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Compliance effects on pore pressure distribution
162A 884057 Instrumentation for torsional shear/resonant column measurements under anisotropic stresses lsenhower, W M; Stokoe, K H; Allen. J C Geotech Test J VIO, N4. Dec 1987. P183-191
884061 Density variations in specimens subjected to cyclic and monotonic loads Gilbert, P A; Marcuson. W F J Geotech Engng Div ASCE VIM. NI. Jan 1988. PI-20
Instrumentation and calibration procedures for a torsion shear/resonant column device capable of applying anisotropic states of confinement with Ko values less than or equal to 1 are presented. The device can perform both torsional shear and resonant column tests on the same hollow or solid sample. Changes in shear modulus and hysteretic damping can be measured in torsional shear mode. In resonant column mode. shear wave velocity and viscous damping behaviour may be measured.
Internal void changes during cyclic and monotonic undrained tnaxial loading have been investigated. Specimens of Banding sand were prepared by wet pluviation. After testing, the specimens were frozen under backpressure and dissected into 96 segments for density variation measurements. Relative density dispersion increased with increasing strain at densities 40, 60, and 70*/0 relative density. Density redistribution increased with pore pressure response. Implications of the results for the use of triaxial testing to evaluate seismically induced liquefaction are discussed.
884058 Triaxial testing of brittle sandstone using a multiple failure state method Cain, P; Yuen, C M K; Le Bel. G R; Crawford, A M; Lau, D H C Geotech Test ,I VIO. N4, Dec 1987. P213-217
884062 Compliance effects on pore pressure distribution Chappell, B A Min Sci Techaol V6. N2. Jan 1988. P191-204
Laboratory tests on a sandstone were undertaken to investigate sandstone/methane outbursts in coal bearing rocks. Since specimens of outburst rocks are limited, a triaxial testing method to determine properties using the minimum number of specimens was necessary. ISRM multiple failure state method was unsuccessful due to the brittle nature of the material, so volumetric strain was used as an alternative imminent failure criterion. This modified procedure gave an accurate determination of the peak strength envelope from a single specimen.
The effect of relative volume and compliances on induced pore pressures, and the effect of porosity on rock mass anisotropy are investigated using deformation and equilibrium models. These indicate that for undrained conditions and low porosities (less than 2%) compliance of the rock material controls the mass compliance, whereas for higher porosities (greater than 10%) the structural frame is the controlling factor. A precise definition of compliance is necessary in rocks with low porosity and where Terzaghi's law of pore pressure is invalid.
884O59 I-D strain in normally consolidated cohesionless soils Hardin, B O J Geoteeh Engng Div ASCE VII3. N12. Dec 1987. PI4491467 A stress-strain model for I-dimensional strain in normally consolidated cohesionless soils, able to accurately represent stress-strain relations over a large stress range, is presented. The effects of initial void ratio and relative density, particle shape, particle size distribution and particle material on the ID strain behaviour are examined, and equations to approximate the effects of these variables are presented. Test results over the stress range 0-1,300 atmospheres are compared with the model. Algorithms for estimation of settlement are presented.
884060 Compression and extension of Ko normally consolidated kaolin clay Atkinson, J H; Richardson, D; Robinson, P J J Geotech Engng Div ASCE VII3. NI2, Dec 1987. PI4681482 Triaxial tests to investigate the strength and state boundary surface for one dimensionally, normally consolidated kaolin clay are presented. The tests comprise various stress and strain controlled loading paths including drained, constant mean effective stress, and undrained tests in compression and extension. Results indicate that strength and stress strain behaviour were significantly affected by one dimensional consolidation stress history. Cam clay models are modified to develop the asymmetric boundary surface for one dimensional consolidation.
884063 Interpretation of the cam-clay model as a simplified doubleyield-surface model. Technical note Hirayama, H Soils Found V27. N3. Sept 1987, PI05-111 Double-yield-surface models are useful in modelling soil behaviour, but finite element analysis is complex. It is proposed that the cam-clay model is re-interpreted as a simplified form of the double-yield-surface model. It is efficient in simulating the behaviour of soils where plastic strain arises due to hydraulic as well as shear stresses.
884064 Contribution of microstructure to repeated loading effect on compacted ullophsncous volcanic ash soil Kitazono, Y; Suzuki, A; Kajiwara, M; Aramaki, S Soils Found 1/27, N4, Dee 1987. P23-33 The hardening effect of repeated loading on saturated volcanic ash soils was investigated. The samples were impact compacted or remoulded, and saturation, sieve analysis, electron microscopy, undrained triaxial and undrained repeated loading tests undertaken. Results show that: (1) soil microstructure influences the behaviour of the soil during triaxial and repeated loading tests; (2) undrained repeated loading tests cause hardening and softening; (3) hardening is caused by an increase in density and anisotropy due to gradual deformation and fracturing of the soil during repeated loading; and (4) the strain ratio method is most appropriate to obtain the yielding repeated load ratio.
C 1988 Pergamon Press plc. Reproduction not permitted
884061 Density variations in specimens subjected to cyclic and monotonic loads Gilbert, P A; Marcuson. W F J Geotech Engng Div ASCE VIM. NI. Jan 1988. PI-20
Instrumentation and calibration procedures for a torsion shear/resonant column device capable of applying anisotropic states of confinement with Ko values less than or equal to 1 are presented. The device can perform both torsional shear and resonant column tests on the same hollow or solid sample. Changes in shear modulus and hysteretic damping can be measured in torsional shear mode. In resonant column mode. shear wave velocity and viscous damping behaviour may be measured.
Internal void changes during cyclic and monotonic undrained tnaxial loading have been investigated. Specimens of Banding sand were prepared by wet pluviation. After testing, the specimens were frozen under backpressure and dissected into 96 segments for density variation measurements. Relative density dispersion increased with increasing strain at densities 40, 60, and 70*/0 relative density. Density redistribution increased with pore pressure response. Implications of the results for the use of triaxial testing to evaluate seismically induced liquefaction are discussed.
884058 Triaxial testing of brittle sandstone using a multiple failure state method Cain, P; Yuen, C M K; Le Bel. G R; Crawford, A M; Lau, D H C Geotech Test ,I VIO. N4, Dec 1987. P213-217
884062 Compliance effects on pore pressure distribution Chappell, B A Min Sci Techaol V6. N2. Jan 1988. P191-204
Laboratory tests on a sandstone were undertaken to investigate sandstone/methane outbursts in coal bearing rocks. Since specimens of outburst rocks are limited, a triaxial testing method to determine properties using the minimum number of specimens was necessary. ISRM multiple failure state method was unsuccessful due to the brittle nature of the material, so volumetric strain was used as an alternative imminent failure criterion. This modified procedure gave an accurate determination of the peak strength envelope from a single specimen.
The effect of relative volume and compliances on induced pore pressures, and the effect of porosity on rock mass anisotropy are investigated using deformation and equilibrium models. These indicate that for undrained conditions and low porosities (less than 2%) compliance of the rock material controls the mass compliance, whereas for higher porosities (greater than 10%) the structural frame is the controlling factor. A precise definition of compliance is necessary in rocks with low porosity and where Terzaghi's law of pore pressure is invalid.
884O59 I-D strain in normally consolidated cohesionless soils Hardin, B O J Geoteeh Engng Div ASCE VII3. N12. Dec 1987. PI4491467 A stress-strain model for I-dimensional strain in normally consolidated cohesionless soils, able to accurately represent stress-strain relations over a large stress range, is presented. The effects of initial void ratio and relative density, particle shape, particle size distribution and particle material on the ID strain behaviour are examined, and equations to approximate the effects of these variables are presented. Test results over the stress range 0-1,300 atmospheres are compared with the model. Algorithms for estimation of settlement are presented.
884060 Compression and extension of Ko normally consolidated kaolin clay Atkinson, J H; Richardson, D; Robinson, P J J Geotech Engng Div ASCE VII3. NI2, Dec 1987. PI4681482 Triaxial tests to investigate the strength and state boundary surface for one dimensionally, normally consolidated kaolin clay are presented. The tests comprise various stress and strain controlled loading paths including drained, constant mean effective stress, and undrained tests in compression and extension. Results indicate that strength and stress strain behaviour were significantly affected by one dimensional consolidation stress history. Cam clay models are modified to develop the asymmetric boundary surface for one dimensional consolidation.
884063 Interpretation of the cam-clay model as a simplified doubleyield-surface model. Technical note Hirayama, H Soils Found V27. N3. Sept 1987, PI05-111 Double-yield-surface models are useful in modelling soil behaviour, but finite element analysis is complex. It is proposed that the cam-clay model is re-interpreted as a simplified form of the double-yield-surface model. It is efficient in simulating the behaviour of soils where plastic strain arises due to hydraulic as well as shear stresses.
884064 Contribution of microstructure to repeated loading effect on compacted ullophsncous volcanic ash soil Kitazono, Y; Suzuki, A; Kajiwara, M; Aramaki, S Soils Found 1/27, N4, Dee 1987. P23-33 The hardening effect of repeated loading on saturated volcanic ash soils was investigated. The samples were impact compacted or remoulded, and saturation, sieve analysis, electron microscopy, undrained triaxial and undrained repeated loading tests undertaken. Results show that: (1) soil microstructure influences the behaviour of the soil during triaxial and repeated loading tests; (2) undrained repeated loading tests cause hardening and softening; (3) hardening is caused by an increase in density and anisotropy due to gradual deformation and fracturing of the soil during repeated loading; and (4) the strain ratio method is most appropriate to obtain the yielding repeated load ratio.
C 1988 Pergamon Press plc. Reproduction not permitted