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TEM study of microstructures associated with solution cleavage in limestone
IliA roughness; and (3) display of jointing or fragmentation pattern. The method has applications in rock mass characterisation, derivation of mechanical properties, modelling of groundwater flow, evaluation of blast fragmentation, and evaluation of blast overbreak and shatter.
893030 Method to characterize fracture density and connectivity through fractai geometry La Pointe, P R lnt 1 Rock Mech Min Sci V25, N6, Dec 1988, P421-429 A new method to quantify volumetric block or fracture density from core data is presented. The method has 2 formulations. The first considers the number of fractures per unit area whilst the second considers the blocks formed by the fractures. Fracture patterns used are both natural and computer generated. Fracture density is shown to be fractal and often scale invariant, and fractal dimension appears most sensitive to number of fractures or blocks, rather than size, orientation or size variability. 893031 Computerised tomography as a core analysis tool: applications, instrument evaluation, and image improvement techniques Hunt, P K; Engler, P; Bajsarowicz, C J Pet Technol V40, N9, Sept 1988. PI203-1210 CT is a nondestructive X ray technology which produces an image of the internal structure of a slice of rock core quickly and with the little specimen preparation. Its uses to visualise mud invasion, for fracture detection, lithologic characterisation, and core screening before laboratory tests are described. The advantages and disadvantages of different generations of commercial CT scanners for core analysis are discussed. Image improvement techniques and error reduction methods for software developed for soft human tissues and used on rock samples are presented.
893032 Mass-physical and geotechnical properties of superficial sediments of the lagoon of Guarapina - State of Rio de Janeiro -Brasil Chassefiere, B Marine Geotechnol V7, N4, 1987..88. P275-288 The effect of organic matter on water content and Atterberg limits was studied by testing organic rich fine kaolinite dominated muds. Water content, bulk density, shear strength, organic matter content and Atterberg limits were determined on 4 cores. Results show a strong relation between organic content and water content and liquid limit. It seems that 2% organic carbon is the lowest level at which relationships become evident and the soil could be classified as an organic clay of high plasticity and compressibility.
893033 TEM study of mierostructures associated with solution cleavage in limestone Meike, A; Wenk, H R Tectonophysics V154, NI/2, 1 Not" 1988, P137-148 Scaglia Rosso limestone of the Italian Appenines is a fine grained (I micron) rock with clay filled seams. Microstructures associated with the seams were characterised by transmission electron microscopy. The TEM revealed dislocations in single calcite grains, not visible optically. Comparisons were made with experimentally deformed calcite and computer simulations. Dislocation concentrations are often associated with
voids or pits which elongate in the direction of a calcite dislocation slip plane, and are interpreted as solution features. Selective dissolution of localized dislocation tangles is suggested as a reason for solution cleavage formation. The solution cleavage surface grows laterally, like a fracture tip.
Deformation and strength characteristics See also: 893305 893034 ln-situ shear modulus of sands by a fiat-plate peoetrometer: a laboratory study Motan, E S: Khan, A Q Geotech Test J VII, N4, Dec 1988, P257-262 A flat blade penetrometer has been designed to estimate in-situ shear modulus of cohesionless soils under repeated loading. The device was tested using mine railings sands and Ottawa sands prepared at different relative densities and loaded vertically. Preliminary results show reasonable agreement between the derived shear modulus and empirical formulations in the literature.
893O35 Automatic volume change and pressure measurement devices for triaxial testing of soils Lade, P V Geotech Test J VII, N4, Dec 1988, P263-268 Requirements for volume change devices are studied, considering volume capacity and precision for application to conventional triaxial tests. A buret type volume change device and a rolling diaphragm and displacement transducer system are described and evaluated. Test control and pressure measurements of both devices are discussed. Both devices meet or exceed requirements for volume capacity and precision necessary for conventional triaxial testing. 893036 Fast triaxial shear device Carroll, W F Geotech Test J VII, N4, Dec 1988, P276-280 The fast triaxial shear device, which axially deforms specimens rapidly using a piston-cylinder assembly driven by compressed nitrogen, is described. The apparatus is evaluated using clayey sand in slow testing (5 minutes) and fast testing (2 milliseconds). The fastest time to failure so far achieved is 0.5 milliseconds.
893037 New simple shear apparatus Budhu, M Geoteeh Test J VII, N4, Dec 1988. P281-287 A new simple shear apparatus has been designed by merging the advantages of the NGI and Cambridge shear apparatus. A cube sample with sides enclosed by a rubber membrane has shear displacement applied through a closed loop servohydraulic actuator. Data acquisition, specimen preparation and computation of stress and strain are described. Results of tests on Ottawa sands and kaolin clay using the new apparatus are described. Use of the device and specimen preparation are simple, and the apparatus facilitates measurement of the complete set of stresses for simple shear deformation from a part of the specimen where uniform conditions of stresses and strains are likely to prevail.
1989 Pergamon Press pie. Reproduction not permitted RMMS 26.3 . ~ M
893030 Method to characterize fracture density and connectivity through fractai geometry La Pointe, P R lnt 1 Rock Mech Min Sci V25, N6, Dec 1988, P421-429 A new method to quantify volumetric block or fracture density from core data is presented. The method has 2 formulations. The first considers the number of fractures per unit area whilst the second considers the blocks formed by the fractures. Fracture patterns used are both natural and computer generated. Fracture density is shown to be fractal and often scale invariant, and fractal dimension appears most sensitive to number of fractures or blocks, rather than size, orientation or size variability. 893031 Computerised tomography as a core analysis tool: applications, instrument evaluation, and image improvement techniques Hunt, P K; Engler, P; Bajsarowicz, C J Pet Technol V40, N9, Sept 1988. PI203-1210 CT is a nondestructive X ray technology which produces an image of the internal structure of a slice of rock core quickly and with the little specimen preparation. Its uses to visualise mud invasion, for fracture detection, lithologic characterisation, and core screening before laboratory tests are described. The advantages and disadvantages of different generations of commercial CT scanners for core analysis are discussed. Image improvement techniques and error reduction methods for software developed for soft human tissues and used on rock samples are presented.
893032 Mass-physical and geotechnical properties of superficial sediments of the lagoon of Guarapina - State of Rio de Janeiro -Brasil Chassefiere, B Marine Geotechnol V7, N4, 1987..88. P275-288 The effect of organic matter on water content and Atterberg limits was studied by testing organic rich fine kaolinite dominated muds. Water content, bulk density, shear strength, organic matter content and Atterberg limits were determined on 4 cores. Results show a strong relation between organic content and water content and liquid limit. It seems that 2% organic carbon is the lowest level at which relationships become evident and the soil could be classified as an organic clay of high plasticity and compressibility.
893033 TEM study of mierostructures associated with solution cleavage in limestone Meike, A; Wenk, H R Tectonophysics V154, NI/2, 1 Not" 1988, P137-148 Scaglia Rosso limestone of the Italian Appenines is a fine grained (I micron) rock with clay filled seams. Microstructures associated with the seams were characterised by transmission electron microscopy. The TEM revealed dislocations in single calcite grains, not visible optically. Comparisons were made with experimentally deformed calcite and computer simulations. Dislocation concentrations are often associated with
voids or pits which elongate in the direction of a calcite dislocation slip plane, and are interpreted as solution features. Selective dissolution of localized dislocation tangles is suggested as a reason for solution cleavage formation. The solution cleavage surface grows laterally, like a fracture tip.
Deformation and strength characteristics See also: 893305 893034 ln-situ shear modulus of sands by a fiat-plate peoetrometer: a laboratory study Motan, E S: Khan, A Q Geotech Test J VII, N4, Dec 1988, P257-262 A flat blade penetrometer has been designed to estimate in-situ shear modulus of cohesionless soils under repeated loading. The device was tested using mine railings sands and Ottawa sands prepared at different relative densities and loaded vertically. Preliminary results show reasonable agreement between the derived shear modulus and empirical formulations in the literature.
893O35 Automatic volume change and pressure measurement devices for triaxial testing of soils Lade, P V Geotech Test J VII, N4, Dec 1988, P263-268 Requirements for volume change devices are studied, considering volume capacity and precision for application to conventional triaxial tests. A buret type volume change device and a rolling diaphragm and displacement transducer system are described and evaluated. Test control and pressure measurements of both devices are discussed. Both devices meet or exceed requirements for volume capacity and precision necessary for conventional triaxial testing. 893036 Fast triaxial shear device Carroll, W F Geotech Test J VII, N4, Dec 1988, P276-280 The fast triaxial shear device, which axially deforms specimens rapidly using a piston-cylinder assembly driven by compressed nitrogen, is described. The apparatus is evaluated using clayey sand in slow testing (5 minutes) and fast testing (2 milliseconds). The fastest time to failure so far achieved is 0.5 milliseconds.
893037 New simple shear apparatus Budhu, M Geoteeh Test J VII, N4, Dec 1988. P281-287 A new simple shear apparatus has been designed by merging the advantages of the NGI and Cambridge shear apparatus. A cube sample with sides enclosed by a rubber membrane has shear displacement applied through a closed loop servohydraulic actuator. Data acquisition, specimen preparation and computation of stress and strain are described. Results of tests on Ottawa sands and kaolin clay using the new apparatus are described. Use of the device and specimen preparation are simple, and the apparatus facilitates measurement of the complete set of stresses for simple shear deformation from a part of the specimen where uniform conditions of stresses and strains are likely to prevail.
1989 Pergamon Press pie. Reproduction not permitted RMMS 26.3 . ~ M