Simulation of a fully coupled thermo-hydro-mechanical system in freezing and thawing rock

This paper describes the application of a numerical model of thermal-mechanical-fluid flow coupling system to the simulation of laboratory freezing and thawing experiments on rocks. A theoretical formulation that accommodates a linear stress-strain constitutive relationship is presented and a two-dimensional (plane stress) numerical modeling is performed based on the finite element method applied to thermo-poro-elasticity. As the primary objective of this research is to simulate the freezing and thawing process, the developed code takes into account the phase change of pore water during freezing. It is found from the numerical simulation that a relatively good prediction can be made of temperature transfer and deformation behavior within the elastic deformation limit. In some cases, however, large deformation results from the freezing processes, leading to material failure. Future research should therefore take into account irreversible and plastic effects. (C) 1999 Elsevier Science Ltd. All rights reserved.