Thermo-Hydro-Mechanical Modelling Of Low Permeability Media Using A Double-Porosity Formulation.

Abstract

The study of engineering problems in porous media is generally dealt with by
assuming that they possess a continuous distribution of one type of voids. However, there are
some media in which, for a proper handling of the problem, it is crucial to consider the
different structural levels involved in the material fabric. This work presents a mathematical
formulation that considers the mechanical, hydraulic and thermal problems in a fully coupled
way. The Thermo-Hydro-Mechanical (THM) approach has been developed to handle
engineering problems in porous media with two dominant structures of voids. The
formulation allows the consideration of non-isothermal multiphase flows in both media,
coupled with the mechanical and the thermal problems. The double porosity approach has
been implemented in a finite element code and it has been used to analyze a variety of
engineering problems. Special attention has been placed on the analysis and design of high
level radioactive waste disposals. A THM modelling of a large scale heating test is also
presented in this paper.