A model for the thermo-hydro-mechanical analysis of multiphase porous media in dynamics

This work presents the development of a mathematical and numerical model for the analysis of the thermo-hydro-mechanical behaviour of multiphase porous materials in dynamics. The fully coupled multiphase model for non-isothermal deformable porous media is developed within the Hybrid Mixture Theory. In order to analyse the thermo-hydro-mechanical behaviour of soil structures in the low frequency domain, e.g. under earthquake excitation, the u-p-T formulation is advocated neglecting the relative fluids acceleration and their convective terms. Moreover, the dynamic seepage forcing terms and the compressibility of the solid grain at the microscopic level are neglected. The standard Bubnov-Galerkin method is applied to the governing equations for the spatial discretization, whereas the generalized Newmark scheme is used for the time discretization. The final algebraic, non-linear and coupled system of equations is solved by the Newton method within the monolithic approach. The formulation and the implemented solution procedure are validated through the comparison with other finite element solutions or analytical solutions when available.