• Abdallah, Adel
• Mrad, M.
• Nowamooz, H.
• Masrouri, F.

Abstract

<jats:p>This paper presents experimental studies performed on a natural swelling soil. Initially, the soil fabric was studied by a mercury porosimetry test, revealing a clear bimodal pore distribution that corresponds to micro- and macrostructural levels. The water-retention curve of the soil was then determined using two suction-imposition techniques: the osmotic and the vapour equilibrium methods. During the main testing program, three successive wetting and drying cycles were applied in a suction range between 0 and 2 MPa under different values of constant vertical net stress using osmotic oedometers. The test samples showed cumulative swelling strains during the cycles. The volumetric strains reached an equilibrium stage, indicating an elastic behaviour of the samples at the end of the suction cycles. Based on these results, the parameters of an elastoplastic model for swelling unsaturated soils (BExM) were derived. This model, implemented in a finite element code (Code_Bright), was applied to a practical problem of a shallow foundation based on a swelling soil. This application studies the effects of hydraulic solicitations on settlements of this foundation. The results show the capacity of the model to solve complex hydromechanically coupled problems.</jats:p>

Topics

• pore
• drying
• porosimetry
• Mercury