Thermodynamic-based model for the thermo-poro-elastoplastic behavior of saturated clay

ABSTRACT: The thermo-poro-mechanical or thermo-hydro-mechanical (THM) coupling in clay related geomaterials is one of the most important issues in sustainable geotechnics. Clay soils have complex mineral composition and microstructure; thus, the study of thermo-poro-mechanical behavior is complicated. Previous studies shed little light on the difference between a thermal plastic strain and thermally induced dehydration behaviors. In this study, we propose a thermodynamic-based constitutive model for describing the thermo-poro-elastoplastic behavior of saturated clay. The proposed model considers the effect of temperature variation and mechanical loading on elastoplastic strains and dehydrations. The thermo-mechanical behavior is captured by using the thermodynamics laws and subloading surface plasticity. The hardening rule is established by using laws of physical conservation, energy dissipation and plastic flow. Dehydration behavior is considered using the laws of thermodynamics for chemical processes. A comparison between model predictions and experimental data for some clay soils with different geological origins is presented and a reasonable result is achieved.