Abstract Collapsible soils present significant geotechnical and structural engineering challenges worldwide. They can be found in arid or semi-arid regions are directly affected by the multi-step wetting procedure due to reduction of soil suction. The main objectives this paper investigate volume change behaviour, collapse mechanism deformation characteristics under control suction net vertical...

Abstract The paper presents a numerical analysis of pressuremeter test in unsaturated cohesive soils. In practice, is commonly expanded up to 10–15% cavity strains. At these strains, limit pressure not usually reached, and its value estimated by extrapolation. Accordingly, authors suggest using at 10% strain ( P 10 ) for the interpretation rather than pressure. this strain, it also assured that...

In this study, the remediation performance of electrokinetic (EK) technology integrated with different surfactants for removing phenanthrene from unsaturated soils was investigated. A synthetic surfactant (Triton X-100) and a biosurfactant (rhamnolipid) were used to enhance phenanthrene solubility and removal efficiency during EK process. Results indicate that the electro-osmotic flow (EOF) rat...

According to the Mualem capillary model, hydraulic conductivity (HC) is integrated theoretically from the function related to soil water retention curves (SWRC). On the other hand, based on the smooth type of SWRC, the predicted HC function decreases abruptly near saturation, which often challenges the stability of numerical solutions. To improve the Mualem HC, van Genuchten’s function for SWRC...

The management and engineering assessments of geotechnical assets within the national transportation inventory require an appropriate knowledge permeability saturated unsaturated soils. Determination soils can be carried out using direct measurements, whereas that is often made indirect methods based on soil water retention curve. In this study attempt was to develop a novel approach for measur...

Steady-state and transient one-dimensional unsaturated flow in vertically stratified porous media are examined. Saturated hydraulic conductivity and the alpha parameter of the exponential hydraulic conductivity function were assumed to vary from soil layer to soil layer. The use of effective unsaturated hydraulic conductivity to compute matric potential in the soil profile is demonstrated. Resu...

The water flow in unsaturated soils is governed by Richards equation, a nonlinear parabolic partial differential equation. In a layered unsaturated soil, enforcing the continuity of both pressure head and flux across the interface of distinct soil materials leads to a non-linear interface equation. This interface equation may exhibit multiple solutions. Using different averaging methods for cel...

Abstract The occurrence of fingered preferential flow depends on both flow and porous media characteristics. The boundary condition of unsaturated infiltration has been investigated to assess whether it produces unstable wetting in homogeneous coarse sands. Laboratory tracer experiments were conducted in two coarse sand materials; for each sand material two initial conditions of air dry and fie...