Thermo-Hydro-Chemo-Mechanical Coupling in Environmental Geomechanics

For isothermal and non isothermal behavior of multi-phase porous media, a suction-based mathematical approach has been developed by the first author since 1990. In this frame of approaches, the "independent variables" are chosen as state variables and the strong coupling effects are considered via "state surface" notion. Temperature-dependent state surface formulations are drived for variation of void ratio and degree of saturation within porous media for the thermal cases. The coupling effects of temperature and moisture content on deformation of skeleton, and the inverse effects are included in this model in a complete manner. In this paper, after a brief description of thermohydromechanical behaviour of unsaturated media, the extension of THM models to thermo-hydro-chemo-mechanical (THCM) models are discussed for the general conditions. Theoretical and numerical developments for this complex formulation are presented. The integration of new development in θ_STOCK software developed previously by the first author has been described. Some validation and application cases are presented to illustrate the correctness of the new developments and the efficiency of finite element θ_STOCK code.