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Shear strength of joint surface profiles
208A 914069 Analysis of random anisotropic damage mechanics problems of rock mass. Part II - Statistical estimation Wohua, Z; Valliappan, S Rock Mech Rock Engng V23. N4. Oct-Dec 1990, P241-259
Previous work (ibid, V23, P91-112), based on measured characteristics of random crack distribution on the surface of a rock specimen, derived a probabilistic law of damage variables of a rock mass as a Beta distribution. A second approach, where statistical estimation of damage state and properties of a randomly damaged rock mass are evaluated using the Rosenblueth point estimate method, is presented. Its application in finite element analysis of settlement of a surface footing and of slope stability is illustrated.
914070 Study of class II rock behaviour He, C; Okubo, S: Nishimatsu, Y Rock Mech Rock Engng V23. N4, Oct-Dec 1990, P261-273
Class II rock behaviour (Wawersik and Fairhurst, 1970) is discussed using a spring model, which is characterised by nonuniform failure. The model can also describe Class I behaviour, depending on strength variation of the springs. Unloadreload tests in the post failure region were carried out for Class I and Class II rocks. Relative increase in non-elastic strain as compared to decrease in elastic strain seems to characterise Class 1 or Class II bchaviour. Plastic strain tends to increase with confining pressure, and in some cases behaviour will change from Class I1 to Class I with increased confining pressure.
914071 Effective characteristics of the deformation properties of stratified rock Vlasov, A N; Merzlyakov, V P; Ukhov, S B Soil Mech Found Engng V27. NI, Jan-Feb 1990, P22-26
Stratified rocks have anisotropic deformation properties, which must be taken into account for foundation design on inclined layered masses. An analysis, using the asymptotic method of averaging, is presented for calculation of the effective elastic properties of a layered mass in terms of individual layer properties and thickness. The system can be treated as a transversely isotropic medium for design considerations.
914072 New field methods for determining the strength characteristics of soils Markin, B P; Balanukhin, N N Soil Mech Found Engng ~ 7 . NI. Jan-Feb 1990. P27-31
Simple methods are described for determination of soil properties in the field with a minimum of tools and labour. Cohesion can be obtained by observations on a vertical soil wall left between two pits, into which a rectangular opening has been cut, which is loaded by the superincumbent soil column, whilst effectively isolated from the rest of the soil wall by two vertical slots. A variation, using a soil plug in the opening, allows simultaneous estimation of cohesion and friction angle. Accuracy is not that of laboratory tests, nor can these methods be applied for cohesionless soils, but they allow rapid preliminary estimation of soil parameters.
914073 Tests of strain analysis by experimental deformation Borradaile, G J; McArthur, J Tectonophysics V185. N3j4. Jan 1991. P325-333
The translation method and Robin's method for strain analysis are compared and applied to experimentally deformed granular materials, calcite-cement aggregate, oolitic limestone, and China Beach sandstone. Strains are overestimated at high pore fluid pressures, where continuum behaviour breaks down and the additional rigid body rotation is not taken into account. Both methods can tolerate some variation in initial shape ratio and some degree of initial preferred orientation at modest strains. For the polymict sandstone, lower than average ductility of competent clasts may compensate for an unfavourable degree of preferred orientation and allow improved strain estimate. 914074 Storage of refrigerated liquefied gases in rock caverns: characteristics of rock under very low temperatures Aoki, K; Hibiya, K; Yoshida, T Tunnig Underground Space Technoi V5, N4, 1990. P319-325
Design of storage caverns for LPG or LNG at very low temperatures requires knowledge of host rock properties under appropriate conditions. To this end, saturated and dry samples of schist, rhyolite, conglomerate, mudstone, and granite were tested in the laboratory. Change in mechanical properties and effective porosity due to up to 300 freeze-thaw cycles (-45 to + 15 deg C), change in physical and mechanical properties in one cycle of thermal shock, and thermal expansion and conductivity down to -160 deg C were examined. Results are discussed considering suitability of the rocks for storage caverns at cryogenic temperatures. 914075 Mathematical model for the shear behaviour of a dilatant rock joint Saeb, S; Amadei, B Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P237-246. Publ Rotterdam." A A Balkema. 1990 A previously proposed graphical method to predict shear response of a dilatant joint under constant or variable applied stiffness boundary conditions is expanded to a more general mathematical form for use in numerical modelling. Existing formulations for joint normal and shear behaviour and dilatancy are used. They are coupled to relate normal load response to shear and dilatant response, and the coupling used to predict the deformability of an initially mated joint as it undergoes shear. The model may be implemented in nonlinear finite element analyses. 914076 Shear strength of joint surface profiles Ueng, T S; Chang, W C Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P245-251. Publ Rotterdam: A A Balkema, 1990 Dilatancy and shear of asperities must be considered when describing the behaviour of rock joints. Strength and frictional properties of the rock can be measured, but joint shear strength is usually expressed by empirical relations which lack clear physical meaning. The relation between shear strength of a matched clean joint and geometry of its surface profile is examined analytically, and predictions compared to laboratory shear results using various joint surfaces. When surface
~© 1991 Pergamon Press pie. Reproduction not permitted
209A roughness is expressed as a Fourier series, it is possible to calculate shear strength on the basis of results of regular tooth type joints.
intact, jointed, and grouted specimens at confining pressure 110MPa. Stress strain behaviour and variation in shear parameters are described, and a strength criterion developed.
914077 Application of models for jointed rock to the analysis of prototype testing for the Yucca Mountain Project Costin, L S Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P253-260. Publ Rotterdam: A A Balkema, 1990
914081 Studies on interfaces and discontinuities and an incremental elasto-plastic constitutive law Aydan, O; Ichikawa, Y; Ebisu, S; Komura, S; Watanabe, A Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P595-602. Publ Rotterdam: A A Balkema, 1990
Application of linear elastic and nonlinear (compliant joint) models of rock mass behaviour to analysis of flatjack tests in the G-tunnel at the Nevada test site is described. Results were used in development of test procedures and evaluation of effects of joint orientation and frequency on rock mass displacement near the slot. Results indicate that at high stresses, realistic of repository conditions, assumptions of linearity will be inaccurate and the rock mass behaves in a highly nonlinear orthotropic manner.
A research program to develop a mechanical model for interfaces and discontinuities is described. Direct shear tests were carried out on grout-rock, grout-steel reinforcement, and grout-grout with soft in inclusions combinations, plus the grout material itself. Micro and macrocracking phenomena of asperities and close to the interfaces were studied. To model the observed behaviour, an incremental elastoplastic constitutive law, based on that of Aydan (1989), is proposed for macroscopic shear of interfaces and discontinuities. Validity and applicability are discussed.
914078 Towards a constitutive model for cemented granular materials Margolin, L G; Trent, B C Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P321-328. Publ Rotterdam: A A Balkema. 1990
914082 Review of predictive capabilities of JRC-JCS model in engineering practice Barton, N; Bandis, S Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P603-610. Publ Rotterdam: A A Balkema, 1990
Studies have been conducted to analyse and model the complex behaviour of cemented granular materials when subjected to large deformations at high strain rates. A program based on the discrete element method was adopted and then modified to incorporate elastic bonds between particle pairs. The process of creating the analytical model and its verification are discussed. Comparison is also made between the simulation results and the underlying theory.
The database used in development of the original BartonBandis joint model is reviewed, and it is shown how tilt test measurements of JRC can be extrapolated both in terms of stress and sample size. Field measurement of JRC is described and relations with Jr in the Q system are developed. Numerical modelling of jointed rock masses, in particular use of the UDEC codes, is outlined.
914079 Response of a Beaufort sea clay to monotonic and cyclic loading McCarron, W O; Been, K Proc 9th International Conference on Offshore Mechanics and Arctic Engineering, Houston, 18-23 February 1990 V4, P329336. Publ New York: ASME, 1990
The design of Arctic offshore gravity production structures will to a large extent be controlled by the performance of the foundation material. The results of tests conducted on a Beaufort sea clay are presented and discussed. The laboratory test programs included consolidation tests and cyclic and postcyclic strength direct simple shear tests.
914080 Strength behaviour of cement grouted sandstone Rao, K S; Viswanath, B N Proc 2nd International Conference on Foundations and Tunnels, London, 19-21 September 1989 VI, P351-357. Publ Edinburgh: Engineering Technics Press, 1989
An attempt at a systematic examination of strength and deformation properties of a grouted rock mass is presented. Samples of fine grained, medium strength Dhoulpur sandstone were prepared with saw cut planar joints at angles from 0-90 deg to the specimen axis and with grout thicknesses in the joints of 1, 2, and 4ram. Triaxial tests were carried out on
914083 Numerical investigation of the boundary conditions effect on rock joint behaviour Cuisiat, F D E; Hyett, A J; Hudson, J A Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P611-616. Publ Rotterdam: A A Balkema, 1990
A boundary element program is used to assess the validity of Barton's joint model under a range of boundary conditions. It can handle pre-peak hardening, post-peak behaviour, unloading, and reloading of the joint. The numerical model is tested against experimental data for a single joint.
914084 Correlation between the jointing index and the rock mass deformability Grossmann, F Proc 1st International Workshop on Scale Effects in Rock Masses, Loen, 7-8 June 1990 P261-265. Publ Rotterdam: A A Balkema, 1990
If it is assumed that lengths of joints in different sets in a given rock mass follow a Poisson distribution, and that rock mass deformability in a given direction depends linearly on the number of discontinuities occurring along that direction in the rock volume considered, it can be shown that for jointing indices usually found, representative elementary volume (REV) is much greater than volumes involved in classical in-situ deformability tests.
© 1991 Pergamon Press pie. Reproduction not permitted
Previous work (ibid, V23, P91-112), based on measured characteristics of random crack distribution on the surface of a rock specimen, derived a probabilistic law of damage variables of a rock mass as a Beta distribution. A second approach, where statistical estimation of damage state and properties of a randomly damaged rock mass are evaluated using the Rosenblueth point estimate method, is presented. Its application in finite element analysis of settlement of a surface footing and of slope stability is illustrated.
914070 Study of class II rock behaviour He, C; Okubo, S: Nishimatsu, Y Rock Mech Rock Engng V23. N4, Oct-Dec 1990, P261-273
Class II rock behaviour (Wawersik and Fairhurst, 1970) is discussed using a spring model, which is characterised by nonuniform failure. The model can also describe Class I behaviour, depending on strength variation of the springs. Unloadreload tests in the post failure region were carried out for Class I and Class II rocks. Relative increase in non-elastic strain as compared to decrease in elastic strain seems to characterise Class 1 or Class II bchaviour. Plastic strain tends to increase with confining pressure, and in some cases behaviour will change from Class I1 to Class I with increased confining pressure.
914071 Effective characteristics of the deformation properties of stratified rock Vlasov, A N; Merzlyakov, V P; Ukhov, S B Soil Mech Found Engng V27. NI, Jan-Feb 1990, P22-26
Stratified rocks have anisotropic deformation properties, which must be taken into account for foundation design on inclined layered masses. An analysis, using the asymptotic method of averaging, is presented for calculation of the effective elastic properties of a layered mass in terms of individual layer properties and thickness. The system can be treated as a transversely isotropic medium for design considerations.
914072 New field methods for determining the strength characteristics of soils Markin, B P; Balanukhin, N N Soil Mech Found Engng ~ 7 . NI. Jan-Feb 1990. P27-31
Simple methods are described for determination of soil properties in the field with a minimum of tools and labour. Cohesion can be obtained by observations on a vertical soil wall left between two pits, into which a rectangular opening has been cut, which is loaded by the superincumbent soil column, whilst effectively isolated from the rest of the soil wall by two vertical slots. A variation, using a soil plug in the opening, allows simultaneous estimation of cohesion and friction angle. Accuracy is not that of laboratory tests, nor can these methods be applied for cohesionless soils, but they allow rapid preliminary estimation of soil parameters.
914073 Tests of strain analysis by experimental deformation Borradaile, G J; McArthur, J Tectonophysics V185. N3j4. Jan 1991. P325-333
The translation method and Robin's method for strain analysis are compared and applied to experimentally deformed granular materials, calcite-cement aggregate, oolitic limestone, and China Beach sandstone. Strains are overestimated at high pore fluid pressures, where continuum behaviour breaks down and the additional rigid body rotation is not taken into account. Both methods can tolerate some variation in initial shape ratio and some degree of initial preferred orientation at modest strains. For the polymict sandstone, lower than average ductility of competent clasts may compensate for an unfavourable degree of preferred orientation and allow improved strain estimate. 914074 Storage of refrigerated liquefied gases in rock caverns: characteristics of rock under very low temperatures Aoki, K; Hibiya, K; Yoshida, T Tunnig Underground Space Technoi V5, N4, 1990. P319-325
Design of storage caverns for LPG or LNG at very low temperatures requires knowledge of host rock properties under appropriate conditions. To this end, saturated and dry samples of schist, rhyolite, conglomerate, mudstone, and granite were tested in the laboratory. Change in mechanical properties and effective porosity due to up to 300 freeze-thaw cycles (-45 to + 15 deg C), change in physical and mechanical properties in one cycle of thermal shock, and thermal expansion and conductivity down to -160 deg C were examined. Results are discussed considering suitability of the rocks for storage caverns at cryogenic temperatures. 914075 Mathematical model for the shear behaviour of a dilatant rock joint Saeb, S; Amadei, B Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P237-246. Publ Rotterdam." A A Balkema. 1990 A previously proposed graphical method to predict shear response of a dilatant joint under constant or variable applied stiffness boundary conditions is expanded to a more general mathematical form for use in numerical modelling. Existing formulations for joint normal and shear behaviour and dilatancy are used. They are coupled to relate normal load response to shear and dilatant response, and the coupling used to predict the deformability of an initially mated joint as it undergoes shear. The model may be implemented in nonlinear finite element analyses. 914076 Shear strength of joint surface profiles Ueng, T S; Chang, W C Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P245-251. Publ Rotterdam: A A Balkema, 1990 Dilatancy and shear of asperities must be considered when describing the behaviour of rock joints. Strength and frictional properties of the rock can be measured, but joint shear strength is usually expressed by empirical relations which lack clear physical meaning. The relation between shear strength of a matched clean joint and geometry of its surface profile is examined analytically, and predictions compared to laboratory shear results using various joint surfaces. When surface
~© 1991 Pergamon Press pie. Reproduction not permitted
209A roughness is expressed as a Fourier series, it is possible to calculate shear strength on the basis of results of regular tooth type joints.
intact, jointed, and grouted specimens at confining pressure 110MPa. Stress strain behaviour and variation in shear parameters are described, and a strength criterion developed.
914077 Application of models for jointed rock to the analysis of prototype testing for the Yucca Mountain Project Costin, L S Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P253-260. Publ Rotterdam: A A Balkema, 1990
914081 Studies on interfaces and discontinuities and an incremental elasto-plastic constitutive law Aydan, O; Ichikawa, Y; Ebisu, S; Komura, S; Watanabe, A Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P595-602. Publ Rotterdam: A A Balkema, 1990
Application of linear elastic and nonlinear (compliant joint) models of rock mass behaviour to analysis of flatjack tests in the G-tunnel at the Nevada test site is described. Results were used in development of test procedures and evaluation of effects of joint orientation and frequency on rock mass displacement near the slot. Results indicate that at high stresses, realistic of repository conditions, assumptions of linearity will be inaccurate and the rock mass behaves in a highly nonlinear orthotropic manner.
A research program to develop a mechanical model for interfaces and discontinuities is described. Direct shear tests were carried out on grout-rock, grout-steel reinforcement, and grout-grout with soft in inclusions combinations, plus the grout material itself. Micro and macrocracking phenomena of asperities and close to the interfaces were studied. To model the observed behaviour, an incremental elastoplastic constitutive law, based on that of Aydan (1989), is proposed for macroscopic shear of interfaces and discontinuities. Validity and applicability are discussed.
914078 Towards a constitutive model for cemented granular materials Margolin, L G; Trent, B C Rock Mechanics Contributions and Challenges: Proc 31st US Symposium, Golden, 18-20 June 1990 P321-328. Publ Rotterdam: A A Balkema. 1990
914082 Review of predictive capabilities of JRC-JCS model in engineering practice Barton, N; Bandis, S Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P603-610. Publ Rotterdam: A A Balkema, 1990
Studies have been conducted to analyse and model the complex behaviour of cemented granular materials when subjected to large deformations at high strain rates. A program based on the discrete element method was adopted and then modified to incorporate elastic bonds between particle pairs. The process of creating the analytical model and its verification are discussed. Comparison is also made between the simulation results and the underlying theory.
The database used in development of the original BartonBandis joint model is reviewed, and it is shown how tilt test measurements of JRC can be extrapolated both in terms of stress and sample size. Field measurement of JRC is described and relations with Jr in the Q system are developed. Numerical modelling of jointed rock masses, in particular use of the UDEC codes, is outlined.
914079 Response of a Beaufort sea clay to monotonic and cyclic loading McCarron, W O; Been, K Proc 9th International Conference on Offshore Mechanics and Arctic Engineering, Houston, 18-23 February 1990 V4, P329336. Publ New York: ASME, 1990
The design of Arctic offshore gravity production structures will to a large extent be controlled by the performance of the foundation material. The results of tests conducted on a Beaufort sea clay are presented and discussed. The laboratory test programs included consolidation tests and cyclic and postcyclic strength direct simple shear tests.
914080 Strength behaviour of cement grouted sandstone Rao, K S; Viswanath, B N Proc 2nd International Conference on Foundations and Tunnels, London, 19-21 September 1989 VI, P351-357. Publ Edinburgh: Engineering Technics Press, 1989
An attempt at a systematic examination of strength and deformation properties of a grouted rock mass is presented. Samples of fine grained, medium strength Dhoulpur sandstone were prepared with saw cut planar joints at angles from 0-90 deg to the specimen axis and with grout thicknesses in the joints of 1, 2, and 4ram. Triaxial tests were carried out on
914083 Numerical investigation of the boundary conditions effect on rock joint behaviour Cuisiat, F D E; Hyett, A J; Hudson, J A Proc International Symposium on Rock Joints, Loen, 4-6 June 1990 P611-616. Publ Rotterdam: A A Balkema, 1990
A boundary element program is used to assess the validity of Barton's joint model under a range of boundary conditions. It can handle pre-peak hardening, post-peak behaviour, unloading, and reloading of the joint. The numerical model is tested against experimental data for a single joint.
914084 Correlation between the jointing index and the rock mass deformability Grossmann, F Proc 1st International Workshop on Scale Effects in Rock Masses, Loen, 7-8 June 1990 P261-265. Publ Rotterdam: A A Balkema, 1990
If it is assumed that lengths of joints in different sets in a given rock mass follow a Poisson distribution, and that rock mass deformability in a given direction depends linearly on the number of discontinuities occurring along that direction in the rock volume considered, it can be shown that for jointing indices usually found, representative elementary volume (REV) is much greater than volumes involved in classical in-situ deformability tests.
© 1991 Pergamon Press pie. Reproduction not permitted