Modelling multiphase geomaterials under frictional heating with application to rapid landslide

Finite element analysis of non-isothermal elasto-plastic multiphase geomaterials in dynamics including frictional heating is presented. A fully coupled general mathematical model for the analysis of the thermo-hydro-mechanical behaviour of multiphase geomaterials is reduced to a computationally efficient formulation within the u-p-T approach. The mathematical model is based on averaging procedures developed within the Hybrid Mixture theory. The modified effective stress state is limited by the Drucker-Prager yield surface. Dynamic analysis of a plain strain localization test of initially water saturated dense sand in globally undrained conditions is presented. The analysis is performed with or without modelling the frictional heating. A case of a strain localization inducing a temperature increase up to water phase change and loss of shear strength is also simulated as prototype of a rapid landslide problem.