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Constant strain rate consolidation of Singapore marine clay
82A restrained and unrestrained initially slurried specimens are illustrated. In the field, soils will be restrained by widely varying amounts by naturally occurring mechanisms. An index for level of restraint applicable to a slurried specimen undergoing drying is proposed.
942170 Preparation of large-size laboratory deposits of cohesive soil McManus, K J; Kulhawy, F H Geotech Test J V16, N3, Sept 1993, P372-383 A method for preparation of large homogeneous specimens of cohesive soil is presented. A slurry is consolidated under controlled surcharge pressure in the tank with excess pore water removed by filters on the upper and lower surfaces. The apparatus, its operation, and control are described. Fifteen medium (0.6m diameter by 1.2m deep) and one large (1.4m diameter by 2.1m deep) specimens of Cornell clay have been prepared. Large numbers of water content measurements and in situ shear tests demonstrate the uniformity and repeatability of the specimens produced.
942171 Swell potential versus overburden pressure. Technical note Sikh, T S Geotech Test J V16, N3, Sept 1993, P393-396 Data have been collected from one-dimensional vertical freeswell tests performed on fill soils from various projects in southern California. The tests were carried out on relatively undisturbed specimens at in-situ moisture content and density and under actual overburden pressure. Effects of overburden pressure on swelling potential have been investigated. For overburden pressure above about 68kPa, swell potential is generally less than 1 % .
942172 Constant strain rate consolidation of Singapore marine clay Lee, K; Choa, V; Lee, S H; Quek, S H Geotechnique V43, N3, Sept 1993, P471-488 Large strain theory (~f Lee (1981) has been applied to analysis of three series of constant strain rate tests on soft Singapore clay samples. Three compression curves and two sets of coefficient of consolidation (Cv) were obtained for different parts of the sample. It is proposed that a successful CRS test is one where compression curves and Cv values agree. This is confirmed by comparison of CRS test and standard oedometer test data. On the basis of this work, suitable strain rates for large strain consolidation tests are suggested.
942174 Improvement of soft Bangkok clay using vertical drains Bergado, D T; Alfaro, M C; Balasubramaniam, A S Geotext Geomem VI2, N7, 1993, P615-663 Documented cases of use of vertical sand or prefabricated drains in improvement of soft Bangkok clay are reviewed. Performance of the drains is evaluated, taking into account drain pattern, influence zone, and well resistance. Effects of soil flow parameters, smear, and disturbance on installation are closely studied, particularly for the prefabricated drains. It is concluded that the vertical drains are a viable ground improvement treatment for soft Bangkok clay.
942175 Modelling of fluid expulsion and deformation behaviour of dewatering sediments. Chang, F T; Lennon, G P; Pamukcu, S; Carson, B lnt J Num Anal Meth Geomech V17, N8, Aug 1993, P531551 An analysis of combined deformation and fluid flow in sediments subjected to external loads is presented. Deformation behaviour of the soil skeleton is described by the force equilibrium equation and implemented using a modified Cam Clay model. Fluid flow is described by the generalized porous media flow equation. Material failure with development of single or multiple faults, which form preferential flow paths, is permitted. The finite element formulation is described. The example of a plane strain saturated sediment is presented and development of failed elements and faults and pore pressure contours are illustrated.
942176 Swelling rock in tunnels: rock characterization, effect of horizontal stresses and construction procedures Steiner, W lnt J Rock Mech Min Sci 1130, N4, Aug 1993, P361-380 Swelling phenomena in tunnels (mainly in Jura Mountain rocks) and laboratory swelling test data and associated in-situ observations have been studied. Effects of construction procedures and influence of horizontal and lateral stresses have been investigated. For shales in the laboratory, measured swelling pressures appear significantly greater than in-situ values. For in-situ stresses from overconsolidation, clay soil experience is extrapolated to Mesozoic sedimentary rocks and calibrated using in-situ measurements. The need to explicitly consider horizontal and lateral stresses and pore pressures is emphasised. An improved laboratory swelling test is suggested.
942173 Prediction of vertical hand-drain performance by the finite element method Bergado, D T; Mukberjee, K; Alfaro, M C; Balasubramaniam, A S Geotext Geomem V12, N6, 1993, P567-586
942177 Triaxial swelling test apparatus. Technical note Yesil, M M; Pasamehmetoglu, A G; Bozdag, T lnt J Rock Meek Min Sci II30, N4, Aug 1993, P443-450
The performance of vertical band drains in large scale laboratory consolidation tests and in the field under embankment loading has been predicted by finite element analysis. The numerical model was developed for transient and axisymmetric flow problems and includes a factor to compensate for smear effects. Results suggest the model is suitable to predict performance of vertical band drains in Bangkok clay provided installation disturbance is taken into account.
A new test device is presented which can be used to simulate the in-situ stress state and determine 3D swelling characteristics of expansive rocks. Axial swelling pressures and strains and axial pressure as a function of permitted axial swelling strain can be determined under various confining pressures. The triaxial cell and axial loading and confining pressure units are illustrated. Testing procedures are described and test data given from a marl sample.
942170 Preparation of large-size laboratory deposits of cohesive soil McManus, K J; Kulhawy, F H Geotech Test J V16, N3, Sept 1993, P372-383 A method for preparation of large homogeneous specimens of cohesive soil is presented. A slurry is consolidated under controlled surcharge pressure in the tank with excess pore water removed by filters on the upper and lower surfaces. The apparatus, its operation, and control are described. Fifteen medium (0.6m diameter by 1.2m deep) and one large (1.4m diameter by 2.1m deep) specimens of Cornell clay have been prepared. Large numbers of water content measurements and in situ shear tests demonstrate the uniformity and repeatability of the specimens produced.
942171 Swell potential versus overburden pressure. Technical note Sikh, T S Geotech Test J V16, N3, Sept 1993, P393-396 Data have been collected from one-dimensional vertical freeswell tests performed on fill soils from various projects in southern California. The tests were carried out on relatively undisturbed specimens at in-situ moisture content and density and under actual overburden pressure. Effects of overburden pressure on swelling potential have been investigated. For overburden pressure above about 68kPa, swell potential is generally less than 1 % .
942172 Constant strain rate consolidation of Singapore marine clay Lee, K; Choa, V; Lee, S H; Quek, S H Geotechnique V43, N3, Sept 1993, P471-488 Large strain theory (~f Lee (1981) has been applied to analysis of three series of constant strain rate tests on soft Singapore clay samples. Three compression curves and two sets of coefficient of consolidation (Cv) were obtained for different parts of the sample. It is proposed that a successful CRS test is one where compression curves and Cv values agree. This is confirmed by comparison of CRS test and standard oedometer test data. On the basis of this work, suitable strain rates for large strain consolidation tests are suggested.
942174 Improvement of soft Bangkok clay using vertical drains Bergado, D T; Alfaro, M C; Balasubramaniam, A S Geotext Geomem VI2, N7, 1993, P615-663 Documented cases of use of vertical sand or prefabricated drains in improvement of soft Bangkok clay are reviewed. Performance of the drains is evaluated, taking into account drain pattern, influence zone, and well resistance. Effects of soil flow parameters, smear, and disturbance on installation are closely studied, particularly for the prefabricated drains. It is concluded that the vertical drains are a viable ground improvement treatment for soft Bangkok clay.
942175 Modelling of fluid expulsion and deformation behaviour of dewatering sediments. Chang, F T; Lennon, G P; Pamukcu, S; Carson, B lnt J Num Anal Meth Geomech V17, N8, Aug 1993, P531551 An analysis of combined deformation and fluid flow in sediments subjected to external loads is presented. Deformation behaviour of the soil skeleton is described by the force equilibrium equation and implemented using a modified Cam Clay model. Fluid flow is described by the generalized porous media flow equation. Material failure with development of single or multiple faults, which form preferential flow paths, is permitted. The finite element formulation is described. The example of a plane strain saturated sediment is presented and development of failed elements and faults and pore pressure contours are illustrated.
942176 Swelling rock in tunnels: rock characterization, effect of horizontal stresses and construction procedures Steiner, W lnt J Rock Mech Min Sci 1130, N4, Aug 1993, P361-380 Swelling phenomena in tunnels (mainly in Jura Mountain rocks) and laboratory swelling test data and associated in-situ observations have been studied. Effects of construction procedures and influence of horizontal and lateral stresses have been investigated. For shales in the laboratory, measured swelling pressures appear significantly greater than in-situ values. For in-situ stresses from overconsolidation, clay soil experience is extrapolated to Mesozoic sedimentary rocks and calibrated using in-situ measurements. The need to explicitly consider horizontal and lateral stresses and pore pressures is emphasised. An improved laboratory swelling test is suggested.
942173 Prediction of vertical hand-drain performance by the finite element method Bergado, D T; Mukberjee, K; Alfaro, M C; Balasubramaniam, A S Geotext Geomem V12, N6, 1993, P567-586
942177 Triaxial swelling test apparatus. Technical note Yesil, M M; Pasamehmetoglu, A G; Bozdag, T lnt J Rock Meek Min Sci II30, N4, Aug 1993, P443-450
The performance of vertical band drains in large scale laboratory consolidation tests and in the field under embankment loading has been predicted by finite element analysis. The numerical model was developed for transient and axisymmetric flow problems and includes a factor to compensate for smear effects. Results suggest the model is suitable to predict performance of vertical band drains in Bangkok clay provided installation disturbance is taken into account.
A new test device is presented which can be used to simulate the in-situ stress state and determine 3D swelling characteristics of expansive rocks. Axial swelling pressures and strains and axial pressure as a function of permitted axial swelling strain can be determined under various confining pressures. The triaxial cell and axial loading and confining pressure units are illustrated. Testing procedures are described and test data given from a marl sample.