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219A of the unconfined compressixe strength of intact rock, quantified lithology and rock mass qualit,,,. The geological, lithological. physical, mechanical and enxironmental factors affecting rock mass strength are presented. Failure and strength criteria are reviewed and a promising new failure criterion is introduced. Rock mass strength and classification indexes are described and the influences of single planes of weakness and of the number and pattern of joints examined. The application of this information to practical problems is considered. The stability of rock slopes and the various failure modes and analytical approaches, and the stability analysis of tunnels, convergence and support loading are investigated. 125 refs.
866047 Influence of width/height ratio on post-failure behaviour of coal. Short communication Das, M N lnt J Min Geol Engng t'4. ,VI, March 1986. P79-87 This note describes the results of uniaxial compression tests on cylindrical specimens of 6 Indian coals, adopting a wider than previously studied range of specimen w/h ratios, 0.5-13.5. A comprehensive picture of stress-strain bchaviour in the postfailure region ~as obtained. 866048 Laboratory-scale penetration experiments into geological targets to impact velocities of 2.1km/s Forrestal, M J: Lce, L M: Jenrctte, B D J Appl Mech (Tran~ A S M E Ser E) V53. N2. Jttm' 19,S'6. P317-320 Laboratory experiments ,acre conducted using bullet projectiles of three profiles and simulated soft sandstone (foundry core) targcts at stead', velocities of 0.6-2. I km,,s. Laser intcrfcrornetry and piezoelectric accclcrometers measured the rigid body penetration ~elocity and acceleration. Deformation of the projectile ~as profile dependent. 866049 Closure of rock joints Brown, S R: Scho[z, C [I J Geophys Res l'Y/, :VB5, 10 April 19,~6, P4939-4948 A generalized form of the Greenwood-Williamson theory describing the elastic contact of two random surl:aces is used to predict the closure of rock joints. The theory is tested quantitati,,cly by comparing joint closure from experinaent with theory. These comparisons were made using topography data from the surfaces of the joints used in the closure experiments. Compression tests were carried on joints fitbricatcd from machined blocks of granite, quartzite and marble. They demonstrate that the limit of elastic deformation is reached for all materials for surface asperities below a givcn dimension and the elastic theory assumption becomes invalid. This dimension is related to the idcntation hardness of the material. 866050 Analyzing permanent drift due to cyclic loads Bouckovalas, G: Marr, W A: Christian, J T J Geotech Engng Dir ASCE VII2, N6. June 19,'~6. P579-593 An analytical model has been developed to predict permanent stresscs and strains in sands under cyclic loading for general drainage and boundary conditions. The model is combined with the finite element method to predict the permanent displacement of a storm barrier under combined tidal and wave loading. The rcsults are comparcd with predictions from previous analyses, yielding a good correlation. The effects of drainage conditions and soil densification on permanent c
displacement are e',aluatcd. The results demonstrate the importance of including in the pore pressure calculation the effects of both the tendcnc,,, for volume change and the change in the average total stress. Auth.
866051 Piston core properties and disturbance effects Olsen, H W: Rice, T L: Mayne, P W; Singh, R D J Geotech Engng Die ASCE V112, N6. June 1986. P60,~-625 A recent study provided an opportunity to examine the usefulness of the SHANSEP method for minimizing disturbance effects in laboratory test results on piston cores, and for interpreting the properties of sediments in situ. This stud~ involved piston cores taken from 31 sites on the mid-Atlantic Upper Continental slope. The purpose of the geotechnical test program was to determine the physical characteristics of the marcrials and to providc a basis for evaluating the in situ consolidation state and shear strength of the sediments. A summary of the study, examining disturbance cffects in the laboratory test results obtained, is given. Result are presented and evahmted in terms of index propcrty correlations with the effective stress friction angle, the undrained strength ratio, and the compression index, and compared with consolidation state values derived from laboratory vane, triaxial, and consolidation test results. 8661)52 Permanent strains from cyclic variable-amplitude luadings Stewart, H E J Geotech Engng Die ASCE I'112. N6..how 19,~'6. 1'646-660 Cyclic triaxial tests were performed on a well-graded railroad ballast with a maximum particle size of 38mm. Samples ~vcre compacted m a split mould to reproducible densit3 states and sul~icctcd to repeated applications of compressive axial stresses. The cumulative permanent axial strains that developed, for constant-amplitude Ioadings, v,crc found to be dependent upon the permanent strain after one c',clc of loadinK, the loading magnitude, and the number of applied loading cycles. Staged tests were conducted in which a sequence of variable loads was applied to the same sample. For these ,.ariable-amplitude tests, the final permanent strains ~verc independent of the order of the applied Ioadings. A supcrposition method is prescntcd to characterize the mixed loading conditions. Results of the variable-amplitude tests indicated that the maximum load controlled the permanent strain dcvelopmcnt, with negligible additional strains developing after returning to a lower repeated stress level. Partial unloading c,,,cles v,erc also investigated which showed very little additional cumulative inelastic strains. Auth. 8664)53 Stress distribution in anisotropic compliance of jointed rock Chappell, B A J Geotech Engng Dit' ASCE 1"112. N7. July 19,~'6, P682-700 Two simple models are uscd to detinc the total rock mass compliance. One rcprcscnts the dcformational mode where the stresses within the composite material are equal, and the second model represents the stress distributions ~ithin the composite material where the strains between the composite material are equal. In addition to neglecting the effects of stress distribution on the compliance of the rock mass, relative volumes of the intact and joint material and their spatial distribution are generally neglected. These relative ',olumes and their spatial distribution relative to thc appticd loads arc an important part of the rock mass compliance, especially v, hcn shear tractions arc applied. Auth.
1986 Pergamon Journals Ltd. Reproduction not permitted
866047 Influence of width/height ratio on post-failure behaviour of coal. Short communication Das, M N lnt J Min Geol Engng t'4. ,VI, March 1986. P79-87 This note describes the results of uniaxial compression tests on cylindrical specimens of 6 Indian coals, adopting a wider than previously studied range of specimen w/h ratios, 0.5-13.5. A comprehensive picture of stress-strain bchaviour in the postfailure region ~as obtained. 866048 Laboratory-scale penetration experiments into geological targets to impact velocities of 2.1km/s Forrestal, M J: Lce, L M: Jenrctte, B D J Appl Mech (Tran~ A S M E Ser E) V53. N2. Jttm' 19,S'6. P317-320 Laboratory experiments ,acre conducted using bullet projectiles of three profiles and simulated soft sandstone (foundry core) targcts at stead', velocities of 0.6-2. I km,,s. Laser intcrfcrornetry and piezoelectric accclcrometers measured the rigid body penetration ~elocity and acceleration. Deformation of the projectile ~as profile dependent. 866049 Closure of rock joints Brown, S R: Scho[z, C [I J Geophys Res l'Y/, :VB5, 10 April 19,~6, P4939-4948 A generalized form of the Greenwood-Williamson theory describing the elastic contact of two random surl:aces is used to predict the closure of rock joints. The theory is tested quantitati,,cly by comparing joint closure from experinaent with theory. These comparisons were made using topography data from the surfaces of the joints used in the closure experiments. Compression tests were carried on joints fitbricatcd from machined blocks of granite, quartzite and marble. They demonstrate that the limit of elastic deformation is reached for all materials for surface asperities below a givcn dimension and the elastic theory assumption becomes invalid. This dimension is related to the idcntation hardness of the material. 866050 Analyzing permanent drift due to cyclic loads Bouckovalas, G: Marr, W A: Christian, J T J Geotech Engng Dir ASCE VII2, N6. June 19,'~6. P579-593 An analytical model has been developed to predict permanent stresscs and strains in sands under cyclic loading for general drainage and boundary conditions. The model is combined with the finite element method to predict the permanent displacement of a storm barrier under combined tidal and wave loading. The rcsults are comparcd with predictions from previous analyses, yielding a good correlation. The effects of drainage conditions and soil densification on permanent c
displacement are e',aluatcd. The results demonstrate the importance of including in the pore pressure calculation the effects of both the tendcnc,,, for volume change and the change in the average total stress. Auth.
866051 Piston core properties and disturbance effects Olsen, H W: Rice, T L: Mayne, P W; Singh, R D J Geotech Engng Die ASCE V112, N6. June 1986. P60,~-625 A recent study provided an opportunity to examine the usefulness of the SHANSEP method for minimizing disturbance effects in laboratory test results on piston cores, and for interpreting the properties of sediments in situ. This stud~ involved piston cores taken from 31 sites on the mid-Atlantic Upper Continental slope. The purpose of the geotechnical test program was to determine the physical characteristics of the marcrials and to providc a basis for evaluating the in situ consolidation state and shear strength of the sediments. A summary of the study, examining disturbance cffects in the laboratory test results obtained, is given. Result are presented and evahmted in terms of index propcrty correlations with the effective stress friction angle, the undrained strength ratio, and the compression index, and compared with consolidation state values derived from laboratory vane, triaxial, and consolidation test results. 8661)52 Permanent strains from cyclic variable-amplitude luadings Stewart, H E J Geotech Engng Die ASCE I'112. N6..how 19,~'6. 1'646-660 Cyclic triaxial tests were performed on a well-graded railroad ballast with a maximum particle size of 38mm. Samples ~vcre compacted m a split mould to reproducible densit3 states and sul~icctcd to repeated applications of compressive axial stresses. The cumulative permanent axial strains that developed, for constant-amplitude Ioadings, v,crc found to be dependent upon the permanent strain after one c',clc of loadinK, the loading magnitude, and the number of applied loading cycles. Staged tests were conducted in which a sequence of variable loads was applied to the same sample. For these ,.ariable-amplitude tests, the final permanent strains ~verc independent of the order of the applied Ioadings. A supcrposition method is prescntcd to characterize the mixed loading conditions. Results of the variable-amplitude tests indicated that the maximum load controlled the permanent strain dcvelopmcnt, with negligible additional strains developing after returning to a lower repeated stress level. Partial unloading c,,,cles v,erc also investigated which showed very little additional cumulative inelastic strains. Auth. 8664)53 Stress distribution in anisotropic compliance of jointed rock Chappell, B A J Geotech Engng Dit' ASCE 1"112. N7. July 19,~'6, P682-700 Two simple models are uscd to detinc the total rock mass compliance. One rcprcscnts the dcformational mode where the stresses within the composite material are equal, and the second model represents the stress distributions ~ithin the composite material where the strains between the composite material are equal. In addition to neglecting the effects of stress distribution on the compliance of the rock mass, relative volumes of the intact and joint material and their spatial distribution are generally neglected. These relative ',olumes and their spatial distribution relative to thc appticd loads arc an important part of the rock mass compliance, especially v, hcn shear tractions arc applied. Auth.
1986 Pergamon Journals Ltd. Reproduction not permitted