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Undrained compression behaviour of sand
172A in the shear strength characteristics of the soil was attributed to the inconsistent cementation of the soil particles by the geothite. 865022 Limits of the Jaumann stress rate Molenkamp, F
lnt J Num Anal Aleth Geomech VIO, N2, March-April 1986, P151-176 The Jaumann stress rate is shown to be inaccurate for moderate deformations with deviatoric strains of more than 10%; in such cases the objective stress is better calculated using the material rotation rate as calculated by polar decomposition. For very large deformations of granular materials this approach becomes invalid too, because then the fabric tends to rotate together with principal stresses. For the numerical calculation of the material rotation for moderate deformations, a numerical subroutine, based on polar decomposition, was developed. 865O23 Further development of a plasticity approach to yield in porous rock. Technical note Elliott, G M; Brown, E T
int J Rock Mech g i n Sci V23. N2, April 1986, PI51-156 The plasticity approach of Gerogiannopoulos and Brown has been redeveloped using information obtained from a detailed experimental study of the behaviour of Bath Stone, a highly porous, soft, uniform, homogeneous, isotropic rock that exhibits linear elastic behaviour up to yield, and elasto-plastic behaviour thereafter. A theoretical relation between the stresses at yield was developed from a plastic work balance equation using the concepts of incremental plasticity. A summary of the experimental studies is included. 865024 Determination of shear failure envelope in rock masses Ucar, R
J Geotech Engng Div A S C E VII2. N3, March 1986, P303315 An analytic expression has been derived which enables the shear strength to be determined using the Hoek-Brown failure criterion, elasticity theory and the basic mathematical concepts for obtaining the failure envelopc of a family of failure circles. Shear strength is evaluated as a function of normal stress at failure, uni,'txial compressive strength of intact rock, and constants dependent on the properties of the rock. This expression will be of great help in developing new methods of analysis in rock engineering. 865025 Undrained compression behaviour of sand Fragaszy. R J; Voss. M E J Geotech Engng Div ASCE V112, N3, March 1986, P334347 A series of high pressure undrained isotropic compression tests was performed on Monterey no 0 and Eniwetok (coral) sands, to verify a proposed theory concerning blast-induced liquefaction. Tests show that liquefaction (zero effective stress) can occur on application of a single cycle of isotropic compressive stress under quasistatic conditions. The behaviour of these sands can be reasonably approximated using data from drained compression tests at the same range of effective stress. The generation of residual excess pore pressure under these conditions is minimally related to initial dry density. The plastic volume changes leading to this excess pressure appear to
arise from particle crushing. Although results support the proposed theory, it remains to determine the relative contributions of compression, shear and surface waves to the phenomenon of blast induced liquefaction. 865026 Field correlation of cone and standard penetration tests. Technical note Kasim, A G; Chu, M Y; Jensen, C N
J Geotech Engng Div A S C E VII2. N3. March 1986. P368372 Robertson and Campanella (1984) have proposed a correlation relating cone tip resistance (qc) to the SPT blow count (N). This correlation was examined on a site overlain by a large hydraulically placed sand fill and underlain by natural sand. Results indicate that the ratio qc/N is significantly less for sands with high fines content than for clean sands,primarily due to the effect of fines fraction on permeability and, hence, pore pressure distribution and the modification of the compressibility and ductility. The significance of these findings when conducting correlation based analyses is discussed. 865027 Overburden correction factors for SPT in sand. Technical note Liao, S S C; Whitman, R V
J Geotech Engng Div A S C E VII2, N3, March 1986, P373377 Several formulae and charts have been published for overburden correction factors for SPTs in sand. Different interpretations of results will be obtained depending on which correlation factor is chosen. The various inconsistent and consistent correction factors are reviewed, and an attempt is made to clarify and resolve some of the differences and develop a standardised correction factor. The need to expand this work to cover a much wider range of soil types is pointed out. 865028 Drop-cone penetration in situ and on minimally disturbed cores Campbell, D J; Hunter, R
J Soil Sci V37. NI, March 1986, P153-163 Drop cone penetration was measured in situ and on minimally disturbed cores for four soils at various water contents. The penetration/water content relation was linear in situ and for the cores, if data at very low water contents is excluded. The slope of the line was, however, much greater for the field data, casting doubt about the applicability of laboratory results to predict field behaviour. Vane shear strength is negatively correlated with in situ drop-cone penetration. The drop-cone test is useful for testing small volumes of soils, but care must be taken in selecting the mass of the cone, which affects the volume of soil which will influence the test results. 865029 Relationships between organic matter and some geotechnical properties of a marine sediment Booth, J S; DaM, A G Marine Geotech V6, N3, 1986, P281-297 By progressive treatment with hydrogen peroxide, a series of marine sediments with different organic contents, but otherwise constant texture and composition, was prepared. The chosen sediment was a clayey silt from the Santa Barbara Basin, off southern California. Laboratory testing showed linear relationships between the quantity of organic carbon present and liquid limit, plastic limit, plasticity and grain specific gravity. It is postulated that the spatial changes in geotechnical properties of some sediments may be independent of
(' 1986 Pergamon Journals Ltd. Reproduction not permitted
lnt J Num Anal Aleth Geomech VIO, N2, March-April 1986, P151-176 The Jaumann stress rate is shown to be inaccurate for moderate deformations with deviatoric strains of more than 10%; in such cases the objective stress is better calculated using the material rotation rate as calculated by polar decomposition. For very large deformations of granular materials this approach becomes invalid too, because then the fabric tends to rotate together with principal stresses. For the numerical calculation of the material rotation for moderate deformations, a numerical subroutine, based on polar decomposition, was developed. 865O23 Further development of a plasticity approach to yield in porous rock. Technical note Elliott, G M; Brown, E T
int J Rock Mech g i n Sci V23. N2, April 1986, PI51-156 The plasticity approach of Gerogiannopoulos and Brown has been redeveloped using information obtained from a detailed experimental study of the behaviour of Bath Stone, a highly porous, soft, uniform, homogeneous, isotropic rock that exhibits linear elastic behaviour up to yield, and elasto-plastic behaviour thereafter. A theoretical relation between the stresses at yield was developed from a plastic work balance equation using the concepts of incremental plasticity. A summary of the experimental studies is included. 865024 Determination of shear failure envelope in rock masses Ucar, R
J Geotech Engng Div A S C E VII2. N3, March 1986, P303315 An analytic expression has been derived which enables the shear strength to be determined using the Hoek-Brown failure criterion, elasticity theory and the basic mathematical concepts for obtaining the failure envelopc of a family of failure circles. Shear strength is evaluated as a function of normal stress at failure, uni,'txial compressive strength of intact rock, and constants dependent on the properties of the rock. This expression will be of great help in developing new methods of analysis in rock engineering. 865025 Undrained compression behaviour of sand Fragaszy. R J; Voss. M E J Geotech Engng Div ASCE V112, N3, March 1986, P334347 A series of high pressure undrained isotropic compression tests was performed on Monterey no 0 and Eniwetok (coral) sands, to verify a proposed theory concerning blast-induced liquefaction. Tests show that liquefaction (zero effective stress) can occur on application of a single cycle of isotropic compressive stress under quasistatic conditions. The behaviour of these sands can be reasonably approximated using data from drained compression tests at the same range of effective stress. The generation of residual excess pore pressure under these conditions is minimally related to initial dry density. The plastic volume changes leading to this excess pressure appear to
arise from particle crushing. Although results support the proposed theory, it remains to determine the relative contributions of compression, shear and surface waves to the phenomenon of blast induced liquefaction. 865026 Field correlation of cone and standard penetration tests. Technical note Kasim, A G; Chu, M Y; Jensen, C N
J Geotech Engng Div A S C E VII2. N3. March 1986. P368372 Robertson and Campanella (1984) have proposed a correlation relating cone tip resistance (qc) to the SPT blow count (N). This correlation was examined on a site overlain by a large hydraulically placed sand fill and underlain by natural sand. Results indicate that the ratio qc/N is significantly less for sands with high fines content than for clean sands,primarily due to the effect of fines fraction on permeability and, hence, pore pressure distribution and the modification of the compressibility and ductility. The significance of these findings when conducting correlation based analyses is discussed. 865027 Overburden correction factors for SPT in sand. Technical note Liao, S S C; Whitman, R V
J Geotech Engng Div A S C E VII2, N3, March 1986, P373377 Several formulae and charts have been published for overburden correction factors for SPTs in sand. Different interpretations of results will be obtained depending on which correlation factor is chosen. The various inconsistent and consistent correction factors are reviewed, and an attempt is made to clarify and resolve some of the differences and develop a standardised correction factor. The need to expand this work to cover a much wider range of soil types is pointed out. 865028 Drop-cone penetration in situ and on minimally disturbed cores Campbell, D J; Hunter, R
J Soil Sci V37. NI, March 1986, P153-163 Drop cone penetration was measured in situ and on minimally disturbed cores for four soils at various water contents. The penetration/water content relation was linear in situ and for the cores, if data at very low water contents is excluded. The slope of the line was, however, much greater for the field data, casting doubt about the applicability of laboratory results to predict field behaviour. Vane shear strength is negatively correlated with in situ drop-cone penetration. The drop-cone test is useful for testing small volumes of soils, but care must be taken in selecting the mass of the cone, which affects the volume of soil which will influence the test results. 865029 Relationships between organic matter and some geotechnical properties of a marine sediment Booth, J S; DaM, A G Marine Geotech V6, N3, 1986, P281-297 By progressive treatment with hydrogen peroxide, a series of marine sediments with different organic contents, but otherwise constant texture and composition, was prepared. The chosen sediment was a clayey silt from the Santa Barbara Basin, off southern California. Laboratory testing showed linear relationships between the quantity of organic carbon present and liquid limit, plastic limit, plasticity and grain specific gravity. It is postulated that the spatial changes in geotechnical properties of some sediments may be independent of
(' 1986 Pergamon Journals Ltd. Reproduction not permitted