Thermo-Hydraulic-Mechanical Behaviour of Unsaturated Soils Under High Temperature

The paper presents a coupled thermo-hydro-mechanical model for unsaturated soil, applicable for temperatures in excess of 100ºC. The thermo-hydraulic formulation follows Luikov’s approach in which three nonlinear partial differential equations representing heat, moisture and air transport are fully coupled. The mechanical model is based on stress-strain equilibrium principle with linear elastic, nonlinear elastic and elastoplastic constitutive models implemented. Numerically, the continuous Galerkin finite element method is employed for spatial discretisation and implicit finite difference scheme for temporal discretisation. An application of the coupled model to a laboratory experiment is presented to demonstrate the capability of the model.