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Swelling behaviour of clay-sulfate rocks
163A examined, which provides accurate results yet requires no more field testing than for conventional deterministic predictions. 923192 Influence of filter jacket and core geometry on the longitudinal permeability of a prefabricated drain. Technical note Ali, F H Soils Found V31, N3, Sept 1991, P120-126 Prefabricated vertical strip drains are widely used to speed consolidation of soft soils under surcharge. They consist of a plastic core surrounded by a filter, generally of geotextile. Longitudinal permeability of strip drains has been examined in laboratory tests simulating field conditions. Results show discharge capacity is influenced by flexibility of the filter jacket and core and by core geometry. Discharge capacity in use is time dependent. 923193 Ko consolidation of undisturbed clays by means of trlaxinl ceil. Technical note Tsucliida, T; Kikucki, Y Soils Found V31, N3, Sept 1991, P127-137 For accurate simulation of field behaviour in the laboratory, undisturbed clay samples must be consolidated with the same stress as in the field. A triaxial cell to enable Ko consolidation is described. PC control is used to maintain zero radial strain conditions while axial and radial stress are applied. Measured Ko values are seen to be affected by the compressibility of the side drain paper, and the final Ko value is influenced by initial isotropic consolidation pressure at which the controlled consolidation started. 923194 Swelling behavionr of clay-suffate rocks Madsen, F T; Nuesch, R Proc 7tk I S R M International Congress on Rock Mechanics, Aachen, 16.20 September 1991 VI, P285-288. Publ Rotterdam: A A Balkema, 1991 Rocks containing both clay and sulphate minerals exhibit complex swelling behaviour. 16 rock samples collected during a drilling program at depths 900-920m in northern Switzerland were examined in the laboratory to determine swelling strain and swelling stress. Mineralogical and textural influences were studied. Maximum swelling pressures and strains can be expected for a hypothetical rock containing 10-15% clay and 70-75% anhydrite. Textures influence the time-swell behaviour. 923195 Problems related to the construction on macroporons collapsible loess soil Todorovic, T Proc 8tk Pamunericna Conference on Soil Mechanics and Foundation Eugi~erlng, Cwrtugena, 15-21 August 1987 V4, Pgl-lOI. Publ SCG: Colombia, 1991 Macroporous loess soils are known to be susceptible to additional settlement or collapse on wetting. Laboratory investigations on large numbers of loess soil samples taken from around Belgrade are described. A critical dry density is seen, below which there is increased risk of wetting induced settlement. The effect of water content on the shear strength parameters of these soils was also studied. The critical radius of water front effect upon collapsible foundation soil in the event of water leakage is evaluated. A foundation treatment using moist hydraulic sand or gravel fill to induce settlement collapse and provide a stable base is described.
923196 E n g i n e e ~ geology in the~ central area of Shanghai: preparation of the data for subsidence mndcllin~o Dassargues, A; Schroeder, C; Monjoie, A Proc 6tb International Congress Imerutional Assodatios of Engineering Geology, Amsterdam, 6.10 August 1990 V3, P1579-1588. Pubi Rotterdam: A A Balkema, 1990 Groundwater withdrawal has led to subsidence of 2.5m in Shanghai since 1920. The engineering geology of the top 70m of Quaternary sediments has been studied to provide data for a mathematical model of the subsidence. The deposits are mainly poorly consolidated and liable to compaction. Site characterisation employed CPTs, well logging, boreholes, and extensive laboratory testing. Site stratigraphy was established. The 3D coupled flow-consolidation model used is presented and computed subsidence-time profiles illustrated. 923197 Swelling eharacterfstics and stabilization of Kom-ombo clay, Egypt EI-Rayes, M K; Hassona, F A K; Hassan, M H; AbuBaker, A M Proc 6tk International Congress lntermm'omd Association of Engineering Geology, Amsterdam, 6-10 August 1990 V3, P1849-1854. Publ Rotterdam: A A Balkema, 1990 Swelling clays were sampled in the Kom-ombo region of Upper Egypt for laboratory investigations of their swelling properties and means to control them. Atterberg limits, free swell, compaction, swelling pressure,and unconfined compressive strength were determined for the natural soil and that with additives of 1-9% lime or 1-9% lime plus ! % NaCI. Adequate lowering of swelling susceptibility and strength increase were found for samples tested after varying periods of curing. 923198 Piles in deep residual clays Pellissier, J P Proc Tenth Regional Conference for Africa on Soil Meclmsies and Foundation Engi:wering and the Tkird International Conference on Tropical and Residul Soils, Musern, 23-27 September 1991 V1, P31-39. Publ Rotterdam: A A Balkema, 1991 The behaviour of the deep residual clays found in Africa differs from that of transported or shallow residual clays, and empirical methods of heave prediction cannot be applied. Severe movements were observed for a piled structure in Vryberg. Excavation by hand was used to expose for examination a 7.5m long pile. Severe distress caused by differential movement in the clay deposit was evident. Stress distribution as a function of depth, and swelling pressure and free swell of the clay were determined. Distribution and identification of these soils are described and some advice given for foundation design where they are encountered. 923199 Stress changes in soil after penetration Imre, E Proc Nimh Damlbe-Europena Confereoce on Soil Meeltamcs and Fomulation F~gineering, Budapest, 2-5 October 1990 P219-224. Pubi Budapest: Akademiai Kiado, 1990 A model to interpret the stress changes after penetration tests has been formulated which combines one dimensional axisymmetric coupled consofidation and phenomenological relaxation. Its predictions have been tested against results of over 100 CPTs in clays, silts, and sands. Applications and limitations are discussed with reference to the soil characteristics.
© 1992 Pergamon Press Ltd. Reproduction not l~rmiucd
923196 E n g i n e e ~ geology in the~ central area of Shanghai: preparation of the data for subsidence mndcllin~o Dassargues, A; Schroeder, C; Monjoie, A Proc 6tb International Congress Imerutional Assodatios of Engineering Geology, Amsterdam, 6.10 August 1990 V3, P1579-1588. Pubi Rotterdam: A A Balkema, 1990 Groundwater withdrawal has led to subsidence of 2.5m in Shanghai since 1920. The engineering geology of the top 70m of Quaternary sediments has been studied to provide data for a mathematical model of the subsidence. The deposits are mainly poorly consolidated and liable to compaction. Site characterisation employed CPTs, well logging, boreholes, and extensive laboratory testing. Site stratigraphy was established. The 3D coupled flow-consolidation model used is presented and computed subsidence-time profiles illustrated. 923197 Swelling eharacterfstics and stabilization of Kom-ombo clay, Egypt EI-Rayes, M K; Hassona, F A K; Hassan, M H; AbuBaker, A M Proc 6tk International Congress lntermm'omd Association of Engineering Geology, Amsterdam, 6-10 August 1990 V3, P1849-1854. Publ Rotterdam: A A Balkema, 1990 Swelling clays were sampled in the Kom-ombo region of Upper Egypt for laboratory investigations of their swelling properties and means to control them. Atterberg limits, free swell, compaction, swelling pressure,and unconfined compressive strength were determined for the natural soil and that with additives of 1-9% lime or 1-9% lime plus ! % NaCI. Adequate lowering of swelling susceptibility and strength increase were found for samples tested after varying periods of curing. 923198 Piles in deep residual clays Pellissier, J P Proc Tenth Regional Conference for Africa on Soil Meclmsies and Foundation Engi:wering and the Tkird International Conference on Tropical and Residul Soils, Musern, 23-27 September 1991 V1, P31-39. Publ Rotterdam: A A Balkema, 1991 The behaviour of the deep residual clays found in Africa differs from that of transported or shallow residual clays, and empirical methods of heave prediction cannot be applied. Severe movements were observed for a piled structure in Vryberg. Excavation by hand was used to expose for examination a 7.5m long pile. Severe distress caused by differential movement in the clay deposit was evident. Stress distribution as a function of depth, and swelling pressure and free swell of the clay were determined. Distribution and identification of these soils are described and some advice given for foundation design where they are encountered. 923199 Stress changes in soil after penetration Imre, E Proc Nimh Damlbe-Europena Confereoce on Soil Meeltamcs and Fomulation F~gineering, Budapest, 2-5 October 1990 P219-224. Pubi Budapest: Akademiai Kiado, 1990 A model to interpret the stress changes after penetration tests has been formulated which combines one dimensional axisymmetric coupled consofidation and phenomenological relaxation. Its predictions have been tested against results of over 100 CPTs in clays, silts, and sands. Applications and limitations are discussed with reference to the soil characteristics.
© 1992 Pergamon Press Ltd. Reproduction not l~rmiucd