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Some microstructures of experimentally deformed argillaceous sediments
50A
T83009METHOD OF DISTINGUISHIN~ REGIONAL DIRECTIONS OF JOINTING AND OF IDENTIFYI~ JOINT SETS ASSOCIATED WITH INDIVIDUAL GEOLOGIC STRUCTURES C1/rrie, J B; Reik, G A Can J Earth Sci, VI4, N6, June 1977, P1211-1228 From study of Joints in Cardi~n strata near South Ram River in the foothills of central Alberta, a method is proposed by which to make this separation. The method is suggested as a means of distimg~ishirAg those widely distributed directions of Jointing that may owe their origin to regional uplift and eroelonsl unloading, from those Joint sets that are directly related to development of a single structure, such as a fold. Because of the close connection between Jointlng anl development of fracture porosity and permeability in the subsurface, there is need to predict both those Joint set orientations which will probably occur on a r~gional scale and those sets which are more likely to be localized in their incidence. 783010 FABRICS, MICROSTEUCTURES AND MICRG2ESTONICS. PROCEEDINGS OF THE CONFERENCE AT LEIDEN, MARCH 3-5, 1976. SPECIAL ISSUE Lister, G S; Williams, P F; Zwart, H J Tectonophysics, V39, NI-3, 1977, P3-499 783011 PLASTIC D~X)RMATION OF Q U A R T Z I T E S A T L O W T ~ PERATURE IN AN A R E A O F NATURAL STRAIN GRADIENT Bouchez, J L Tectonophysics, V39, N1-3, 1977, P25-50 The study relates to the kinematics of zones of large scale flow such as sheer zones or thrust zonesg 783012 DEFECT MICROSTRUCTURES IN DEFORMED AND RECOVERED DOLOMITES Barber, D J Tectonophysics, V39, N1-3, 1977, P193-213 783013 SOME MICROSTRUCTURES OF EXPERIMENTALLY DEFORMED ARGILLACEOUS SEDIMENTS Maltman, A J
Tectonophyslcs, V39, NI-3, 1977, P417-436 Fracture processes 783014 CHIP FORMATION IN ANISOTROPIC ROCK Altiero, N J; Sikarskie, D L Rock Mech, V10, N3, March 1978 , P125-137 A two dimensional, isotropic theory for the initiation and growth of damage regions in elastic brittle materials (rock) subjected to globally compressive stress fields has been extended to anisotropic fracture behaviour. The specific anlsotropy considered is of the bedding plane type, i e there is a preferred mlerocrack distribution parallel to the bedding plane. The theory defines damage as coalescence of propagatl,g microcraeks. The growth of this damage is described quantitatively by fracture function contours, constructed for three cases; the bedding plane vertical, at 45 de~ and horizontal. ~ne prescribed displacement boundary condition provides accurate initiation and initial growth results while the prescribed traction bournary condition provides a better approximation of the latter stages of fracture growth. Chip shape for all eases as defined by the contours appears intuitively reasonable.
783015 PHENOMENA REINING TO THE FAILURE OF HARD ROCK ADJACENT TO AN INDENTOR Hood, M J S Air Inst M_in Metall, V78, NS, Dec 1977, Pi13-123 It is shown that, when a flat-bottomed indentor is pressed into the surface of a strong rock, the ncrmal force necessary to cause failure of the rock is reduced substantially if a sheer force is applied to the indentor. A mathematical analysis is described, which shows that higher s%resses are induced in an elastic material close to the free surface of the material ahead of a punch when a shear force together with a normal force is applied to the punch. Therefore, failure of the material would occur with lower forces applied to the punch. Stress trajectories show that fractures develop in the rock along lines of maximum principal stresses. Auth. 783016 STATISTICAL THEORIES OF CRACK PROPATATION Vere-Jones, D J Int Ass Math Geol, Vg, NS, Oct 1977,
P455-481 Considers crack growth in rocks as related to engineering and earthquake prediction. One feature which appears to play a significant role in the fracture mechanism is the formation of mlcrofractures prior to a major failure. Microfractures also play a key role in statistical theories as developed by Weibull add later writers. Some recent work in these two fields is reviewed and it is suggested that it may be possible to extend the statistical model so as to describe the dynamics of crack formation. As a preliminary step in this direction, it is shown that a branching model for the coalescence of microfractures leads to a simple derivation of the frequency-magnitude l ~ of fracture energies. Other methods of introducing statistical ideas into the d y r ~ c s of crack propagation are also briefly reviewed, and compared to deterministic models of crack growth. 783017 LIMITING DEFORMATIONS AS CRITERIA OF ROCK FRACTURE Veksler, Y A; G u m e r ~ , G N Soy Min Sci, VI3, NI, Jan-Feb 1977, P74-75 Reports uniaxial compression tests, hollow cylinder tests and beam tests on sandstone, argillite, siltstone and coal from the Karaganda coalfield. 783018 SOME ASPECTS OF MODELING ROCK FRACTURE BY THE OPYICAL POLARIZATION METHOD Khesin, G L; Taratorin, B I; Sakharov, V N Soy Min Sol, VI2, N6, NOv-Dec 19%, P580-584 783019 SHEAR OF AN INDIVIDUAL ELEMENT OF SLICE DURING ROCK CUI~ING Vasilev, L M Soy Min Sci, V12, N6, Nov-Dec 1976 , P597-600 783020 INFLUENCE OF CRACK PROPAGATION VELOCITY ON THE ENERGY CONTENT OF THE FRACIVJRE PROCESS Bobryakov, A P; Polrovskii, G N; Serpeninov, B N Soy Min Sci, VI2, NS, Sept-Oct 1976 , P518-525 Relates to the determination of the effective surface energy density and other energy consumption of fracture.
T83009METHOD OF DISTINGUISHIN~ REGIONAL DIRECTIONS OF JOINTING AND OF IDENTIFYI~ JOINT SETS ASSOCIATED WITH INDIVIDUAL GEOLOGIC STRUCTURES C1/rrie, J B; Reik, G A Can J Earth Sci, VI4, N6, June 1977, P1211-1228 From study of Joints in Cardi~n strata near South Ram River in the foothills of central Alberta, a method is proposed by which to make this separation. The method is suggested as a means of distimg~ishirAg those widely distributed directions of Jointing that may owe their origin to regional uplift and eroelonsl unloading, from those Joint sets that are directly related to development of a single structure, such as a fold. Because of the close connection between Jointlng anl development of fracture porosity and permeability in the subsurface, there is need to predict both those Joint set orientations which will probably occur on a r~gional scale and those sets which are more likely to be localized in their incidence. 783010 FABRICS, MICROSTEUCTURES AND MICRG2ESTONICS. PROCEEDINGS OF THE CONFERENCE AT LEIDEN, MARCH 3-5, 1976. SPECIAL ISSUE Lister, G S; Williams, P F; Zwart, H J Tectonophysics, V39, NI-3, 1977, P3-499 783011 PLASTIC D~X)RMATION OF Q U A R T Z I T E S A T L O W T ~ PERATURE IN AN A R E A O F NATURAL STRAIN GRADIENT Bouchez, J L Tectonophysics, V39, N1-3, 1977, P25-50 The study relates to the kinematics of zones of large scale flow such as sheer zones or thrust zonesg 783012 DEFECT MICROSTRUCTURES IN DEFORMED AND RECOVERED DOLOMITES Barber, D J Tectonophysics, V39, N1-3, 1977, P193-213 783013 SOME MICROSTRUCTURES OF EXPERIMENTALLY DEFORMED ARGILLACEOUS SEDIMENTS Maltman, A J
Tectonophyslcs, V39, NI-3, 1977, P417-436 Fracture processes 783014 CHIP FORMATION IN ANISOTROPIC ROCK Altiero, N J; Sikarskie, D L Rock Mech, V10, N3, March 1978 , P125-137 A two dimensional, isotropic theory for the initiation and growth of damage regions in elastic brittle materials (rock) subjected to globally compressive stress fields has been extended to anisotropic fracture behaviour. The specific anlsotropy considered is of the bedding plane type, i e there is a preferred mlerocrack distribution parallel to the bedding plane. The theory defines damage as coalescence of propagatl,g microcraeks. The growth of this damage is described quantitatively by fracture function contours, constructed for three cases; the bedding plane vertical, at 45 de~ and horizontal. ~ne prescribed displacement boundary condition provides accurate initiation and initial growth results while the prescribed traction bournary condition provides a better approximation of the latter stages of fracture growth. Chip shape for all eases as defined by the contours appears intuitively reasonable.
783015 PHENOMENA REINING TO THE FAILURE OF HARD ROCK ADJACENT TO AN INDENTOR Hood, M J S Air Inst M_in Metall, V78, NS, Dec 1977, Pi13-123 It is shown that, when a flat-bottomed indentor is pressed into the surface of a strong rock, the ncrmal force necessary to cause failure of the rock is reduced substantially if a sheer force is applied to the indentor. A mathematical analysis is described, which shows that higher s%resses are induced in an elastic material close to the free surface of the material ahead of a punch when a shear force together with a normal force is applied to the punch. Therefore, failure of the material would occur with lower forces applied to the punch. Stress trajectories show that fractures develop in the rock along lines of maximum principal stresses. Auth. 783016 STATISTICAL THEORIES OF CRACK PROPATATION Vere-Jones, D J Int Ass Math Geol, Vg, NS, Oct 1977,
P455-481 Considers crack growth in rocks as related to engineering and earthquake prediction. One feature which appears to play a significant role in the fracture mechanism is the formation of mlcrofractures prior to a major failure. Microfractures also play a key role in statistical theories as developed by Weibull add later writers. Some recent work in these two fields is reviewed and it is suggested that it may be possible to extend the statistical model so as to describe the dynamics of crack formation. As a preliminary step in this direction, it is shown that a branching model for the coalescence of microfractures leads to a simple derivation of the frequency-magnitude l ~ of fracture energies. Other methods of introducing statistical ideas into the d y r ~ c s of crack propagation are also briefly reviewed, and compared to deterministic models of crack growth. 783017 LIMITING DEFORMATIONS AS CRITERIA OF ROCK FRACTURE Veksler, Y A; G u m e r ~ , G N Soy Min Sci, VI3, NI, Jan-Feb 1977, P74-75 Reports uniaxial compression tests, hollow cylinder tests and beam tests on sandstone, argillite, siltstone and coal from the Karaganda coalfield. 783018 SOME ASPECTS OF MODELING ROCK FRACTURE BY THE OPYICAL POLARIZATION METHOD Khesin, G L; Taratorin, B I; Sakharov, V N Soy Min Sol, VI2, N6, NOv-Dec 19%, P580-584 783019 SHEAR OF AN INDIVIDUAL ELEMENT OF SLICE DURING ROCK CUI~ING Vasilev, L M Soy Min Sci, V12, N6, Nov-Dec 1976 , P597-600 783020 INFLUENCE OF CRACK PROPAGATION VELOCITY ON THE ENERGY CONTENT OF THE FRACIVJRE PROCESS Bobryakov, A P; Polrovskii, G N; Serpeninov, B N Soy Min Sci, VI2, NS, Sept-Oct 1976 , P518-525 Relates to the determination of the effective surface energy density and other energy consumption of fracture.