Numerical modelling of hygro-thermal behaviour and deformations of soils by means of mechanics of multiphase porous media

A mathematical model of fully and partially saturated soils, treated as deforming porous media, is presented. The heat, water and gas flows and water phase changes are taken into account. The modified effective stress state is limited by the Drucker-Prager yield surface. Small strains and quasi-static loading conditions are assumed. Numerical solution of the model equations by means of the Finite Elemet Method, taking into account plastic strains, is presented. Three numerical examples, dealing with different practical applications of the model, are solved and discussed. The first one deals with the cavitation phenomenon which developes during the strain localisation in a dense sand. The second example presents results of numerical simulations of a slope stability experiment, while the third one is a case study of the initiation of flowslide due to rainfall in a pyroclastic soil.