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Induced anisotropy in a sand
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standard methods; two evaluation techniques were used to determine the failure meehenisms for each test mode and each rock type. Primary sad secondary failure mechanisms were determined for selected rocks in each of the three failure ~Dde s o 77~027 HIGH LOAD TUNNEL JACKING TEST Hudson, J A; McCaul, C; Priest, S D Ground Engng, V10, N4, ~ 1977, P22-26 Reports Jacking tests carried out using the gripper pads of a tunnelling machine in chalk at Chinnor, sad comparison of the ground modulus with that obtained from the site investigation cores and the values back.calculated from long term settlement due to excavation of the tunnel. The measured values were found to be similar, with modulus reduction factors in the range 5-10 per cent. 774028 SOME OBSERVATIONS ON LIQUID LIMIT vALUES WITH REFERENCE TO PENETRATION AND CASAGRANDE TESTS Littleton, I; Farmilo, M Ground E ~ n g , VlO, N4, bay 1977, F39-40 Briefly reviews the literature of liquid limit tests and reports an investigation comparing the Casagrande sad cone penetration tests, using cones according to various American, British, Indian and Russian specifications. It was found that the cone %0 BS1377(1975) gave the best correlation with the Caaagrande cup over the range examined, and that there was a considerable variation between the cones. 774029 RESPRESENTATIVENF2~ OF PHYSICAL AND MECHANICAL CHARACTERISTICS OF ROCKS SURROUNDING COAL SEAF~, AND METHODS oF ESTIMATING THeM Smirnov, B V; Brulko, Y P; Dymna, A I Sov Min Sci, VI2, N3, May-June 1976, P235-237 Reports tests of the variability of a lithologically homogeneous stratum of siltstones at the Obukhovskaya Zapsdnaya pit in the Donbass. A random variation was found in the compressive breaking strength of the rock. 774030 STRENGTHS OF SOLIDS UNDER UNIAXIAL COMPRESSION Beisetaev, R B; Nikiforovskil, V S Soy Min Sci, V12, N3, bay.June 1976, P244248 Analyses the stress distribution in uniaxial compression test specimens sad the factors influencing the strength, and concludes that the unlaxial com~resslve strength is a convenient technical strength characteristic of the specimen rather than a charsnteristic of the material. 774031 DYNAMIC TENSILE STRENGTH IN BLASTING OF PRESTRESSED ROCK Khanukaev: A N; Belyatakli, V P; Ionln, A A Soy Min Sci, V12, N2, March-Aprll 1976, P167-170 Reports an experimental investigation of d ~ a m l c tensile stresses for various prestressing loads in diabase, marble and oil shale. 774032 SIMPLIFIED METHOD OF DET~IRMINING THE LONG TERM STRENGTHS OF ROCKS Afsaasev, B F; Pushkarev, V I SoY Min Sci, V12, N2, March-April 1976, P219-221 Reports a simplified version of the previously
published strength relaxation method of the authors, which can be used to determine the long term strengths of rocks under compression~ shear, rupture, flexure and torsion. 774033 FORECASTING THE STRENGTH OF FISSURED ROCKS OF DZF~ZKAZGAN Martynov, Y I Soy Min Scl, VI2, N2, March-April 1976, P22h-226 774034 TENSILE STRENGTH OF ROCKS SUBJECTED TO EXPLOSIVE LOADING Ehanukaev, A N; Belyatskii, V P; Ionin, A A Soy Min Sci, VI2, N3, May.June 1976, P283285 Rods of rectangular cross-section were fractured in tension by the reflection of a compression pulse, created by explosive loading of one end of the rod, from the other end as a tension pulse. The parameters of the pulse sad the dimensions of the detached fragments were determined for diabase, granite, limestone, marble, conbustible shale sad coal. 774035 SOIL DEFORMATION RESULTING FROM SOME LABORATORY FREEZE-THAW EXPERIMENTS Washburn, A I; Burrous, C; Rein, R Washington Univ Report, 1977, C82P
Deformation characteristics 774036 INDUCED ANISOTRoFY IN A SAND Arthur, J R F; Chua, K S; Dunstan, T Geotechnique, V27, NI, 1977, P13-20 Controlled changes of principal stress direction were applied to dense sand samples undergoing plane strain. The results indicate that induced anisotropy can have a large effect on magnitudes of strain increments sad cause a sr~l~ end quickly reducing ~evlatlon of the principal axes of stress and strain increment. There is a strong indication that for plastic strain re-extension directions define axes of induced ~isotr opy. 774037 ANISOTROPY IN oVERCONSOLIDATED CLAYS Calrncross, A M; James, R G Geotechnique, V27, NI, 1977, P31-36 The question of whether a single set of incremental elastic constants is applicable to a clay in a given condition is examined. It is suggested that anlsotropy observed in overconsolidated clays arises from a variation in stiffness moduli with the direction of incremental shear - experiments show that data obtained in laboratory tests in only one mode of shear (active or passive) may be quite inapplicable to a field situation involvlm~ shear in another direction, 774038 D~DRMATION CHARACTERISTICS OF WEATHERED BANGKOK CLAY IN TRIAXIAL EXTENSION Balasubrammalam, A S; Waheed.U~aln Geotechnique, V27, N1, 1977, P75-92 Two series of strain controlled undrained triaxial extension tests were carried out on isotropically consolidated samples of weathered Bangkok clay. Stress-strain sad strength data are presented for tests in which (a) the axial stress was reduced with the lateral stress held constant, s.nd(b) the axial stress was held constant while the lateral stress was increased.
standard methods; two evaluation techniques were used to determine the failure meehenisms for each test mode and each rock type. Primary sad secondary failure mechanisms were determined for selected rocks in each of the three failure ~Dde s o 77~027 HIGH LOAD TUNNEL JACKING TEST Hudson, J A; McCaul, C; Priest, S D Ground Engng, V10, N4, ~ 1977, P22-26 Reports Jacking tests carried out using the gripper pads of a tunnelling machine in chalk at Chinnor, sad comparison of the ground modulus with that obtained from the site investigation cores and the values back.calculated from long term settlement due to excavation of the tunnel. The measured values were found to be similar, with modulus reduction factors in the range 5-10 per cent. 774028 SOME OBSERVATIONS ON LIQUID LIMIT vALUES WITH REFERENCE TO PENETRATION AND CASAGRANDE TESTS Littleton, I; Farmilo, M Ground E ~ n g , VlO, N4, bay 1977, F39-40 Briefly reviews the literature of liquid limit tests and reports an investigation comparing the Casagrande sad cone penetration tests, using cones according to various American, British, Indian and Russian specifications. It was found that the cone %0 BS1377(1975) gave the best correlation with the Caaagrande cup over the range examined, and that there was a considerable variation between the cones. 774029 RESPRESENTATIVENF2~ OF PHYSICAL AND MECHANICAL CHARACTERISTICS OF ROCKS SURROUNDING COAL SEAF~, AND METHODS oF ESTIMATING THeM Smirnov, B V; Brulko, Y P; Dymna, A I Sov Min Sci, VI2, N3, May-June 1976, P235-237 Reports tests of the variability of a lithologically homogeneous stratum of siltstones at the Obukhovskaya Zapsdnaya pit in the Donbass. A random variation was found in the compressive breaking strength of the rock. 774030 STRENGTHS OF SOLIDS UNDER UNIAXIAL COMPRESSION Beisetaev, R B; Nikiforovskil, V S Soy Min Sci, V12, N3, bay.June 1976, P244248 Analyses the stress distribution in uniaxial compression test specimens sad the factors influencing the strength, and concludes that the unlaxial com~resslve strength is a convenient technical strength characteristic of the specimen rather than a charsnteristic of the material. 774031 DYNAMIC TENSILE STRENGTH IN BLASTING OF PRESTRESSED ROCK Khanukaev: A N; Belyatakli, V P; Ionln, A A Soy Min Sci, V12, N2, March-Aprll 1976, P167-170 Reports an experimental investigation of d ~ a m l c tensile stresses for various prestressing loads in diabase, marble and oil shale. 774032 SIMPLIFIED METHOD OF DET~IRMINING THE LONG TERM STRENGTHS OF ROCKS Afsaasev, B F; Pushkarev, V I SoY Min Sci, V12, N2, March-April 1976, P219-221 Reports a simplified version of the previously
published strength relaxation method of the authors, which can be used to determine the long term strengths of rocks under compression~ shear, rupture, flexure and torsion. 774033 FORECASTING THE STRENGTH OF FISSURED ROCKS OF DZF~ZKAZGAN Martynov, Y I Soy Min Scl, VI2, N2, March-April 1976, P22h-226 774034 TENSILE STRENGTH OF ROCKS SUBJECTED TO EXPLOSIVE LOADING Ehanukaev, A N; Belyatskii, V P; Ionin, A A Soy Min Sci, VI2, N3, May.June 1976, P283285 Rods of rectangular cross-section were fractured in tension by the reflection of a compression pulse, created by explosive loading of one end of the rod, from the other end as a tension pulse. The parameters of the pulse sad the dimensions of the detached fragments were determined for diabase, granite, limestone, marble, conbustible shale sad coal. 774035 SOIL DEFORMATION RESULTING FROM SOME LABORATORY FREEZE-THAW EXPERIMENTS Washburn, A I; Burrous, C; Rein, R Washington Univ Report, 1977, C82P
Deformation characteristics 774036 INDUCED ANISOTRoFY IN A SAND Arthur, J R F; Chua, K S; Dunstan, T Geotechnique, V27, NI, 1977, P13-20 Controlled changes of principal stress direction were applied to dense sand samples undergoing plane strain. The results indicate that induced anisotropy can have a large effect on magnitudes of strain increments sad cause a sr~l~ end quickly reducing ~evlatlon of the principal axes of stress and strain increment. There is a strong indication that for plastic strain re-extension directions define axes of induced ~isotr opy. 774037 ANISOTROPY IN oVERCONSOLIDATED CLAYS Calrncross, A M; James, R G Geotechnique, V27, NI, 1977, P31-36 The question of whether a single set of incremental elastic constants is applicable to a clay in a given condition is examined. It is suggested that anlsotropy observed in overconsolidated clays arises from a variation in stiffness moduli with the direction of incremental shear - experiments show that data obtained in laboratory tests in only one mode of shear (active or passive) may be quite inapplicable to a field situation involvlm~ shear in another direction, 774038 D~DRMATION CHARACTERISTICS OF WEATHERED BANGKOK CLAY IN TRIAXIAL EXTENSION Balasubrammalam, A S; Waheed.U~aln Geotechnique, V27, N1, 1977, P75-92 Two series of strain controlled undrained triaxial extension tests were carried out on isotropically consolidated samples of weathered Bangkok clay. Stress-strain sad strength data are presented for tests in which (a) the axial stress was reduced with the lateral stress held constant, s.nd(b) the axial stress was held constant while the lateral stress was increased.