Inclusion of expansive clay behaviour in coupled thermo hydraulic mechanical models

摘要

This paper discusses the development of a modelfor the coupled flow of heat, moisture and air in expansive clays.In particular, the results of recent research work on the inclusionof expansive behaviour exhibited by some clays are presented.Initially, a full coupled thermal/hydro/mechanical (THM)simulation of a heating experiment is presented. The observedTHM behaviour in unsaturated soil was predicted by the model,with the best correlation found in the thermal field. The influenceof the osmotic potential on the soil via the effect of chemicalsolute concentration is explored in a non-linear elasticconstitutive relationship. The ability of such a model to representthe large strains that can occur during free swelling of expansivesoils has been demonstrated. Finally, the representation of thedevelopment of irreversible strains within an expansive soil hasbeen investigated via a double structure elasto-plasticrelationship. The ability of such an approach to simulate theaccumulation of plastic strains during wetting-drying cycles has been shown.