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Mobilization of soil-geofabric interface friction
77A design of tilting table suggest basic friction angle should be measured using naturally surfaced sliders placed on plates wet lapped with no 80 grit. Results are similar to those from direct shear tests, but obtained more rapidly and easily. 9O2097 Mobilization of soil-geofabric interface friction Makiuchi, K; Miyamori, T Proc International Geoteclmical Symposium on Theory and Practice of Earth Reinforcement, Fukuoka Kyusha, 5-7 October 1988 P129-134. Publ Rotterdam: A A Balkema, 1988 Soii-geotextile friction was investigated using a large direct shear apparatus for several types of textile in contact with cohesionless and cohesive soils. The displacement induced mobilization of frictional resistance between fabric and soil has been evaluated. Mobilized friction parameters of the textile are generally lower than those of the soil itself, and are affected by thickness and texture of the geotextile and type, density and moisture content of the soil.
Physico-chemical properties See also: 902021, 902325 902098 Mineralogy, porosity and fluid control on thermal conductivity of sedimentary rocks Brigaud, F; Vasseur, G Geophys J V98, N3, Sept 1989, P525-542 Data were collected from 82 non-clay and 28 clay rock samples from cores and cuttings, outcrops or laboratory reconstitution. First order control of mineralogy, porosity, and fluid content on bulk conductivity was verified. It was then demonstrated that such influences can be predicted accurately using a geometric mean model. The data are then analysed using an inverse method to evaluate individual mineral conductivity components. Bulk conductivities of moist/water saturated and air saturated rocks can be predicted with accuracy of + / - 10% and +/-20% respectively. 902099 Heating unsaturated medium sand Ewen, J; Thomas, H R Geotechnique V39, N3, Sept 1989, P455-470 Mass and heat flow in unsaturated sand has been studied using theoretical,experimental and numerical approaches. Simultaneous liquid, heat, and vapour transfer was analysed using a modification of the Philip and de Vries approach. Material parameters were measured in the laboratory. Laboratory experiments monitored steady temperatures achieved in sand in which a rod was buried and heated. Numerical analysis used a finite difference algorithm. Good agreement between simulated and measured temperatures was seen, suggesting the formulations developed are suitable for application to practical problems. 902100 Thermal permeability enhancement of blocky rocks: onedimensional flows Elseworth, D lnt J Rock Mech Min Sci V26, N3/4, July 1989, P329-339 A simplified treatment of a HDR reservoir modelled as a two phase continuum of solid rock blocks separated by fluid filled discontinuities is presented. Ubiquitous, orthagonal jointing is assumed. Transient development of rock joint deformation resulting from changes in fluid pressure and thermal straining
within an initially stressed formation are described. Rock mass displacements and stresses are not explicitly accommodated. Macroscopic volume remains constant, all volume changes being restricted to within the solid phase. An analytical transfer function is used to gauge the unsteady behaviour and magnitude of permeability enhancement for heat production from the blocks and volumetric deformation of the mass. 902101 Modelling behaviour in artificially stimulated rock masses matching field pressure records Hopkirk, R J; Rybach, L Int J Rock Mech Min Sci V26, N3/4, July 1989, P341-349 A computer code has been developed to model the coupled thermal, hydraulic and mechanical processes in a potential hot dry rock reservoir. It has been tested using field data from injection tests in granite at depths 2150 and 2600m at Rosemanowes Quarry, Cornwall. The practical approach taken, which allows simple models of the site to be constructed initially, when few data are available, is demonstrated. Some parameter sensitivity studies are presented and discussed. 902102 Thermoelastic theory of fluid-filled porous materials Kurashige, M Int J Solids Struct V25, Ng, 1989, P1039-1052 Cleary theory is extended to develop a quasi-linear, quasistatic thermoelastic theory for a fluid saturated porous material subjected to both mechanical and thermal disturbances. The displacement field is completely coupled with pore pressure and temperature fields in the general case, although for irrotational displacement, the first field becomes decoupled from the last two. The theory is applied to the injection of hot or cold water from a spherical cavity into an infinite body at uniform temperature. Effect of heat transport by fluid flow on temperature distribution and thermal stress depends on type of rock, being negligible for a granite, significant for a sandstone. 902103 Sensitive strata in Bootlegger Cove Formation Olsen, H W J Geotech Engng Div ASCE VI15, Ng, Sept 1989, P12391251 Recent laboratory, subsurface geological, geotechnical and geochemical data from the Bootlegger Cove Formation, Alaska, are appraised. Strata of highly sensitive clays are found in the middle and lower zones of the formation, with low to medium sensitivity soils in between. Pore fluid chemistry of the most sensitive layers differs from that of remaining layers. Of known causes of high and very high sensitivity, only presence of organic and/or anionic dispersants is consistent with the vertical variation of sensitivity. Sources of these remain to be discovered. 902104 Relationships between the unsaturated electric and saturated hydraulic properties of soils Kelly, W E; Gorman, T; Curtis, B J Hydrol V109, NI/2, July 1989, P115-123 A relation is developed between electrical resistivity of soils in the unsaturated state at natural water contents and the saturated hydraulic conductivity of the same soils, using existing theory and data from the literature. The relation forms the basis for using surface electrical resistivity methods to compare and evaluate alternative sites for artificial recharge of groundwater.
© 1990 Pergamon Press plc. Reproduction not permitted
Physico-chemical properties See also: 902021, 902325 902098 Mineralogy, porosity and fluid control on thermal conductivity of sedimentary rocks Brigaud, F; Vasseur, G Geophys J V98, N3, Sept 1989, P525-542 Data were collected from 82 non-clay and 28 clay rock samples from cores and cuttings, outcrops or laboratory reconstitution. First order control of mineralogy, porosity, and fluid content on bulk conductivity was verified. It was then demonstrated that such influences can be predicted accurately using a geometric mean model. The data are then analysed using an inverse method to evaluate individual mineral conductivity components. Bulk conductivities of moist/water saturated and air saturated rocks can be predicted with accuracy of + / - 10% and +/-20% respectively. 902099 Heating unsaturated medium sand Ewen, J; Thomas, H R Geotechnique V39, N3, Sept 1989, P455-470 Mass and heat flow in unsaturated sand has been studied using theoretical,experimental and numerical approaches. Simultaneous liquid, heat, and vapour transfer was analysed using a modification of the Philip and de Vries approach. Material parameters were measured in the laboratory. Laboratory experiments monitored steady temperatures achieved in sand in which a rod was buried and heated. Numerical analysis used a finite difference algorithm. Good agreement between simulated and measured temperatures was seen, suggesting the formulations developed are suitable for application to practical problems. 902100 Thermal permeability enhancement of blocky rocks: onedimensional flows Elseworth, D lnt J Rock Mech Min Sci V26, N3/4, July 1989, P329-339 A simplified treatment of a HDR reservoir modelled as a two phase continuum of solid rock blocks separated by fluid filled discontinuities is presented. Ubiquitous, orthagonal jointing is assumed. Transient development of rock joint deformation resulting from changes in fluid pressure and thermal straining
within an initially stressed formation are described. Rock mass displacements and stresses are not explicitly accommodated. Macroscopic volume remains constant, all volume changes being restricted to within the solid phase. An analytical transfer function is used to gauge the unsteady behaviour and magnitude of permeability enhancement for heat production from the blocks and volumetric deformation of the mass. 902101 Modelling behaviour in artificially stimulated rock masses matching field pressure records Hopkirk, R J; Rybach, L Int J Rock Mech Min Sci V26, N3/4, July 1989, P341-349 A computer code has been developed to model the coupled thermal, hydraulic and mechanical processes in a potential hot dry rock reservoir. It has been tested using field data from injection tests in granite at depths 2150 and 2600m at Rosemanowes Quarry, Cornwall. The practical approach taken, which allows simple models of the site to be constructed initially, when few data are available, is demonstrated. Some parameter sensitivity studies are presented and discussed. 902102 Thermoelastic theory of fluid-filled porous materials Kurashige, M Int J Solids Struct V25, Ng, 1989, P1039-1052 Cleary theory is extended to develop a quasi-linear, quasistatic thermoelastic theory for a fluid saturated porous material subjected to both mechanical and thermal disturbances. The displacement field is completely coupled with pore pressure and temperature fields in the general case, although for irrotational displacement, the first field becomes decoupled from the last two. The theory is applied to the injection of hot or cold water from a spherical cavity into an infinite body at uniform temperature. Effect of heat transport by fluid flow on temperature distribution and thermal stress depends on type of rock, being negligible for a granite, significant for a sandstone. 902103 Sensitive strata in Bootlegger Cove Formation Olsen, H W J Geotech Engng Div ASCE VI15, Ng, Sept 1989, P12391251 Recent laboratory, subsurface geological, geotechnical and geochemical data from the Bootlegger Cove Formation, Alaska, are appraised. Strata of highly sensitive clays are found in the middle and lower zones of the formation, with low to medium sensitivity soils in between. Pore fluid chemistry of the most sensitive layers differs from that of remaining layers. Of known causes of high and very high sensitivity, only presence of organic and/or anionic dispersants is consistent with the vertical variation of sensitivity. Sources of these remain to be discovered. 902104 Relationships between the unsaturated electric and saturated hydraulic properties of soils Kelly, W E; Gorman, T; Curtis, B J Hydrol V109, NI/2, July 1989, P115-123 A relation is developed between electrical resistivity of soils in the unsaturated state at natural water contents and the saturated hydraulic conductivity of the same soils, using existing theory and data from the literature. The relation forms the basis for using surface electrical resistivity methods to compare and evaluate alternative sites for artificial recharge of groundwater.
© 1990 Pergamon Press plc. Reproduction not permitted