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Strength and deformation properties of reinforced jointed media under true triaxial conditions
147A 923062
923O66
Undrained cyclic shear strength and residual shear strain of saturated sand by cyclic triaxial tests Hyodo, M; Murata, H; Yasufuku, N; Fujii, T Soils Found V31, N3, Sept 1991, P60-76
S ~ ~ of Neogeae days and marls Coric, S; Markovic, G; Bozinovic, D; Caki, L Proc 7tk ISRM lntersatiomd Comgress om Rock Meebunics, Aocben, 16-20 September 1991 V1, P209-214. Publ Rotterdam: A A Balkema, 1991
Undrained cyclic triaxial shear tests were carded out on isotropically and anisotropically consolidated samples of Toyoura sand. Various initial static and cyclic shear stress levels were used. Shear strength and residual cyclic shear strain and its relation to effective stress ratio at the end of each cyclic are discussed. A unique relation is found between effective stress ratio and cyclic strength ratio. An empirical relation is developed to predict development of pore pressure and residual shear strain for given testing conditions. 923063
Deformation characteristics of rockflll materials Balasubramaniam, A S; Ratnayake, A M P; Wej, N P; Huy, L Y Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 VI, P187-194. Publ Rotterdam: `4 `4 Balkema, 1991 An incremental stress strain theory is developed for rockfills in a manner similar to that for normally consolidated clays of Roscoe and Poorooshasb (1963). Initial correlation between drained and undrained behaviour is examined through drained and undrained shear tests and anisotropic consolidation tests. Yield locus and critical state parameters are evaluated. Modifications to the initial theory to fit rockfill materials are discussed. 923064 New considerations in the determination of Hoek and Brown
material constants Betournay, M C; Gorski, B; Labrie, D; Jackson, M; Gyenge, M Proc 7tit ISRM lnternatiomd Congress on Rock Mec&mics, Aachen, 16-20 September 1991 VI, P195-200. Publ Rotterdam: A .4 Balkema, 1991 Results of tests on a wide variety of rocks of different classes carded out at C A N M E T are presented which examined the effects of including Brazilian test data in the calculation of the m value of the Hoek and Brown failure criterion. Inclusion of Brazilian strength to compression strength data alters the value of m, reducing it where m is greater than 8 and increasing it where m is less than 8. Direct tensile test data have less influence than Brazilian data for high values of m and more influence for low values. 92306$
Strength and deformation properties of reinforced Dinted media under true triaxial conditions Egger, P; Pellet, F Proc 7tk ISRM Imeruntiouni Congress on Rock Mechanics, Aachen, 16-20 September 1991 It], P215-220. Publ Rotterdam: A A Baikema, 1991 The effects of reinforcement in jointed media were examined by a series of true triaxial tests using the TRIROC testing machine and large scale (300x300x600mm) prismatic specimens made by assembling plaster plates. The specimens contalned several smooth joints at various angles of dip and were reinforced by passive fully bonded steel bars. Results show that strengthening can be considered as an additional cohesion (dependent on bolt density) or an additional confining pressure (dependent on pullout resistance of the bars). Deformation moduli change with this value of confining pressure.
A study of the nature and mechanical properties of the overconsolidated Belgrade clays and marls has been carded out. Large numbers of triaxial tests were carried out on samples from the Pannonian and Sarmation formations. Stress dependent, nonlinear, inelastic, and anisotropic behaviour was observed. A hyperbolic stress strain relation is derived, which describes the behaviour of these and similar clays and is suitable for implementation in numerical analyses. 923O67 Stress-strain relationships in the analysis of the failure process of weak rock masses Gijon, M F; De Vallejo, L G Proc 7th ISRM lmermaiounl Congress on Rock Meckunics, Aocben, 16-20 September 1991 VI, P225-230. Publ Rotterdam: A A Balkema, 1991 Failure criteria in which failure initiates before peak strength is reached may be more appropriate than those developed for brittle materials when dealing with weak rock masses. Stress strain relations have been examined for carboniferous shales from an open pit slope. Laboratory strain values and the shape of the stress strain curve are described. Different behaviour patterns are seen, which are used in failure criteria for finite element slope stability analysis. 97.3O68
Scale effect on the modulus of deformation of jointed rock mass Fishman, Y A; lofts, I M Proc 7tli ISRM lntertmtionai Congress on Rock Mechanics, Aocben, 16-20 September 1991 VI, P231-235. Publ Rotterdam: A A Balkema, 1991 In situ plate bearing tests were carried out on jointed limestone rocks forming part of the foundation of the Inguri arch dam, USSR, using plates of diameter 0.8, 1.14, and 1.6m. The tests were also modelled using the distinct block method. Scale effects have been studied. In most real cases, the deformability increases with size of the loading plate. It is emphasised that boundary conditions may have significant effects on the scale effect in numerical or laboratory modelling. 923O69
Bebavinur of laboratory specimens composed by different rocks Oreco, 0 D; Ferrero, A; Peila, D Proc 7tL ISRM Istermuriomd Congress on Rock Mechanics, Aocben, 1620 September 1991 VI, P241-245. Publ Rotterdam: ,4 A Balkema, 1991 Work was carded out on natural stratified rock materials and specimens assembled from disks of rock, some free, others glued or separated by rubber sheets. Axial and radial strain were measured in compression tests. Effects of interface properties and contrasts between layer properties on mechanical behaviour were examined. Finite element simulation of the tests was used to compute the different stresses in different parts of the specimen. Results may be applied to predict behaviour of pillars in stratified formations.
© 1992 Pergamon Press Ltd. Reproduction not permitted
923O66
Undrained cyclic shear strength and residual shear strain of saturated sand by cyclic triaxial tests Hyodo, M; Murata, H; Yasufuku, N; Fujii, T Soils Found V31, N3, Sept 1991, P60-76
S ~ ~ of Neogeae days and marls Coric, S; Markovic, G; Bozinovic, D; Caki, L Proc 7tk ISRM lntersatiomd Comgress om Rock Meebunics, Aocben, 16-20 September 1991 V1, P209-214. Publ Rotterdam: A A Balkema, 1991
Undrained cyclic triaxial shear tests were carded out on isotropically and anisotropically consolidated samples of Toyoura sand. Various initial static and cyclic shear stress levels were used. Shear strength and residual cyclic shear strain and its relation to effective stress ratio at the end of each cyclic are discussed. A unique relation is found between effective stress ratio and cyclic strength ratio. An empirical relation is developed to predict development of pore pressure and residual shear strain for given testing conditions. 923063
Deformation characteristics of rockflll materials Balasubramaniam, A S; Ratnayake, A M P; Wej, N P; Huy, L Y Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 VI, P187-194. Publ Rotterdam: `4 `4 Balkema, 1991 An incremental stress strain theory is developed for rockfills in a manner similar to that for normally consolidated clays of Roscoe and Poorooshasb (1963). Initial correlation between drained and undrained behaviour is examined through drained and undrained shear tests and anisotropic consolidation tests. Yield locus and critical state parameters are evaluated. Modifications to the initial theory to fit rockfill materials are discussed. 923064 New considerations in the determination of Hoek and Brown
material constants Betournay, M C; Gorski, B; Labrie, D; Jackson, M; Gyenge, M Proc 7tit ISRM lnternatiomd Congress on Rock Mec&mics, Aachen, 16-20 September 1991 VI, P195-200. Publ Rotterdam: A .4 Balkema, 1991 Results of tests on a wide variety of rocks of different classes carded out at C A N M E T are presented which examined the effects of including Brazilian test data in the calculation of the m value of the Hoek and Brown failure criterion. Inclusion of Brazilian strength to compression strength data alters the value of m, reducing it where m is greater than 8 and increasing it where m is less than 8. Direct tensile test data have less influence than Brazilian data for high values of m and more influence for low values. 92306$
Strength and deformation properties of reinforced Dinted media under true triaxial conditions Egger, P; Pellet, F Proc 7tk ISRM Imeruntiouni Congress on Rock Mechanics, Aachen, 16-20 September 1991 It], P215-220. Publ Rotterdam: A A Baikema, 1991 The effects of reinforcement in jointed media were examined by a series of true triaxial tests using the TRIROC testing machine and large scale (300x300x600mm) prismatic specimens made by assembling plaster plates. The specimens contalned several smooth joints at various angles of dip and were reinforced by passive fully bonded steel bars. Results show that strengthening can be considered as an additional cohesion (dependent on bolt density) or an additional confining pressure (dependent on pullout resistance of the bars). Deformation moduli change with this value of confining pressure.
A study of the nature and mechanical properties of the overconsolidated Belgrade clays and marls has been carded out. Large numbers of triaxial tests were carried out on samples from the Pannonian and Sarmation formations. Stress dependent, nonlinear, inelastic, and anisotropic behaviour was observed. A hyperbolic stress strain relation is derived, which describes the behaviour of these and similar clays and is suitable for implementation in numerical analyses. 923O67 Stress-strain relationships in the analysis of the failure process of weak rock masses Gijon, M F; De Vallejo, L G Proc 7th ISRM lmermaiounl Congress on Rock Meckunics, Aocben, 16-20 September 1991 VI, P225-230. Publ Rotterdam: A A Balkema, 1991 Failure criteria in which failure initiates before peak strength is reached may be more appropriate than those developed for brittle materials when dealing with weak rock masses. Stress strain relations have been examined for carboniferous shales from an open pit slope. Laboratory strain values and the shape of the stress strain curve are described. Different behaviour patterns are seen, which are used in failure criteria for finite element slope stability analysis. 97.3O68
Scale effect on the modulus of deformation of jointed rock mass Fishman, Y A; lofts, I M Proc 7tli ISRM lntertmtionai Congress on Rock Mechanics, Aocben, 16-20 September 1991 VI, P231-235. Publ Rotterdam: A A Balkema, 1991 In situ plate bearing tests were carried out on jointed limestone rocks forming part of the foundation of the Inguri arch dam, USSR, using plates of diameter 0.8, 1.14, and 1.6m. The tests were also modelled using the distinct block method. Scale effects have been studied. In most real cases, the deformability increases with size of the loading plate. It is emphasised that boundary conditions may have significant effects on the scale effect in numerical or laboratory modelling. 923O69
Bebavinur of laboratory specimens composed by different rocks Oreco, 0 D; Ferrero, A; Peila, D Proc 7tL ISRM Istermuriomd Congress on Rock Mechanics, Aocben, 1620 September 1991 VI, P241-245. Publ Rotterdam: ,4 A Balkema, 1991 Work was carded out on natural stratified rock materials and specimens assembled from disks of rock, some free, others glued or separated by rubber sheets. Axial and radial strain were measured in compression tests. Effects of interface properties and contrasts between layer properties on mechanical behaviour were examined. Finite element simulation of the tests was used to compute the different stresses in different parts of the specimen. Results may be applied to predict behaviour of pillars in stratified formations.
© 1992 Pergamon Press Ltd. Reproduction not permitted