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Kaiser effect in thermo-cycled rocks
76A are briefly reviewed. Results from uniaxial and triaxial tests on Indiana limestone are presented. Data indicate both preload principal stresses can be determined from AE,MS monitoring data from a uniaxial test on a single specimen. 912104 Identification of fracture in coal by AE in dynamic tests Khair, A W; Jung, S Proc 4th Conference on Acoustic EmissionlMicroseismic Activity in Geological Structures and Materials, Pennsylvania, 22-24 October 1985 P57-72. Publ Clausthal-Zellerfeld: Trans Tech Publications, 1989
Coal blocks, laterally confined to a pre-determined in situ stress, were subject to impact indentation by dropping weighted coal cutting bits from various heights. Surface strains, depth of penetration, and AE were monitored. After testing, the fractured surfaces were photographed and intensity and extent of the fracture zone examined using ultrasonic techniques. By correlating measured parameters, it was possible to identify and characterize the fracture zones under a given set of test parameters. 912105 AE detection of prestress in soil and rock Korncr, R M: Lord, A E Proc 4th Conference on Acoustic Emission/Microseismic Activity in Geological Structures and Materials, Pennsylvania, 22-24 October 1985 P73-86. Publ Clausthal-Zellerfeld." Trans Tech Publications, 1989
The Kaiser effect was evaluated for I I soils from coarse granular to highly plastic at various water contents, and for gneiss, schist, carbonate, limestone, mudstone, and sandstone rocks. Previously applied stress could be determined to within 10% for all soils. The rocks were tested at load of 25, 50, 75, and 100% of fracture stress and delay times of 0.01-10000 hours (in decade steps) after initial preload was applied. The Kaiser effect was essentially lost beyond 1000 hours. Rock type influences felicity ratio and reliability of the Kaiser effect. 912106 Kaiser effect in thermo-cycled rocks Montoto, M; Ruiz de Argandona, V G; Calleja, L: Suarez del Rio, L M Proc 4th Conference on Acoustic Emission/Microseismic Activity in Geological Structures and Materials, Pennsylvania, 22-24 October 1985 P97-116. Publ Clausthal-Zellerfeld: Trans Tech Publications, 1989
Intact specimens of granodiorite, epidiorite, and serpentinite were subject to thermal cycling with increasing temperatures of 130. 230. 330, and 430 deg C. The maximum thermal stress in previous cycles was clearly discernable from results of AE/MS monitoring. AE/MS was related to rock mineralogy and microstructure. The effect of heating on some rock properties was also examined. 912107 Effects of depth on rock fracture Cleary, M P Proc International Symposium on Rock at Great Depth, Pau, 28-31 August 1989 V3. P1153-1163. Publ Rotterdam: A A Balkema, 1989
Behaviour of rock changes with depth, one major feature being the change of dominance of fracture energy or toughness to control of fracture growth by confining stress. Fracture interactions with stress and other fractures, factors controlling fracture shape, role of pore fluids, and thermal conduction and
convention effects are examined. These phenomena are discussed with specific interest to hydraulic fracture, Areas for further work are outlined. 912108 Rock fabric during mode II tests: analysis of acoustic emissions and sonic properties (In French) Benzaim, A Proe International Symposium on Rock at Great Depth, Pau, 28-31 August 1989 V3, P1295-1312. Publ Rotterdam: ,4 A Balkema. 1989
The analogy between earthquakes and acoustic emission, widely used to study damage of rocks and concrete, is examined quantitatively. Parameters measured during mode II rupture experiments provide a possible method of classification of materials, which must be confirmed by further testing. This work suggests several avenues of approach to better understand damage mechanisms. 912109 Mechanism of deformation and fracture of brittle rock Salganic, R L; Dyskin, A V; Germanovich, L N: Tsyrulnikov, M N Proc International Symposium on Rock at Great Depth, Pan, 28-31 August 1989 V3. P1321-1328. Publ Rotterdam: A A Balkema, 1989
A model of dilatancy and fracture of brittle materials due to crack growth under uniaxial compression is presented. It assumes the largest and least frequent cracks increase in size considerably and play a major role. Tensile fractures grow from shear cracks expanded perpendicular to the axis of compression. Theoretical results are compared to experimental data from the literature.
Time dependent behaviour See a~o: 912245, 912286. 912287. 912385. 912509 912110 Strain, pore pressure and fatigue characteristics of sandstone under various load conditions Tien Y M; Lee, D H; Juang, C H lnt J Rock Mech Min Sci V27. N4, Aug 1990, P283-289
Results of tests on a saturated sandstone under quasi-static, repeated, and cyclic undrained triaxial loading are analysed, and a relation developed between accumulated axial strain and fatigue life. Under some conditions, a critical strain was seen beyond which failure occurred almost instantaneously. Variation of pore water pressure under the different Ioadings was studied. Three distinct modes were seen under cyclic loading. In all cases, pore pressure falls rapidly immediately before failure. Pore pressure variations are interpreted in terms of structural changes within the specimens. 912111 Solid-state flow of polymineralic rocks Handy, M R J Geophys Res V95. NB6. June 1990. P8647-8661
Mechanical and microstructural behaviour of polyminerallic rock will depend on relative volumes and theologic properties of the constituent minerals. A concept of strain energy partitioning in polyphase aggregates is presented for prediction of bulk mechanical properties in terms of those of its constituents. Biminerallic strength-composition relations predicted are highly nonlinear, yet accurately mimic those observed in experimental behaviour. Examination of quartzo-feldspathic
~C 1991 Pergamon Press plc. Reproduction not permitted
Coal blocks, laterally confined to a pre-determined in situ stress, were subject to impact indentation by dropping weighted coal cutting bits from various heights. Surface strains, depth of penetration, and AE were monitored. After testing, the fractured surfaces were photographed and intensity and extent of the fracture zone examined using ultrasonic techniques. By correlating measured parameters, it was possible to identify and characterize the fracture zones under a given set of test parameters. 912105 AE detection of prestress in soil and rock Korncr, R M: Lord, A E Proc 4th Conference on Acoustic Emission/Microseismic Activity in Geological Structures and Materials, Pennsylvania, 22-24 October 1985 P73-86. Publ Clausthal-Zellerfeld." Trans Tech Publications, 1989
The Kaiser effect was evaluated for I I soils from coarse granular to highly plastic at various water contents, and for gneiss, schist, carbonate, limestone, mudstone, and sandstone rocks. Previously applied stress could be determined to within 10% for all soils. The rocks were tested at load of 25, 50, 75, and 100% of fracture stress and delay times of 0.01-10000 hours (in decade steps) after initial preload was applied. The Kaiser effect was essentially lost beyond 1000 hours. Rock type influences felicity ratio and reliability of the Kaiser effect. 912106 Kaiser effect in thermo-cycled rocks Montoto, M; Ruiz de Argandona, V G; Calleja, L: Suarez del Rio, L M Proc 4th Conference on Acoustic Emission/Microseismic Activity in Geological Structures and Materials, Pennsylvania, 22-24 October 1985 P97-116. Publ Clausthal-Zellerfeld: Trans Tech Publications, 1989
Intact specimens of granodiorite, epidiorite, and serpentinite were subject to thermal cycling with increasing temperatures of 130. 230. 330, and 430 deg C. The maximum thermal stress in previous cycles was clearly discernable from results of AE/MS monitoring. AE/MS was related to rock mineralogy and microstructure. The effect of heating on some rock properties was also examined. 912107 Effects of depth on rock fracture Cleary, M P Proc International Symposium on Rock at Great Depth, Pau, 28-31 August 1989 V3. P1153-1163. Publ Rotterdam: A A Balkema, 1989
Behaviour of rock changes with depth, one major feature being the change of dominance of fracture energy or toughness to control of fracture growth by confining stress. Fracture interactions with stress and other fractures, factors controlling fracture shape, role of pore fluids, and thermal conduction and
convention effects are examined. These phenomena are discussed with specific interest to hydraulic fracture, Areas for further work are outlined. 912108 Rock fabric during mode II tests: analysis of acoustic emissions and sonic properties (In French) Benzaim, A Proe International Symposium on Rock at Great Depth, Pau, 28-31 August 1989 V3, P1295-1312. Publ Rotterdam: ,4 A Balkema. 1989
The analogy between earthquakes and acoustic emission, widely used to study damage of rocks and concrete, is examined quantitatively. Parameters measured during mode II rupture experiments provide a possible method of classification of materials, which must be confirmed by further testing. This work suggests several avenues of approach to better understand damage mechanisms. 912109 Mechanism of deformation and fracture of brittle rock Salganic, R L; Dyskin, A V; Germanovich, L N: Tsyrulnikov, M N Proc International Symposium on Rock at Great Depth, Pan, 28-31 August 1989 V3. P1321-1328. Publ Rotterdam: A A Balkema, 1989
A model of dilatancy and fracture of brittle materials due to crack growth under uniaxial compression is presented. It assumes the largest and least frequent cracks increase in size considerably and play a major role. Tensile fractures grow from shear cracks expanded perpendicular to the axis of compression. Theoretical results are compared to experimental data from the literature.
Time dependent behaviour See a~o: 912245, 912286. 912287. 912385. 912509 912110 Strain, pore pressure and fatigue characteristics of sandstone under various load conditions Tien Y M; Lee, D H; Juang, C H lnt J Rock Mech Min Sci V27. N4, Aug 1990, P283-289
Results of tests on a saturated sandstone under quasi-static, repeated, and cyclic undrained triaxial loading are analysed, and a relation developed between accumulated axial strain and fatigue life. Under some conditions, a critical strain was seen beyond which failure occurred almost instantaneously. Variation of pore water pressure under the different Ioadings was studied. Three distinct modes were seen under cyclic loading. In all cases, pore pressure falls rapidly immediately before failure. Pore pressure variations are interpreted in terms of structural changes within the specimens. 912111 Solid-state flow of polymineralic rocks Handy, M R J Geophys Res V95. NB6. June 1990. P8647-8661
Mechanical and microstructural behaviour of polyminerallic rock will depend on relative volumes and theologic properties of the constituent minerals. A concept of strain energy partitioning in polyphase aggregates is presented for prediction of bulk mechanical properties in terms of those of its constituents. Biminerallic strength-composition relations predicted are highly nonlinear, yet accurately mimic those observed in experimental behaviour. Examination of quartzo-feldspathic
~C 1991 Pergamon Press plc. Reproduction not permitted