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Elevation of direct simple shear tests on clay
131A suggest that the texture coefficient is a quantitative measure of the resistance of the microstructure of the rock to crack propagation.
874018 Elevation of direct simple shear tests on cla~ Airey, D W: Wood. D M Geotechnique ~37. N1, Mareh 1987, P25-35
874014 New apparatus for investigating the stress-strain characteristics of sand Alarcon, A: Chameau, J L: Leonards, G A Geotech Test J I'9. N4. Dec 1986, P204-212
Two direct simple shear apparatuses used to zest normally consolidated samples of kaolin are described. In all tests the samples fail by developing approximately horizontal ruptures. Results are compared with results from two similar tests in a standard Geonor direct simple shear device.
A hybrid resonant column torsional shear apparatus has been developed, which allows the determination of soil response to monotonic and cyclic loading, including liquefaction potential, over the complete range of shear strain amplitudes of engineering interest. The apparatus is described in detail and representative test results presented to demonstrate its capability. 874015 Cyclic simple shear testing of granular materials Shaw, P; Brown, S F Geotech Test J V9, N4, Dec 1986, P213-220 A modification has been made to the simple shear apparatus for dr~ granular materials to allow application of cyclic shear and normal stresses. Boundary transducers were of limited success for stress measurement, because of local dilation, and a predictive method was adopted for complete description of stress state. Tests on uniform crushed limestone showed that increased volume strains were developed under normal stress and bidirectional shearing. Shear strains were little influenced by cyclic application of normal stress. 874016 Comparison of truly undrained and constant volume direct simple shear tests Dyvik, R: Berre, T: Lacasse, S; Raadim, B Geotechnique V37, N], March 1987, P3-10 A chamber for the Norwegian Geotechnical Institute's direct simple shear device is described, which enables undrained tests to be run with pore pressure measurements. Results of undrained tests on normally consolidated Drammen clay are compared with the results of conventional constant volume direct simple shear tests. The comparison shows that the stress-strain and effective stress plots obtained by the two methods are identical for all purposes. It is shown that the changes in vertical stress required to keep constant volume throughout a direct simple shear test are equal to the measured pore pressures in an undrained direct simple shear test for normally consolidated clay. 874017 Finite element analysis of the direct shear box test Ports, D M; Dounias, G T; Vaughan, P R Geotechnique V37, NI, March 1987, PI1-23
874019 Behaviour of normally consolidated clay as obsersed in undrained direct shear tests Wroth, C P Geoteehnique V37, NI, March 1987, P37-43 The anisotropic behaviour of soil specimens as related to the determination of shear strength of normally consolidated clay in the direct shear test is discussed. The basic conditions of the test are examined.
874020 Influence of fissures in a stiff clay subjected to direct shear Vallejo, L E Geoteehnique V37, N1, March 1987, P69-82 The purpose of the present investigation was to study the effect that fissures have on the failure process of stiff fissured clay when subjected to direct shear. The new ~ersion of the direct shear apparatus developed consists of an open shear box, which facilitates the recording of the failure zone as well as the effects of fissures on this surface. Prismatic samples of brittle kaolinite clay with pre-existing cracks were tested using the new equipment. Cracks were found to ha~e a marked influence on the development of the failure surface, which was irregular and formed by the linking of the pre-existing and secondary cracks. With the use of linear elastic fracture mechanics theory, it was determined that the secondary cracks developed in regions of tensile stresses induced in the clay samples by the shearing loads.
874021 Constant normal stiffness direct shear testing for socketed pile design in weak rock Johnston, I W; Lain, T S; Williams, A F Geotechnique V37, NI, March 1987, P83-89 It is demonstrated that the development of side shear resistance of piles socketed in weak rock can be controlled by conditions of constant stiffness. To model this behaviour and to provide data for the development of more rational and economic methods of design, constant normal stiffness direct shear test equipment has been manufactured. The principles and details of this testing technique are presented along with a brief discussion of applications.
The stress state in an ideal shear box in which strains are uniform is that of simple shear, and is considered to provide a reference state with which the analyses of the direct shear box can be compared. The effects of the non-uniformities of stress introduced by the rigid ends of a direct shear box, 60mm long by 20mm deep, are then examined, using the finite element method. The soil is modelled using an elasto-plastic constit~urive law, and the influences of volume change, initial stress, and strain softening are examined. In each case comparison is 874022 made with the same material loaded in simple shear. The stress -Shear strength of prestressed cohesive soils. Technical note strain behaviour is found to be dependent on the volume Lutenegger, A J change, as well as on the shear stress-strain properties of the J Geotech Engng Div A S C E Vl13, N2. Feb 198-. P163-168 soil. The analyses showed that the non-uniformities within the The purpose of the study was to determine what effect direct shear box sample have little effect, and little error arises prestressing had on the drained Mohr-Coulomb envelope of if it is interpreted as if it were a simple shear test. some natural cohesive soils as obtained from in situ tests. .~': 1987 Pergamon Journals Ltd. Reproduction not permitted
874018 Elevation of direct simple shear tests on cla~ Airey, D W: Wood. D M Geotechnique ~37. N1, Mareh 1987, P25-35
874014 New apparatus for investigating the stress-strain characteristics of sand Alarcon, A: Chameau, J L: Leonards, G A Geotech Test J I'9. N4. Dec 1986, P204-212
Two direct simple shear apparatuses used to zest normally consolidated samples of kaolin are described. In all tests the samples fail by developing approximately horizontal ruptures. Results are compared with results from two similar tests in a standard Geonor direct simple shear device.
A hybrid resonant column torsional shear apparatus has been developed, which allows the determination of soil response to monotonic and cyclic loading, including liquefaction potential, over the complete range of shear strain amplitudes of engineering interest. The apparatus is described in detail and representative test results presented to demonstrate its capability. 874015 Cyclic simple shear testing of granular materials Shaw, P; Brown, S F Geotech Test J V9, N4, Dec 1986, P213-220 A modification has been made to the simple shear apparatus for dr~ granular materials to allow application of cyclic shear and normal stresses. Boundary transducers were of limited success for stress measurement, because of local dilation, and a predictive method was adopted for complete description of stress state. Tests on uniform crushed limestone showed that increased volume strains were developed under normal stress and bidirectional shearing. Shear strains were little influenced by cyclic application of normal stress. 874016 Comparison of truly undrained and constant volume direct simple shear tests Dyvik, R: Berre, T: Lacasse, S; Raadim, B Geotechnique V37, N], March 1987, P3-10 A chamber for the Norwegian Geotechnical Institute's direct simple shear device is described, which enables undrained tests to be run with pore pressure measurements. Results of undrained tests on normally consolidated Drammen clay are compared with the results of conventional constant volume direct simple shear tests. The comparison shows that the stress-strain and effective stress plots obtained by the two methods are identical for all purposes. It is shown that the changes in vertical stress required to keep constant volume throughout a direct simple shear test are equal to the measured pore pressures in an undrained direct simple shear test for normally consolidated clay. 874017 Finite element analysis of the direct shear box test Ports, D M; Dounias, G T; Vaughan, P R Geotechnique V37, NI, March 1987, PI1-23
874019 Behaviour of normally consolidated clay as obsersed in undrained direct shear tests Wroth, C P Geoteehnique V37, NI, March 1987, P37-43 The anisotropic behaviour of soil specimens as related to the determination of shear strength of normally consolidated clay in the direct shear test is discussed. The basic conditions of the test are examined.
874020 Influence of fissures in a stiff clay subjected to direct shear Vallejo, L E Geoteehnique V37, N1, March 1987, P69-82 The purpose of the present investigation was to study the effect that fissures have on the failure process of stiff fissured clay when subjected to direct shear. The new ~ersion of the direct shear apparatus developed consists of an open shear box, which facilitates the recording of the failure zone as well as the effects of fissures on this surface. Prismatic samples of brittle kaolinite clay with pre-existing cracks were tested using the new equipment. Cracks were found to ha~e a marked influence on the development of the failure surface, which was irregular and formed by the linking of the pre-existing and secondary cracks. With the use of linear elastic fracture mechanics theory, it was determined that the secondary cracks developed in regions of tensile stresses induced in the clay samples by the shearing loads.
874021 Constant normal stiffness direct shear testing for socketed pile design in weak rock Johnston, I W; Lain, T S; Williams, A F Geotechnique V37, NI, March 1987, P83-89 It is demonstrated that the development of side shear resistance of piles socketed in weak rock can be controlled by conditions of constant stiffness. To model this behaviour and to provide data for the development of more rational and economic methods of design, constant normal stiffness direct shear test equipment has been manufactured. The principles and details of this testing technique are presented along with a brief discussion of applications.
The stress state in an ideal shear box in which strains are uniform is that of simple shear, and is considered to provide a reference state with which the analyses of the direct shear box can be compared. The effects of the non-uniformities of stress introduced by the rigid ends of a direct shear box, 60mm long by 20mm deep, are then examined, using the finite element method. The soil is modelled using an elasto-plastic constit~urive law, and the influences of volume change, initial stress, and strain softening are examined. In each case comparison is 874022 made with the same material loaded in simple shear. The stress -Shear strength of prestressed cohesive soils. Technical note strain behaviour is found to be dependent on the volume Lutenegger, A J change, as well as on the shear stress-strain properties of the J Geotech Engng Div A S C E Vl13, N2. Feb 198-. P163-168 soil. The analyses showed that the non-uniformities within the The purpose of the study was to determine what effect direct shear box sample have little effect, and little error arises prestressing had on the drained Mohr-Coulomb envelope of if it is interpreted as if it were a simple shear test. some natural cohesive soils as obtained from in situ tests. .~': 1987 Pergamon Journals Ltd. Reproduction not permitted