extent.

  20. Monitoring technique for seepage line of tailings dam

    Institute of Scientific and Technical Information of China (English)

    李夕兵; 蒋卫东

    2003-01-01

    An automatic monitoring technique of the seepage line, including the monitoring design, the automatic monitoring system and the backfill technique of the measuring probe of pore-water pressure, was used in a tailings dam, and a shallow refractive seismic method was investigated for obtaining the seepage line of those areas outside the monitoring zone. The results show that the automatic monitoring has the error within ± 3 % relative to piezometric tube method and improves monitoring efficiency greatly, and the shallow refractive seismic method has the error within ± 10% but expands the area of monitoring. Both of them can be used for a daily measurement in monitoring the seepage line. The result of the automatic monitoring also shows that not only the design of the survey line and the backfill technique of the measuring probe of pore-water pressure are reasonable and economic but also the reliability and safety of the automatic monitoring system are better. Testing result by the shallow refractive seismic method in tailings reveals that the energy excited by hammering iron sheet-pole is strong enough and safe, and that the character of anti-jamming by the detectors with long tailcone is better.

  1. Evolution in performance assessment modeling as a result of regulatory review

    Energy Technology Data Exchange (ETDEWEB)

    Rowat, J.H.; Dolinar, G.M.; Stephens, M.E. [AECL Chalk River Labs., Ontario (Canada)] [and others

    1995-12-31

    AECL is planning to build the IRUS (Intrusion Resistant Underground Structure) facility for near-surface disposal of LLRW. The PSAR (preliminary safety assessment report) was subject to an initial regulatory review during mid-1992. The regulatory authority provided comments on many aspects of the safety assessment documentation including a number of questions on specific PA (Performance Assessment) modelling assumptions. As a result of these comments as well as a separate detailed review of the IRUS disposal concept, changes were made to the conceptual and mathematical models. The original disposal concept included a non-sorbing vault backfill, with a strong reliance on the wasteform as a barrier. This concept was altered to decrease reliance on the wasteform by replacing the original backfill with a sand/clinoptilolite mix, which is a better sorber of metal cations. This change lead to changes in the PA models which in turn altered the safety case for the facility. This, and other changes that impacted performance assessment modelling are the subject of this paper.

  2. Tuning the strength of chemical patterns for directed self-assembly of block copolymers

    Science.gov (United States)

    Williamson, Lance; Lin, Guanyang; Cao, Yi; Gronheid, Roel; Nealey, Paul

    2014-03-01

    Directed self-assembly (DSA) of block copolymers (BCP) via chemo-epitaxy is a potential lithographic solution to patterns of dense features. The LiNe (Liu-Nealey) flow was used to fabricate the chemical pattern, which guides the BCP due to the different wetting behavior of the materials. Fine control of both the chemical pattern chemistry and geometry are important for DSA of BCP. Furthermore, wetting behavior considerations for DSA extend beyond pattern design and include the surrounding region. BCP DSA would be easier to integrate into device design if the patterned region were isolated with a featureless region (horizontal lamellar BCP assembly) rather than undirected BCP fingerprint structures. This paper addresses two processing steps found to be modifying the guide material. For one, the backfill brush grafts to the cross-linked polystyrene (XPS), albeit at a lower rate than the brush grafts to the exposed substrate. Undersaturating the backfill brush only moderately improves the XPS wetting behavior, but also negatively impacts the background region of the chemical pattern. Replacing the brush grafting functionality so that the brush grafts at lower annealing conditions also did not avoid the side reaction between the brush and the XPS. The other step modifying the XPS is the trim etch. Replacing the trim etch process was effective at generating a chemical pattern that can orient the BCP horizontally on a stripe 11 L0 wide passing through a field of chemical pattern.

  3. Stress Corrosion Cracking of the Drip Shield, The Waste Package Outer Barrier and the Stainless Steel Structural Material

    Energy Technology Data Exchange (ETDEWEB)

    C. Stephen

    2000-04-17

    One of the potential failure modes of the drip shield (DS), the waste package (WP) outer barrier, and the stainless structural material is the initiation and propagation of stress corrosion cracking (SCC) induced by the WP environment and various types of stresses that can develop in the DSs or the WPs. For the current design of the DS and WP, however, the DS will be excluded from the SCC evaluation because stresses that are relevant to SCC are insignificant in the DS. The major sources of stresses in the DS are loadings due to backfill and earthquakes. These stresses will not induce SCC because the stress caused by backfill is generally compressive stress and the stress caused by earthquakes is temporary in nature. The 316NG stainless steel inner barrier of the WP will also be excluded from the SCC evaluation because the SCC performance assessment will not take credit from the inner barrier. Therefore, the purpose of this document is to provide a detailed description of the process-level models that can be applied to assess the performance of the material (i.e., Alloy 22) used for the WP outer barrier subjected to the effects of SCC. As already mentioned in the development plan for the WP PMR (CRWMS M and O 1999e), this Analyses and Models Report (AMR) is to serve as a feed to the Waste Package Degradation (WPD) Total System Performance Assessment (TSPA) and Process Model Report (PMR).

  4. Solution of the capacity increase of the waste dump at the Merkur surface mine in Czechoslovakia

    Energy Technology Data Exchange (ETDEWEB)

    Musil, P.

    1987-06-01

    The methods used in the past for backfilling the large dump at the Merkur surface mine have, due to an ignorance of the factors influencing dump stability, resulted in significant capacity reductions of the dump. This ignorance was the result of insufficient knowledge, research, and poor practice at the operation. Recent re-evaluation of the actual stability conditions has led to a solution which permits an increase in the dump capacity, such that it is compatible with future mining plans. By considering the structure of the soils being used as backfill, specific technological processes are being defined which enable the preservation of the highest possible shear strength of the clayey soils, and thereby maximize the utilization of the internal capacity with at least short term stability. Questions regarding the behaviour and properties of the loose clayey material are also being answered, and new methods of stability calculation for the high dump are being developed. The key to these solutions has been the knowledge gained regarding the shear strength of the loose clayey material under various effective stress conditions, while realizing that three different zones can exist simultaneously within the body of the dump: the slope areas (having the greatest failure-inducing stress), the temporary areas (having a somewhat lower applied stress), and the dump core (where the tendency to fail is nearly zero). Through a sound application of this knowledge, the capacity of the waste dump at the large Merkur surface mine has been adequately expanded for the future.

  5. Three Sisters Mountain Village development transformation of old coal mine properties into modern day use

    Energy Technology Data Exchange (ETDEWEB)

    Fox, B. [Golder Paste Technology Ltd., Sudbury, ON (Canada)

    2006-07-01

    This paper discussed the development of the Three Sisters Mountain Village, located close to Canmore, Alberta. The paper provided the history and background of the mining and development of the site. It discussed underground mining methodology and planned housing and industrial development. The village included plans for 10,000 residential homes, 2 golf courses, a wellness centre, a school, commercial buildings and wildlife corridors. Environmental concerns were also addressed, as Canmore contains a series of natural wildlife corridors, which act as migration and travelling routes for elk and deer as well as cougars, grizzly bears, and other animals. These routes are essential for the survival of the different herds and animal species. The development progress strategy was discussed. The Three Sisters Mountain Village Development commissioned Golder Associates Ltd. to study and address the environmental concerns of the stakeholders regarding the migrating routes of wildlife. Mining works mitigation, including mapping of the constraint zones, knowledge of subsidence issues and the effects of subsidence on structural stress and the ability to analysis field data to predict potential problems was also presented along with a methodology for mitigation and choice of backfill material to be used to fill the mine workings. The advantages of using concrete paste backfill were also identified.

  6. Visible calculation of mining index based on stope 3D surveying and block modeling

    Institute of Scientific and Technical Information of China (English)

    Liu Xiaoming; Luo Zhouquan; Yang Biao; Lu Guang; Cao Shengxiang; Jiang Xinjian

    2012-01-01

    Aimed at the CMS laser scanning theory and characteristic,a combined actual situation of stope N4-5 of Fankou Lead-Zinc Mine and complementary monitoring of the stope were carried out by carefully choosing two measuring points.The cavity 3D visible model was created by large-scale mining industry software Surpac after changing the measured data.The stope mine design model,bottom structural model and backfill model of the south and north sides of the stope N4-5 were established according to the stope design data.On this basis,the stope block model was established,and then block attribute was estimated.The amount the ore remains,mullock,backfill and total mined ore were calculated through the solid model restrains.Finally,the stope mining dilution rate and loss rate reached 8.2%and 1.47%,respectively.The practice indicates that the mining index visible calculation method based on cavity 3D monitoring and stope block modeling can make up the deficiency of adopting the solid model to directly carry out the Boolean operation.The stope mining indexes obtained by this method are accurate and reliable,and can be used to guide the actual production management and estimate the mining quality.

  7. Galerkin solution of Winkler foundation-based irregular Kirchhoff plate model and its application in crown pillar optimization

    Institute of Scientific and Technical Information of China (English)

    彭康; 尹旭岩; 尹光志; 许江; 黄滚; 殷志强

    2016-01-01

    Irregular plates are very common structures in engineering, such as ore structures in mining. In this work, the Galerkin solution to the problem of a Kirchhoff plate lying on the Winkler foundation with two edges simply supported and the other two clamped supported is derived. Coordinate transformation technique is used during the solving process so that the solution is suitable to irregular shaped plates. The mechanical model and the solution proposed are then used to model the crown pillars between two adjacent levels in Sanshandao gold mine, which uses backfill method for mining operation. After that, an objective function, which takes security, economic profits and filling effect into consideration, is built to evaluate design proposals. Thickness optimizations for crown pillars are finally conducted in both conditions that the vertical stiffness of the foundation is known and unknown. The procedure presented in the work provides the guidance in thickness designing of complex shaped crown pillars and the preparation of backfill materials, thus to achieve the best balance between security and profits.

  8. EEC Round Robin test on the repository system simulation - clay option. Final report EEC research contract No. Fl 1W-0116-l

    Energy Technology Data Exchange (ETDEWEB)

    Cantale, C.; Castelli, S.; Donato, A.; Traverso, D.M.

    1989-06-01

    The objective of the 'Reporting System Simulation Test (RSST) was to define a test method for the evaluation of waste performances in various geological disposal scenarios, with the possibility to simulate various additional materials, like canister, backfilling, overpack and host rock. The test procedure for the clay-option needed to be developed, especially with reference to the solution preparation and Eh (redox potential) measurements. The necessity to work in an argon atmosphere glove box brings in some operational complications, mainly in the case of the Eh measurement, filtering and final volume determination. The reproducibility of the experimental data does not seem to be particularly good, probably due to the difficulties in standardizing the experimental procedure. An effort should be done to improve these aspects. The tightness of the container and the physical stability of the rock/backfill/grill with pins/synthetic interstitial claywater system are excellent. The leaching data reveal that the clay contribution to the final ionic concentration of the solution is not negligible and should be better evaluated. The overall data-set shows that the glass leach rate, as expressed by Boron mass loss, decreases with time.

  9. Nuclear Waste Management under Approaching Disaster: A Comparison of Decommissioning Strategies for the German Repository Asse II.

    Science.gov (United States)

    Ilg, Patrick; Gabbert, Silke; Weikard, Hans-Peter

    2016-06-14

    This article compares different strategies for handling low- and medium-level nuclear waste buried in a retired potassium mine in Germany (Asse II) that faces significant risk of uncontrollable brine intrusion and, hence, long-term groundwater contamination. We survey the policy process that has resulted in the identification of three possible so-called decommissioning options: complete backfilling, relocation of the waste to deeper levels in the mine, and retrieval. The selection of a decommissioning strategy must compare expected investment costs with expected social damage costs (economic, environmental, and health damage costs) caused by flooding and subsequent groundwater contamination. We apply a cost minimization approach that accounts for the uncertainty regarding the stability of the rock formation and the risk of an uncontrollable brine intrusion. Since economic and health impacts stretch out into the far future, we examine the impact of different discounting methods and rates. Due to parameter uncertainty, we conduct a sensitivity analysis concerning key assumptions. We find that retrieval, the currently preferred option by policymakers, has the lowest expected social damage costs for low discount rates. However, this advantage is overcompensated by higher expected investment costs. Considering all costs, backfilling is the best option for all discounting scenarios considered.

  10. Modeling of irradiated graphite (14)C transfer through engineered barriers of a generic geological repository in crystalline rocks.

    Science.gov (United States)

    Poskas, Povilas; Grigaliuniene, Dalia; Narkuniene, Asta; Kilda, Raimondas; Justinavicius, Darius

    2016-11-01

    There are two RBMK-1500 type graphite moderated reactors at the Ignalina nuclear power plant in Lithuania, and they are under decommissioning now. The graphite cannot be disposed of in a near surface repository, because of large amounts of (14)C. Therefore, disposal of the graphite in a geological repository is a reasonable solution. This study presents evaluation of the (14)C transfer by the groundwater pathway into the geosphere from the irradiated graphite in a generic geological repository in crystalline rocks and demonstration of the role of the different components of the engineered barrier system by performing local sensitivity analysis. The speciation of the released (14)C into organic and inorganic compounds as well as the most recent information on (14)C source term was taken into account. Two alternatives were considered in the analysis: disposal of graphite in containers with encapsulant and without it. It was evaluated that the maximal fractional flux of inorganic (14)C into the geosphere can vary from 10(-11)y(-1) (for non-encapsulated graphite) to 10(-12)y(-1) (for encapsulated graphite) while of organic (14)C it was about 10(-3)y(-1) of its inventory. Such difference demonstrates that investigations on the (14)C inventory and chemical form in which it is released are especially important. The parameter with the highest influence on the maximal flux into the geosphere for inorganic (14)C transfer was the sorption coefficient in the backfill and for organic (14)C transfer - the backfill hydraulic conductivity.

  11. Centrifuge modelling of the pushover failure of an electricity transmission tower

    Energy Technology Data Exchange (ETDEWEB)

    Richards, D.J. [Southampton Univ. (United Kingdom). School of Civil Engineering and the Environment; White, D.J. [Western Australia Univ., Crawley, WA (Australia). Centre for Offshore Foundation Systems, Faculty of Engineering, Computing and Mathematics

    2010-04-15

    The foundation systems of broad-based lattice power transmission towers must be designed to resist uplift, lateral and downward forces arising from the tower's weight, and tension within the conductor wires and wind loadings. This study investigated foundation failure mechanisms during the rapid horizontal pushover of a power transmission tower. The centrifuge model tests were designed to simulate a wind gust loading or broken transmission line response. The tower was supported on 4 pad foundations set in clay and backfilled with sand. The loads at each foundation were measured during fast and flow pushover. The influence of tensile resistance mobilized at the underside of the footings was investigated. The measured performance of the tower footings showed good agreement with results obtained from a series of tests conducted to measure a single footing subjected to vertical loading. Tower response was back-analyzed as a simple push-pull model. The calculated uplift capacity of the footing backfill showed good agreement with the observed response of tower footings subjected to slow pushover. The additional capacity mobilized during fast pushover was caused by tensile resistance created by the reverse bearing capacity beneath the base of the footings. 30 refs., 3 tabs., 11 figs.

  12. Metals attenuation in minerally-enhanced slurry walls

    Energy Technology Data Exchange (ETDEWEB)

    Evans, J.C.; Prince, M.J. [Bucknell Univ., Lewisburg, PA (United States); Adams, T.L. [Woodward-Clyde Consultants, Blue Bell, PA (United States)

    1997-12-31

    In current practice, a soil-bentonite slurry trench cutoff wall is a mixture of water, soil, and bentonite that is designed to serve as a passive barrier to ground water and contaminant transport. This study evaluated the transformation of a passive slurry trench cutoff wall barrier to an active barrier system. Conventional soil-bentonite vertical barriers presently serve as passive barriers to contaminated ground water. An active barrier will not only fulfill the functions of the present passive barrier system, but also retard contaminant transport by adsorptive processes. Attapulgite, Na-chabazite, and Ca-chabazite were added to {open_quotes}activate{close_quotes} the conventional soil-bentonite backfill. Batch extraction tests were performed to determine the partitioning coefficients of cadmium and zinc between the liquid and solid phase when in contact with the backfill mixes. Batch extraction and mathematical modeling results demonstrate the ability of an active barrier to retard the transport of cadmium and zinc. The reactivity of the soil-bentonite vertical barrier depends heavily on the inorganic being adsorbed. The reactivity of the barrier also depends on the adsorptive capabilities of the clay minerals added to the conventional soil-bentonite vertical barrier. The results of laboratory studies suggest that passive barrier systems can be transformed to active systems. Further, the data suggests that although conventional soil-bentonite vertical barriers are presently designed as passive barriers, they already have adsorptive capacity associated with active barriers.

  13. Comparing the Thixotropic and Lightly Solidified Hardening Behavior of a Dredged Marine Clay

    Directory of Open Access Journals (Sweden)

    C. M. Chan

    2014-10-01

    Full Text Available When a soil is disturbed upon remolding, it may lose part or all of its strength. As time passes, the structural arrangement of the soil particles would be restored to a stable form and the soil would regain hardness under constant volume and water content. The process is known as “thixotropic hardening”. On another note, dredged marine soils of the fine-grained type can be reused as a backfill material instead of being disposed to the open sea. The rest period required for the relocated soil to regain strength and stiffness, i.e. thixotropic hardening, needs to be estimated precisely. For this purpose, a study on the phenomena of strength and stiffness gain by a dredged marine clay was carried out. The strength and stiffness improvement with time was measured using the vane shear and fall cone tests respectively. The clay was remolded at different water contents in multiples of the soil’s liquid limit (LL, namely 0.75LL, 1.00LL and 1.25LL, in order to evaluate the effect of initial water content on thixotropic hardening. A separate series of samples were prepared with light solidification using cement, to examine the possibilities of enhancing the soil’s improvement in a shorter rest period. The results showed the dredged marine clay can potentially be used as a backfill material for reclamation works, with lower initial water content and light solidification contributing to accelerated better performance

  14. 50 years of science at CERN - More than 300 years of science in the Library

    CERN Multimedia

    2004-01-01

    Surprisingly many people consider articles published 20-30 years ago as old and become overwhelmed when they realise that such information sources are still available in the Library. Quite apart from the purely historical interest, many past issues do in fact reoccur even if in a somewhat different context, making the complete coverage of past information an essential tool for on-going research. Even in the pre-electronic days this was the case for the CERN Library, but with the development of electronic journals and access to their so-called 'back-files' (the retrospective scanning of articles back to volume 1) this possibility has expanded dramatically. We can now all consult online a vast historical archive, including the famous Philosophical Transactions of the Royal Society of London which started in 1665. More than three million articles are directly available from our desktops at this moment in time! The Library recently gained access to another collection of electronic back-files, those for Elsevier ...

  15. 南水北调中线干线工程渠道逆止阀的施工工艺和质量控制%Construction Technique and Quality Control of Channel Check Valve in the Middle Route of South-to-North Water Diversion Project

    Institute of Scientific and Technical Information of China (English)

    高大勇; 朱云飞

    2013-01-01

    以南水北调鹤壁段第二施工标段为例,介绍了渠道逆止阀的安装工艺,如遵循“基础开挖→回填第一层粗砂→埋置集水暗管→回填暗管周边粗砂→铺设保温板→铺设复合土工膜→安装逆止阀”的施工流程;质量控制方法,如控制逆止阀安装位置、高程、数量等。%The installation technique of channel check valve is introduced by taking the example of Hebi section , the second construction section of South-to-North Water Diversion Project .The technique are in accordance with following orders:foundation excavation , backfilling the first layer of coarse sand , burying water collecting pipe , backfilling coarse sand surrounding pipes , laying warm keeping board , laying composite geomembrane and installing check valve .Mean-while , the quality control methods , such as control check valve installation position , elevation and quantity are also covered .

  16. Dual-sided microstructured semiconductor neutron detectors (DSMSNDs)

    Science.gov (United States)

    Fronk, Ryan G.; Bellinger, Steven L.; Henson, Luke C.; Ochs, Taylor R.; Smith, Colten T.; Kenneth Shultis, J.; McGregor, Douglas S.

    2015-12-01

    Microstructured semiconductor neutron detectors (MSNDs) have in recent years received much interest as high-efficiency replacements for thin-film-coated thermal neutron detectors. The basic device structure of the MSND involves micro-sized trenches that are etched into a vertically-oriented pvn-junction diode that are backfilled with a neutron converting material. Neutrons absorbed within the converting material induce fission of the parent nucleus, producing a pair of energetic charged-particle reaction products that can be counted by the diode. The MSND deep-etched microstructures produce good neutron-absorption and reaction-product counting efficiencies, offering a 10× improvement in intrinsic thermal neutron detection efficiency over thin-film-coated devices. Performance of present-day MSNDs are nearing theoretical limits; streaming paths between the conversion-material backfilled trenches, allow a considerable fraction of neutrons to pass undetected through the device. Dual-sided microstructured semiconductor neutron detectors (DSMSNDs) have been developed that utilize a complementary second set of trenches on the back-side of the device to count streaming neutrons. DSMSND devices are theoretically capable of greater than 80% intrinsic thermal neutron detection efficiency for a 1-mm thick device. The first such prototype DSMSNDs, presented here, have achieved 29.48±0.29% nearly 2× better than MSNDs with similar microstructure dimensions.

  17. Groundwater salinity at Olkiluoto and its effects on a spent fuel repository

    Energy Technology Data Exchange (ETDEWEB)

    Vieno, T. [VTT Energy, Espoo (Finland)

    2000-06-01

    The Olkiluoto island rose from the Baltic Sea 2500 to 3000 years ago. The layered sequence of groundwaters can be related to climatic and shoreline changes from modern tune through former Baltic stages to the deglaciation phase about 10 000 years ago and even to preglacial times. Fresh groundwater is found to the depth of about 150 metres, brackish between 100 and 400 metres, deeper groundwaters are saline. At the depth of 500 meters, the content of Total Dissolved Solids (TDS) varies between 10 and 25 g/l. The most saline waters at depths greater than 800 metres have TDS values between 30 and 75 g/l. These deep saline waters seem to have been undisturbed during the most recent glaciation and even much longer in the past. Today fresh water infiltrating at the surface gradually displaces brackish and saline groundwater in the bedrock. Due to the still ongoing postglacial land uplift, Olkiluoto is likely to become an inland site with brackish or fresh groundwater at the depth of 500 metres within the next 10 000 years. During the construction and operation phases groundwater will be drawn into the repository from the surrounding bedrock. As a consequence, more saline groundwaters, presently laying 100 to 200 metres below the repository level, may rise to the disposal level. After the closing of the repository the salinity distribution will gradually return towards the natural state. During the glacial cycle groundwater salinity may increase, for example, during freezing of groundwater into permafrost, when dissolved solids concentrate in the remaining water phase, and in a situation where deep saline groundwaters from under the centre of the glacier are pushed to the upper parts of the bedrock at the periphery of the glacier. The most significant open issue related to saline groundwater is the performance of the tunnel backfill which in the BS-3 concept has been planned to consist of a mixture of crushed rock and 10-30% of bentonite. Saline groundwater may

  18. Engineering for Operation of a Future Belgian Deep Geological Repository for ILW and HLW - 12379

    Energy Technology Data Exchange (ETDEWEB)

    Haverkamp, B.; Biurrun, E.; Nieder-Westermann, G.H. [DBE TECHNOLOGY GmbH, Peine (Germany); Van Humbeeck, H. [ONDRAF/NIRAS, Brussels (Belgium); Van Cotthem, Alain [Tractebel Engineering SA, Brussels (Belgium)

    2012-07-01

    In Belgium, an advanced conceptual design is being elaborated for deep geologic disposal of high level waste (HLW) and for low and intermediate level waste (LILW) not amenable for surface disposal. The concept is based on a shielded steel and concrete container for disposal of HLW, i.e., the Super-container. LILW will be disposed of in separately designed concrete caissons. The reference host rock is the Boom Clay, a poorly indurated clay formation in northeastern Belgium. Investigations into the potential host rock are conducted at the HADES underground research laboratory in Mol, Belgium. In 2009 the Belgian Agency for Management of Radioactive Waste and Enriched Fissile Materials (ONDRAF/NIRAS) initiated a four year research project aimed at confirming the fundamental feasibility of building and operating a repository. The goal of the program is to demonstrate at a detailed conceptual level that the proposed geologic disposal system can be safely constructed, operated, and progressively closed. Part of the broader research efforts being conducted includes evaluations optimization of the waste transportation shaft, subsurface transportation system, ventilation system, and evaluation of backfilling and sealing concepts for the repository design. The potential for implementation of a waste retrieval strategy encompassing the first 100 years after emplacement is also considered. In the framework of a four year research program aimed at confirming the fundamental feasibility of building and operating a repository in poorly indurated clay design studies have been underway to optimize the waste transportation shaft, subsurface transportation system, and ventilation system. Additionally backfilling and sealing concepts proposed for the potential repository have been reviewed in conjunction with impacts related to the potential future inclusion of a retrievability requirement in governing regulations. The main engineering challenges in the Belgian repository concept are

  19. Review of SKB's Work on Coupled THM Processes Within SR-Can. External review contribution in support of SKI's and SSI's review of SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, Jonny; Chin-Fu Tsang (Lawrence Berkeley National Laboratory, Berkeley, CA (US))

    2008-03-15

    SKB should conduct further analyses to show that such extreme drying of the buffer to below 20% could not occur, or that such drying would not result in a peak temperature higher than 100 deg C. 2) We found that SKB's estimates for the time of full resaturation of the buffer might be underestimated, because the analysis is based on models assuming nearby water feeding conditions. Moreover, SKB's analysis does not consider the potential impact and uncertainties regarding water-retention properties of the rock mass and the potential impact of ventilation-induced drying during the operational phase is not addressed. SKB's estimated time to full resaturation is valid for an assumed distance to water feeding boundary of 12 m and for one single assumed retention curve of the rock. We believe SKB should provide additional analyses to show that the assumed distance to the water-feeding boundary is reasonable and conduct additional sensitivity analyses on water-retention properties and ventilation effects. 3) We found that SKB's reliance on the backfill as an important source for water supply to resaturate the buffer, in the case of extremely dry rock conditions, may be unjustified. If a bentonite-rock mixture (30/70) is used, the buffer may be resaturated by water supply from the backfill, but then the saturation in the backfill would decrease, preventing it from swelling and thereby keeping it from fulfilling an important safety function indicator criterion. If Friedland Clay is used as backfill, its capillary suction at emplacement would be higher than that of the buffer, and therefore water would be sucked from the buffer into the backfill, effectively keeping the buffer dry. We believe SKB should conduct further studies or reconsider the backfill design, to assure buffer resaturation from the backfill in the case of extremely dry rock conditions. 4) We found that SKB's geomechanical analysis of the potential for rock-mass failure correctly

  20. 南水北调中线工程改性土余料再利用研究%Research on re-utilization of surplus modified soil in Middle Route Project of South to North Water Diversion

    Institute of Scientific and Technical Information of China (English)

    张胜明; 王德云; 刘勇

    2014-01-01

    The useable soil sources for the most bidding sections of Middle Route Project of South to North Water Diversion are insufficient and using cement-mixed modified soil to replace the canal soil is a main measure for guaranteeing the canal slope stability. In the backfilling construction, large amount of surplus modified soil was produced after slope cutting and the indoor and field tests discovered that the surplus modified soil could be used as backfilling soil. In the test, the selection method of the maxi-mum dry density, construction technology and application scope of the modified soil were determined. The soil re-utilization has increased backfilling soil sources in weak expansive soil area, which could save farmland, resources and protect environment.%南水北调中线工程大部分标段可用土料源不足,采用弱膨胀土掺入水泥(简称水泥改性土,下同)后对膨胀土渠段进行换填施工,是确保膨胀土渠段边坡稳定的主要措施之一。在填筑施工中,按设计坡比削坡后产生大量的改性土削坡余料,通过室内试验及现场试验验证了改性土余料亦可用于工程回填。为此,确定了改性土余料最大干密度的选择方法、改性土余料的施工工艺及使用部位。对余料土的再利用,保证了弱膨胀土地区土方施工的回填料源,避免或减少了农田占压面积,取得了节约资源与保护环境的双重效果。

  1. Experimental study on back filling and rolling compaction of coarse-grained salty soil%粗颗粒盐渍土回填碾压试验研究

    Institute of Scientific and Technical Information of China (English)

    刘志伟; 程东幸; 张希宏

    2012-01-01

    在新疆大规模的开发建设中,大量的工程场地将遇到粗颗粒盐渍土。因厂址区附近建筑材料缺乏,外运距离远,场地回填及地基换填料同时成为工程面临的难题。本文遵循就地取材的原则,开展了粗颗粒盐渍土现场回填碾压试验和专题研究,确定了粗颗粒盐渍土作为回填料的适宜性及相关设计施工参数。试验研究表明:当粗颗粒盐渍土易溶盐含量不是很高,具轻微溶陷性,并不考虑盐胀时,场地料重新回填可消除原有的溶陷性,且地基承载力可达170kPa,通过级配改良,混合料回填碾压后地基承载力可达300kPa,有了较大提高。其成果的获得,具有明显的工程效益。%In the large-scale development and construction in Xinjiang Uygur Autonomous Region, the most engineering site will encounter the coarse-grained salty soil. Due to the lack of building materials near the site and the long-distance transport, the materials for the back filling and soil replacement are facing the engineering problems. Following the principle to obtain raw material locally, the backfill compaction tests with coarse-grained salty soil and the special study in the field are carried out, and the suitability of the coarse-grained salty soil as backfill material and the relative design and construction parameters are determined. When the easy resolving salt content in coarse-grained salty soil is not very high, and with slight thaw collapsibility, without considering the expansion of salts, the experimental study shows that the thaw collapsibility has been eliminated after the back filling and rolling compaction with the site soil, and the bearing capacity can reach 170kPa. Through improving the gradation, the strength of the compacted backfill has been greatly improved; the bearing capacity of the mixed material can reach 300kPa, which obtain the favorable engineering benefit.

  2. Aespoe Hard Rock Laboratory Annual Report 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-08-01

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

  3. Hydrology and water-quality monitoring considerations, Jackpile uranium mine, northwestern New Mexico

    Science.gov (United States)

    Zehner, H.H.

    1985-01-01

    The Jackpile Uranium Mine, which is on the Pueblo of Laguna in northwestern New Mexico, was operated from 1953 to 1980. The mine and facilities have affected 3,141 acres of land, and about 2,656 acres were yet to be reclaimed by late 1980. The intended use of the restored land is stock grazing. Fractured Dakota Sandstone and Mancos Shale of Cretaceous age overlie the Jackpile sandstone and a 200-ft-thick tight mudstone unit of the Brushy Basin Member underlies the Jackpile. The hydraulic conductivity of the Jackpile sandstone probably is about 0.3 ft/day. The small storage coefficients determined from three aquifer tests indicate that the Jackpile sandstone is a confined hydrologic system throughout much of the mine area. Sediment from the Rio Paguate has nearly filled the Paguate Reservoir near Laguna since its construction in 1940. The mean concentrations of uranium, Ra-226, and other trace elements generally were less than permissible limits established in national drinking water regulations or New Mexico State groundwater regulations. No individual surface water samples collected upstream from the mine contained concentrations of Ra-226 in excess of the permissible limits. Ra-226 concentrations in many individual samples collected from the Rio Paguate from near the mouth of the Rio Moquino to the sampling sites along the downstream reach of the Rio Paguate, however, exceeded the recommended permissible concentration of Ra-226 for public drinking water supplies. Concentrations in surface water apparently are changed by groundwater inflow near the confluence of the two streams. The altitude of the water tables in the backfill of the pits will be controlled partly by the water level in the Rio Paguate. Other factors controlling the altitudes of the water tables are the recharge rate to the backfill and the hydraulic conductivities of the backfill, alluvium, Jackpile sandstone, and mudstone unit of the Brushy Basin Member. After reclamation, most of the shallow

  4. Mechanical Analysis of Stability of Movable Block Body at Underhand Cut-and-fill Drift Side%下向进路侧帮可动块体的稳定性力学分析

    Institute of Scientific and Technical Information of China (English)

    何书; 赵奎

    2012-01-01

    In order to study the deformation characteristics of the side-wall rock of underhand drift under overlaying filling pressure, and based on the comprehensive analysis of the forming criterions of movable block body in connecting between the backfill body and underhand cut-and-fill drift, the mechanical effects of the backfill body on the underhand cut-and-fill drift is analyzed with elastic theory. The results show that the effects of the backfdl body on the stability of the rock of underhand cut-and-fill drift relate with the aspect ratio of the underhand drift, the mechanical properties of the orebody, and the dip angle of the movable rock mass's sliding surface. The deformation and failure mechanism of the movable block body under filling pressure was discussed, and the methods for calculating the stability coefficient of movable block body and the force on the movable block body from the backfill body were put forward. Finally, the applied effect of the method is verified with a practical engineering case in Wushan copper mine.%为了研究下向进路侧帮矿体在上覆充填体作用下的变形特征,在综合分析侧帮矿体与充填体交接处可动块体形成条件的基础上,应用弹性理论分析了充填体对进路侧帮可动块体的力学效应.结果表明,充填体对侧帮可动块体的稳定性影响与进路高宽比、侧帮矿体的力学性质及可动块体的滑移面倾角有关,阐明了充填体作用下下向进路侧帮可动块体的变形破坏机理,推导了可动块体顶面受充填体作用力大小的计算方法,以及可动块体在充填体作用下的稳定性系数计算方法.武山铜矿开采的工程实例应用证明了该方法的应用效果.

  5. Shallow burial of district heating pipes; Grund foerlaeggning av fjaerrvaermeledningar

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Stefan; Saellberg, Sven-Erik; Bergstroem, Gunnar [Swedish National Testing and Research Inst., Boraas (Sweden)

    2006-07-28

    Previous studies have shown that the investment costs for district heating installations in suburban areas can be lowered with more rational construction work. This project has studied the possibilities of decreasing the laying depth for pipes in residential-area roads without risking damage on neither pipe nor road surface. An inventory of regulations from national and local authorities and district heating companies in Sweden was done. The larger cities have specific requirements regarding laying depth in road structures. In most places, however, the guidelines issued by the Swedish District Heating Association are followed. And in smaller cities, the question is handled directly by the municipal district heating company. In some places, e.g., Goeteborg, Joenkoeping and Luleaa, the local authorities and the district heating company have agreed on a smaller laying depth under certain circumstances. An analysis of the costs related to the excavation work, backfilling and asphalt laying showed that the costs can be reduced with about 30 % by decreasing the laying depth from 600 mm to 350 mm. A field trial was done with four twin pipes of dimension 2 x DN 32/160 laid 600 mm, 380 mm, 280 mm and 180 mm below the asphalt surface in a road with heavy traffic. Apart from the laying depth, the installation work was done in accordance with the guidelines from the Swedish District Heating Association. During traffic loading, measurements of internal deformations of the pipes, wheel-track depths in the asphalt surface and load-bearing capacity of the road structure were made. The deformation of the pipes is negligible at all laying depths. This is likely due to an arching action from the backfill which supports most of the forces from the traffic load. Significant wheel-tracks were measured, but they seem to correspond directly to settlements in the new soil. Hence, a shallower pipe trench leads to less prominent wheel-tracks. Shallow pipe burial yields slightly larger heat

  6. Argillaceous formations and clays in the context of deep geological radioactive waste disposal in Ukraine

    Energy Technology Data Exchange (ETDEWEB)

    Khrushchov, D.P.; Shekhunova, S.B. [Academy of sciences, Institute of geological science National, Lab. on geological problems of underground space utilization, Kiev (Ukraine)

    2005-07-01

    Dniper-Donets depression and bedded Permian salt formation in Donbass region. Triassic series composed of clays and sandstones (Dronovka suite) is of interest as a natural analog for radionuclides intrusion into sedimentary rock mass. In connection with technical options concerning engineering barriers (backfill, sealing) in repository concepts clays have been considered as a basic material in accordance with generally accepted approaches. Resources of clays of montmorillonite composition are represented with a number of deposits in different regions of the Ukraine (Cherkasy etc). The quality of clays is high. Special investigations on crystal structure, crystal chemistry, radiation and thermal stability of clay mineral have been carried out in the frames of state budget contract IAEA project. Special studies aimed at backfill efficiency increase have been conducted. Several types of mineral and mineral-synthetic compositions (clays + organic component) were proposed. These compositions secure additional improvement of backfill stability and isolation properties (including radionuclides sorption). (authors)

  7. 考虑土拱效应的非垂直挡墙地震主动土压力%SEISMIC ACTIVE EARTH PRESSURE FOR NON-VERTICAL RIGID RETAINING WALL CONSIDERING SOIL ARCHING EFFECT

    Institute of Scientific and Technical Information of China (English)

    周亦涛; 陈福全

    2015-01-01

    The stresses on the wall and sliding plane of the sliding backfill mass at arbitrary depths were obtained according to the soil arching effect. A formula of the seismic active failure angle behind the non-vertical rigid retaining wall under translation mode was obtained on the basis of the pseudo-static method and the equilibrium total forces. A formula of the seismic active earth pressure against the non-vertical rigid retaining wall under translation mode was derived according to the method of differential level layer. The seismic active earth force and the action point were obtained. The distribution of seismic active earth pressure from the proposed formula was non-linear along the height of wall. In addition,the influences of the wall-back inclination,internal friction angle of backfill,wall-soil friction angle,seismic coefficient and load against the backfill surface on the seismic failure angle,seismic active earth pressure and its coefficient,seismic active earth force and height of its application were investigated.%由土拱效应原理得到滑裂土体的墙面和滑裂面上的应力,然后根据拟静力法和滑裂土体的整体受力平衡,得到平移模式下非垂直刚性挡土墙的地震主动破裂角计算式.进一步根据水平层分法获得墙背地震主动土压力及其系数、地震主动土压力合力及其作用点高度等的计算式.此外,分别讨论墙背倾角、填土内摩擦角、墙土摩擦角、地震系数和填土表面荷载等对地震主动破裂角、法向地震主动土压力分析、地震主动土压力合力系数、地震主动土压力合力及其作用点相对高度等的影响.

  8. 各向异性砂土主动侧土压力计算方法%Evaluation of earth pressure at active side for anisotropic sand

    Institute of Scientific and Technical Information of China (English)

    宋飞; 张建民

    2011-01-01

    Evaluation of earth pressure is one of the key research subjects in soil mechanics and geotechnical engineering.The backfill displays anisotropic mechanical characteristics because of compaction in engineering practice; it is always at the non-limit state between the active and passive states.Classic Rankine and Coulomb earth pressure theories do not consider the effea of anisotropy and backfill deformation on the earth pressure.Based on a series of constant strain increment ratio tests, the unique relation between the earth pressure coefficient and the lateral strain constraint is established for anisotropic sand.On this basis.a method is proposed for estimating the earth pressure at the active side for anisotropic backfill sand under translational wall movement mode; and corresponding formulas are derived.Besides, the effectiveness of the suggested method is confirmed experimentally.%土压力是土力学和岩土工程领域的基本研究课题之一.由于碾压作用墙后填土具有不同程度的各向异性,并且通常处于主动与被动状态之间的非极限状态.经典的朗肯和库仑土压力理论没有考虑填土各向异性的力学性质及挡墙位移效应对于土压力的影响.基于各向异性砂土的等应变增量比系列试验结果建立了土压力系数与与用应变增量比表述的应变约束条件之间所具有的惟一性关系,在此基础上给出了平动位移模式下各向异性砂土的主动土压力计算方法,并通过土压力离心模型试验结果对其计算方法进行了验证,初步表明了其有效性和合理性.

  9. STABILITY ANALYSIS OF WATER FRONT RETAINING WALL SUBJECTED TO SEISMIC LOADS USING PSEUDO-DYNAMIC METHOD%强地震荷载作用下临水挡土墙的拟动力法稳定性分析

    Institute of Scientific and Technical Information of China (English)

    周小平; 季璇; 钱七虎

    2012-01-01

    It is assumed that failure surfa.ce of backfill soil is composite curved one. Pseudo-dynamic method, in which time-history curves of acceleration was simulated by sinusoidal motions, was adopted to research the stability of the water front retaining wall subjected to seismic loads. The damping force and the inertial force acting on retaining wall and backfill soil were investigated. The closed-form solutions of passive earth pressure and dynamic factor of safety against sliding and rotation of the retaining wall during earthquake were obtained. Finally, effects of seismic acceleration, amplification factor, wall height, physico-mechanical parameters of backfill soil and hydrodynamic pressure acting on water front retaining wall on sliding displacement, dynamic factor of safety against sliding and rotation of the retaining wall were quantitatively analyzed. It is concluded that the stability of the water front retaining wall is getting worse when the earthquake speeds up, the water level gets higher and the internal friction angle gets smaller.%假设墙后填土破坏面为曲面,用正弦波模拟地震加速度时程曲线,采用拟动力法对临水挡土墙进行稳定性分析,确定了挡土墙和墙后填土所受的阻尼力和惯性力,获得地震荷载作用下挡土墙的被动土压力、抗滑和抗倾覆稳定性系数的封闭形式解析解.定量分析地震加速度、放大系数、墙后填土的物理力学参数和动水压力对挡土墙的滑动位移、挡土墙的抗滑和抗倾覆稳定性系数的影响,得出当地震加速度、放大系数越大,水位越高,内摩擦角越小,临水挡土墙的稳定性越差.

  10. Repository for spent nuclear fuel. Plant description layout D - Forsmark; Slutfoervarsanlaeggning foer anvaent kaernbraensle. Anlaeggningsbeskrivning layout D - Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-15

    This document describes the final repository for spent nuclear fuel, SFK, which is located at Forsmark, in Oesthammar. The bedrock at the site is part of a so-called tectonic lens, in which the rock composition is relatively homogeneous and less deformed than outside the lens. The bedrock consists mainly of granite with high quartz content and good thermal conductivity. The central parts above ground are grouped in an operations area, located at the Soederviken on the south side of the intake duct for cooling water for nuclear power plant. Operating area is divided into an internal, secured portion, where the canisters of fuel are handled and there are links to the underground part, and a outer part, where the buffer, backfill and sealing used in the repository's barriers are produced. The above-ground part of the plant and also include storage of excavated rock, ventilation stations, and supplies of bentonite. The underground portion consists of a central area and a storage area. Caverns of the central area contain features for the underground operation. It communicates with the internal operating range above ground via a spiral ramp and several shafts. The ramp used to transport capsules of spent fuel and other heavy or bulky transport. The shafts are used to transport rock, buffer, backfill and staff, as well as for ventilation. The largest part of the space below ground is the repository where the canisters with the spent fuel are disposed. The capsules are deposited in vertical holes in the tunnels. When the deposit in a tunnel is complete, the tunnel is re-filled. The two main activities underground is rock work and disposal work, which are conducted separately from each other. Rock works covers all steps required to excavate tunnels and drill deposition holes, as well as to make temporary installations in the tunnels. To the landfill works count, besides the deposit of the capsule, the placement of the bentonite buffer in the deposition hole and

  11. Aespoe Hard Rock Laboratory. Annual report 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

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

  12. Strategies for creating antifouling surfaces using selfassembled poly(ethylene glycol) thiol molecules

    DEFF Research Database (Denmark)

    Lokanathan, Arcot R.

    2011-01-01

    conditions for the reversible, initial attachment of microbial cells. This effect can be obtained by grafting hydrophilic polymeric chains onto surfaces and thereby provide a steric barrier between the substrate surface and the microbial cell. Poly (ethylene glycol) (PEG) is one of the most widely used....... The work focuses on novel strategies to self assemble PEG thiol monolayers with high graft density. One of the strategies investigated involved backfilling a self assembled layer of 2000 Da PEG thiol with shorter oligo (ethylene glycol) (OEG) thiol molecules to form a mixed monolayer. Detailed quantitative......Microorganisms are one of the most important parts of our ecosystem influencing the sustenance of human society. The beneficial microbes are of high relevance to food industry, development of antibiotics and processing of many raw materials. Mankind has indeed benefitted a lot from large number...

  13. Gamma and beta logging of underground sewer and process lines

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, M.J.; Martz, D.E.; Langner, G.H. Jr.

    1989-11-01

    The GammaSnake can be useful for locating uranium mill tailings used as backfill for sewer lines or storm drains where the lines can be readily accessed from a cleanout access port or other opening. The time required to determine if contamination is present using the GammaSnake method is considerably less than when using the delta gamma or drilling methods. There is, also, less potential hazard to the equipment operators when using the GammaSnake method. The GammaSnake method is generally limited to a distance of 100 feet or less. Used with the MAC-51B line locator, the GammaSnake method can provide useful information without extensive drilling or surveying. 7 figs., 2 tabs.

  14. Nuclear waste management. Quarterly progress report, April-June 1981

    Energy Technology Data Exchange (ETDEWEB)

    Chikalla, T.D.; Powell, J.A.

    1981-09-01

    Reports and summaries are presented for the following: high-level waste process development; alternative waste forms; TMI zeolite vitrification demonstration program; nuclear waste materials characterization center; TRU waste immobilization; TRU waste decontamination; krypton implantation; thermal outgassing; iodine-129 fixation; NWVP off-gas analysis; monitoring and physical characterization of unsaturated zone transport; well-logging instrumentation development; verification instrument development; mobility of organic complexes of radionuclides in soils; handbook of methods to decrease the generation of low-level waste; waste management system studies; waste management safety studies; assessment of effectiveness of geologic isolation systems; waste/rock interactions technology program; high-level waste form preparation; development of backfill materials; development of structural engineered barriers; disposal charge analysis; and analysis of spent fuel policy implementation.

  15. Wohin mit den älteren medizinischen Zeitschriftenbänden? - Die Benutzungserhebung 2004 an der Universitätsbibliothek der Medizinischen Universität Wien / Where to put the back numbers? - Usage of older medical journals at the Medical University Library Vienna in 2004

    Directory of Open Access Journals (Sweden)

    Bauer, Bruno

    2006-05-01

    Full Text Available The increasing usage of e-journals questions the library's print archive. This is particularly valid for medical libraries where mainly up to date literature is required. From March to June 2004 the use of back numbers at the Medical University Library Vienna was recorded in order to assess utilisation of print journals published before 1986. During these four month 10.286 bound volumes were taken out from the print archive. Journal title, publication year and type of usage (local or interlibrary loan was registered. A ranking list of the most used journals was compiled including their impact factor. On average it came to about 105 uses per workday. This remarkable demand for back numbers is a clear argument for keeping the library's print archive inhouse regarding the publishers' patchy online backfile collections.

  16. Neutralization/prevention of acid rock drainage using mixtures of alkaline by-products and sulfidic mine wastes.

    Science.gov (United States)

    Alakangas, Lena; Andersson, Elin; Mueller, Seth

    2013-11-01

    Backfilling of open pit with sulfidic waste rock followed by inundation is a common method for reducing sulfide oxidation after mine closure. This approach can be complemented by mixing the waste rock with alkaline materials from pulp and steel mills to increase the system's neutralization potential. Leachates from 1 m3 tanks containing sulfide-rich (ca.30 wt %) waste rock formed under dry and water saturated conditions under laboratory conditions were characterized and compared to those formed from mixtures. The waste rock leachate produced an acidic leachate (pH9). The decrease of elemental concentration in the leachate was most pronounced for Pb and Zn, while Al and S were relatively high. Overall, the results obtained were promising and suggest that alkaline by-products could be useful additives for minimizing ARD formation.

  17. SR-Site Pre-modelling: Sensitivity studies of hydrogeological model variants for the Laxemar site using CONNECTFLOW

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, Steven; Hoek, Jaap; Hartley, Lee (Serco (United Kingdom)); Marsic, Niko (Kemakta Konsult AB, Stockholm (Sweden))

    2010-12-15

    This study investigated a number of potential model variants of the SR-Can hydrogeological models of the temperate period and the sensitivity of the performance measures to the chosen parameters. This will help to guide the choice of potential variants for the SR-Site project and provide an input to design premises for the underground construction of the repository. It was found that variation of tunnel backfill properties in the tunnels had a significant effect on performance measures, but in the central area, ramps and shafts it had a lesser effect for those property values chosen. Variation of tunnel EDZ properties only had minor effects on performance measures. The presence of a crown space in the deposition tunnels had a significant effect on the tunnel performance measures and a lesser effect on the rock and EDZ performance measures. The presence of a deposition hole EDZ and spalling also had an effect on the performance measures.

  18. Closure Report for Corrective Action Unit 428: Area 3 Septic Waste Systems 1 and 5 Tonopah Test Range, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    D. H. Cox

    2001-06-01

    The following site closure activities were performed at the CAU 428 site located at the TTR and are documented in this report: Preplanning and site preparation; Excavating and removing impacted soil; Removing septic tank contents; Closing septic tanks by filling them with clean soil; Collecting verification samples to verify that COCs have been removed to approved levels; Backfilling the excavations to surface grade with clean soil; Disposal of excavated materials following applicable federal, state, and DOE/NV regulations in accordance with Section 2.3 of the CAP (DOE/NV, 2000); and Decontamination of equipment as necessary. Closure was accomplished following the approved CAP (DOE/NV, 2000). Verification sample data demonstrate that all COCs were removed to the remediation standards. Therefore, the site is clean-closed.

  19. 石坝冲水库除险加固设计%Design of Danger Removal and Reinforcement of Shibachong Reservoir

    Institute of Scientific and Technical Information of China (English)

    殷小林; 杨华舒; 李晋豫

    2012-01-01

    针对石坝冲水库存在的安全隐患,对大坝进行防渗及下游坝坡培厚加固.溢洪道在原基础上进行完善.输水涵、隧洞进行清淤及回填灌浆加固设计.通过加固处理,保证了水库的安全和正常运行.为类似工程的除险加固提供了参考依据.%According to the problems of the Shibachong reservoir. Seepage prevention for the dam and reinforcement thick culture for the downstream dam slope are designed. Spillway perfectes in the original basis. Water tunnels clear depositions and backfill grouting reinforcement design. Through the reinforcement, ensure safety and normal operation of the reservoir provide reference and basis for reinforcement of similar engineering.

  20. Charbonnages de France. 1998 annual report - Environment; Charbonnages de France. Rapport annuel 1998 - Environnement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    This 1998 annual report of the Charbonnages de France group presents the environmental actions carried out by the group after the Kyoto summit for the reduction of greenhouse gases and the preservation of fossil resources: the goals of the group and its environmental strategy; the use of waste products (bagasse-coal-fueled power plants, recovery of methane from coal mines, valorization of coal washing wastes, valorization of fly-ashes in cement industry); the reduction of pollutant emissions (development of supercritical, combined and hybrid cycles, fluidized bed boilers, reduction of pollutants during the dismantling of shutdown installations); water preservation (processing of acid mine waters, purification of waters from coke factories, cleansing of abandoned sites); sites rehabilitation (backfilling of abandoned mines, soil cleansing of dismantled coal processing facilities, reinforcing of abandoned cavities, prevention of erosion of spoil heaps etc..); improvement of landscapes (rehabilitation, revegetation); research and innovation (hydrological and geological impact studies, soil cleansing processes, phyto-remediation..). (J.S.)

  1. Reliability assessment of underground shaft closure

    Energy Technology Data Exchange (ETDEWEB)

    Fossum, A.F. [RE/SPEC, Inc., Rapid City, SD (United States); Munson, D.E. [Sandia National Labs., Albuquerque, NM (United States)

    1994-12-31

    The intent of the WIPP, being constructed in the bedded geologic salt deposits of Southeastern New Mexico, is to provide the technological basis for the safe disposal of radioactive Transuranic (TRU) wastes generated by the defense programs of the United States. In determining this technological basis, advanced reliability and structural analysis techniques are used to determine the probability of time-to-closure of a hypothetical underground shaft located in an argillaceous salt formation and filled with compacted crushed salt. Before being filled with crushed salt for sealing, the shaft provides access to an underground facility. Reliable closure of the shaft depends upon the sealing of the shaft through creep closure and recompaction of crushed backfill. Appropriate methods are demonstrated to calculate cumulative distribution functions of the closure based on laboratory determined random variable uncertainty in salt creep properties.

  2. Experimental study on countermeasure against liquefaction-induced flotation of manhole using recycled materials packed in sandbags

    Institute of Scientific and Technical Information of China (English)

    Masaho Yoshida; Masaru Tonoo; Masakatsu Miyajima; Masaru Kitaura

    2006-01-01

    The 2004 Niigata-ken Chuetsu earthquake in Japan caused serious damage to sewage facilities such as uplift of manholes and settlement of pavement above backfill soil for pipes. This paper deals with shake table tests in a 1 g gravity field on application of recycled materials for ground improvement to mitigation of liquefaction-induced flotation of manhole during earthquakes. The recycled materials used in tests were tire chips made of waste tires and crushed gravels made of waste reinforced concrete, and they were packed in sandbags. From the test results, it was confirmed that the recycled materials packed in sandbags could be treated as one of the countermeasures to restrain the flotation of manholes and settlement of ground surrounded by sandbags.

  3. High-efficiency microstructured semiconductor neutron detectors that are arrayed, dual-integrated, and stacked

    Energy Technology Data Exchange (ETDEWEB)

    Bellinger, Steven L., E-mail: slb3888@ksu.edu [Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Fronk, Ryan G. [Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Sobering, Timothy J. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); McGregor, Douglas S. [Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)

    2012-07-15

    Silicon diodes with large aspect ratio 3D microstructures backfilled with {sup 6}LiF show a significant increase in neutron detection efficiency beyond that of conventional thin-film coated planar devices. Described in this work are advancements in the technology using detector stacking methods and summed-detector 6 Multiplication-Sign 6-element arraying methods to dramatically increase the sensitivity to thermal neutrons. The intrinsic detection efficiency of the 6 Multiplication-Sign 6 array for normal-incident 0.0253 eV neutrons was found 6.8% compared against a calibrated {sup 3}He proportional counter. - Highlights: Black-Right-Pointing-Pointer Solid-state semiconductor neutron detectors utilizing {sup 6}LiF. Black-Right-Pointing-Pointer Large aspect ratio 3D microstructured silicon diodes. Black-Right-Pointing-Pointer Arrayed solid-state semiconductor neutron detectors.

  4. Application of rock mechanics to cut-and-fill mining. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-15

    The conference on application of rock mechanics to cut-and-fill mining was held June 1-3, 1980, at the University of Luleaa, Sweden. The conference began with reviews of the application of rock mechanics to mining and back filling in Australia, Canada and the USA. More particular papers involved mines in Sweden, Italy, Australia (pre reinforcement of walls with steel cables cemented in) and at the Con Mine in Canada. Two papers involved backfill material and specifications. Eight papers involved the use of the mathematical models for calculating the stresses developed in the rock mass by computer calculations and therefore, the probable stability. Such calculations are particularly necessary in deep mines. Papers of general interest were entered individually into EDB. (LTN)

  5. 我国铀矿冶废物的利用与有用资源的回收%Recycling of wastes from uranium mining and metallurgy and recovery of useful resources in China

    Institute of Scientific and Technical Information of China (English)

    潘英杰; 薛建新; 陈仲秋

    2012-01-01

    Recycling of wastes from uranium mining and metallurgy in China and recovery of useful resources are summarized from the aspects such as recovery of uranium from mine water, reusing of waste water, decontaminating and recycling of radioactivity contaminated metal, backfill of gangues and tailings, and comprehensive recovery and utilization of associated uranium deposits.%概述了铀矿冶系统矿井水中铀回收、水冶废水复用,污染废旧钢铁熔炼去污再利用,废石、尾矿回填利用,以及伴生铀矿综合回收利用等方面的实践.

  6. The dissolution of high-FeO olivine rock from the Lovasjaervi intrusion (SE-Finland) at 25 deg. C as a function of pH

    Energy Technology Data Exchange (ETDEWEB)

    Duro, Lara [Enviros-Spain S.L. Passeig de Rubi, 29-31, 08197 Valldoreix (Spain); El Aamrani, Fatima [Departament d' Enginyeria Quimica, ETSEIB-UPC (H4), Av. Diagonal 647, 08028 Barcelona (Spain); Rovira, Miquel [CTM-Centre Technologic, Avda. Bases de Manresa 1, 08240 Manresa (Spain); Gimenez, Javier [Departament d' Enginyeria Quimica, ETSEIB-UPC (H4), Av. Diagonal 647, 08028 Barcelona (Spain)]. E-mail: francisco.javier.gimenez@upc.edu; Casas, Ignasi [Departament d' Enginyeria Quimica, ETSEIB-UPC (H4), Av. Diagonal 647, 08028 Barcelona (Spain); Pablo, Joan de [CTM-Centre Technologic, Avda. Bases de Manresa 1, 08240 Manresa (Spain); Bruno, Jordi [Enviros-Spain S.L. Passeig de Rubi, 29-31, 08197 Valldoreix (Spain)

    2005-07-15

    The high-FeO olivine-rich rock from the Lovasjaervi intrusion (65% olivine, 20% plagioclase, 8% magnetite, 4% pyroxene and 3% serpentine) has been proposed as a potential redox-active backfill-additive in deep high level nuclear waste repositories. In this work, the authors report on kinetic dissolution studies of this solid under different pH and redox conditions performed by using a flow-through methodology. Assuming that silicon is mainly released to solution from the olivine contained in the solid, the experimental results have been adjusted to an empirical rate law as a function of proton concentration. The proton concentration reaction orders agree with results found in the literature for both acidic and alkaline pH ranges. The calculations conducted with the reactive transport code RETRASO show that at alkaline pH, the olivine rock might have a lower redox buffer capacity than expected.

  7. Development of technology for the design of shallow land burial facilities at arid sites

    Science.gov (United States)

    Nyhan, J. W.; Abeele, W. V.; Drennon, B. J.; Herrera, W. J.; Lopez, E. A.; Langhorst, G. J.; Stallings, E. A.; Walker, R. D.; Martinez, J. L.

    The Los Alamos field research program involving technology development for arid shallow land burial (SLB) sites is described. Field data are presented for an integrated field experiment, which was designed to test individual SLB component experiments related to erosion control, biobarriers, and subsurface capillary and migration barriers. Field tests of biointrusion barriers at waste disposal sites and in experimental plots are reported. The results of a joint DOE/NRC experiment to evaluate leaching and transport of sorbing (Cs, Sr, Li) and nonsorbing (I, Br) solutes in sandy silt backfill are presented for steady-state and unsteady-state flow conditions. A capillary barrier experiment performed in a large caisson (3-m diameter, 6.1 m deep) is described and a year's worth of field data is presented.

  8. Development of technology for the design of shallow land burial facilities at arid sites

    Energy Technology Data Exchange (ETDEWEB)

    Nyhan, J.W.; Abeele, W.V.; Drennon, B.J.; Herrera, W.J.; Lopez, E.A.; Langhorst, G.J.; Stallings, E.A.; Walker, R.D.; Martinez, J.L.

    1985-01-01

    The Los Alamos field research program involving technology development for arid shallow land burial (SLB) sites is described. Field data are presented for an integrated field experiment, which was designed to test individual SLB component experiments related to erosion control, biobarriers, and subsurface capillary and migration barriers. Field tests of biointrusion barriers at waste disposal sites and in experimental plots are reported. The results of a joint DOE/NRC experiment to evaluate leaching and transport of sorbing (Cs, Sr, Li) and nonsorbing (I, Br) solutes in sandy silt backfill are presented for steady-state and unsteady-state flow conditions. A capillary barrier experiment performed in a large caisson (3-m diameter, 6.1 m deep) is described and a year's worth of field data is presented.

  9. Effects of Military Traffic on Buried, High-Pressure Pipe.

    Science.gov (United States)

    1984-02-01

    Observation Pit Samples, 3/7/83 Weight, g Yw Yd wSample No. Material Wet Dry Water pcf pLf Percent 3 Backfill 380.27 343.49 36.28 79 72 10.5 10 Virgin...content, surface material, roadway crown Weight (g) w Sample No. Location Wet Dry Water Percent 103 5 ft south of pipe 268.6 256.9 11.7 4.6 133 Directly...tubes, oven dry, roadway crown Sample Weight (g) Yw Yd w No. Location Wet Dry Water pcf pcf Percent 183 5 ft south of pipe 550.8 533.9 16.9 114.7 111.2

  10. 天津地铁3号线水上北路站基坑涌水处治措施%The study of water gushing treatment measures at Shuishangbeilu station foundation pit of Tianjin metro line 3

    Institute of Scientific and Technical Information of China (English)

    王天翔

    2015-01-01

    The paper analyzes the gushing water at the foundation pits on Shuishangbeilu station of Tianjin metro line 3, indicates reasons for the gushing water accidents, and adopts two-shot grouting leaking stoppage, backfilling of foundation pits, and consolidation of pit bottom, so as to ensure the safety of the foundation pit, so as to provide some reference for similar foundation pit projects.%对天津地铁3号线水上北路站基坑基底突发涌水的情况进行了分析,论述了涌水事故发生的原因,通过采用双液注浆堵漏、基坑回填、坑底加固等措施,确保了基坑安全,为类似基坑工程提供了参考和借鉴。

  11. Low-pH concrete plug for sealing the KBS-3V deposition tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Malm, Richard (Vattenfall Power Consultant AB (Sweden))

    2012-01-15

    In SKB's main alternative for final repository of radioactive material, KBS-3V, the backfilled deposition tunnels will be separated from the remaining tunnel system with concrete plugs. These concrete plugs will be designed for a life span of 100 years and their function shall maintain until the transport tunnels outside the plug are backfilled and the natural geohydrological conditions have been restored. The purpose of this report is to document the results and the evaluation from this project and motivate the choice of the most appropriate design for closing the deposition tunnels in the spent fuel repository. The purpose has also been to investigate and present the loads acting on the plug system and determine the load capacity of the concrete plug. This report is the result of a project conducted between 2009-01-01 - 2010-12-31 and the project group has made its assessment based on the conditions and requirements that are present today. The entire design of the plug system is part of this project, where the plug system consists of a filter, a bentonite seal and a cast-in-place concrete plug. Two different conceptual design alternatives for the concrete plug have been studied in this report, one long tapered plug and one dome shaped plug. The results in this report focus on the choice of the conceptual design for the concrete plug and its possibility to assist the entire plug system to satisfy its requirements. It is a complicated task to dispose the radioactive waste and it sets high technical requirements on the design and the production of the backfill and the closing of the deposition tunnels. The aim of this project is to design and develop a plug system suitable for production. This is done by the means of numerical calculations and analyses. The primary function of the concrete plug is to act as a resistance to the external loads originated from the axial expansion of the backfill and the water pressure. However, the entire plug system has a

  12. Smart electric vehicle (EV) charging and grid integration apparatus and methods

    Energy Technology Data Exchange (ETDEWEB)

    Gadh, Rajit; Mal, Siddhartha; Prabhu, Shivanand; Chu, Chi-Cheng; Sheikh, Omar; Chung, Ching-Yen; He, Lei; Xiao, Bingjun; Shi, Yiyu

    2015-05-05

    An expert system manages a power grid wherein charging stations are connected to the power grid, with electric vehicles connected to the charging stations, whereby the expert system selectively backfills power from connected electric vehicles to the power grid through a grid tie inverter (if present) within the charging stations. In more traditional usage, the expert system allows for electric vehicle charging, coupled with user preferences as to charge time, charge cost, and charging station capabilities, without exceeding the power grid capacity at any point. A robust yet accurate state of charge (SOC) calculation method is also presented, whereby initially an open circuit voltage (OCV) based on sampled battery voltages and currents is calculated, and then the SOC is obtained based on a mapping between a previously measured reference OCV (ROCV) and SOC. The OCV-SOC calculation method accommodates likely any battery type with any current profile.

  13. 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.

  14. The impact of alkali pretreatment and post-pretreatment conditioning on the surface properties of rice straw affecting cellulose accessibility to cellulases.

    Science.gov (United States)

    Karuna, Nardrapee; Zhang, Lu; Walton, Jeffrey H; Couturier, Marie; Oztop, Mecit H; Master, Emma R; McCarthy, Michael J; Jeoh, Tina

    2014-09-01

    Rice straw was pretreated with sodium hydroxide and subsequently conditioned to reduce the pH to 5-6 by either: (1) extensive water washing or (2) acidification with hydrochloric acid then water washing. Alkali pretreatment improved the enzymatic digestibility of rice straw by increasing the cellulose accessibility to cellulases. However, acidification after pretreatment reversed the gains in cellulose accessibility to cellulases and enzymatic digestibility due to precipitation of solubilized compounds. Surface composition analyses by ToF-SIMS confirmed a reduction in surface lignin by pretreatment and water washing, and suggested that acidification precipitated a chemically modified form of lignin on the surfaces of rice straw. The spin-spin relaxation times (T2) of the samples indicated increased porosity in alkali pretreated rice straw. The acidified pretreated rice straw had reduced amounts of water in the longer T2 proton pools associated with water in the pores of the biomass likely due to back-filling by the precipitated components.

  15. SPECIFICATIONS FOR HIGH TEMPERATURE LATTICE TEST REACTOR BUILDING 318 PROJECT CAH-100

    Energy Technology Data Exchange (ETDEWEB)

    Vitro Engineering Company

    1964-07-15

    This is the specifications for the High Temperature Lattice Test Reactor Building 318 and it is divided into the following 21 divisions or chapters: (1) Excavating, Backfill & Grading; (2) Reinforced Concrete; (3) Masonry; (4) Structural Steel & Miscellaneous Metal Items, Contents - Division V; (5) Plumbing, Process & Service Piping; (6) Welding; (7) Insulated Metal Siding; (8) Roof Decks & Roofing; (9) Plaster Partitions & Ceiling; (10) Standard Doors, Windows & Hardware; (11) Shielding Doors; (12) Sprinkler System & Fire Extinguishers, Contents - Division XIII; (13) Heating, Ventilating & Air Conditioning; (14) Painting, Protective Coating & Floor Covering, Contents - Division XV; (15) Electrical; (16) Communications & Alarm Systems; (17) Special Equipment & Furnishings; (18) Overhead Bridge Crane; (19) Prefabricated Steel Building; (20) Paved Drive; and (21) Landscaping & Irrigation Sprinklers.

  16. Optimization of performance of cement matrices for solidification and encapsulation of radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Khotle, M.K. [South African Nuclear Energy Corporation Limited, Church Street West Ext Pelindaba, BRITS, North Western Province (South Africa)

    2008-07-01

    Full text of publication follows: Vaalputs is South Africa's near surface radioactive waste disposal site for low level and medium level waste. Metal and concrete drums are used as waste containers, placed in trenches and covered with backfill material. Due to the chemical contents of the waste material and experimental evidence regarding the expected lifetime of the current cement waste containers require a more stringent requirement on the waste matrix. This presentation will be based on the research that has gone into the development of the matrices with low sorption and low porosity for future use by waste generators. The resulting matrices were tested for Carbon-14 immobilization and other anion nuclides as well as other nuclides such as Tritium, Iodine etc. The results will be presented. (author)

  17. Recycling of Pre-Washed Municipal Solid Waste Incinerator Fly Ash in the Manufacturing of Low Temperature Setting Geopolymer Materials

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-08-01

    Full Text Available In this work, three samples of municipal solid waste incinerators fly ash (MSWI-FA have been stabilized in systems containing coal fly ash to create geopolymers through a polycondensation reaction. Monolithic products have been obtained with both MSWI fly ash as received and after the partial removal of chloride and sulfate by water washing. The polycondensation products have been characterized qualitatively by means of Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy and quantitatively, through the determination of the volume of reacted water and silicate. Furthermore, the heavy metals and chloride releases together with the physico-mechanical properties have been evaluated on the hardened products. In conclusion, considering the technological and environmental performances of the obtained geopolymers, they could be suitable for many non-structural applications, such as backfilling of abandoned quarries, decorative materials or brick fireplaces, hearths, patios, etc.

  18. Rolling Resistance and Mechanical Properties of Grinded Copper Surfaces Using Molecular Dynamics Simulation

    Science.gov (United States)

    Liang, Shih-Wei; Wang, Chih-Hao; Fang, Te-Hua

    2016-09-01

    Mechanical properties of copper (Cu) film under grinding process were accomplished by molecular dynamics simulation. A numerical calculation was carried out to understand the distributions of atomic and slip vector inside the Cu films. In this study, the roller rotation velocity, temperature, and roller rotation direction change are investigated to clarify their effect on the deformation mechanism. The simulation results showed that the destruction of materials was increased proportionally to the roller rotation velocity. The machining process at higher temperature results in larger kinetic energy of atoms than lower temperature during the grinding process of the Cu films. The result also shows that the roller rotation in the counterclockwise direction had the better stability than the roller rotation in the clockwise direction due to significantly increased backfill atoms in the groove of the Cu film surface. Additionally, the effects of the rolling resistances on the Cu film surfaces during the grinding process are studied by the molecular dynamics simulation method.

  19. Rolling Resistance and Mechanical Properties of Grinded Copper Surfaces Using Molecular Dynamics Simulation.

    Science.gov (United States)

    Liang, Shih-Wei; Wang, Chih-Hao; Fang, Te-Hua

    2016-12-01

    Mechanical properties of copper (Cu) film under grinding process were accomplished by molecular dynamics simulation. A numerical calculation was carried out to understand the distributions of atomic and slip vector inside the Cu films. In this study, the roller rotation velocity, temperature, and roller rotation direction change are investigated to clarify their effect on the deformation mechanism. The simulation results showed that the destruction of materials was increased proportionally to the roller rotation velocity. The machining process at higher temperature results in larger kinetic energy of atoms than lower temperature during the grinding process of the Cu films. The result also shows that the roller rotation in the counterclockwise direction had the better stability than the roller rotation in the clockwise direction due to significantly increased backfill atoms in the groove of the Cu film surface. Additionally, the effects of the rolling resistances on the Cu film surfaces during the grinding process are studied by the molecular dynamics simulation method.

  20. Thin hydroxyapatite surface layers on titanium produced by ion implantation

    CERN Document Server

    Baumann, H; Bilger, G; Jones, D; Symietz, I

    2002-01-01

    In medicine metallic implants are widely used as hip replacement protheses or artificial teeth. The biocompatibility is in all cases the most important requirement. Hydroxyapatite (HAp) is frequently used as coating on metallic implants because of its high acceptance by the human body. In this paper a process is described by which a HAp surface layer is produced by ion implantation with a continuous transition to the bulk material. Calcium and phosphorus ions are successively implanted into titanium under different vacuum conditions by backfilling oxygen into the implantation chamber. Afterwards the implanted samples are thermally treated. The elemental composition inside the implanted region was determined by nuclear analysis methods as (alpha,alpha) backscattering and the resonant nuclear reaction sup 1 H( sup 1 sup 5 N,alpha gamma) sup 1 sup 2 C. The results of X-ray photoelectron spectroscopy indicate the formation of HAp. In addition a first biocompatibility test was performed to compare the growing of m...

  1. The shakeout scenario: Meeting the needs for construction aggregates, asphalt, and concrete

    Science.gov (United States)

    Langer, W.H.

    2011-01-01

    An Mw 7.8 earthquake as described in the ShakeOut Scenario would cause significantdamage to buildings and infrastructure. Over 6 million tons of newly mined aggregate would be used for emergency repairs and for reconstruction in the five years following the event. This aggregate would be applied mostly in the form of concrete for buildings and bridges, asphalt or concrete for pavement, and unbound gravel for applications such as base course that goes under highway pavement and backfilling for foundations and pipelines. There are over 450 aggregate, concrete, and asphalt plants in the affected area, some of which would be heavily damaged. Meeting the increased demand for construction materials would require readily available permitted reserves, functioning production facilities, a supply of cement and asphalt, a source of water, gas, and electricity, and a trained workforce. Prudent advance preparations would facilitate a timely emergency response and reconstruction following such an earthquake. ?? 2011, Earthquake Engineering Research Institute.

  2. Smart Pebble: wireless sensors for structural health monitoring of bridge decks

    Science.gov (United States)

    Watters, David G.; Jayaweera, Palitha; Bahr, Alfred J.; Huestis, David L.; Priyantha, Namal; Meline, Robert; Reis, Robert; Parks, Douglas

    2003-08-01

    SRI International is developing a wireless sensor for monitoring the level of chloride ingress into concrete bridge decks. We call this device a Smart Pebble since it has roughly the size and weight of a typical piece of the rock aggregate that is used in such structures. It is "smart" in that it contains a chloride sensor and a radio-frequency identification (RFID) chip that can be queried remotely both to identify it and to indicate chloride concentration levels. The Smart Pebble is also powered remotely, thus precluding the need for any lifetime-limiting batteries. It is designed to be inserted in the bridge deck either during the initial construction (or during refurbishment) or in a back-filled core hole. This paper will discuss the Smart Pebble design, operation, and status.

  3. Modelling the field behaviour of a granular expansive barrier

    Science.gov (United States)

    Alonso, Eduardo; Hoffmann, Christian

    The large scale “Engineered Barrier” (EB) experiment, performed at the Mont Terri Underground Laboratory is described. A coupled hydromechanical model is then used to simulate the test performance. Constitutive parameters for the bentonite granular backfill are based on experimental work described in a companion paper. An elastoplastic model describes the granular fill, while the host rock is simulated by a damage model. Predictions of EDZ development around the tunnel are compared with some indirect measurements. Calculated evolutions of relative humidity and stresses within the buffer are compared with sensor records. Good agreement was found for the bentonite blocks supporting the canister. The granular expansive fill exhibit a more irregular behavior. Calculated displacements of the canister agree in absolute terms with actual measurements.

  4. Erective Sea Embankment with PCC Piles

    Institute of Scientific and Technical Information of China (English)

    LIU Han-long; FEI Kang; DENG An; ZHANG Ting

    2005-01-01

    The sea embankment is a critical civil works in marine and coastal engineering. In this study, an innovative technique is proposed for constructing erective sea embankments. In the construction of sea embankments, this technique integrates PCC pile installation, PVDs drainage systems, and geotextile reinforcements, resulting in sea embankments with PCC piles. In the application of a sea embankment with PCC piles, PCC piles are employed as the retaining structures;the soft sea ground inside PCC piles is drained and improved by PVDs and vacuum-surcharge combined preloading; geotextile-reinforced backfills lying over the improved soft ground form the embankment body. Brief descrptions of the fundamentals, design and construction of the sea embankment with PCC piles are presented. A case study on the stability of sea embankment with PCC piles is presented as well.

  5. Scaling up ATLAS Event Service to production levels on opportunistic computing platforms

    CERN Document Server

    Benjamin, Douglas; The ATLAS collaboration; Ernst, Michael; Guan, Wen; Hover, John; Lesny, David; Maeno, Tadashi; Nilsson, Paul; Tsulaia, Vakhtang; van Gemmeren, Peter; Vaniachine, Alexandre; Wang, Fuquan; Wenaus, Torre

    2016-01-01

    Continued growth in public cloud and HPC resources is on track to overcome the dedicated resources available for ATLAS on the WLCG. Example of such platforms are Amazon AWS EC2 Spot Instances, Edison Cray XC30 supercomputer, backfill at the Tier-2 and Tier-3 sites, opportunistic resources at the Open Science Grid, and ATLAS High Level Trigger farm between the data taking periods. Because of opportunistic resources specifics such as preemptive job scheduling and data I/O, their efficient usage requires workflow innovations provided by the ATLAS Event Service. Thanks to the finer granularity of the Event Service data processing workflow, the opportunistic resources are used more efficiently. We report on our progress in scaling opportunistic resource usage to double-digit levels in ATLAS production.

  6. 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

  7. Simulations of EBS task force BMT 1.3

    Energy Technology Data Exchange (ETDEWEB)

    Lempinen, A. (Marintel Ky, Turku (Finland))

    2007-08-15

    The Aespoe HRL International Joint Committee has set up a Task Force on Engineered Barrier Systems (EBS). Its long time objective is to develop effective tools for analysis of THM(C) behaviour of buffer and backfill. The idea of the Task Force is to offer a forum to develop the tools of the work groups. Bench Mark Test (BMT) 1.3 was a small-scale heating test with no external water supply. The experiment was conducted by Technical University of Catalonia. It was a thermal-hydraulic-mechanical test, although only temperature was measured continuously. Simulation results are presented here. These simulations were performed with Freefem++ software, which is a high-level programming language for solving partial differential equations with finite element method. The mathematical model used is based on continuum thermodynamics. With the model improvements for BMT 1.3, also BMT 1.2 was recalculated. (orig.)

  8. Simulations for EBS Task Force BMT 1

    Energy Technology Data Exchange (ETDEWEB)

    Lempinen, A. [Marintel Ky, Turku (Finland)

    2006-12-15

    The Aespoe HRL International Joint Committee has set up a Task Force on Engineered Barrier Systems (EBS). Its long time objective is to develop effective tools for analysis of THM(C) behaviour of buffer and backfill. The idea of the Task Force is to offer a forum to develop the tools of the work groups. This BMT has two parts: BMT 1.1 and BMT 1.2 based on the performance of THM mock-up experiments on MX-80 bentonite by CEA and FEBEX bentonite by CIEMAT, respectively. Simulation results are presented here. These simulations are performed with Freefem++ software, which is a high-level programming language for solving partiel differential equations with finite element method. The mathematical model used is based on continuum thermodynamics. The simulations repeat the evolution of relevant THM variables of the experiments fairly well, but some modificatios of parameters is needed, especially in hydraulic behaviour. (orig.)

  9. The application of new water supply and drainage pipeline key technology in municipal road%新型给排水管道关键技术在市政道路中的应用

    Institute of Scientific and Technical Information of China (English)

    武宝平

    2014-01-01

    From the trench excavation, pipe base construction, pipeline installation, backfill construction and other aspects, system analyzed the technical key points of new water supply and drainage pipeline construction in municipal road drainage engineering, and put forward some specific measures according to existing problems in construction, in order to improve the construction quality of municipal road drainage pipeline.%从沟槽开挖、管基施工、管道安装、回填施工等方面入手,系统分析了市政道路排水工程中新型给排水管道施工的技术要点,并针对施工中出现的问题提出了具体的解决措施,以提高市政道路排水管道的施工质量。

  10. The construction of HDPE double wall corrugated pipe%HDPE 双壁波纹管的施工

    Institute of Scientific and Technical Information of China (English)

    邢东博

    2014-01-01

    简述了 HDPE 双壁波纹管的优点,从管道基础及沟槽开挖、管道安装、修补、闭水试验、连接、回填六方面出发,对 HDPE 双壁波纹管施工工序及要点作了全面的阐述,以最大限度地发挥该管材的作用。%This paper discussed simply the advantages of HDPE double wall corrugated pipe,from the pipeline foundation and trench excavation, pipeline installation,repair,closed water test,connection,backfill six aspects,fully elaborated the HDPE double wall corrugated pipe construc-tion process and main points,in order to maximize the role of pipe material.

  11. The construction key points of city pipeline engineering%城市管道工程施工要点

    Institute of Scientific and Technical Information of China (English)

    程文海

    2012-01-01

    Combining with the working practice,this paper summarized the construction key points of city pipeline project,including the trench excavation,pipe installation,pipe anti-corrosion insulation,pipe functional test and backfilling etc.,provided reference for a variety of pipeline construction.%结合工作实践,综述了城市管道工程的施工要点,包括沟槽开挖、管道安装、管道防腐保温、管道功能性试验及回填等,为城市各种管道工程施工提供参考与借鉴。

  12. Examination of the behavior of gravity quay wall against liquefaction under the effect of wall width and soil improvement.

    Science.gov (United States)

    Firoozi, Ali Akbar; Taha, Mohd Raihan; Mir Moammad Hosseini, S M; Firoozi, Ali Asghar

    2014-01-01

    Deformation of quay walls is one of the main sources of damage to port facility while liquefaction of backfill and base soil of the wall are the main reasons for failures of quay walls. During earthquakes, the most susceptible materials for liquefaction in seashore regions are loose saturated sand. In this study, effects of enhancing the wall width and the soil improvement on the behavior of gravity quay walls are examined in order to obtain the optimum improved region. The FLAC 2D software was used for analyzing and modeling progressed models of soil and loading under difference conditions. Also, the behavior of liquefiable soil is simulated by the use of "Finn" constitutive model in the analysis models. The "Finn" constitutive model is especially created to determine liquefaction phenomena and excess pore pressure generation.

  13. Stabilisation of bank slopes that are prone to liquefaction in ecologically sensitive areas.

    Science.gov (United States)

    Nestler, P; Stoll, R D

    2001-01-01

    A consequence of lignite stripping in the Lusatia mining district (East Germany) is the backfilling of dumps that mainly consist of low-compacted fine and medium-grained sands. When the ground-water table, which had been lowered while stripping the coal, is rising again, these dumps might be affected by a settlement flow due to the liquefaction of soils. Common methods for stabilisation as, for instance, blasting or vibrator-jetting deep compaction, are not very useful in ecologically sensitive areas, where dumps have been afforested and embankment areas of residual lakes have developed into highly valuable biotopes. A new so-called air-impulse method in combination with directional horizontal drilling has been developed, which does not have a considerably negative impact on the vegetation during compaction. The experience gained during the first employment of this method at the lake "Katja", a residual lake of lignite stripping, is presented in this paper.

  14. Stability of submerged rock berms exposed to motion of liquefied soil in waves

    DEFF Research Database (Denmark)

    Sumer, B. Mutlu; Dixen, Figen Hatipoglu; Fredsøe, Jørgen

    2011-01-01

    The paper describes the results of an experimental study on the behaviour of a submerged rock berm in liquefied backfill soil. The soil is liquefied by waves, and the rock berm is subject to the orbital motion of the liquefied soil. The soil used in the experiments was silt with d50=0.075mm....... Various berm materials were used, stones of size 0.74–2.5cm, plastic balls of size 3.6cm, brass of size 2.5cm and steel of size 1.0cm. The experiments show that rock berms that are stable under very large waves can be unstable when they are exposed to the motion of liquefied soil. The limited data...

  15. CSIR: Mining Technology annual review 1995/96

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    CSIR: Mining Technology works in close collaboration and strategic partnership with the mining industry, government institutions and employee organizations by acquiring, developing and transferring technologies to improve the safety and health of their employees, and to improve the profitability of the mining industry. The annual report describes achievements over the year in the areas of: rock engineering (including rockburst control, mine layout, coal pillar design, shallow bord and pillar workings); environmental safety and health (on topics such as mine rescue, ventilation systems, radiation protection, control of diesel exhaust emissions, reduction of underground mining hazards, and water quality); and mining systems, (rock breaking, backfill and hydraulic technology etc.). A list of Mining Technology`s 1995/96 publications is given.

  16. Prototype Repository - Sensor data report (period 100917-110101) Report no 24

    Energy Technology Data Exchange (ETDEWEB)

    Goudarzi, Reza [Clay Technology AB, Lund (Sweden)

    2012-08-15

    The Prototype Repository Test consists of two sections. The installation of the first Section of Prototype Repository was made during summer and autumn 2001 and Section 2 was installed in spring and summer 2003. At the end of November 2010 stared the dismantling of the outer section. This report presents data from measurements in the Prototype Repository during the period 2001-09-17-2011-01-01. The report is organized so that the actual measured results are shown in Appendix 1-10, where Appendix 8 deals with measurements of canister displacements (by AITEMIN), Appendix 9 deals with geo-electric measurements in the backfill (by GRS), Appendix 10 deals with stress and strain measurement in the rock (by AaF) and Appendix 11 deals with measurement of water pressure in the rock (by VBB/VIAK). The main report and Appendix 1-7 deal with the rest of the measurements.

  17. MICROBIAL TRANSFORMATIONS OF PLUTONIUM AND IMPLICATIONS FOR ITS MOBILITY.

    Energy Technology Data Exchange (ETDEWEB)

    FRANCIS, A.J.

    2000-09-30

    The current state of knowledge of the effect of plutonium on microorganisms and microbial activity is reviewed, and also the microbial processes affecting its mobilization and immobilization. The dissolution of plutonium is predominantly due to their production of extracellular metabolic products, organic acids, such as citric acid, and sequestering agents, such as siderophores. Plutonium may be immobilized by the indirect actions of microorganisms resulting in changes in Eh and its reduction from a higher to lower oxidation state, with the precipitation of Pu, its bioaccumulation by biomass, and bioprecipitation reactions. In addition, the abundance of microorganisms in Pu-contaminated soils, wastes, natural analog sites, and backfill materials that will be used for isolating the waste and role of microbes as biocolloids in the transport of Pu is discussed.

  18. Technetium diffusion in clay-based materials under oxic and anoxic conditions. AECL research No. AECL-11419

    Energy Technology Data Exchange (ETDEWEB)

    Hume, H.B.

    1995-12-31

    Describes experiments to determine diffusion coefficients for technetium in compacted clay-based material (soils) saturated with a synthetic groundwater solution whose principal ions were calcium, sodium, and chlorine. Tests were conducted in anoxic conditions established by conducting the experiments in a low- oxygen glove box and by mixing 0.5% by weight of powdered iron with the soils (Lake Agassiz clay and a 1:3 mix of dry mass of clay and crushed granite aggregate). Effective diffusion coefficients were also measured in oxic conditions in Avonlea bentonite, Lake Agassiz clay, and illite/smectite. Implications of the results for transport of radionuclides through backfill material and clay barriers used in underground disposal of nuclear fuel waste are discussed.

  19. Site-specific analysis of radiological and physical parameters for cobbly soils at the Gunnison, Colorado, processing site

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    The remedial action at the Gunnison, Colorado, processing site is being performed under the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978 [Public Law (PL) 95-6041]. Under UMTRCA, the US Environmental Protection Agency (EPA) is charged with the responsibility of developing appropriate and applicable standards for the cleanup of radiologically contaminated land and buildings at 24 designated sites, including the Gunnison, Colorado, inactive processing site. The remedial action at the processing site will be conducted to remove the tailings and contaminated materials to meet the EPA bulk soil cleanup standards for surface and subsurface soils. The site areas disturbed by remedial action excavation will be either contoured or backfilled with radiologically uncontaminated soil and contoured to restore the site. The final contours will produce a final surface grade that will create positive drainage from the site.

  20. Realization of a 33 GHz phononic crystal fabricated in a freestanding membrane

    Directory of Open Access Journals (Sweden)

    Drew F. Goettler

    2011-12-01

    Full Text Available Phononic crystals (PnCs are man-made structures with periodically varying material properties such as density, ρ, and elastic modulus, E. Periodic variations of the material properties with nanoscale characteristic dimensions yield PnCs that operate at frequencies above 10 GHz, allowing for the manipulation of thermal properties. In this article, a 2D simple cubic lattice PnC operating at 33 GHz is reported. The PnC is created by nanofabrication with a focused ion beam. A freestanding membrane of silicon is ion milled to create a simple cubic array of 32 nm diameter holes that are subsequently backfilled with tungsten to create inclusions at a spacing of 100 nm. Simulations are used to predict the operating frequency of the PnC. Additional modeling shows that milling a freestanding membrane has a unique characteristic; the exit via has a conical shape, or trumpet-like appearance.

  1. SKB Annual Report 1994. Including summaries of technical reports issued during 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    The report gives an overview of SKB activities in different fields, and a description of R and D on nuclear waste disposal performed during 1994. SKB is in charge of a comprehensive program on geological disposal of nuclear waste. The total cost for R and D 1994 was 186 MSEK of which 59 MSEK were investments in the Aespoe Hard Rock Laboratory. Some of the main areas for SKB research are: Groundwater movements; Bedrock stability; Groundwater chemistry and nuclide migration; Methods and instruments for in situ characterization of crystalline bedrock; Characterization and leaching of spent fuel; Properties of bentonite for buffer, backfilling and sealing; Radionuclide transport in biosphere and dose evaluation; Development of performance and safety assessment methodology and assessment models; Construction of an underground research laboratory. 66 figs, 6 tabs.

  2. ARM Climate Research Facility Spectral Surface Albedo Value-Added Product (VAP) Report

    Energy Technology Data Exchange (ETDEWEB)

    McFarlane, S; Gaustad, K; Long, C; Mlawer, E

    2011-07-15

    This document describes the input requirements, output data products, and methodology for the Spectral Surface Albedo (SURFSPECALB) value-added product (VAP). The SURFSPECALB VAP produces a best-estimate near-continuous high spectral resolution albedo data product using measurements from multifilter radiometers (MFRs). The VAP first identifies best estimates for the MFR downwelling and upwelling shortwave irradiance values, and then calculates narrowband spectral albedo from these best-estimate irradiance values. The methodology for finding the best-estimate values is based on a simple process of screening suspect data and backfilling screened and missing data with estimated values when possible. The resulting best-estimate MFR narrowband spectral albedos are used to determine a daily surface type (snow, 100% vegetation, partial vegetation, or 0% vegetation). For non-snow surfaces, a piecewise continuous function is used to estimate a high spectral resolution albedo at 1 min temporal and 10 cm-1 spectral resolution.

  3. Overcoming the pitfalls of abandoned mine workings in the Sydney coalfield

    Energy Technology Data Exchange (ETDEWEB)

    Forrester, D.; Noble, B. [AECOM, Sydney, NS (Canada)

    2010-07-01

    Previous coal mining activities in Sydney, Nova Scotia (NS) have included the creation of shallow, unrecorded underground coal extraction sites known as bootleg pits. The sites are a public safety hazard and can also impact groundwater flow. This paper presented an outline of the remediation strategies used to mitigate the hazards associated with the bootleg pits as part of a mine site closure and reclamation program currently being completed by the Cape Breton Corporation (ECBC). The strategies included the use of sinkhole subsidence hazard maps. Long-term visual monitoring is also being used in areas associated with sinkhole development. Larger abandoned areas have been cleared, backfilled and re-graded while including provisions for the ongoing drainage of mine waters. Gas monitoring and safety procedures were also reviewed. 2 refs., 4 figs.

  4. Policy for metal leaching and acid rock drainage at mine sites in British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    One of the major environmental issues facing the provincial government of British Columbia is the prevention of environmental impacts from metal leaching and acid rock drainage (ML/ARD). The government`s major challenge in regulating ML/ARD is to ensure that all mines are planned and operated in a manner that allows for effective problem detection and mitigation, and that the mines emphasize problem prevention at the outset. This paper reviews the legislated requirements regarding ML/ARD prevention and lists guiding principles for the regulation of ML/ARD in the province. Some of the measures to predict and to mitigate ML/ARD include underwater storage of problematic materials, engineered covers, blending of wastes and drainage collection and treatment. Requirements applicable to construction materials, backfill, geotechnical and hydrological considerations, and security of funds for ML/ARD measures are also discussed.

  5. Scaling up ATLAS Event Service to production levels on opportunistic computing platforms

    Science.gov (United States)

    Benjamin, D.; Caballero, J.; Ernst, M.; Guan, W.; Hover, J.; Lesny, D.; Maeno, T.; Nilsson, P.; Tsulaia, V.; van Gemmeren, P.; Vaniachine, A.; Wang, F.; Wenaus, T.; ATLAS Collaboration

    2016-10-01

    Continued growth in public cloud and HPC resources is on track to exceed the dedicated resources available for ATLAS on the WLCG. Examples of such platforms are Amazon AWS EC2 Spot Instances, Edison Cray XC30 supercomputer, backfill at Tier 2 and Tier 3 sites, opportunistic resources at the Open Science Grid (OSG), and ATLAS High Level Trigger farm between the data taking periods. Because of specific aspects of opportunistic resources such as preemptive job scheduling and data I/O, their efficient usage requires workflow innovations provided by the ATLAS Event Service. Thanks to the finer granularity of the Event Service data processing workflow, the opportunistic resources are used more efficiently. We report on our progress in scaling opportunistic resource usage to double-digit levels in ATLAS production.

  6. Scaling up ATLAS Event Service to production levels on opportunistic computing platforms

    CERN Document Server

    Benjamin, Douglas; The ATLAS collaboration; Ernst, Michael; Guan, Wen; Hover, John; Lesny, David; Maeno, Tadashi; Nilsson, Paul; Tsulaia, Vakhtang; van Gemmeren, Peter; Vaniachine, Alexandre; Wang, Fuquan; Wenaus, Torre

    2016-01-01

    Continued growth in public cloud and HPC resources is on track to exceed the dedicated resources available for ATLAS on the WLCG. Examples of such platforms are Amazon AWS EC2 Spot Instances, Edison Cray XC30 supercomputer, backfill at Tier 2 and Tier 3 sites, opportunistic resources at the Open Science Grid (OSG), and ATLAS High Level Trigger farm between the data taking periods. Because of specific aspects of opportunistic resources such as preemptive job scheduling and data I/O, their efficient usage requires workflow innovations provided by the ATLAS Event Service. Thanks to the finer granularity of the Event Service data processing workflow, the opportunistic resources are used more efficiently. We report on our progress in scaling opportunistic resource usage to double-digit levels in ATLAS production.

  7. Aespoe Hard Rock Laboratory. Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    origin and age of matrix fluids, i.e. accessible pore water, in fissures and small-scale fractures and their possible influence on fluid chemistry in the bedrock. When the EC-project EQUIP, which concentrated on the formulation of a methodology for how to conduct a palaeo hydrogeological study, ended in 2000 there was a need for continued fracture mineral investigations and model testing of the obtained results and a new EC-project was initiated in the beginning of 2002. This project is called PADAMOT (Palaeo hydrogeological Data Analysis and Model Testing) and includes further developments of analytical techniques and modelling tools to interpret data, but also further research to investigate specific processes that might link climate and groundwater properties in low permeability rocks. The project Demonstration of repository technology provides a full-scale demonstration of canister deposition under radiation-shielded conditions and works with testing of canister and bentonite handling in full size deposition holes. The Prototype Repository project focuses on testing and demonstrating repository system function in full scale and is co-funded by the EC. The experiment comprises six full size canisters with electrical heaters surrounded by bentonite. The Backfill and Plug Test is a test of the hydraulic and mechanical function of different backfill materials, emplacement methods, and a full-scale plug. The 28 m long test region is located in the ZEDEX drift. The inner part of the drift is backfilled with a mixture of bentonite and crushed rock and the outer part is filled with crushed rock. The wetting of the backfill started late 1999 and the final step of increasing the water pressure in the mats to 500 kPa was taken in January 2002. The Canister Retrieval Test, located in the main test area at the 420 m level, is aiming at demonstrating the readiness for recovering of emplaced canisters also after the time when the bentonite is fully saturated. The Long Term Test of

  8. Environmental measurement-while-drilling-gamma ray spectrometer (EMWD-GRS) system technology demonstration plan for use at the Savannah River Site F-Area Retention Basin

    Energy Technology Data Exchange (ETDEWEB)

    Williams, C.V.; Lockwood, G.J.; Normann, R.A. [Sandia National Labs., Albuquerque, NM (United States); Gruebel, R.D. [Tech Reps, Inc., Albuquerque, NM (United States)

    1996-08-01

    The Environmental Measurement-While-Drilling-Gamma Ray Spectrometer (EMWD-GRS) system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drillbit data during drilling operations. This demonstration plan presents information on the EMWD-GRS technology, demonstration design, Cs-137 contamination at the Savannah River Site F-Area Retention Basin, responsibilities of demonstration participants, and the policies and procedures for the demonstration to be conducted at the Savannah River Site F-Area Retention Basin. The EMWD-GRS technology demonstration will consist of continuously monitoring for gamma-radiation contamination while drilling two horizontal boreholes below the backfilled retention basin. These boreholes will pass near previously sampled vertical borehole locations where concentrations of contaminant levels are known. Contaminant levels continuously recorded by the EMWD-GRS system during drilling will be compared to contaminant levels previously determined through quantitative laboratory analysis of soil samples.

  9. Thermo-hydro-mechanical processes in the nearfield around a HLW repository in argillaceous formations. Vol. I. Laboratory investigations

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chun-Liang; Czaikowski, Oliver; Rothfuchs, Tilmann; Wieczorek, Klaus

    2013-06-15

    All over the world, clay formations are being investigated as host medium for geologic disposal of radioactive waste because of their favourable properties, such as very low hydraulic conductivity against fluid transport, good sorption capacity for retardation of radionuclides, and high potential of self-sealing of fractures. The construction of a repository, the disposal of heat-emitting high-level radioactive waste (HLW), the backfilling and sealing of the remaining voids, however, will inevitably induce mechanical (M), hydraulic (H), thermal (T) and chemical (C) disturbances to the host formation and the engineered barrier system (EBS) over very long periods of time during the operation and post-closure phases of the repository. The responses and resulting property changes of the clay host rock and engineered barriers are to be well understood, characterized, and predicted for assessing the long-term performance and safety of the repository.

  10. Application of Electrical Resistivity Imaging for Engineering Site Investigation. A Case Study on Prospective Hospital Site, Varamin, Iran

    Science.gov (United States)

    Amini, Amin; Ramazi, Hamidreza

    2016-12-01

    The article addresses the application of electrical resistivity imaging for engineering site investigation in Pishva Hospital, Varamin, Iran. Some aqueduct shafts exist in the study area backfilled by loose materials. The goals of this study are to detect probable aqueduct tunnels and their depth, investigate filling quality in the shafts as well as connection(s) between them. Therefore, three profiles were surveyed by dipoledipole electrode array. Also, to investigate the potentially anomalous areas more accurately, five additional resistivity profiles were measured by a Combined Resistivity Sounding-Profiling array (CRSP). According to the results of 2-D inversion modelling, a main aqueduct tunnel was detected beneath the central part of the site. Finally, the resistivity pattern of the detected aqueduct system passing the investigated area was provided using the obtained results.

  11. Thick silicon growth techniques

    Science.gov (United States)

    Bates, H. E.; Mlavsky, A. I.; Jewett, D. N.

    1973-01-01

    Hall mobility measurements on a number of single crystal silicon ribbons grown from graphite dies have shown some ribbons to have mobilities consistent with their resistivities. The behavior of other ribbons appears to be explained by the introduction of impurities of the opposite sign. Growth of a small single crystal silicon ribbon has been achieved from a beryllia dia. Residual internal stresses of the order of 7 to 18,000 psi have been determined to exist in some silicon ribbon, particularly those grown at rates in excess of 1 in./min. Growth experiments have continued toward definition of a configuration and parameters to provide a reasonable yield of single crystal ribbons. High vacuum outgassing of graphite dies and evacuation and backfilling of growth chambers have provided significant improvements in surface quality of ribbons grown from graphite dies.

  12. Nuclear waste management technical support in the development of nuclear waste form criteria for the NRC. Task 1. Waste package overview

    Energy Technology Data Exchange (ETDEWEB)

    Dayal, R.; Lee, B.S.; Wilke, R.J.; Swyler, K.J.; Soo, P.; Ahn, T.M.; McIntyre, N.S.; Veakis, E.

    1982-02-01

    In this report the current state of waste package development for high level waste, transuranic waste, and spent fuel in the US and abroad has been assessed. Specifically, reviewed are recent and on-going research on various waste forms, container materials and backfills and tentatively identified those which are likely to perform most satisfactorily in the repository environment. Radiation effects on the waste package components have been reviewed and the magnitude of these effects has been identified. Areas requiring further research have been identified. The important variables affecting radionuclide release from the waste package have been described and an evaluation of regulatory criteria for high level waste and spent fuel is presented. Finally, for spent fuel, high level, and TRU waste, components which could be used to construct a waste package having potential to meet NRC performance requirements have been described and identified.

  13. A versatile method to generate multiple types of micropatterns

    CERN Document Server

    Segerer, F J; Schuster, S; Alberola, A Piera; Zahler, S; Rädler, J O

    2015-01-01

    Micropatterning techniques have become an important tool for the study of cell behavior in controlled microenvironments. As a consequence, several approaches for the creation of micropatterns have been developed in recent years. However, the diversity of substrates, coatings and complex patterns used in cell science is so great that no single existing technique is capable of fabricating designs suitable for all experimental conditions. Hence, there is a need for patterning protocols that are flexible with regard to the materials used and compatible with different patterning strategies to create more elaborate setups. In this work, we present a novel and versatile approach to micropatterning. The protocol is based on plasma treatment, protein coating, and a PLL-PEG backfill step, and produces homogeneous patterns on a variety of substrates. Protein density within the patterns can be controlled, and gradients of surface-bound protein can be formed. Moreover, by combining the method with microcontact printing, i...

  14. Application of Electrical Resistivity Imaging for Engineering Site Investigation. A Case Study on Prospective Hospital Site, Varamin, Iran

    Directory of Open Access Journals (Sweden)

    Amini Amin

    2016-12-01

    Full Text Available The article addresses the application of electrical resistivity imaging for engineering site investigation in Pishva Hospital, Varamin, Iran. Some aqueduct shafts exist in the study area backfilled by loose materials. The goals of this study are to detect probable aqueduct tunnels and their depth, investigate filling quality in the shafts as well as connection(s between them. Therefore, three profiles were surveyed by dipoledipole electrode array. Also, to investigate the potentially anomalous areas more accurately, five additional resistivity profiles were measured by a Combined Resistivity Sounding-Profiling array (CRSP. According to the results of 2-D inversion modelling, a main aqueduct tunnel was detected beneath the central part of the site. Finally, the resistivity pattern of the detected aqueduct system passing the investigated area was provided using the obtained results.

  15. Non-dissociative activation of chemisorbed dinitrogen on Ni(110) by co-adsorbed lithium

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tao, E-mail: tgliu24@gmail.com; Temprano, Israel; Jenkins, Stephen J.; King, David A. [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2013-11-14

    Weakening the intramolecular N–N bond is essential to promote direct hydrogenation of adsorbed N{sub 2} on catalyst surfaces. The interaction of N{sub 2} with Li on Ni(110) surfaces has been investigated. We show that the N–N bond is significantly weakened with increasing Li coverage, evidenced by large redshifts in N–N stretch frequency of up to 380 cm{sup −1} compared to the gas phase. Some increased thermal stability of the most weakened N{sub 2,ads} states is also observed. We speculate that the various observed redshifts in N–N stretch frequency are associated with an enhanced backfilling of the 2π* antibonding orbital of N{sub 2} due to both the Li-induced surface electrostatic field, and the formation of Li{sub x}(N{sub 2}){sub y} surface complexes.

  16. Design and Implementation of a Two Level Scheduler for HADOOP Data Grids

    Directory of Open Access Journals (Sweden)

    Dr G. Sudha sadhasivam

    2010-03-01

    Full Text Available Hadoop is a large scale distributed processing infrastructure designed to handle data intensive applications. In a commercial large scale cluster framework, a scheduler distributes user jobs evenly among the cluster resources. The proposed work enhances Hadoop’s fair scheduler that queues the jobs for execution in a fine grained manner using task scheduling. In contrast, the proposed approach allows backfilling ofjobs submitted to the scheduler. Thus job level and task level scheduling is enabled by this approach. The jobs are fairly scheduled with fairness among users, pools and priority. The outcome of the proposed work is that short narrow jobs will be executed in the slot if sufficient resource is not available for larger jobs. Thus shorter jobs get executed faster by the scheduler when compared to the existing fair scheduling policy that schedules tasks based on their fairness of remaining execution time. This approach prevents the starvation of smaller jobs if sufficient resources are available.

  17. Production Experience with the ATLAS Event Service

    CERN Document Server

    Benjamin, Douglas; The ATLAS collaboration

    2016-01-01

    The ATLAS Event Service (ES) has been designed and implemented for efficient running of ATLAS production workflows on a variety of computing platforms, ranging from conventional Grid sites to opportunistic, often short-lived resources, such as spot market commercial clouds, supercomputers and volunteer computing. The Event Service architecture allows real time delivery of fine grained workloads to running payload applications which process dispatched events or event ranges and immediately stream the outputs to highly scalable Object Stores. Thanks to its agile and flexible architecture the ES is currently being used by grid sites for assigning low priority workloads to otherwise idle computing resources; similarly harvesting HPC resources in an efficient back-fill mode; and massively scaling out to the 50-100k concurrent core level on the Amazon spot market to efficiently utilize those transient resources for peak production needs. Platform ports in development include ATLAS@Home (BOINC) and the Goggle Comput...

  18. 厂区素填土的地基基础施工%On foundation construction of plain fill of factories

    Institute of Scientific and Technical Information of China (English)

    尹祖华

    2011-01-01

    According to the analysis of the experience in the foundation construction in the large backfill area of some factory in Chongqing,the paper points out some experimental methods for the foundation construction of the plain fill,and indicates the selection of the foundation forms of the factory and the selection of the foundation treatment,so as to accumulate some beneficial experience for the foundation construction of the plain fill.%通过对重庆某厂区大面积回填区域基础施工经验的分析,提出一些素填土基础施工经验性方法,并对该厂区基础形式的选择和地基处理的选择作了详细论述,为素填土地基施工积累了一些有益的经验。

  19. Experiments, conceptual design, preliminary cost estimates and schedules for an underground research facility

    Energy Technology Data Exchange (ETDEWEB)

    Korbin, G.; Wollenberg, H.; Wilson, C.; Strisower, B.; Chan, T.; Wedge, D.

    1981-09-01

    Plans for an underground research facility are presented, incorporating techniques to assess the hydrological and thermomechanical response of a rock mass to the introduction and long-term isolation of radioactive waste, and to assess the effects of excavation on the hydrologic integrity of a repository and its subsequent backfill, plugging, and sealing. The project is designed to utilize existing mine or civil works for access to experimental areas and is estimated to last 8 years at a total cost for contruction and operation of $39.0 million (1981 dollars). Performing the same experiments in an existing underground research facility would reduce the duration to 7-1/2 years and cost $27.7 million as a lower-bound estimate. These preliminary plans and estimates should be revised after specific sites are identified which would accommodate the facility.

  20. Numerical Modeling for Impact-resistant Pipes Buried at Shallow Depth

    Science.gov (United States)

    Wang, Ching-Jong; Hsu, Jung-Fu

    2010-05-01

    The plastic pipes buried at shallow depth are popular for underground telecommunication lines. To assess their impact-worthiness under loads from heavy traffics, the study establishes a numerical model to correlate with field data. Field impact tests were carried out where a 50-kg mass free-falling at 2.2 m height was dropped onto the soil backfill directly above a buried pipe. A contact-impact model incorporating finite elements of disjoined material regions is developed to simulate the phenomena of mass-soil-pipe interaction and soil dent. Plastic soil deformations are accounted for. Also implemented is a new erosion scheme for dealing with numerical instability caused by crumpled elements during heavy impact. Reasonable agreements can be observed between the analyzed and measured soil dent. This model is versatile in making design evaluations for buried pipes to withstand impact loads. It has potential applications to cemented soil fills and blast loads.

  1. Process for the preparation of calcium superoxide

    Science.gov (United States)

    Ballou, E. V.; Wood, P. C.; Wydeven, T. J.; Spitze, L. A. (Inventor)

    1978-01-01

    Calcium superoxide is prepared in high yields by spreading a quantity of calcium peroxide diperoxyhydrate on the surface of a container, positioning said container in a vacuum chamber on a support structure through which a coolant fluid can be circulated, partially evacuating said vacuum chamber, allowing the temperature of the diperoxyhydrate to reach the range of about 0 to about 40 C; maintaining the temperature selected for a period of time sufficient to complete the disproproriation of the diperoxyhydrate to calcium superoxide, calcium hydroxide, oxygen, and water; constantly and systematically removing the water as it is formed by sweeping the reacting material with a current of dry inert gas and/or by condensation of said water on a cold surface; backfilling the chamber with a dry inert gas; and finally, recovering the calcium superoxide produced.

  2. 3D deformation effect and optimal excavated design of surface mine

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-ren; FENG Ji-li

    2009-01-01

    The three-dimensional (3D) deformation effect of the slope engineering under the step-by-step excavation for the Antaibao surface mine was analyzed using the FLAC3D technique. An optimal excavated scheme with a relatively steeper slope angle of 47° instead of 30° was successfully implemented at the west wall in the geological section 73200 of the mine area, where the 3D effect of the nonlinear large deformation of the slope was taken into account. Based on the above research conclusion, put forward the countermeasures of shortening mining length, excavating by different regions, timely foot backfilling to protect the excavated slope, and monitoring and feedback adjustment by studying the nonlinear effect. The results show that these countermeasures are effective in controlling maximum deformation and increasing the stability of the slope.

  3. Monolithic multilayer microfluidics via sacrificial molding of 3D-printed isomalt†

    Science.gov (United States)

    Gelber, Matthew K.

    2015-01-01

    Here we demonstrate a method for creating multilayer or 3D microfluidics by casting a curable resin around a water-soluble, freestanding sacrificial mold. We use a purpose-built 3D printer to pattern self-supporting filaments of the sugar alcohol isomalt, which we then back-fill with a transparent epoxy resin. Dissolving the sacrificial mold leaves a network of cylindrical channels as well as input and output ports. We use this technique to fabricate a combinatorial mixer capable of producing 8 combinations of two fluids in ratios ranging from 1 : 100 to 100 : 1. This approach allows rapid iteration on microfluidic chip design and enables the use of geometry and materials not accessible using conventional soft lithography. The ability to precisely pattern round channels in all three dimensions in hard and soft media may prove enabling for many organ-on-chip systems. PMID:25671493

  4. Transport and handling of construction materials in the hard coal mining industry and tunnel construction

    Energy Technology Data Exchange (ETDEWEB)

    Bartsch, Stephan [Olko-Maschinentechnik GmbH, Olfen (Germany)

    2008-08-21

    In the German hard coal mining industry construction materials with the most diverse compositions are required for various applications. The largest proportion of the materials is required for the construction of roadside packs and for the backfilling of roadways because of the ever increasing depths and the resulting rock mechanical problems. Over the last 30 years handling, transport and processing systems have been developed to cope with these quantities of materials and to avoid further loads on the shaft hoisting installation. Nowadays these systems are standardised and are characterised by mobility, flexibility, small space requirement and the latest control engineering. This applies in particular to pneumatic and hydraulic transport and distribution of the construction materials. In future all mines will monitor and control all installations above and below ground from a central control room. The methods developed in the mining industry are also successfully used in tunnel and underground railway construction. (orig.)

  5. Using rockbolting in constructing a double entry roadway system arranged skin to skin with a coal pillar; Einsatz der Ankertechnik bei der Auffahrung einer Abbaubegleitstrecke neben einer Kohlenfeste

    Energy Technology Data Exchange (ETDEWEB)

    Woll, T.; Polysos, N.; Luettig, F. [Deutsche Steinkohle AG (Germany)

    2004-07-01

    The common procedure of mining at Saar mine is the extraction of two panels for the same time. The faces are following close to each other in the mid roadway. It is neccessary to develop about 10 km of roadways for one double-panel system. In the Schwalbach seam it was planned due to geological and operational requirements to develop a double entry roadway system arranged skin to skin with a 3 m coal pillar between the panels. The leading face uses the mainway in retreat and at the same time the tailgate for the next panel is developed using a combined support system with backfilled steel arches and rockbolts. The geotechnical planning, the support design and the development technique are described in this report.

  6. Production Experience with the ATLAS Event Service

    CERN Document Server

    Benjamin, Douglas; The ATLAS collaboration

    2017-01-01

    The ATLAS Event Service (AES) has been designed and implemented for efficient running of ATLAS production workflows on a variety of computing platforms, ranging from conventional Grid sites to opportunistic, often short-lived resources, such as spot market commercial clouds, supercomputers and volunteer computing. The Event Service architecture allows real time delivery of fine grained workloads to running payload applications which process dispatched events or event ranges and immediately stream the outputs to highly scalable Object Stores. Thanks to its agile and flexible architecture the AES is currently being used by grid sites for assigning low priority workloads to otherwise idle computing resources; similarly harvesting HPC resources in an efficient back-fill mode; and massively scaling out to the 50-100k concurrent core level on the Amazon spot market to efficiently utilize those transient resources for peak production needs. Platform ports in development include ATLAS@Home (BOINC) and the Google Comp...

  7. Installing met towers in marine environments

    Energy Technology Data Exchange (ETDEWEB)

    Hanberg, Jackie [DNV Canada (Canada)

    2011-07-01

    Onshore measurements are taken to supplement offshore wind resource measurement campaigns. To maximize the quality of the measured data, the conditions presented by marine environments must be well understood and mitigated. This paper discusses the several factors that need attention prior to installation of the met towers. The towers experience high corrosion from their exposure to moist, salt-laden, marine air. Careful instrumentation and material selection can prevent or decrease corrosion. Stainless or galvanized hardware and coating sensor terminals with petroleum jelly are both helpful. Soil in the marine environment has variable moisture levels and is extremely wet, which makes grounding systems and backfill enhancers necessary. Weather conditions in these environments also tend to be unpredictable; hence, towers should be strong enough to handle typical marine weather. In conclusion, successful marine wind resource assessment campaigns require environmental research, careful planning, and awareness of the specific issues.

  8. Relaxed resource advance reservation policy in grid computing

    Institute of Scientific and Technical Information of China (English)

    XIAO Peng; HU Zhi-gang

    2009-01-01

    The advance reservation technique has been widely applied in many grid systems to provide end-to-end quality of service (QoS). However, it will result in low resource utilization rate and high rejection rate when the reservation rate is high. To mitigate these negative effects brought about by advance reservation, a relaxed advance reservation policy is proposed, which allows accepting new reservation requests that overlap the existing reservations under certain conditions. Both the benefits and the risks of the proposed policy are presented theoretically. The experimental results show that the policy can achieve a higher resource utilization rate and lower rejection rate compared to the conventional reservation policy and backfilling technique. In addition, the policy shows better adaptation when the grid systems are in the presence of a high reservation rate.

  9. Coal mine site reclamation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-02-15

    Coal mine sites can have significant effects on local environments. In addition to the physical disruption of land forms and ecosystems, mining can also leave behind a legacy of secondary detrimental effects due to leaching of acid and trace elements from discarded materials. This report looks at the remediation of both deep mine and opencast mine sites, covering reclamation methods, back-filling issues, drainage and restoration. Examples of national variations in the applicable legislation and in the definition of rehabilitation are compared. Ultimately, mine site rehabilitation should return sites to conditions where land forms, soils, hydrology, and flora and fauna are self-sustaining and compatible with surrounding land uses. Case studies are given to show what can be achieved and how some landscapes can actually be improved as a result of mining activity.

  10. Pseudo-Glassification Material for G-Demption

    Energy Technology Data Exchange (ETDEWEB)

    Casella, Andrew M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Buck, Edgar C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gates, Robert O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Riley, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-09-01

    G-Demption, LLC has requested that PPNL provide design input for a “pseudo-glassification” process associated with their proposed technology for generating gamma irradiation stations from used nuclear fuel. The irradiation design currently consists of an aluminum enclosure designed to allow for proper encapsulation of and heat flow from a used fuel rod while minimally impacting the streaming of gamma rays from the fuel. In order to make their design more robust, G-Demption is investigating the benefits of backfilling this aluminum enclosure with a setting material once the used fuel rod is properly placed. This process has been initially referred to as “pseudo-glassification”, and strives not to impact heat transport or gamma streaming from the used fuel rod while providing increased fuel rod protection and fission gas retention. PNNL has compiled an internal material evaluation and discussion for the “pseudo-glassification” process in this report.

  11. Investigation and characterization of mining subsidence in Kaiyang Phosphorus Mine

    Institute of Scientific and Technical Information of China (English)

    DENG Jian; BIAN Li

    2007-01-01

    In Kaiyang Phosphorus Mine, serious environmental and safety problems are caused by large scale mining activities in the past 40 years. These problems include mining subsidence, low recovery ratio, too much dead ore in pillars, and pollution of phosphorus gypsum. Mining subsidence falls into four categories: curved ground and mesa, ground cracks and collapse hole, spalling and eboulement, slope slide and creeping. Measures to treat the mining subsidence were put forward: finding out and managing abandoned stopes, optimizing mining method (cut and fill mining method), selecting proper backfilling materials (phosphogypsum mixtures), avoiding disorder mining operation, and treating highway slopes. These investigations and engineering treatment methods are believed to be able to contribute to the safety extraction of ore and sustainable development in Kaiyang Phosphorus Mine.

  12. ИЗУЧЕНИЕ СЕЛЕКТИВНЫХ СВОЙСТВ ГЕЛЕОБРАЗУЮЩЕГО СОСТАВА ПРИ ОГРАНИЧЕНИИ ПРИТОКА ВОДЫ В УСЛОВИЯХ КАРБОНАТНЫХ КОЛЛЕКТОРОВ

    Directory of Open Access Journals (Sweden)

    Шагиахметов, А.М.

    2016-05-01

    Full Text Available Article is devoted to the problem of limiting water inflow in a production well. The authors consider the main features of the reservoir, which contribute to premature flooding. This paper presents the basic classification of backfill selective compositions, outlines the advantages and disadvantages of each type. Gel composed of carboxymethylcellulose, chromium acetate and copper sulfate was developed for water production restraining. An alternative way was offered to determine the optimal concentrations of oil-well compositions on the change in the total porosity and x-ray density measured in the x-ray tomograph. Dynamics of the effective viscosity on the magnitude of the gap, simulating the crack was obtained – the viscosity decreases logarithmically. Filtration experiments confirmed the selective properties of the gel-forming composition.

  13. Pseudo-Glassification Material for G-Demption

    Energy Technology Data Exchange (ETDEWEB)

    Casella, Andrew M.; Buck, Edgar C.; Gates, Robert O.; Riley, Brian J.

    2014-09-30

    G-Demption, LLC has requested that PPNL provide design input for a “pseudo-glassification” process associated with their proposed technology for generating gamma irradiation stations from used nuclear fuel. The irradiation design currently consists of an aluminum enclosure designed to allow for proper encapsulation of and heat flow from a used fuel rod while minimally impacting the streaming of gamma rays from the fuel. In order to make their design more robust, G-Demption is investigating the benefits of backfilling this aluminum enclosure with a setting material once the used fuel rod is properly placed. This process has been initially referred to as “pseudo-glassification”, and strives not to impact heat transport or gamma streaming from the used fuel rod while providing increased fuel rod protection and fission gas retention. PNNL has compiled an internal material evaluation and discussion for the “pseudo-glassification” process in this report.

  14. Data report for the safety assessment SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Vahlund, Fredrik [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Andersson, Johan [JA Streamflow AB, Aelvsjoe (Sweden); Loefgren, Martin [Kemakta Konsult AB, Stockholm (Sweden)

    2006-11-15

    This report is the data report derived within the project SR-Can. The purpose of the data report is to present input data, with uncertainty estimates, for the SR-Can assessment calculations. Data presented in the report have been derived using standardised procedures following a methodology which is presented in the initial part of the report. In this part, a template is presented that has been used when assessing input data in supporting documents as illustrated in subsequent chapters of the data report. By using the template, decisions by the SR-Can team are separated from expert input. This increases the traceability of assessment decisions. The data report supplies assessment data for all parts of the repository system, the fuel, the canister, the buffer and backfill and the geosphere. For the geosphere, many of the data are based on information obtained during the site investigation programme.

  15. ATLAS and LHC computing on CRAY

    CERN Document Server

    Sciacca, Gianfranco; The ATLAS collaboration

    2017-01-01

    Access and exploitation of large scale computing resources, such as those offered by general purpose HPC centres, is one important measure for ATLAS and the other Large Hadron Collider experiments in order to meet the challenge posed by the full exploitation of the future data within the constraints of flat budgets. We report on the effort moving the Swiss WLCG T2 computing, serving ATLAS, CMS and LHCb, from a dedicated cluster to the large Cray systems at the Swiss National Supercomputing Centre CSCS. These systems do not only offer very efficient hardware, cooling and highly competent operators, but also have large backfill potentials due to size and multidisciplinary usage and potential gains due to economy at scale. Technical solutions, performance, expected return and future plans are discussed.

  16. ATLAS and LHC computing on CRAY

    CERN Document Server

    Haug, Sigve; The ATLAS collaboration

    2016-01-01

    Access and exploitation of large scale computing resources, such as those offered by general purpose HPC centres, is one import measure for ATLAS and the other Large Hadron Collider experiments in order to meet the challenge posed by the full exploitation of the future data within the constraints of flat budgets. We report on the effort moving the Swiss WLCG T2 computing, serving ATLAS, CMS and LHCb from a dedicated cluster to the large CRAY systems at the Swiss National Supercomputing Centre CSCS. These systems do not only offer very efficient hardware, cooling and highly competent operators, but also have large backfill potentials due to size and multidisciplinary usage and potential gains due to economy at scale. Technical solutions, performance, expected return and future plans are discussed.

  17. Evaluation of Maximum Radionuclide Groundwater Concentrations for Basement Fill Model. Zion Station Restoration Project

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-05-20

    ZionSolutions is in the process of decommissioning the Zion Nuclear Power Station (ZNPS). After decommissioning is completed, the site will contain two reactor Containment Buildings, the Fuel Handling Building and Transfer Canals, Auxiliary Building, Turbine Building, Crib House/Forebay, and a Waste Water Treatment Facility that have been demolished to a depth of 3 feet below grade. Additional below ground structures remaining will include the Main Steam Tunnels and large diameter intake and discharge pipes. These additional structures are not included in the modeling described in this report but the inventory remaining (expected to be very low) will be included with one of the structures that are modeled as designated in the Zion Station Restoration Project (ZSRP) License Termination Plan (LTP). The remaining underground structures will be backfilled with clean material. The final selection of fill material has not been made.

  18. Monolithic multilayer microfluidics via sacrificial molding of 3D-printed isomalt.

    Science.gov (United States)

    Gelber, Matthew K; Bhargava, Rohit

    2015-04-07

    Here we demonstrate a method for creating multilayer or 3D microfluidics by casting a curable resin around a water-soluble, freestanding sacrificial mold. We use a purpose-built 3D printer to pattern self-supporting filaments of the sugar alcohol isomalt, which we then back-fill with a transparent epoxy resin. Dissolving the sacrificial mold leaves a network of cylindrical channels as well as input and output ports. We use this technique to fabricate a combinatorial mixer capable of producing 8 combinations of two fluids in ratios ranging from 1 : 100 to 100 : 1. This approach allows rapid iteration on microfluidic chip design and enables the use of geometry and materials not accessible using conventional soft lithography. The ability to precisely pattern round channels in all three dimensions in hard and soft media may prove enabling for many organ-on-chip systems.

  19. Device and method for automated separation of a sample of whole blood into aliquots

    Science.gov (United States)

    Burtis, Carl A.; Johnson, Wayne F.

    1989-01-01

    A device and a method for automated processing and separation of an unmeasured sample of whole blood into multiple aliquots of plasma. Capillaries are radially oriented on a rotor, with the rotor defining a sample chamber, transfer channels, overflow chamber, overflow channel, vent channel, cell chambers, and processing chambers. A sample of whole blood is placed in the sample chamber, and when the rotor is rotated, the blood moves outward through the transfer channels to the processing chambers where the blood is centrifugally separated into a solid cellular component and a liquid plasma component. When the rotor speed is decreased, the plasma component backfills the capillaries resulting in uniform aliquots of plasma which may be used for subsequent analytical procedures.

  20. Agricultural terraces montoring and modeling: a field survey in Chianti region, Firenze, Italy - First part

    Science.gov (United States)

    Preti, Federico; Caruso, Marco; Dani, Andrea; Errico, Alessandro; Guastini, Enrico; Trucchi, Paolo

    2015-04-01

    The two abstracts present the design and set-up of an experimental field plant whose aim is the study and modeling of water circulation in a terraced slope together with its influence on the stability of the retaining dry stone walls. The pilot plant is located at "Fattoria di Lamole" (Greve in Chianti, Firenze, Italy) where both ancient and recently restored or rebuilt dry stone retaining walls are present. The intense vineyards cultivation makes it very representative in terms of range of external stresses that affect both hillslopes and walls. The research is developed within a bigger framework of landscape preservation as a way to prevent hydrogeological instabilities and landslide risks. First Part A first/preliminary field survey was carried out in order to estimate the hydraulic and mechanical soil characteristics. Field saturated hydraulic conductivity measurements with the Simplified Falling Head (SFH) method on a terrace along an alignment were performed. Infiltrometer tests with a double ring device and soil texture determinations with both fine particle-size and skeleton fraction distributions were also performed. The Direct shear test on undisturbed and reconstituted soil samples will offer an estimation of the Mohr-Coulomb failure envelope parameters (friction angle and cohesion). A reference portion of a dry stone wall will be also monitored. Lateral earth pressure at backfill-retaining wall interface (compared to temperature and air pressure measured values), backfill volumetric water content (both in saturated and unsaturated states) and ground-water level are measured. Acknowledgements Italian Research Project of Relevant Interest (PRIN2010-2011), prot. 20104ALME4, National network for monitoring, modeling, and sustainable management of erosion processes in agricultural land and hilly-mountainous area

  1. Basin Depth Control on the Autogenic Timescale of Fluviodeltaic Systems

    Science.gov (United States)

    Carlson, B.; Kim, W.; Piliouras, A.

    2013-12-01

    ABSTRACT Autogenic processes are inherent processes in sediment transport that influence landscape building and leave distinct signatures in the sedimentary record. It is of great interest to understand autogenic processes in order to decouple internal processes from external controls, such as tectonics or climate change. Here we present results from a series of delta-building experiments to determine the variability of the fluviodeltaic autogenic timescale in response to varying basin water depth. This internal timescale was measured as the time that is required for the delta topset to be reworked through a full cycle of storage and release of sediment. The topset aggrades by fluvial sedimentation until it reaches a maximum slope, at which point a large amount of sediment starts to release, typically resulting in strong channelization. This is followed by a period of avulsions, lateral migration, and backfilling of channels on the topset. These storage and release events are repeated. We used time-lapse images to track shoreline positions and observe changes in progradation rate. The changes in topset topography were also used to determine storage and release duration. The experimental results indicate that the autogenic timescales generally increase with increasing basin water depth. These observations may be explained by the amount of time required to build a lobe with an area large enough to trigger a switch from a lobe-building release event to a backfilling storage event. Individual lobes show a similar surface area regardless of basin depth in the experiments. Deeper basin depth simply requires a larger volume to be filled within this area, thus more time to complete one autogenic process. However, when channel depth is significantly smaller than basin depth, e.g., in very deep basins, stochastic variability in sediment transport and channel lateral mobility outweighs the autogenic cyclicity. This study suggests that internal dynamics and its stratigraphic

  2. The effect of sea-water intrusion due to the large scale construction in a coastal region

    Science.gov (United States)

    Hyun, S.; Jin, S.; Woo, N. C.; Lee, J.; Lee, H.; Kim, Y.

    2010-12-01

    This study was carried out for estimating the seawater intrusion at the disturbed aquifer by a large scale construction when building a power plant in a coastal region, located in southeastern part of the Korean peninsula. Groundwater sampling and vertical profiling of electrical conductivity(EC) for 8 monitoring wells were carried. EC profiling results shows that maximum EC for PW-5, 6 and 7 is over 40 mS/cm, for PZ-1, 3, 4 and 8 is 18.76, 4.46, 26.16, 21.42 mS/cm and for PZ-2 is 0.79 mS/cm,respectively. Chemical composition of water samples shows that water types of Na-Cl for PZ-5, 6, and 7 (excavated and backfilled area), Na-Cl-SO4 for PZ-4 and PZ-8, Na-Ca-Mg-Cl for PZ-1, Ca-Na-SO4-Cl for PZ-2, and Mg-Ca-Na-SO4 for PZ-3. In addition, the bivariate plot of SO4/Cl(meq ratios) and SO4(mmol/L) indicates that PZ-4, 5, 6, 7 and 8 appear to be seawater, PZ-1 is located at mixing zone between freshwater and seawater, and PZ-2 is freshwater. However, based on the high SO42- level and (HCO3-/Sum anions} ratio less than 0.8, groundwater at PZ-3 seems to show the gypsum dissolution. The gypsum dissolution was attributed to the effect of sea-water intrusion on ageing of lean concrete that was used for backfill around the PZ-3. Key words : large scale construction, EC profiling, hydrochemistry, sea-water intrusion, concrete ageing Acknowledgement This study has been carried out under the Nuclear R&D Program [No. 2010-0001070] supported by the Ministry of Education, Science and Technology, Republic of Korea.

  3. Constitutive modeling of the behavior of a sand-bentonite mixture

    Energy Technology Data Exchange (ETDEWEB)

    Saadat, F.

    1989-01-01

    The Canadian concept for disposal of nuclear fuel waste proposes a compacted mixture of sand and bentonite (known as buffer) as one of several barriers limiting radionuclide escape to the biosphere. To ensure acceptable performance of the buffer, it is necessary to understand its stress-strain-time behavior under rising groundwater pressure up to 10 MPa in the vault. High pressure triaxial laboratory tests have been performed at mean effective pressures up to 9 MPa, and porewater pressures up to 7 MPa at ambient temperatures. The results indicate that the strength of the buffer is dominated by the bentonite, and the material exhibits strain-softening behavior in shear. Three different approaches for constitutive modeling of the buffer behavior are examined in this thesis. A three-modulus anisotropic hyperelastic model is proposed for the small strain range. This model accounts for the anisotropic nature of the buffer and permits coupling of mean pressures with shear strains, or deviator stresses with volume strains. A second three-function hypoelastic model is also developed to describe constitutive relationships for straining-to-failure. The third elastic-plastic model (belonging to the Cam clay family) accounts for non-reversibility, non-linearity and dilatancy in the plastic range. In addition to these predictive models, a conceptual model is proposed based on critical state soil mechanics to provide a coherent framework for describing the behavior of buffer compacted to different densities. Finally, the interactions between buffer, container, rock and backfill are examined in the non-linear finite element analyses using the proposed elastic-plastic model for the buffer. The preliminary results suggest that swelling of the buffer against compressive backfill could potentially produce large shear strains in the buffer.

  4. PreBIND and Textomy – mining the biomedical literature for protein-protein interactions using a support vector machine

    Directory of Open Access Journals (Sweden)

    Baskin Berivan

    2003-03-01

    Full Text Available Abstract Background The majority of experimentally verified molecular interaction and biological pathway data are present in the unstructured text of biomedical journal articles where they are inaccessible to computational methods. The Biomolecular interaction network database (BIND seeks to capture these data in a machine-readable format. We hypothesized that the formidable task-size of backfilling the database could be reduced by using Support Vector Machine technology to first locate interaction information in the literature. We present an information extraction system that was designed to locate protein-protein interaction data in the literature and present these data to curators and the public for review and entry into BIND. Results Cross-validation estimated the support vector machine's test-set precision, accuracy and recall for classifying abstracts describing interaction information was 92%, 90% and 92% respectively. We estimated that the system would be able to recall up to 60% of all non-high throughput interactions present in another yeast-protein interaction database. Finally, this system was applied to a real-world curation problem and its use was found to reduce the task duration by 70% thus saving 176 days. Conclusions Machine learning methods are useful as tools to direct interaction and pathway database back-filling; however, this potential can only be realized if these techniques are coupled with human review and entry into a factual database such as BIND. The PreBIND system described here is available to the public at http://bind.ca. Current capabilities allow searching for human, mouse and yeast protein-interaction information.

  5. Use of geosynthetics for performance enhancement of earth structures in cold regions

    Institute of Scientific and Technical Information of China (English)

    Jie Han; Yan Jiang

    2013-01-01

    Earth structures, such as roadways, embankments and slopes, and earth retaining walls, have been commonly used in cold regions for transportation and other applications. In addition to typical design considerations for earth structures at normal temperature, a design must also consider the unique problems associated with low temperature, such as frost heave, lateral expansion, thaw settlement and weakening, and degradation of material properties. Geosynthetics have been used in cold regions to stabilize earth structures during construction and mitigate potential problems during their service at low tem-perature. This paper provides a state of practice review of the use of geosynthetics for performance enhancement of earth structures in cold regions. This paper starts with basic information on available geosynthetic products and their functions, evaluates properties and behavior of geosynthetics and soil-geosynthetic systems at low temperature, and discusses past studies and their key results on the use of geosynthetics to enhance the performance of roadways, embankments, and earth retaining walls in cold regions. This review reveals that geosynthetics at low temperature have higher tensile strength and stiffness, lower creep rate, and lower elongation at failure. The effect of temperature becomes significant when nonwoven geotextiles are subjected to moistening and soil intrusion at subfreezing temperature. Freeze-thaw cycles may degrade hydraulic and mechanical properties of geosynthetic-soil systems. The inclusion of geosynthetics in soil provides drainage and/or barrier to water flow, retains mechanical properties, and reduces frost heave during and after freeze-thaw cycles. Effectiveness of geosynthetics has been confirmed in the field in bridging over voids, stabilizing roadways over temper-ature-susceptible soils during thaw, and proving drainage and barrier to temperature-susceptible soils before freeze. To avoid frost heave and lateral expansion of backfill

  6. Dynamic Resource Management for Parallel Tasks in an Oversubscribed Energy-Constrained Heterogeneous Environment

    Energy Technology Data Exchange (ETDEWEB)

    Imam, Neena [ORNL; Koenig, Gregory A [ORNL; Machovec, Dylan [Colorado State University, Fort Collins; Khemka, Bhavesh [Colorado State University, Fort Collins; Pasricha, Sudeep [Colorado State University; Maciejewski, Anthony A [Colorado State University, Fort Collins; Siegel, Howard [Colorado State University, Fort Collins; Wright, Michael [Department of Defense; Hilton, Marcia [Department of Defense; Rambharos, Rejendra [Department of Defense

    2016-01-01

    Abstract: The worth of completing parallel tasks is modeled using utility functions, which monotonically-decrease with time and represent the importance and urgency of a task. These functions define the utility earned by a task at the time of its completion. The performance of such a system is measured as the total utility earned by all completed tasks over some interval of time (e.g., 24 hours). To maximize system performance when scheduling dynamically arriving parallel tasks onto a high performance computing (HPC) system that is oversubscribed and energy-constrained, we have designed, analyzed, and compared different heuristic techniques. Four utility-aware heuristics (i.e., Max Utility, Max Utility-per-Time, Max Utility-per-Resource, and Max Utility-per-Energy), three FCFS-based heuristics (Conservative Backfilling, EASY Backfilling, and FCFS with Multiple Queues), and a Random heuristic were examined in this study. A technique that is often used with the FCFS-based heuristics is the concept of a permanent reservation. We compare the performance of permanent reservations with temporary place-holders to demonstrate the advantages that place-holders can provide. We also present a novel energy filtering technique that constrains the maximum energy-per-resource used by each task. We conducted a simulation study to evaluate the performance of these heuristics and techniques in an energy-constrained oversubscribed HPC environment. With place-holders, energy filtering, and dropping tasks with low potential utility, our utility-aware heuristics are able to significantly outperform the existing FCFS-based techniques.

  7. Impact of coal gangue on the level of main trace elements in the shallow groundwater of a mine reclamation area

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Chen Longqian; Zhou Tianjian; Tang Qibao; Zhang Ting

    2011-01-01

    Coal gangue is the most used filling material during reclamation of areas suffering subsidence from mining.Main trace element levels (F,As,Hg,and Pb) in shallow groundwater in the reclamation area may be affected by leaching from the gangue.This can has an impact on the application of the water for agricultural irrigation or use as drinking water.Therefore,it is of great significance to understand the effect coal gangue has on the shallow groundwater of a reclaimed area.We studied the effect of coal gangue on fluorine,arsenic,mercury,and lead levels in the shallow groundwater of a reclamation area by testing the water and the coal gangue.One well near the reclamation area was used as a control well and element levels in water from this well and from the soil next to the well were also measured.The results show that the levels of these elements are increasing in the reclamation area over time.The increase in fluorine,arsenic,mercury,and lead in monitor wells varies from 7.42% to 8.26%,from 7.13% to 7.90%,from 4.85% to 6.48%,and from 4.69% to 6.42%,respectively.Fluorine and arsenic levels are lower in monitor wells than in the control water.The other elements are found in greater concentration than in the control.The Nemerow index also indicates that the shallow groundwater in the reclamation area Ⅰ is moderately affected by the back-filling coal gangue,while the shallow groundwater in the reclamation area Ⅱ and Ⅲ are slightly affected by the back-filling coal gangue.This shallow groundwater could be used for agricultural irrigation or for drinking.

  8. Post-Closure Inspection Report for the Tonopah Test Range, Nevada, For Calendar Year 2011

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2012-02-21

    This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2011 and includes inspection and repair activities completed at the following CAUs: (1) CAU 400: Bomblet Pit and Five Points Landfill (TTR); (2) CAU 407: Roller Coaster RadSafe Area (TTR); (3) CAU 424: Area 3 Landfill Complexes (TTR); (4) CAU 453: Area 9 UXO Landfill (TTR); and (5) CAU 487: Thunderwell Site (TTR) Inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Appendix B. The inspection checklists are included in Appendix C, field notes are included in Appendix D, and photographs taken during inspections are included in Appendix E. The annual post-closure inspections were conducted May 3 and 4, 2011. Maintenance was performed at CAU 424, CAU 453, and CAU 487. At CAU 424, two surface grade monuments at Landfill Cell A3-3 could not be located during the inspection. The two monuments were located and marked with lava rock on July 13, 2011. At CAU 453, there was evidence of animal burrowing. Animal burrows were backfilled on July 13, 2011. At CAU 487, one use restriction warning sign was missing, and wording was faded on the remaining signs. A large animal burrow was also present. The signs were replaced, and the animal burrow was backfilled on July 12, 2011. As a best management practice, the use restriction warning signs at CAU 407 were replaced with standard Federal Facility Agreement and Consent Order signs on July 13, 2011. Vegetation monitoring was performed at the CAU 400 Five Points Landfill and CAU 407 in June 2011, and the vegetation monitoring report is included in Appendix F.

  9. Effective use of fly ash slurry as fill material.

    Science.gov (United States)

    Horiuchi, S; Kawaguchi, M; Yasuhara, K

    2000-09-15

    A lot of effort has been put into increasing coal ash utilization; however, 50% of total amount is disposed of on land and in the sea. Several attempts have been reported recently concerning slurried coal fly ash use for civil engineering materials, such as for structural fill and backfill. The authors have studied this issue for more than 15 years and reported its potential for (1) underwater fills, (2) light weight backfills, and (3) light weight structural fills, through both laboratory tests and construction works. This paper is an overview of the results obtained for slurry, focusing on the following. (1) Coal fly ash reclaimed by slurry placement shows lower compressibility, higher ground density, and higher strength than by the other methods. This higher strength increases stability against liquefaction during earthquake. (2) Higher stability of the fly ash ground formed by slurry placement is caused by higher density and its self-hardening property. (3) Stability of fly ash reclaimed ground can be increased by increasing density and also by strength enhancement by cement addition. (4) Technical data obtained through a man-made island construction project shows the advantages of fly ash slurry in terms of mechanical properties such as higher stability against sliding failure, sufficient ground strength, and also in terms of cost saving. (5) Concentration in leachates from the placed slurry is lower than the Japanese environmental law. (6) In order to enlarge the fly ash slurry application toward a lightweight fill, mixtures of air foam, cement and fly ash were examined. Test results shows sufficient durability of this material against creep failure. This material was then used as lightweight structural fill around a high-rise building, and showed sufficient quality. From the above data, it can be concluded that coal fly ash slurry can be effectively utilized in civil engineering projects.

  10. Integrated waste and water management in mining and metallurgical industries

    Institute of Scientific and Technical Information of China (English)

    B.K.C.CHAN; S.BOUZALAKOS; A.W.L.DUDENEY

    2008-01-01

    Extractive operations usually co-produce large quantities of unmarketable materials (mineral wastes),most of which are conventionally discarded to dumps (coarse material) and tailings ponds (fines).Escalating cost and regulation worldwide highlight an increasing need for reduction and re-use of such wastes.The present paper introduces a new integrated waste management scheme for solids and water.The scheme was exemplified by novel treatment of synthetic waste and process water linked to the biohydrometallurgical processing of metal sulphide flotation concentrates.Bioleaching of sulphide concentrate leads to two types of solid waste:a ferrihydrite/gypsum precipitate from neutralisation of the bioleach liquor and un-leached gangue.The paper indicates that,depending upon the minor components involved,the solid phases in admixture might be usefully distributed among three types of product:conventional underground backfill,cemented civil engineering backfill (particularly controlled low strength material or CLSM) and manufactured soil.It emphasizes CLSM containing simulated mineral waste,showing that such material can exhibit the required characteristics of strength,porosity and permeability.When toxic components,e.g.,arsenic from refractory gold ore,are present,encapsulation will be required.Process water is typically recycled as far as possible,although any excess should be treated before re-use or discharge.The paper also highlights treatment by reverse osmosis (one of the few methods able to generally remove dissolved components),particularly showing that arsenic in oxidation state +6 can be readily removed for discharge (<50×10-12 As),although additional ion exchange is needed for potable water (<10×10-12 As).

  11. 城市道路地下管道对沥青路面结构影响的力学分析%Mechanical analysis of asphalt pavement structure affected by underground pipeline of urban road

    Institute of Scientific and Technical Information of China (English)

    方诗圣; 李宏卓; 李贺才

    2011-01-01

    This paper establishes a three-dimensional finite element model of typical asphalt pavement structure for numerical simulation. Under the asphalt pavement weight and the vehicle load, the laws that the underground pipeline depth and backfill modulus change affect the asphalt pavement are analyzed. Under the asphalt pavement weight, the existence of underground pipelines and trenches changes the local stiffness of the asphalt pavement structure and causes the surface differential settlement.While under the vehicle load, the laws that the different underground pipeline depth and backfill modulus affect the surface settlement and internal forces are revealed. The study provides a theoretical reference for designing and constructing the municipal asphalt pavement structure on the top of the underground pipelines.%文章通过典型沥青路面结构的三维有限元数值模拟,分别计算了在路面重力和车辆荷载作用下,地下管道埋深以及回填土模量变化对沥青路面的影响规律.在沥青路面自重荷载作用下,由于地下管道和沟槽的存在改变了道路结构的局部刚度,路表产生了差异沉降;在车辆荷载的作用下,分析了不同管道埋深和回填土模最对路面沉降和内力的影响规律,为市政道路管道上方路面设计和施工提供了理论参考.

  12. Visualization experiment to investigate capillary barrier performance in the context of a Yucca Mountain emplacement drift.

    Science.gov (United States)

    Tidwell, Vincent C; Glass, Robert J; Chocas, Connie; Barker, Glenn; Orear, Lee

    2003-01-01

    The use of capillary barriers as engineered backfill systems to divert water away from radioactive waste potentially stored in a Yucca Mountain emplacement drift is investigated. We designed and conducted a flow visualization experiment to investigate capillary barrier performance in this context. A two-dimensional, thin slab, test system replicated the physical emplacement drift to one-quarter scale (1.4-m diameter) and included the simulated drift wall, waste canister, pedestal, capillary barrier backfill, and host-rock fracture system. Water was supplied at the top of the simulated drift and allowed to discharge by way of wicks located along the left wall of the cell (simulated fractures) or by a gravity drain at the bottom of the right side (simulated impermeable rock with floor drain). Photographs captured the migration of water and a blue dye tracer within the system, analytical balances measured the mass balance of water, while tensiometers measured the capillary pressure at numerous locations. Of particular concern to this test was the drainage of the capillary barrier, which terminates against the drift wall. We found that while the simulated fractures (left side) and drain (right side) each influenced the performance of the capillary barrier at early time, they had little differential affect at later times. Also of concern was the small disparity in capillary properties between the fine and coarse layer (limited by the need of a fine-grained material that would not filter into the coarse layer under dry conditions). While the capillary barrier was able to divert the majority of flow toward the edges of the system and away from the simulated waste canister, the barrier did not preclude flow in the coarse layer, which was noted to be visually wet next to the waste canister on day 92 and was continuing to take on water at termination on day 112.

  13. Dike Propagation Near Drifts

    Energy Technology Data Exchange (ETDEWEB)

    NA

    2002-03-04

    The purpose of this Analysis and Model Report (AMR) supporting the Site Recommendation/License Application (SR/LA) for the Yucca Mountain Project is the development of elementary analyses of the interactions of a hypothetical dike with a repository drift (i.e., tunnel) and with the drift contents at the potential Yucca Mountain repository. This effort is intended to support the analysis of disruptive events for Total System Performance Assessment (TSPA). This AMR supports the Process Model Report (PMR) on disruptive events (CRWMS M&O 2000a). This purpose is documented in the development plan (DP) ''Coordinate Modeling of Dike Propagation Near Drifts Consequences for TSPA-SR/LA'' (CRWMS M&O 2000b). Evaluation of that Development Plan and the work to be conducted to prepare Interim Change Notice (ICN) 1 of this report, which now includes the design option of ''Open'' drifts, indicated that no revision to that DP was needed. These analyses are intended to provide reasonable bounds for a number of expected effects: (1) Temperature changes to the waste package from exposure to magma; (2) The gas flow available to degrade waste containers during the intrusion; (3) Movement of the waste package as it is displaced by the gas, pyroclasts and magma from the intruding dike (the number of packages damaged); (4) Movement of the backfill (Backfill is treated here as a design option); (5) The nature of the mechanics of the dike/drift interaction. These analyses serve two objectives: to provide preliminary analyses needed to support evaluation of the consequences of an intrusive event and to provide a basis for addressing some of the concerns of the Nuclear Regulatory Commission (NRC) expressed in the Igneous Activity Issue Resolution Status Report.

  14. Hybrid Finite-Discrete Element Simulation of the EDZ Formation and Mechanical Sealing Process Around a Microtunnel in Opalinus Clay

    Science.gov (United States)

    Lisjak, Andrea; Tatone, Bryan S. A.; Mahabadi, Omid K.; Grasselli, Giovanni; Marschall, Paul; Lanyon, George W.; Vaissière, Rémi de la; Shao, Hua; Leung, Helen; Nussbaum, Christophe

    2016-05-01

    The analysis and prediction of the rock mass disturbance around underground excavations are critical components of the performance and safety assessment of deep geological repositories for nuclear waste. In the short term, an excavation damaged zone (EDZ) tends to develop due to the redistribution of stresses around the underground openings. The EDZ is associated with an increase in hydraulic conductivity of several orders of magnitude. In argillaceous rocks, sealing mechanisms ultimately lead to a partial reduction in the effective hydraulic conductivity of the EDZ with time. The goal of this study is to strengthen the understanding of the phenomena involved in the EDZ formation and sealing in Opalinus Clay, an indurated claystone currently being assessed as a host rock for a geological repository in Switzerland. To achieve this goal, hybrid finite-discrete element method (FDEM) simulations are performed. With its explicit consideration of fracturing processes, FDEM modeling is applied to the HG-A experiment, an in situ test carried out at the Mont Terri underground rock laboratory to investigate the hydro-mechanical response of a backfilled and sealed microtunnel. A quantitative simulation of the EDZ formation process around the microtunnel is first carried out, and the numerical results are compared with field observations. Then, the re-compression of the EDZ under the effect of a purely mechanical loading, capturing the increase of swelling pressure from the backfill onto the rock, is considered. The simulation results highlight distinctive rock failure kinematics due to the bedded structure of the rock mass. Also, fracture termination is simulated at the intersection with a pre-existing discontinuity, representing a fault plane oblique to the bedding orientation. Simulation of the EDZ re-compression indicates an overall reduction of the total fracture area as a function of the applied pressure, with locations of ineffective sealing associated with self

  15. A summary of the models used for the mechanical response of disposal rooms in the Waste Isolation Pilot Plant with regard to compliance with 40 CFR 191, Subpart B

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, B.M.; Mendenhall, F.T.

    1993-08-01

    A summary is presented of the results of a number of studies conducted prior to March 1992 that have led to a conceptual model describing how the porosity (and therefore the permeability) of waste and backfill in a Waste Isolation Pilot Plant disposal room changes with time and also describes how results from calculations involving mathematical models of these processes are used to provide input into performance assessment of the repository. Included in the report are descriptions of essential material response or constitutive models that include the influence of gas generation and the response of simple gas-pressurized cracks and fractures in salt, marker beds, and clay seams. Two-dimensional versus three-dimensional disposal room configurations and descriptions of the differences between numerical codes are also discussed. Calculational results using the mathematical models for disposal room response are described, beginning with closure of empty rooms and becoming progressively more complex. More recent results address some of the effects of gas generation in a room containing waste and backfill and intersected by a gas permeable marker bed. Developments currently in progress to improve the evaluation of the disposal room performance are addressing the coupling between brine flow and closure and the two-dimensional capability for analyzing a complete panel of rooms. Next, a method is described for including disposal room closure results into performance assessment analyses that determine if the repository is in compliance with regulatory standards. The coupling is accomplished using closure surfaces that describe the relationship among porosity, total amount of gas in the repository, and time. A number of conclusions about room response and recommendations for further work are included throughout the report.

  16. Experimental Research on Mechanical Properties of Recrystallized Solid of Phosphogypsum%磷石膏再结晶体力学特性试验研究

    Institute of Scientific and Technical Information of China (English)

    高洁; 赵国彦

    2013-01-01

    With comparative method, tests on phosphogypsum dehydration and recrystallization were conducted. After analyzing the effect of each index on mechanical properties of recrystallized solid of phosphogypsum, the optimal indexes were decided. The mechanical properties of solid prepared with dehydrated and ordinary phosphogypsum was also studied. Results show that phosphogypsum with the addition of 2% quicklime, after being heated at 180℃ for 3 hours and aged for 3 days, was used for backfilling underground at the concentration of 55% with neutral pH value. Its recrystallized solid can reach 6. 82 MPa in compression strength after 28 days, suitable for all kinds of backfilling in underground mining. The material prepared with ordinary phosphogypsum and dehydrated phosphogypsum in the proportion of 1:2 solidified for 28 days, resulted in the compression strength merely 6% of dehydrated phosphogypsum.%采用比较法设计了磷石膏失水与再结晶试验,分析了各参数对再结晶体力学性能的影响,获得了最优参数.研究了失水磷石膏与常态磷石膏混掺情况下固化体的力学特性.研究表明:掺加2%生石灰的磷石膏,在180℃下热处理3h、陈化3d、以55%浓度充填井下,其浆体pH呈中性,再结晶体28 d抗压强度达到6.82 MPa,可适用于各种充填采矿方法;常态磷石膏和失水磷石膏按1∶2配制的混合材料,固化体28 d抗压强度仅为失水磷石膏强度的6%.

  17. Sorption (Kd) measurements on cinder block and grout in support of dose assessments for Zion Nuclear Station decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Milian L.; Sullivan T.

    2014-06-24

    The Zion Nuclear Power Station is being decommissioned. ZionSolutions proposes to leave much of the below grade structures in place and to fill them with a backfill to provide structural support. Backfills under consideration include “clean” concrete demolition debris from the above grade parts of the facility, a flowable grout, cinder block construction debris and sand. A previous study (Yim, 2012) examined the sorption behavior of five nuclides (Fe-55, Co-60, Ni-63, Sr-85, and Cs-137) on concrete and local soils. This study, commissioned by ZionSolutions and conducted by the Brookhaven National Laboratory (BNL) examines the sorption behavior on cinder block and grout materials. Specifically, this study measured the distribution coefficient for four radionuclides of concern using site-groundwater and cinder block from the Zion site and a flowable grout. The distributions coefficient is a measure of the amount of the radionuclide that will remain sorbed to the solid material that is present relative to the amount that will remain in solution. A high distribution coefficient indicates most of the radionuclide will remain on the solid material and will not be available for transport by the groundwater. The radionuclides examined in this set of tests were Co-60, Ni-63, Sr-85, and Cs-137. Tests were performed following ASTM C1733-10, Standard Test Methods for Distribution Coefficients of Inorganic Species by the Batch Method. Sr-85 was used in the testing as an analogue for Sr-90 because it behaves similarly with respect to sorption and has a gamma emission that is easier to detect than the beta emission from Sr-90.

  18. Study on Transportation Performance of High -density Slurry Based on Roundpipe Experiment%基于环管试验的高浓度料浆输送性研究

    Institute of Scientific and Technical Information of China (English)

    郑伯坤; 李向东; 盛佳

    2012-01-01

    The pipeline transportation of unclassified tailings slurry with a high density was simulated by round - pipe experiment, and the transportation performance of the unclassified tailings slurry was studied. Based on the flow property, bleeding and subsiding studies of slurry with different concentration, the high - concentration ranges of slurry was defined, and the test object was determined. By round -pipe experiment and data analysis, the resistance losses of the slurry transportation in pipeline was measured and analyzed in theory, and the rheological properties of the backfilling slurry was obtained. Several experiential formula for calculating resistance losses of backfilling slurry transportation in pipeline were derived based on fitting analysis and the basic theory of fluid mechanics. The experimental study had widens application areas of round - pipe experiment.%通过环管试验对高浓度全尾砂充填料浆管道输送过程进行模拟,研究了对全尾砂高浓度料浆的输送性能。通过对不同浓度料浆的流动性、泌水性、沉缩性进行研究,界定高浓度料浆的浓度范围,从而确定试验对象。基于环管试验直接测取的阻力损失参数,进行理论分析和数据处理,获得料浆的流变参数,结合拟合分析和流体力学基本理论推导出经验公式,用于阻力损失参数的预测,拓宽了环管试验的应用范围。

  19. Post-Closure Inspection Report for the Tonopah Test Range, Nevada, for Calendar Year 2013

    Energy Technology Data Exchange (ETDEWEB)

    Silvas, A. J.

    2014-03-03

    This report provides the results of the annual post-closure inspections conducted at the closed Corrective Action Units (CAUs) located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2013 and includes inspection and repair activities completed at the following CAUs: • CAU 400: Bomblet Pit and Five Points Landfill (TTR) • CAU 407: Roller Coaster RadSafe Area (TTR) • CAU 424: Area 3 Landfill Complexes (TTR) • CAU 453: Area 9 UXO Landfill (TTR) • CAU 487: Thunderwell Site (TTR) Inspections were conducted according to the post-closure plans in the approved Closure Reports and subsequent correspondence with the Nevada Division of Environmental Protection. The post-closure inspection plans and subsequent correspondence modifying the requirements for each CAU are included in Appendix B. The inspection checklists are included in Appendix C. Field notes are included in Appendix D. Photographs taken during inspections are included in Appendix E. The annual post-closure inspections were conducted on May 14, 2013. Maintenance was performed at CAU 400, CAU 424, and CAU 453. At CAU 400, animal burrows were backfilled. At CAU 424, erosion repairs were completed at Landfill Cell A3-3, subsidence was repaired at Landfill Cell A3-4, and additional lava rock was placed in high-traffic areas to mark the locations of the surface grade monuments at Landfill Cell A3-3 and Landfill Cell A3-8. At CAU 453, two areas of subsidence were repaired and animal burrows were backfilled. Vegetation monitoring was performed at the CAU 400 Five Points Landfill and CAU 407 in June 2013. The vegetation monitoring report is included in Appendix F.

  20. 基于ANSYS和GeoStudio耦合的充填体底板稳定性分级%Stability classification of filling body ’s base plate based on ANSYS and GeoStudio coupling

    Institute of Scientific and Technical Information of China (English)

    林国洪

    2014-01-01

    Cracks of different widths and depths are observed in the cemented backfill roof in Wushan Copper Mine resulted from gravity stress and blasting vibration. The stability of backfill is affected when the cracks reach a point. This paper uses ANSYS software and GeoStudio2007 SIGMA/W module to simulate the stress-strain in the roof fissure filling body. The stability classification of filling body's base plate is studied based on ANSYS and GeoStudio coupling. Corresponding suggestions are put forward according to different stability statuses.%武山铜矿胶结充填体顶板在自重应力、爆破振动等作用下产生的不同宽度和深度的裂隙,当裂隙达到一定规模时将影响充填体的稳定性,文中采用ANSYS软件和GeoStudio2007的SIGMA/W模块来模拟含裂隙充填体顶板的应力应变情况,通过2个数值模拟软件的模拟结果的对比验证,研究含裂隙条件下的充填体稳定性,对充填体顶板在不同深度、宽度裂隙影响下的稳定性进行了分级并针对含裂隙顶板的不同稳定性状态提出了合理的支护建议。

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-15

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

  2. Deformation Monitoring of Motorway Underpasses Using Laser Scanning Data

    Science.gov (United States)

    Puente, I.; González-Jorge, H.; Riveiro, B.; Arias, P.

    2012-07-01

    The motorway Ourense - Celanova will become the next years in one of the main roads of inland Galicia (northwest region of Spain) that will connect quickly with the cities of Northern Portugal. This highway is projected as a public - private partnership between the regional government of Xunta de Galicia and the construction companies Copasa SA and Extraco SA. There are currently under construction the 19 km of this road and presents a number of structures as viaducts, overpasses and underpasses. The viaducts are part of the main road, allowing passage of the vehicles at conventional speed. Overpasses are mainly used in the connection of the highway with secondary roads. Moreover, the underpasses are better suited for the passage of wildlife animals, persons or agricultural machinery. The underpass arch-shape structures used for this project consist of two reinforced concrete voussoirs placed on two small concrete walls. For each set of voussoirs there are three joining points, two between the walls and the voussoirs and one between the both voussoirs at the top of the structure. These underpasses suffer significant mechanical stress during construction, because during the backfilling process asymmetric loads are applied to both sides. Thus, it is very important the monitoring of the structure using geodetic techniques as total stations, levels or laser scanners The underpass selected for this study is located at the kilometric point 4.9 of the highway, with a total length of 50.38 m, maximum span of 13.30 m and rise of 7.23 m. Voussoirs has a thickness of 0.35 m and a length of 2.52 m. The small lateral walls exhibit a height of 2.35 m and thickness of 0.85 m. The underpass presents a slope of approximately 4 % and the maximum height of the backfill over the top of the structure is 3.80 m. The foundation consists of a concrete slab arch-shape (curvature opposite the main arch) with a thickness of 0.7 m. The geodetic technology used for the deformation monitoring

  3. RD and D-Programme 2001. Programme for research, development and demonstration of methods for the management and disposal of nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-09-01

    An overall goal for SKB is to start the initial operation of a deep repository for spent fuel in 2015. This presumes that site investigations have been commenced at the beginning of 2002 and that the different phases have been executed without major changes. The encapsulation plant should be ready to start roughly one year before the deep repository is finished. Spent fuel is the waste that is to be isolated in the deep repository. Various processes will with time alter the conditions in the fuel and in the voids of the canister. Many of these process only occur if the isolation of the canister is breached and water enters the canister. Radiolysis of water is an example of such a process, which can in turn influence the chemical conditions in the canister. Water in the canister can also cause corrosion of the fuel's cladding tubes. If water comes into contact with the fuel it can lead to dissolution of radionuclides. Dissolved radionuclides can diffuse in the water and thereby escape from a damaged canister. Fuel dissolution is a priority area in RDandD Programme 2001. Large resources are being devoted to studies of copper corrosion and stress corrosion cracking in the copper canister. SKB will also investigate the long-term safety of a canister type with a slightly thinner shell but a heavier-duty insert. The buffer of bentonite clay is supposed to protect the canister mechanically against minor rock movements. It is also supposed to retard solute transport. The initial evolution of the buffer is studied in the Aespoe HRL and by means of models. The long-term evolution of the backfill is controlled by largely the same processes as in the buffer. The backfill is more sensitive to saline water than the more compacted buffer. Several processes in the geosphere are important for the safety assessment, such as groundwater flow, earthquakes, microbial processes and matrix diffusion. The models for groundwater flow will be further refined in order to handle the

  4. Sustainable Horizontal Bioventing and Vertical Biosparging Implementation (Invited)

    Science.gov (United States)

    Leu, J.; Lin, J.; Ferris, S.

    2013-12-01

    A former natural gas processing site with total petroleum hydrocarbons (TPH) and benzene, toluene, ethylbenzene, and xylene (BTEX) impacts in both soil and groundwater was partially excavated to remove 2,400 cubic yards of impacted soil. However, due to active natural gas pipelines within the impacted footprint, excavation was discontinued and an area of impacted soil containing maximum concentrations of 5,000 mg/kg gasoline-range organics (GRO), 8,600 mg/kg diesel-range organics (DRO), and 130 mg/kg motor oil-range organics (ORO). Groundwater was impacted with concentrations up to 2,300 μg/L GRO and 4,200 μg/L DRO remained in place. Taking advantage of the open excavation, horizontal-screened piping was placed in the backfill to deliver air for bioventing, which resulted in successful remediation of soil in a physically inaccessible area. The combined use of excavation of the source area, bioventing of surrounding inaccessible soil, and biosparging of the groundwater and smear zone resulted in nearing a no-further-action status at the site. The sustainable bioventing system consisted of one 3-HP blower and eight horizontal air injection wells. Five dual-depth nested vapor monitoring points (VMPs) were installed at 5 feet and 10 feet below ground surface as part of the monitoring system for human health and system performance. The bioventing system operated for one year followed by a three-month rebound test. During the one-year operation, air flow was periodically adjusted to maximize removal of volatile organic compounds (VOCs) from the vent wells with elevated photo-ionization detector readings. After the bioventing successfully remediated the inaccessible impacted soil, the biosparging system incorporated the pre-existing bioventing unit with an upgraded 5-HP blower and three vertical biosparging wells to biodegrade dissolved phase impacts in the groundwater. The subsequent monitoring system includes the VMPs, the air injection wells, and four groundwater

  5. Development of the KBS-3 method. Survey of SKB's research programs and safety assessments, reviews by Government authorities and SKB's international research cooperation; Utvecklingen av KBS-3-metoden. Genomgaang av forskningsprogram, saekerhetsanalyser, myndighetsgranskningar samt SKB:s internationella forskningssamarbete

    Energy Technology Data Exchange (ETDEWEB)

    2010-11-15

    The purpose of this report is to outline the origin and development over the past 30 years (up to 2009) of the KBS-3 method proposed by the Swedish Nuclear Fuel and Waste Management Co (SKB) for final disposal of spent nuclear fuel. The KBS-3 method is based on three protective barriers. The spent nuclear fuel is encapsulated in impermeable copper canisters. The canisters are placed in crystalline basement rock at a depth of 400-700 metres, embedded in bentonite clay. After disposal the tunnels and rock caverns are sealed. The account does not claim to cover all parts of the extensive technical and scientific research and development work conducted by SKB in form of collecting data, refining methods and increasing process understanding. The report forms part of the background material which SKB has gathered as a basis for future applications regarding permits under the Environmental Code and the Nuclear Activities Act to build and operate facilities for encapsulation and final disposal of spent nuclear fuel. A prominent feature of the industrial development work on the final disposal of spent nuclear fuel has been an openness for a constant input of ideas and opinions from society and public bodies (the Government, national authorities, universities and other institutes of higher education, municipalities and various non-governmental organizations). The presentation sheds light on developments in a number of areas that are of central importance for safety in a KBS-3 repository. In SKB's RDandD Programme 2007, these areas go under the headings rock line, buffer line, canister line, backfilling line and closure line. Furthermore, attention has been given to issues related to the possible retrieval of deposited canisters, variants of KBS-3, deposition technology and safety assessment, as well as a number of interdisciplinary issues. The development of methods for the safety assessment has been an important part of the development of the KBS-3 method. The work

  6. Aespoe Hard Rock Laboratory. Annual report 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    instrumented. Characterisation of the rock mass in the area of the Prototype repository in progress. The Backfill and Plug Test includes tests of backfill materials and emplacement methods and a test of a full-scale plug. The backfill and rock will be instrumented with about 230 transducers for measuring the thermo-hydro-mechanical processes. The Retrieval Test is aiming at demonstrating the readiness for recovering of emplaced canisters also after the time when the bentonite has swollen. Planning and preparations for these experiments has continued during 1998. The Long Term Tests of Buffer Material aim to validate models of buffer performance at standard KBS-3 repository conditions, and at quantifying clay buffer alteration processes at adverse conditions. Two test holes were instrumented late 1996 and the temperature was raised to 90 and 130 deg C, respectively. The test parcels have now been retrieved and analysed. All tests and analyses except those concerning microstructure have been completed. No unexpected results have been obtained. Ten organisations from nine countries are currently participating in the Aespoe Hard Rock Laboratory in addition to SKB.

  7. Low pH self compacting concrete for deposition tunnel plugs

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, Carsten; Lagerblad, Bjoern; Wallin, Kjell; Baldy, Franziska (Swedish Cement and Concrete Research Institute, Stockholm (Sweden)); Jonasson, Jan-Erik (Luleaa Univ. of Technology, Luleaa (Sweden))

    2009-04-15

    The temporary plugs in the entrance of the deposition tunnel have three purposes, i.e. to bring about a water pressure in the deposition holes as quickly as possible in order to facilitate the wetting of the buffer, to reduce the groundwater's pressure gradient in the backfill so that piping is prevented, and to keep the backfill in place during the operating phase until the main tunnel has been backfilled. In the repository concept, low-pH-concrete shall be used instead of conventional concrete. A low-pH concrete is a concrete with a leachate pH below 11, which is lower than in normal concrete (pH > 12.5). The low-pH concrete developed is achieved by replacing 40% by weight of the cement with silica fume. According to the current understanding, low-pH concrete should not disturb the function of the bentonite. This is accomplished by avoiding the development of a high-pH leachate by replacing leachable calcium compounds with silica in the low-pH-concrete. There are different demands on the concrete in fresh and hardened state in order to fulfil its purpose. The geometry of the plug requires the fresh concrete to be self-compacting. The method of placement requires that the fresh concrete keeps its self-compacting properties for at least two hours. All components of the mix design must be commercially available and it must be possible to produce the concrete in a normal concrete factory. The concrete shall release low exothermic heat during curing. The volume changes of the young and mature concrete shall be minimised. The properties of the young and mature concrete need to be quantified in order to design and construct the plugs so that they fulfil the intended purpose. Low-pH concrete with self-compacting properties has been developed and is presented in the report. The low-pH SCC (Self-Compacting Concrete) contains ordinary Portland cement, densified silica fume, limestone filler, super plasticizer, high quality natural fine aggregates and average quality

  8. A Preliminary Assessment of a Deep Borehole disposal of Spent Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Younmyoung; Jeon, Jongtae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Deep borehole disposal (DBD) of such radioactive waste as spent nuclear fuels (SFs) and other waste forms has been investigating mainly at Sandia National Labs for the US DOE as an alternative option. DBD can give advantages over less deep geological disposal since the disposal of wastes at a great depth where a low degree of permeability in the potentially steady rock condition will be beneficial for nuclide movement. Groundwater in the deep basement rock can even have salinity and less chance to mix with groundwater above. The DBD concept is quite straightforward and even simple: Waste canisters are simply emplaced in the lower 2 km part of the borehole down to 5 km deep. Through this study, a conceptual DBD is assessed for a similar case as the US DOE's approach, in which 400 SF canisters are to be emplaced at a deep bottom between 3km and 5km depths, upon which an additional 1km-thick compacted bentonite is overbuffered, and the remaining upper part of the borehole is backfilled again with a mixture of crushed rock and bentonite. Then, the total 5km-deep borehole has three zones: a disposal zone at the bottom 2km, a buffer zone at the next 1km, and backfill zone at the rest top 2km, as illustrated conceptually in Fig. 1. To demonstrate the feasibility in view of long-term radiological safety, a rough model for a safety assessment of this conceptual deep borehole repository system, providing detailed models for nuclide transport in and around the geosphere and biosphere under normal nuclide release scenarios that can occur after a closure of the repository, has been developed using GoldSim. A simple preliminary result in terms of the dose exposure rate from a safety assessment of the DBD is also presented and compared to the case of direct disposal of SFs in a KBS-3V vertical type repository, carried out in previous studies. For different types and shapes of repositories at each different depth, direct comparison between a DBD and a KBS-3 type disposal of

  9. Technical Approach for Determining Key Parameters Needed for Modeling the Performance of Cast Stone for the Integrated Disposal Facility Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Yabusaki, Steven B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rockhold, Mark L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Guohui [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-30

    the critical link between the short-term understanding from laboratory and field tests, and the prediction of repository performance over repository time frames and scales. One common recommendation is that experiments be designed to permit the appropriate scaling in the models. There is a large contrast in the physical and chemical properties between the Cast Stone waste package and the IDF backfill and surrounding sediments. Cast Stone exhibits low permeability, high tortuosity, low carbonate, high pH, and low Eh whereas the backfill and native sediments have high permeability, low tortuosity, high carbonate, circumneutral pH, and high Eh. These contrasts have important implications for flow, transport, and reactions across the Cast Stone – backfill interface. Over time with transport across the interface and subsequent reactions, the sharp geochemical contrast will blur and there will be a range of spatially-distributed conditions. In general, COC mobility and transport will be sensitive to these geochemical variations, which also include physical changes in porosity and permeability from mineral reactions. Therefore, PA modeling must address processes, properties, and conditions that alter the physical and chemical controls on COC transport in the cementitious waste forms over time. Section 2 of this document reviews past Hanford PAs and SRS Saltstone PAs, which to date have mostly relied on the lumped parameter COC release conceptual models for TSPA predictions, and provides some details on the chosen values for the lumped parameters. Section 3 provides more details on the hierarchical modeling strategy and processes and mechanisms that control COC release. Section 4 summarizes and lists the key parameters for which numerical values are needed to perform PAs. Section 5 provides brief summaries of the methods used to measure the needed parameters and references to get more details.

  10. Initial state report for the safety assessment SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Pers, Karin (ed.) [Kemakta Konsult AB, Stockholm (Sweden)

    2006-10-15

    A comprehensive description of the initial state of the engineered parts of the repository system is one of the main bases for the safety assessment. There is no obvious definition of the time of the initial state. For the engineered part of their repository system, the time of deposition is a natural starting point and the initial state in SR-Can is, therefore, defined as the state at the time of deposition for the engineered barrier system. The initial state of the engineered parts of the repository system is largely obtained from the design specifications of the repository, including allowed tolerances or allowance for deviations. Also the manufacturing, excavation and control methods have to be described in order to adequately discuss and handle hypothetical initial states outside the allowed limits in the design specifications. It should also be noted that many parts of the repository system are as yet not finally designed, there can be many changes in the future. The design and technical solutions presented here are representative of the current stage of development. The repository system is based on the KBS-3 method, in which copper canisters with a cast iron insert containing spent nuclear fuel are surrounded by bentonite clay and deposited at 400-700 m depth in saturated granitic rock. The facility design comprises rock caverns, tunnels, deposition positions etc. Deposition tunnels are linked by tunnels for transport and communication and shafts for ventilation. One ramp and five shafts connect the surface facility to the underground repository. The ramp is used for heavy and bulky transports and the shafts are for utility systems and for transport of excavated rock, backfill and staff. For the purposes of the safety assessment, the engineered parts of the repository system have been sub-divided into a number of components or sub-systems. These are: The fuel, (also including cavities in the canister since strong interactions between the two occur if the

  11. Prototype repository - Microbes in the retrieved outer section

    Energy Technology Data Exchange (ETDEWEB)

    Arlinger, Johanna; Bengtsson, Andreas; Edlund, Johanna; Eriksson, Lena; Johansson, Jessica; Lydmark, Sara; Rabe, Lisa; Pedersen, Karsten [Microbial Analytics Sweden, Moelnlycke (Sweden)

    2013-10-15

    The Prototype repository is an international project to build and study a full-scale model of the planned Swedish final repository for spent nuclear fuel. The Prototype consists of two sections with four and two full-scale copper canisters, respectively. In 2011, the outer section with two canisters (nos. 5 and 6) was excavated. Groundwater surrounding the Prototype has been demonstrated to include microorganisms such as iron-reducing bacteria (IRB) and sulphate-reducing bacteria (SRB) with the ability to affect the repository through reduction of structural Fe(III) in the buffer or by the production of sulphide, respectively. During excavation, samples were taken for microbiological and molecular biological analysis from backfill, buffer, and canister surfaces and analysed with an emphasis on microbial presence and number. The underground environment is anaerobic, but the construction of a repository will raise the oxygen levels. Oxygen is not favourable for the longevity of the copper canister, but oxygen levels will decrease over time, partly due to microbial activity that consumes oxygen. Therefore, evaluating the presence and numbers of the heterotrophic aerobic bacteria that consume oxygen as well as monitoring the oxygen levels are important. The oxygen content of the bentonite itself is also a primary concern, and a method for measuring how the oxygen diffuses through the clay has long been needed. In the work reported here, we performed two pilot studies to address this need. One of these studies tested a method for differentiating between oxygen saturation in aerobic versus anaerobic bentonite; this method has potential for further development. The tunnel above the Prototype canisters was backfilled with a mixture of bentonite and crushed rock. Sixty-three randomly chosen samples from a cross-section through the backfill were analysed for culturable heterotrophic aerobic bacteria. All but one exhibited growth, with four samples exhibiting numbers over 106

  12. The Basement Roof Subsidence Pre Closed the Construction Technology of Post-cast Strip%地下室顶板沉降后浇带预封闭施工技术

    Institute of Scientific and Technical Information of China (English)

    蒋虎山

    2014-01-01

    目前,高层建筑周边均设置了沉降后浇带,以满足高层建筑在主体施工期间的沉降需要。其中,顶板后浇带的存在给地下室顶板整体防水施工、土方回填和场地的布置利用带来了一定的影响。鉴于此,传统的做法为对后浇带钢筋防锈处理后进行临时苫盖,车库顶板防水施工至后浇带两侧预留接槎,同时在两侧砌筑挡土墙,以满足回填等后续施工。部分案例还采用了预封闭盖板、从下部进行压力灌注混凝土的方式。天保B01项目部在对既有的施工方式进行了相应改进和完善后,成功实现了沉降后浇带的预封闭,并取得了较好的效果。%At present, high-rise buildings are set around the settlement after pouring belt, in order to meet the high-rise building subsidence needs during the subject construction. Among them, the roof after the existence of the pouring belt to the basement roof waterproof construction, earthwork backfilling and of the whole site layout using a certain impact. In view of this, the traditional approach to the reinforcement of post-cast strip rust proofing after they are temporary, garage roof waterproof construction on both sides of post-cast strip to reserve if, in the masonry retaining wall on both sides at the same time, in order to meet the backfill and other follow-up construction. Part of the case also adopted closed cover plate, from the lower pressure grouting concrete way. Tianbao B01 projects department in the existing way of construction for the corresponding improvement and perfect, closed in advance of settlement of post-cast strip is implemented, and achieved good results.

  13. Application of geogrid in sheet pile wharfs%土工格栅在板桩码头工程中的应用

    Institute of Scientific and Technical Information of China (English)

    张福贵; 朱庆华

    2009-01-01

    Based on geotechnicai principles, a method for determining the strength indices of compound soils with geogrid is put forward. A sheet pile wharf filled with compound soils, with the geogrid acting as reinforcement material behind the sheet pile wall, was analyzed. The proposed method was employed to determine the strength indices of the compound soils, and the stresses acting on the sheet pile wharf structure were analyzed. The results show that the strength of the compound soils behind the sheet pile wall can be improved by adding geogrid, which can also reduce the active soil pressure of the backfill soils on the sheet pile wall so as to optimize the sheet pile wharf structure and to reduce the construction cost. Engineering cases indicate the efficacy of reducing the soil pressure behind the sheet pile wall by using of the geogrid to reinforce the backfill soils.%基于土工原理,提出了一种计算土工格栅复合土体强度指标的分析方法.针对板桩码头工程,在板桩墙后采用以土工格栅为筋材的复合土体进行回填,按照该计算方法确定复合土体的强度,并据此对板桩码头结构进行受力分析.结果表明:在板桩墙后的回填土体中加入土工格栅可以提高复合土体的强度,减小回填土体对板桩墙的主动土压力作用,从而优化板桩码头结构,降低工程造价.实际工程应用表明,在板桩码头板桩墙后采用土工格栅加筋回填土,对减少墙后土压力具有良好的效果.

  14. Long-term effects of synthetic fibers on concrete pipes

    Science.gov (United States)

    Farrokhi Gozarchi, Sasan

    The studies undertaken by this research were to evaluate the long-term performance and durability of synthetic fiber-reinforced concrete pipes. The target long-term performance is for 9000 hours. Two sets of pipes 8 ft. (2400 mm) long with inside diameters of 24 in. (600 mm) and 36 in. (1200 mm) were manufactured, with a wall thickness of 3 and 4 in., respectively. The pipes were produced based on ASTM C76, for a Class III type with a Wall B. The two set of pipes included RCP's (as control) and SYN-FRCP's. The SYN-FRCP's had several fiber dosages ranging from 6 lb/yd3 (3.5 kg/m 3) to 12 lb/yd3 (7.0 kg/m3) in order to evaluate the long-term performance of synthetic fiber-reinforced concrete pipes. The pipes were pre-cracked until the first visible crack was observed in the three-edge bearing test. As a result, the sustained load simulated, was calculated from the Peak D-load observed; and also the appropriate fiber dosages required for the 24. in (600 mm) and 36 in. (900 mm) pipes were obtained. Three of the 24 in. and three of the 36 in. pipes were installed in 7 ft. (2100 mm) and 8 ft. (2400 mm) wide trenches with 16 ft. (4800 mm) and 18 ft. (5500 mm) of cover respectively. The pipe was initially backfilled with native soil up to 2 ft. (600 mm) and 4 ft. (1200 mm) over the top of the pipe then backfilled again with pea-gravel weighing 100 lb/ft3, to a height of 14ft. to simulate the sustained loading. A type two installation was used during the development of the test setup. Once the long-term test set up was complete, the data was immediately recorded, and vertical deflections were observed from the time-dependent behavior of the pipes. It was observed from results obtained from the three-edge bearing test, that synthetic fibers improve the mechanical properties of concrete pipes, in dry-cast manufacturing. Also, it was observed from the time-dependent deformation, that there was no significant deformation of SYN-FRCP, while the shear capacity was enhanced. Based

  15. Design of Wet Coal Separation System in Underground Mine%煤矿井下湿法分选系统设计

    Institute of Scientific and Technical Information of China (English)

    马占国; 孙凯; 赵国贞; 潘银光; 范金泉

    2011-01-01

    随着煤矿薄煤层开采过程中矸石量的不断增多,很大程度上降低了矿井的实际产能.若把选煤厂转移到煤矿井下,实现井下煤炭的分选,将会取得较大的社会效益和经济效益.因此根据我国高含矸率煤炭的分选提出了煤炭井下分选构思:①改变原煤提升至地面排矸、地面分选的传统工艺,实现井下分选和矸石充填一体化,解决矸石污染和采空区地表沉陷问题;②通过井下分选系统,实现精煤上井、矸石充填、井下水循环的高效绿色开采模式;③对设备提出防爆隔爆、防尘、防静电等技术要求,以达到分选设备在井下工作的要求.%With the coal rejects quantity continuously increased in the mine thin seam mining, the mine actual production capacity would be highly decreased.ff the coal preparation plant move and set up in the underground mine to prepare the coal in the underground mine,high social and economic benefits would be obtained.Thus based on the coal preparation of the high coal reject content coal in China, the paper provided the conception of the coal separation in underground mine.① To change the traditional technique of the raw coal lifting to the surface for the coal rejects and coal separation and to have a coal preparation and coal rejects backfilling integration in underground mine could solve the coal rejects pollution and goaf surface subsidence problems.②The application of the coal preparation system in underground mine would have a high efficient green mining mode with cleaned coal lifted to surface, coal rejects backfilling in the underground mine and mine water recycled in the underground mine.③The technical requirements of the flame proof, explosion proof, dust control, electrostatic prevention and others were provided for the equipment in order to let the coal preparation equipment meet the underground operation requirements.

  16. Early Stage Hydration Process of Cementitious Material Prepared with Red Mud, Slag, Gypsum and Small Smounts of Cement Clinker%赤泥-矿渣-石膏-少熟料胶凝材料的初期水化过程

    Institute of Scientific and Technical Information of China (English)

    祝丽萍; 倪文; 高术杰; 王中杰; 张玉燕

    2012-01-01

    赤泥-矿渣-石膏-少熟料胶凝材料在胶结充填过程中表现出良好的保水性及早强、高强等性能,可以作为充填专用胶结剂.本文综合净浆试块的凝结时间、强度发展以及扫面电镜下的微观结构,分析了材料的初期水化过程,并采用XPS研究了不同元素之间旧组合分解和新组合的形成.结果表明水化3h时体系生成Ca(OH)2和凝胶类物质,这些水化产物使得浆体凝结硬化.4h后矿渣中的部分硅氧四面体参与反应,缩聚成了聚合度较高的硅酸盐矿物,净浆试块产生强度.水化6h后,S2 p3/2的结合能大幅增长,体系生成了较多的硫酸盐矿物,它们对强度的发展起到了较大作用.%The cementitious material prepared with red mud, ground granulated blast furnace slag ( GGBS) , flue gas desulfurization gypsum ( FGDG) and a small amount of cement clinker obtained good performances in water-retention, early strength and high strength when it used for cemented backfilling. This material can be used as special cement for backfilling. The early stage hydration of the material was analyzed through the setting time, strength development and microstructure. The decomposition of old system and the formation of the new mineral were also studied by X-ray photoelectron spectroscopy (XPS). Results show that Ca(0H)2 and gels formed at 3 h after hydration, resulting in the setting and hardening for the cement paste. The samples obtained strength at 4 h, which is attributed to the formation of silicates with higher polymerization degree, which condensed from oxygen-silicon tetrahedron. At 6 h, the binding energy of S2 p3/2 increased suddenly, and some sulfate minerals formed, which made a great contribution to the rise of strength.

  17. 考虑土拱效应的刚性挡墙主动土压力分析%Analysis of active earth pressure on rigid retaining walls considering soil arching

    Institute of Scientific and Technical Information of China (English)

    王杰; 夏唐代; 贺鹏飞; 黄博

    2014-01-01

    以墙后填土为无黏性土的刚性挡土墙为研究对象,考虑墙后土体的土拱效应,修改了 Shubhra Geol 抛物线形土拱表达式,推导了对应不同内摩擦角和墙-土摩擦角的挡土墙平动模式下的主动土压力系数。基于水平微分单元法,得到考虑土拱效应的主动土压力分布、合力大小和合力作用点高度的理论表达式,并与现有经典理论解及前人理论研究成果和模型试验数据进行对比分析,结果表明,主动土压力与墙-土接触面摩擦角、土体内摩擦角、土体重度和挡墙高度相关,土压力分布为非线性,与其他结果比较吻合,从而验证了该研究成果的正确性。%Taking a rigid retaining wall with cohesionless backfill for example, considering the soil arching, the active earth pressure factor is derived for retaining wall under translation mode with different internal friction angles and wall-soil friction angles. The Shubhra Geol parabolic soil arching expression is modified. Based on horizontal differential element method, new formulations are proposed for calculating the active earth pressure, the resultant earth pressure and its action point. In order to check the accuracy of the proposed formulation, the predictions from the equation are compared with the results of full-scale test and existing classical theory. The results show that the active earth pressure is related to wall-soil friction angle, the internal friction angle, the unit weight of backfill and the height of retaining wall. It is shown that the earth pressure is nonlinear and the previous research results show great agreement with each other;and the correctness of the results is verified.

  18. 考虑单元划分方式的平动挡墙主动土压力分析%Analysis of active earth pressure of considering translational unit modes for retaining wall

    Institute of Scientific and Technical Information of China (English)

    王梅; 侯新平; 李琦

    2015-01-01

    考虑平移模式下刚性挡土墙墙后填土中的土拱效应,分析沿圆弧形拱的切线和割线方向划分微分单元对主动土压力分布的影响。在此基础上,采用二分法求解最优划分方式,得到了作用在挡土墙上的主动土压力公式。与沿切线和割线方法及试验监测结果的对比分析表明:本文方法得到的平移模式下刚性挡墙墙后主动土压力强度小于沿切线划分单元的计算结果,略大于沿割线划分单元的计算值。本文方法得到的刚性挡墙墙后主动土压力分布与模型试验结果吻合最好。%Considering the soil-arching effect of retaining wall backfill of rigid translational mode , the pa-per analyzed the influence of division differential unit on along the arc arch tangent and secant .On above basis,it obtained the formula for the active earth pressure against a rigid retaining wall by means of di -chotomy to the optimum dipartition mode .Through comparing the formula with the theoretical solutions of tangent direction , secant direction and the results of measured test ,the result can be goten that the active earth pressure proposed is smaller than those of tangent direction and larger than those of secant direc -tion.The active earth pressure distribution of rigid wall backfill gotten by the method match best with the physical model test .

  19. Geochemical modelling of bentonite porewater in high-level waste repositories

    Science.gov (United States)

    Wersin, Paul

    2003-03-01

    The description of the geochemical properties of the bentonite backfill that serves as engineered barrier for nuclear repositories is a central issue for perfomance assessment since these play a large role in determining the fate of contaminants released from the waste. In this study the porewater chemistry of bentonite was assessed with a thermodynamic modelling approach that includes ion exchange, surface complexation and mineral equilibrium reactions. The focus was to identify the geochemical reactions controlling the major ion chemistry and acid-base properties and to explore parameter uncertainties specifically at high compaction degrees. First, the adequacy of the approach was tested with two distinct surface complexation models by describing recent experimental data performed at highly varying solid/liquid ratios and ionic strengths. The results indicate adequate prediction of the entire experimental data set. Second, the modelling was extended to repository conditions, taking as an example the current Swiss concept for high-level waste where the compacted bentonite backfill is surrounded by argillaceous rock. The main reactions controlling major ion chemistry were found to be calcite equilibrium and concurrent Na-Ca exchange reactions and de-protonation of functional surface groups. Third, a sensitivity analysis of the main model parameters was performed. The results thereof indicate a remarkable robustness of the model with regard to parameter uncertainties. The bentonite system is characterised by a large acid-base buffering capacity which leads to stable pH-conditions. The uncertainty in pH was found to be mainly induced by the pCO 2 of the surrounding host rock. The results of a simple diffusion-reaction model indicate only minor changes of porewater composition with time, which is primarily due to the geochemical similarities of the bentonite and the argillaceous host rock. Overall, the results show the usefulness of simple thermodynamic models to

  20. Long Term Corrosion/Degradation Test Six Year Results

    Energy Technology Data Exchange (ETDEWEB)

    M. K. Adler Flitton; C. W. Bishop; M. E. Delwiche; T. S. Yoder

    2004-09-01

    The Subsurface Disposal Area (SDA) of the Radioactive Waste Management Complex (RWMC) located at the Idaho National Engineering and Environmental Laboratory (INEEL) contains neutron-activated metals from non-fuel, nuclear reactor core components. The Long-Term Corrosion/Degradation (LTCD) Test is designed to obtain site-specific corrosion rates to support efforts to more accurately estimate the transfer of activated elements to the environment. The test is using two proven, industry-standard methods—direct corrosion testing using metal coupons, and monitored corrosion testing using electrical/resistance probes—to determine corrosion rates for various metal alloys generally representing the metals of interest buried at the SDA, including Type 304L stainless steel, Type 316L stainless steel, Inconel 718, Beryllium S200F, Aluminum 6061, Zircaloy-4, low-carbon steel, and Ferralium 255. In the direct testing, metal coupons are retrieved for corrosion evaluation after having been buried in SDA backfill soil and exposed to natural SDA environmental conditions for times ranging from one year to as many as 32 years, depending on research needs and funding availability. In the monitored testing, electrical/resistance probes buried in SDA backfill soil will provide corrosion data for the duration of the test or until the probes fail. This report provides an update describing the current status of the test and documents results to date. Data from the one-year and three-year results are also included, for comparison and evaluation of trends. In the six-year results, most metals being tested showed extremely low measurable rates of general corrosion. For Type 304L stainless steel, Type 316L stainless steel, Inconel 718, and Ferralium 255, corrosion rates fell in the range of “no reportable” to 0.0002 mils per year (MPY). Corrosion rates for Zircaloy-4 ranged from no measurable corrosion to 0.0001 MPY. These rates are two orders of magnitude lower than those specified in