A constitutive model and numerical simulation for coupled chemo-thermo-hydro-mechanical process in porous media

A coupled chemo-thermo-hydro-mechanical (CTHM) constitutive model of porous media is developed in this paper. The model is developed on the basis of the following existing component constitutive models for porous media, i.e., the thermo-hydro-mechanical (THM) constitutive model presented in Reference1, the constitutive model of contaminant transport presented in References2,3 and the chemo-mechanical constitutive model presented in Reference4. The chemo-softening function is introduced into the constitutive model to simulate the effects of organic contaminants in pore water on the mechanical properties of the porous media. The effect of temperature on the mechanism governing contaminant transport in porous media is considered. The present coupled CTHM constitutive model has been integrated into the coupled thermo-hydro-mechanical mathematical model including contaminant in porous media. Within the framework of CTHM constitutive model, a consistent tangent modulus matrix for the fivefold yield surfaces in the four dimensional stress-suction-temperature space, describing the mechanical behavior of porous media coupled with thermo-hydro process and contaminant transport and taking into account the chemo-plastic effect, is derived. The numerical results are illustrated to particularly emphasize the effects of the contaminant concentration on the coupled CTHM system in porous media.