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Failure and deformation of sand in torsional shear
132A 874023 Evaluation of structural properties of coal seams Szwilski. A B Min Engng V39. N2. Feb 1987. Pl15-123 Mineability and coal processing costs are influenced largely by the structural and physical properties of the coal seam. The mining process involves coal cutting, pillar support, crushing, and floating. A correlation between the rank, ash content, and coal strength/stiffness is discussed. The coefficients of variability of rebound tests on the face of various coal seams are compared with those of laboratory compressive strength tests by other investigators. Auth. 874024 Risk of slip along discontinuities in a heterogeneous medium Chowdhury, R N Min Sci Technol V4, N3, March 1987, P241-255
The methodology for the calculation of risk or probability of slip along planar discontinuities within a rock mass is examined. A risk model is presented in which both geometrical and shear strength parameters may be regarded as random variables. Attention is focused on the randomness of shear strength parameters. Relevant equations and calculation procedures are outlined and typical results presented. 874025 Application of a new numerical model of joint behaviour to rock mechanics problems Bandis, S C; Barton, N R; Christianson, M Norw Geotech lnst Publ N164, 1986, l l P
A model has been developed which allows simulation of effective normal stress and scale dependent coupling of shear stress, shear displacement, dilation and closure, and changes in fluid permeability. Three key input parameters are used, joint roughness coefficient, joint wall compressive strength and initial conducting aperture. The modelling principles are briefly reviewed, then the application of the model to such problems as rock bolt design, grout take estimates, stress path errors, petroleum reservoir settlement and site characterisation for nuclear waste disposal is presented. 874026 Acoustic monitoring of in situ static deformation modulus at a dam site By, T L Norw Geotech Inst Publ N164, 1986, 5P
The Alta hydroelectric power scheme, Norway, includes a large concrete dam in a narrow gorge. Acoustic measurements performed in a cross section of the foundation rock led to realistic values of in situ static deformability. The in situ static Young's modulus was determined for different areas of the rock mass using the Petite Sismique technique (Schneider, 1967), traditional elastic theory and cross tunnel measurements, allowing a large volume of rock to be investigated at reasonable cost. 874027 Probabifistic computer modeling of a rockfill dam - a case of Khao Laem Dam, Thailand Bergado, D T; Ju, Y C " Soils Found V26, N4, Dec 1986, P47-66
Adequate, realistically scaled test facilities for rock fill are not readily available. An attempt is made to model the shear strength (friction angle) of rock fill material by stochastic generation of permeability and porosity values with a Monte
Carlo simulation, using actual parameters from the construction of the Khao Laem dam. Results were used to model the probability of failure and factor of safety of the dam structure.
874028 True tests on normally consolidated c l a y and analysis of the observed shear behaviour using elastoplastic constitutive models Nakai, T; Matsuoka, H; Okuno, N; Tsuzuki, K Soils Found V26, N4, Dec 1986, P67-78 A true triaxial test has been developed and drained triaxial shear tests carried out on a normally consolidated clay. The abilities of the Cam clay model (1963) and a new model (Nakai and Matsuoka, 1986) to describe the observed deformation and strength characteristics of the clay are compared. The new model is seen to account better for the influence of intermediate principal stress on the soil behaviour.
874029 Failure and deformation of sand in torsional shear Tatsuoka, F; Sonoda, S; Hara, K; Fukushima, S; Pradham, T B S Soils Found V26, N4, Dec 1986, P79-97 Deformation and strength behaviour of sand under torsional shear in a hollow cylinder apparatus was: studied, Very precise measurements of axial loads, torque, and confining pressure are described, and measured stress values were corrected for membrane forces. Results are presented and compared to those from plane strain compression tests. The usefulness of the torsional test is discussed.
874030 Accuracy of automated volume change m e u ~ e m e n t by means of a differential pressure t r a ~ e r ~ Technical note Pradham, T BS; Tatsuoka, F; Molenkamp, F Soils Found V26, N4, Dec 1986, P150-158
A simple method of measurement of s ~ i m e n volume change during drained shear tests, using a low capacity differential pressure transducer (LC-DPT), is described, The apparatus was calibrated against a method using a Very sensitive electronic balance. Errors are identified, bUt they may be kept very small with suitable care and modification of the equipment.
874031 Stress distribution within an artificially loaded, jointed ~ k Brown, S M; Leijon, B A; Hustrulid~ W A Proc International Symposimn on Rock Stress and Rock Stress Measurement, Stockholm, 1-3 Sept 1986 P429-439. Publ Lutea: Centek, 1986
The in situ response of an 8 cubic metre block of jointedbiotitic gneiss to uniaxial and biaxial boundary l o ~ n g was monitored using two types of b0rehole gaU~Si the USBM Borehole Deformation Gauge and the L ~ Triaxial Strain Ceil. From the displacements and strains recorded by the gauges as loads were applied, point~se stresses were caleu, lated assuming both isotropic and anisotropic rock behaviour. Independent of instrument type, the results obtaified are char' acterized by large variations between the stress magnitudes measured in different parts of the block. The measured stress directions are however in close agreement with the directions of the applied boundary loads. Auth.
© 1987 Pergamon Journals Ltd. Reproduction not permitted
The methodology for the calculation of risk or probability of slip along planar discontinuities within a rock mass is examined. A risk model is presented in which both geometrical and shear strength parameters may be regarded as random variables. Attention is focused on the randomness of shear strength parameters. Relevant equations and calculation procedures are outlined and typical results presented. 874025 Application of a new numerical model of joint behaviour to rock mechanics problems Bandis, S C; Barton, N R; Christianson, M Norw Geotech lnst Publ N164, 1986, l l P
A model has been developed which allows simulation of effective normal stress and scale dependent coupling of shear stress, shear displacement, dilation and closure, and changes in fluid permeability. Three key input parameters are used, joint roughness coefficient, joint wall compressive strength and initial conducting aperture. The modelling principles are briefly reviewed, then the application of the model to such problems as rock bolt design, grout take estimates, stress path errors, petroleum reservoir settlement and site characterisation for nuclear waste disposal is presented. 874026 Acoustic monitoring of in situ static deformation modulus at a dam site By, T L Norw Geotech Inst Publ N164, 1986, 5P
The Alta hydroelectric power scheme, Norway, includes a large concrete dam in a narrow gorge. Acoustic measurements performed in a cross section of the foundation rock led to realistic values of in situ static deformability. The in situ static Young's modulus was determined for different areas of the rock mass using the Petite Sismique technique (Schneider, 1967), traditional elastic theory and cross tunnel measurements, allowing a large volume of rock to be investigated at reasonable cost. 874027 Probabifistic computer modeling of a rockfill dam - a case of Khao Laem Dam, Thailand Bergado, D T; Ju, Y C " Soils Found V26, N4, Dec 1986, P47-66
Adequate, realistically scaled test facilities for rock fill are not readily available. An attempt is made to model the shear strength (friction angle) of rock fill material by stochastic generation of permeability and porosity values with a Monte
Carlo simulation, using actual parameters from the construction of the Khao Laem dam. Results were used to model the probability of failure and factor of safety of the dam structure.
874028 True tests on normally consolidated c l a y and analysis of the observed shear behaviour using elastoplastic constitutive models Nakai, T; Matsuoka, H; Okuno, N; Tsuzuki, K Soils Found V26, N4, Dec 1986, P67-78 A true triaxial test has been developed and drained triaxial shear tests carried out on a normally consolidated clay. The abilities of the Cam clay model (1963) and a new model (Nakai and Matsuoka, 1986) to describe the observed deformation and strength characteristics of the clay are compared. The new model is seen to account better for the influence of intermediate principal stress on the soil behaviour.
874029 Failure and deformation of sand in torsional shear Tatsuoka, F; Sonoda, S; Hara, K; Fukushima, S; Pradham, T B S Soils Found V26, N4, Dec 1986, P79-97 Deformation and strength behaviour of sand under torsional shear in a hollow cylinder apparatus was: studied, Very precise measurements of axial loads, torque, and confining pressure are described, and measured stress values were corrected for membrane forces. Results are presented and compared to those from plane strain compression tests. The usefulness of the torsional test is discussed.
874030 Accuracy of automated volume change m e u ~ e m e n t by means of a differential pressure t r a ~ e r ~ Technical note Pradham, T BS; Tatsuoka, F; Molenkamp, F Soils Found V26, N4, Dec 1986, P150-158
A simple method of measurement of s ~ i m e n volume change during drained shear tests, using a low capacity differential pressure transducer (LC-DPT), is described, The apparatus was calibrated against a method using a Very sensitive electronic balance. Errors are identified, bUt they may be kept very small with suitable care and modification of the equipment.
874031 Stress distribution within an artificially loaded, jointed ~ k Brown, S M; Leijon, B A; Hustrulid~ W A Proc International Symposimn on Rock Stress and Rock Stress Measurement, Stockholm, 1-3 Sept 1986 P429-439. Publ Lutea: Centek, 1986
The in situ response of an 8 cubic metre block of jointedbiotitic gneiss to uniaxial and biaxial boundary l o ~ n g was monitored using two types of b0rehole gaU~Si the USBM Borehole Deformation Gauge and the L ~ Triaxial Strain Ceil. From the displacements and strains recorded by the gauges as loads were applied, point~se stresses were caleu, lated assuming both isotropic and anisotropic rock behaviour. Independent of instrument type, the results obtaified are char' acterized by large variations between the stress magnitudes measured in different parts of the block. The measured stress directions are however in close agreement with the directions of the applied boundary loads. Auth.
© 1987 Pergamon Journals Ltd. Reproduction not permitted