Geotechnical properties of collapsible soils

Geotechnical properties of collapsible soils

345A 906180 Oedometer suction controlled tests (In French) Mieussens, C; Nardone, A; Ghliss, N Proc 12th International Conference on Soil Mechanics a...

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345A

906180 Oedometer suction controlled tests (In French) Mieussens, C; Nardone, A; Ghliss, N Proc 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, 13-18 August 1989 V1, P69-70. Publ Rotterdam: A A Balkema, 1989 The principles and design of an oedometer device for testing unsaturated clay soils in the void ratio-suction-total stress space are illustrated. Test procedures are described, and some results presented.

906181 Constraint modulus of mixed-grained cohesive soils Rattay, W W; Gunther, G Proc 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, 13-18 August 1989 V1, P93-95. Publ Rotterdam: A A Balkema, 1989 Mixed grained cohesive soils, boulder clays and boulder marls, contain clay, silt, sand, and gravel components. Stress strain behaviour can be assessed using large diameter oedometer tests, an inside diameter of about 300mm being necessary to allow realistic results from gravelly soils. Some test results are presented, with influence of water content, density, and fine grain content on compressibility being illustrated.

906182 Geotechnical properties of collapsible soils Rizkallah, V; Keese, K Proc 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, 13-18 August 1989 VI, P101-104. Publ Rotterdam: A A Balkema, 1989 Collapsibility of eolian fine grained elastic sediments from Lower Saxony (Germany) has been examined using a compression apparatus which allows measurement of the effective load at the bottom of the sample, and thus evaluation of the side wall friction effects. Influences of water content,sample geometry, surcharge during wetting, and friction in the oedometer on settlement were evaluated.

906183 Analysis of large strain nonlinear consolidation Wu, C L; Guo, S J Proc International Conference on Engineering Problems of Regional Soils, Beifing, 11-15 August 1988 P485-488. Publ Beijing: International Academic Publishers, 1989 Consolidation of soft soils cannot be described by classical Terzaghi theory, being characterised by large strain, nonlinearity, and coefficient of consolidation varying with time and depth. Extensions of small strain theory lead to differential equations which are complex and hard to solve. A new approach is presented which involves idealising and dispersing the real consolidation process and introducing the Solid Material Coordinate System to represent the spatial variable. This allows accurate, relatively simple solutions of large strain nonlinear consolidation

906184 Secondary deformation of soft clay Zeng, G X; Pan, Q Y; Liu, S M Proc International Conference on Engineering Problems of Regional Soils, Belting, I 1-15 August 1988 P509-512. Publ Beijing: International Academic Publishers, 1989 Based on analysis of stress controlled triaxiai compression and one dimensional consolidation tests with pore pressure measurement, a method has been developed to separate the primary and secondary consolidation components of

deformation. Rate of secondary deformation in the triaxial test is inversely proportional to the ratio of radial to axial pressure. In one dimensional consolidation, percentage of secondary consolidation is inversely proportional to load increment ratio. Analysis of settlement of a coalyard on soft clay indicates the secondary component is insignificant at the primary stage.

906185 Deformation anisotropy behaviour of soft clay Zeng, G X; Shi, Z Y Proc International Conference on Engineering Problems of Regional Soils, Beifing, 11-15 August 1988 P513-517. Publ Beijing: International Academic Publishers, 1989 A nonlinear constitutive model for clay is developed in which effects of dilatancy and stress path are considered. It is used in a finite element program based on Biot's theory to model consolidation of soft clay for the cases of plane strain, axial symmetry, and three dimensional consolidation. Parameter determination is described. The applicability of the FEM program and the model arc examined against data from two case studies.

906186 Theory of three-dimensional consolidation on large strain theory Zhou, Z M Proc International Conference on Engineering Problems of Regional Soils, Beijing, 11-15 August 1988 P538-540. Publ Beijing: International Academic Publishers, 1989 Small strain theory, Biot consolidation analysis is not realistic in many practical cases. Similarly, homogenous, isotropic soil masses are rarely found. To overcome these limitations, three dimensional consolidation of a saturated soil is analysed using large strain theory and a Eulerian approach. A nonlinear constitutive equation is used to describe soil anisotropy.

906187 Properties of expansive soils in Wuhan, China Chen, X Y; Zhou, Z P Proc International Conference on Engineering Problems of Regional Soils, Bering, 11-15 August 1988 P564-567. Publ Beifing: International Academic Publishers, 1989 The geology of expansive soils in Wuhan has been determined by static sounding, penetration and bearing capacity tests, and regional hydrogeology examined. Liquid limit, density, shrinkage and expansion properties were measured in the laboratory, and microstructural and mineralogical aspects examined by scanning electron microscopy and X ray analysis. Possible consequences of constructing buildings on these soils are considered, and remedial and preventative measures against damage suggested.

9O6188 Finite difference analysis of consolidation by vertical drains with well resistance Onoue, A Proc 6th International Conference on Numerical Methods in Geomechanics, Innsbrnck, 11-15 April 1988 VI, P619-624. Publ Rotterdam: A A Balkema, 1988 Observed consolidation of an anisotropic multilayered soil by drains is analysed using the finite difference method with well resistance taken into account. Based on this analysis, a new procedure is presented to obtain degree of consolidation of multilayered soils using Hansbo's equation. Calculated settlements are seen to agree well with field behaviour.

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