A simple computational framework for THM processes in saturated geomaterials

Abstract

Investigations of thermo-hydro-mechanical (THM) processes in geomaterials have become a continuing concern due to the increasing interests in the application of geothermal energy. In the last two decades, a number of THM coupled constitutive models were proposed for soils and rocks based on either the elastoplastic theory or the thermodynamics. The practical application of the constitutive models inevitably requires computational approaches such as finite element or finite difference methods. In this paper, a simple computational framework for THM processes in saturated geomaterials is proposed. An effort is made to explain the details and major concerns related to the governing equations of three physical fields. The computational framework is validated through the benchmark problem of 1D THM processes in saturated linear elastic material by comparing with the analytical solution. We then further investigate some key factors of the multiphysical processes and their influence on the time-dependent evolution of excess pore pressure, effective stress and strain. The flexibility of the framework allows the effect of some coupling components, such as the temperature-dependent dynamic viscosity of pore fluids, which are often ignored in previous studies, to be examined. The framework serves as the basis for the next-step in-depth analysis of theoretical multiphysical problems and practical design of energy foundations.