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Loess model for wetted settlement
150A 903155 Loess model for wetted settlement Qian, J H: Zhu, B H Proc International Conference on Engineering Problems o f Regional Soils, Beijing, 11-15 August 1988 P305-307. Publ Beijing: International Academic Publishers. 1989 A five element rheologic model and its corresponding equation for predicting wetted settlement of a loess foundation under conditions of steady seepage are presented. Rheological parameters can be determined from laboratory oedometer tests. The equation was applied to settlement of a test pit in the field. Predictions are in good agreement with field values.
903156 Compaction of collapsing loess soils by the energy of deep explosions Ryzhov. A Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P308-315. Publ Beijing: International Academic" Publishers. 1989 A procedure for calculating the potential strain of a collapsible soil is developed. This allows the assessment of necessary preconstruction design soil density to withstand a given structural load. Soil compaction by deep blasting is then discussed and analysed. Field results presented show that deep layers of collapsible soils can be densified to a high degree by explosions, and better compaction is achieved than that by wetting procedures alone.
903157 Natural and lime stabilised properties of Bandung clay Younger, J S Proc 2nd International Conference on Geomechanics in Tropical Soils', Singapore, 12-14 December 1988 VI, P437444. Publ Rotterdam: A A Balkema, 1988 An investigation into the consolidation and stability characteristics of the soft, high moisture content clay was carried out. Index properties are first outlined. Oedometer tests were performed on natural and lime-treated soils and results used to analyse rate of consolidation and settlement potential. In situ vane shear and laboratory undrained triaxial tests were conducted to determine strength characteristics. Lime did not have a substantial strengthening effect due to high initial moisture content.
903158 Collapsible and expansive soils in Brazil Vargas, M Proc 2nd International Conference on Geomechanics in Tropical Soils. Singapore, 12-14 December 1988. Supplementary Documentation P38-41. Publ Singapore: ISSMFE, 1988 Tropical residual soils, formed by in situ weathering, are often described in Brazil as occurring in two layers, surface lateric and deeper saprolitic. The upper layer can occur as lateritic gravels, a hardened residual clay or sandy clay layer, or a porous sandy or clayey layer. The deeper horizon has a relict structure. Collapsible soils in Brazil are found in the porous lateritic layer, whilst expansive soils are generally residual saprolitic or colluvial, derived from rocks leaving expansive clay minerals. Occurrence, distribution, and properties are described.
903159 Preeonsolidation of Bangkok clay by nondisplacement sand drains and surcharge Moh. Z C: Woo. S M Proc Ninth Southeast Asian Geotechnical Conference. Bangkok, 7-11 December 1987 V2, P8.171-8.I84. Publ Bangkok." Southeast Asian Geotechnical Society, 1987 A proposed site for Bangkok airport is underlain by soft clay layers. At an instrumented test site, settlement, lateral displacement, and pore pressures were monitored for surcharged sections, with and without the installation of water jetted sand drains. Results show that use of non-displacement sand drains is an effective method of accelerating settlement and consolidation of the Bangkok clay, and that water content of the very soft layers can be significantly reduced. Generally good agreement was found between estimated and measured settlements.
Dynamic properties 903160 Representability of cracked media by periodically layered media Douma, J Geophys Prospect 1/37, NT, Oct 1989, P831-849 Periodically layered media and media containing aligned cracks or ellipsoidal inclusions show transverse isotropy with respect to elastic wave propagation. Crack induced anisotropy as described by the Hudson and Nishizawa models is compared to anisotropy caused by sequences of thin isotropic layers. Stability and geometric conditions necessary to allow layer models to be applied to crack induced anisotropy are determined. Media containing dry inclusions cannot be modelled by isotropic layers.
903161 Elastic-wave attenuation in fluid-saturated Berea sandstone. Short note O'Hara, S G Geophysics V54, N6, June 1989, P785-788 Attenuation in Berea sandstone at a given temperature and effective stress has been shown to be dependent on fluid viscosity and pore fluid-matrix chemistry. Previous work using brinc and n-heptane is supplemented by experiments with propane and n-dodecane pore fluids. Results are presented for the three paraffins with similar chemistry but different viscosity, and brine, which is dissimilar on both counts.
903 ! 62 Experimental and theoretical comparison between static and dynamic torsional soil tests Bolton, M D; Wilson, J M R Geotechnique V39, N4, Dec 1989, P585-599 Dynamic properties of dry Leighton Buzzard sand measured using a resonant column apparatus are compared with those from very low frequency cyclic loading tests on similar specimens. Results indicate properties of dry sand are frequency independent. A one dimensional kinematic hardening plasticity soil model using input parameters from static tests gives predictions in good agreement with measured data. Frequency response properties are discussed with reference to dynamic analysis of offshore structures or machine foundations.
~ 1990 Pergamon Press plc. Reproduction not permitted
903156 Compaction of collapsing loess soils by the energy of deep explosions Ryzhov. A Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P308-315. Publ Beijing: International Academic" Publishers. 1989 A procedure for calculating the potential strain of a collapsible soil is developed. This allows the assessment of necessary preconstruction design soil density to withstand a given structural load. Soil compaction by deep blasting is then discussed and analysed. Field results presented show that deep layers of collapsible soils can be densified to a high degree by explosions, and better compaction is achieved than that by wetting procedures alone.
903157 Natural and lime stabilised properties of Bandung clay Younger, J S Proc 2nd International Conference on Geomechanics in Tropical Soils', Singapore, 12-14 December 1988 VI, P437444. Publ Rotterdam: A A Balkema, 1988 An investigation into the consolidation and stability characteristics of the soft, high moisture content clay was carried out. Index properties are first outlined. Oedometer tests were performed on natural and lime-treated soils and results used to analyse rate of consolidation and settlement potential. In situ vane shear and laboratory undrained triaxial tests were conducted to determine strength characteristics. Lime did not have a substantial strengthening effect due to high initial moisture content.
903158 Collapsible and expansive soils in Brazil Vargas, M Proc 2nd International Conference on Geomechanics in Tropical Soils. Singapore, 12-14 December 1988. Supplementary Documentation P38-41. Publ Singapore: ISSMFE, 1988 Tropical residual soils, formed by in situ weathering, are often described in Brazil as occurring in two layers, surface lateric and deeper saprolitic. The upper layer can occur as lateritic gravels, a hardened residual clay or sandy clay layer, or a porous sandy or clayey layer. The deeper horizon has a relict structure. Collapsible soils in Brazil are found in the porous lateritic layer, whilst expansive soils are generally residual saprolitic or colluvial, derived from rocks leaving expansive clay minerals. Occurrence, distribution, and properties are described.
903159 Preeonsolidation of Bangkok clay by nondisplacement sand drains and surcharge Moh. Z C: Woo. S M Proc Ninth Southeast Asian Geotechnical Conference. Bangkok, 7-11 December 1987 V2, P8.171-8.I84. Publ Bangkok." Southeast Asian Geotechnical Society, 1987 A proposed site for Bangkok airport is underlain by soft clay layers. At an instrumented test site, settlement, lateral displacement, and pore pressures were monitored for surcharged sections, with and without the installation of water jetted sand drains. Results show that use of non-displacement sand drains is an effective method of accelerating settlement and consolidation of the Bangkok clay, and that water content of the very soft layers can be significantly reduced. Generally good agreement was found between estimated and measured settlements.
Dynamic properties 903160 Representability of cracked media by periodically layered media Douma, J Geophys Prospect 1/37, NT, Oct 1989, P831-849 Periodically layered media and media containing aligned cracks or ellipsoidal inclusions show transverse isotropy with respect to elastic wave propagation. Crack induced anisotropy as described by the Hudson and Nishizawa models is compared to anisotropy caused by sequences of thin isotropic layers. Stability and geometric conditions necessary to allow layer models to be applied to crack induced anisotropy are determined. Media containing dry inclusions cannot be modelled by isotropic layers.
903161 Elastic-wave attenuation in fluid-saturated Berea sandstone. Short note O'Hara, S G Geophysics V54, N6, June 1989, P785-788 Attenuation in Berea sandstone at a given temperature and effective stress has been shown to be dependent on fluid viscosity and pore fluid-matrix chemistry. Previous work using brinc and n-heptane is supplemented by experiments with propane and n-dodecane pore fluids. Results are presented for the three paraffins with similar chemistry but different viscosity, and brine, which is dissimilar on both counts.
903 ! 62 Experimental and theoretical comparison between static and dynamic torsional soil tests Bolton, M D; Wilson, J M R Geotechnique V39, N4, Dec 1989, P585-599 Dynamic properties of dry Leighton Buzzard sand measured using a resonant column apparatus are compared with those from very low frequency cyclic loading tests on similar specimens. Results indicate properties of dry sand are frequency independent. A one dimensional kinematic hardening plasticity soil model using input parameters from static tests gives predictions in good agreement with measured data. Frequency response properties are discussed with reference to dynamic analysis of offshore structures or machine foundations.
~ 1990 Pergamon Press plc. Reproduction not permitted