This paper extends the modified Cam-Clay model to describe behaviour of unsaturated soils by replacing effective stress with scaled stress. The accounts for mechanical effect capillarity factoring Bishop’s a power function degree saturation. extendedmodified postulates existence yield curve in mean

Tests were conducted to determine the variation of water content and pore water suction for compacted clayey soils. The soils had varying amounts of clay fraction with plasticities ranging from low to high plasticity. The unsaturated soil behavior was investigated for six conditions, covering a range of compactive efforts and water contents. The experimental data were fit to four commonly used ...

In this paper a new approach is presented based on evolutionary polynomial regression (EPR) for modelling of soil–water characteristic curve in unsaturated soils. EPR is an evolutionary data mining technique that generates a transparent and structured representation of the behaviour of a system directly from data. This method can operate on large quantities of data in order to capture nonlinear...

Highly unsaturated soil mixtures (clay, sand and gravel) are used as building materials in many parts of the world, and there is increasing interest in understanding their mechanical and hydraulic behaviour. In the laboratory, xray computed tomography (XRCT) is becoming more widely used to investigate the microstructures of soils, however a crucial issue for such investigations is the choice of...

Determining the constitutive properties that describe incipient hydraulic behavior of materials, including matrix domains and distribution macro micropores, is crucial to analyzing preferential water flow in saturated soils, ks, unsaturated, ku. This study focused on determining conductivity porous media under total partial saturation conditions. The infiltration characteristics three reconstit...

Flow movement in unsaturated soil can be expressed by a partial differential equation, named Richards equation. The objective of this study is the finding of an appropriate implicit numerical solution for head based Richards equation. Some of the well known finite difference schemes (fully implicit, Crank Nicolson and Runge-Kutta) have been utilized in this study. In addition, the effects of di...

Laboratory column experiments were conducted to study the effects of anionic polyacrylamide (PAM) polymer and surfactant linear alkylbenzene sulfonate (LAS) on the movement of Escherichia coli and the FRNA phage MS-2. The study was designed to evaluate if PAM or PAM + LAS would enhance the mobility of human pathogens in tropical soils under unsaturated conditions. No breakthrough of phage was o...

Bender element testing of unsaturated isotropically compacted speswhite kaolin samples was used to investigate the variation of small strain elastic shear modulus G under unsaturated conditions. Testing was performed in a suction-controlled triaxial cell and involved combinations of isotropic loading and unloading stages and wetting and drying stages. Analysis of the experimental results indica...