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Characterization of granitic saprolitic soils
206A
914053 Characterization of granitic saprolitic soils Massey, J B; Irfan, T Y; Cipullo, A Proe 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, 13-18 August 1989 VI. P533-542. Publ Rotterdam: A A Balkema. 1989
914057 Chalk fabric and its relation to certain geotechnical properties Bell, F G; Cripps, J C: Edmonds. C N; Culshaw, M G Proc International Chalk Symposium, Brighton, 4-7 September 1989 P187-193. Publ London. Thomas Telford. 1990
Engineering properties of residual soils and saprolites depend on grain size and void ratio, together with the microfabric of the soil, which depends on the nature and intensity of the weathering and alteration which have taken place. Weathering microenvironment can be highly variable, even in a relatively uniform geological profile. An attempt is made to quantify microfabric, using a micropetrographic index, relating sound and unsound constituents, and a modified degree of decomposition index. Relations between microfabric and shear and deformation behaviour are examined.
The depositional and post depositional histories of chalk, as they influence microstructure, lithification, and cementation, are described. UK chalks from three locations, Yorkshire, Norfolk, and Kent, are compared in terms of specific gravity, dry and saturated densities, saturation moisture content, effective and absolute porosities, dry and saturated unconfined compressive strength, Brazilian tensile strength, point load strength, Schmidt hammer and Shore schleroscope hardness, and elastic properties. Stress strain behaviour under triaxial conditions is discussed.
914054 Characterisation of tropical weathering profile derived from Precambrian gneiss-migmatite complex in parts of South Western Nigeria Oni, S F Proc 6th International Congress International Association of Engineering Geology, Amsterdam, 6-10 August 1990 VI, P431-439. Publ Rotterdam: A A Balkema. 1990 The profile from topsoil to weathered rock was examined to study any relations between geotechnical, chemical, and mineralogical characteristics. Index properties were determined according to BSI377. Sieved samples were examined chemically and mineralogically using atomic absorption spectrophotometry and X ray diffraction. Results obtained arc compared to the weathering profile defined by Adekoya (1987).
914055 Quantitative approach on micro-structure of engineering clay Wu, Y X; Zhang, Z H; Ling, Z M Proc 6th International Congress International Association of Engineering Geology, Amsterdam, 6-10 August 1990 V/, t)505-510. Publ Rotterdam: A A Balkema, 1990 A temperature gradient vacuum sublimation apparatus to dry frozen samples of undisturbed soils and a computer based image analysis system capable of providing data on porosity, void ratio, grain size, and grain shape are described. Using data so obtained, the concept of system structure of clays is developed, in which specified levels of structure are found at specified energy states. Relations between structural changes and properties of the clay are analysed.
914056 Comparative studies on the petrophysical properties of chalk from England,Greece and the North Sea Patsoules, M G; Cripps, J C Proc International Chalk Symposium, Brighton, 4-7 September 1989 PI79-186. Publ London: Thomas Telford, 1990 Upper Cretaceous chalks from Yorkshire, the Ekofisk reservoir, and the Ionian Sea have been compared. Properties of chalk of equivalent sedimentological facies and age are examined, including porosity, permeability, and pore size distribution. Grain morphology on a microscopic scale, pore geometry, and geochemical data are discussed with respect to hydrocarbon generation and saturation.
Deformation and strength characteristics See a~o: 914003. 914296, 914297. 914298, 914373
9 ! 4058 Unconfined compressive strength versus degree of saturation for sedimentary rock. Technical note Day, R W Bull Assoc Engng Geoi V27. N4, Not, 1990, P505-507 UCS is one of the most easily measured strength parameters. To quantify the importance of degree of saturation on UCS, tests were carried out on Torry Sandstone, Del Mar Siltstone, and Monterey Diatomaceous Rock. All showed strength decrease with increasing water content, with reductions at saturation, as compared to the air dry state, of 45, 67, and 92% respectively for the sandstone, siltstone, and diatomaceous rocks.
914059 Generalized stress-path-dependent soil behaviour with a new hollow cylinder torsional apparatus Void, Y P; Sayao, A; Hou, E; Negussey, D Can Geotech J V27, N5, Oct 1990, P601-616 A new apparatus is illustrated which is suitable for testing under generalised stress paths, including principal stress rotation, characteristic of offshore wave or earthquake loading. A more rational index of stress nonuniformity across the wall of the specimen in terms of variation in stress ratio shows that a more restricted region of stress space than was previously supposed is available for investigation without introducing serious stress nonuniformity. Specimen preparation and tests on drained loose and dense sands are described, and results demonstrate the capability of the apparatus.
914060 Influence of storage and reconsolidation procedures on clay properties. Graham, J; Jamieson, M R; Ho, D Y F; Azizi, F Geoteeh Test J V13, N4, Dec 1990, P280-290 Results of undrained shear tests on an illite clay, stored for periods of up to ! week and reconsolidated using 3 different techniques, are discussed. Best recovery of stress strain behaviour is seen for samples stored undrained at constant volume for the shortest possible time, then reconsolidated to their ground stress before shearing. This will allow undrained strength and pore pressure parameters to be recovered with accuracy +/-6%. Larger differences are found for relative stiffness.
1991 Pergamon Press pie. Reproduction not permitted
914053 Characterization of granitic saprolitic soils Massey, J B; Irfan, T Y; Cipullo, A Proe 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, 13-18 August 1989 VI. P533-542. Publ Rotterdam: A A Balkema. 1989
914057 Chalk fabric and its relation to certain geotechnical properties Bell, F G; Cripps, J C: Edmonds. C N; Culshaw, M G Proc International Chalk Symposium, Brighton, 4-7 September 1989 P187-193. Publ London. Thomas Telford. 1990
Engineering properties of residual soils and saprolites depend on grain size and void ratio, together with the microfabric of the soil, which depends on the nature and intensity of the weathering and alteration which have taken place. Weathering microenvironment can be highly variable, even in a relatively uniform geological profile. An attempt is made to quantify microfabric, using a micropetrographic index, relating sound and unsound constituents, and a modified degree of decomposition index. Relations between microfabric and shear and deformation behaviour are examined.
The depositional and post depositional histories of chalk, as they influence microstructure, lithification, and cementation, are described. UK chalks from three locations, Yorkshire, Norfolk, and Kent, are compared in terms of specific gravity, dry and saturated densities, saturation moisture content, effective and absolute porosities, dry and saturated unconfined compressive strength, Brazilian tensile strength, point load strength, Schmidt hammer and Shore schleroscope hardness, and elastic properties. Stress strain behaviour under triaxial conditions is discussed.
914054 Characterisation of tropical weathering profile derived from Precambrian gneiss-migmatite complex in parts of South Western Nigeria Oni, S F Proc 6th International Congress International Association of Engineering Geology, Amsterdam, 6-10 August 1990 VI, P431-439. Publ Rotterdam: A A Balkema. 1990 The profile from topsoil to weathered rock was examined to study any relations between geotechnical, chemical, and mineralogical characteristics. Index properties were determined according to BSI377. Sieved samples were examined chemically and mineralogically using atomic absorption spectrophotometry and X ray diffraction. Results obtained arc compared to the weathering profile defined by Adekoya (1987).
914055 Quantitative approach on micro-structure of engineering clay Wu, Y X; Zhang, Z H; Ling, Z M Proc 6th International Congress International Association of Engineering Geology, Amsterdam, 6-10 August 1990 V/, t)505-510. Publ Rotterdam: A A Balkema, 1990 A temperature gradient vacuum sublimation apparatus to dry frozen samples of undisturbed soils and a computer based image analysis system capable of providing data on porosity, void ratio, grain size, and grain shape are described. Using data so obtained, the concept of system structure of clays is developed, in which specified levels of structure are found at specified energy states. Relations between structural changes and properties of the clay are analysed.
914056 Comparative studies on the petrophysical properties of chalk from England,Greece and the North Sea Patsoules, M G; Cripps, J C Proc International Chalk Symposium, Brighton, 4-7 September 1989 PI79-186. Publ London: Thomas Telford, 1990 Upper Cretaceous chalks from Yorkshire, the Ekofisk reservoir, and the Ionian Sea have been compared. Properties of chalk of equivalent sedimentological facies and age are examined, including porosity, permeability, and pore size distribution. Grain morphology on a microscopic scale, pore geometry, and geochemical data are discussed with respect to hydrocarbon generation and saturation.
Deformation and strength characteristics See a~o: 914003. 914296, 914297. 914298, 914373
9 ! 4058 Unconfined compressive strength versus degree of saturation for sedimentary rock. Technical note Day, R W Bull Assoc Engng Geoi V27. N4, Not, 1990, P505-507 UCS is one of the most easily measured strength parameters. To quantify the importance of degree of saturation on UCS, tests were carried out on Torry Sandstone, Del Mar Siltstone, and Monterey Diatomaceous Rock. All showed strength decrease with increasing water content, with reductions at saturation, as compared to the air dry state, of 45, 67, and 92% respectively for the sandstone, siltstone, and diatomaceous rocks.
914059 Generalized stress-path-dependent soil behaviour with a new hollow cylinder torsional apparatus Void, Y P; Sayao, A; Hou, E; Negussey, D Can Geotech J V27, N5, Oct 1990, P601-616 A new apparatus is illustrated which is suitable for testing under generalised stress paths, including principal stress rotation, characteristic of offshore wave or earthquake loading. A more rational index of stress nonuniformity across the wall of the specimen in terms of variation in stress ratio shows that a more restricted region of stress space than was previously supposed is available for investigation without introducing serious stress nonuniformity. Specimen preparation and tests on drained loose and dense sands are described, and results demonstrate the capability of the apparatus.
914060 Influence of storage and reconsolidation procedures on clay properties. Graham, J; Jamieson, M R; Ho, D Y F; Azizi, F Geoteeh Test J V13, N4, Dec 1990, P280-290 Results of undrained shear tests on an illite clay, stored for periods of up to ! week and reconsolidated using 3 different techniques, are discussed. Best recovery of stress strain behaviour is seen for samples stored undrained at constant volume for the shortest possible time, then reconsolidated to their ground stress before shearing. This will allow undrained strength and pore pressure parameters to be recovered with accuracy +/-6%. Larger differences are found for relative stiffness.
1991 Pergamon Press pie. Reproduction not permitted