ABSTRACT
This chapter examines the behaviour of unsaturated slopes subjected to rainfall and water infiltration by means of the three-phase single-point Material Point Method. It is assumed that the instability of a slope is essentially governed by the evolution of soil shear strength variables (cohesion and friction angle), which evolve with suction. Initially, a suction-dependent elastic-plastic Mohr-Coulomb model is presented. It is expressed in terms of net stress and suction variables. Then, the instability of a slope subjected to rain infiltration, inspired from a real case, is solved and discussed. The model shows the development of the initial failure surface in a region of deviatoric strain localisation, the evolution of stress and suction states in some characteristic locations, and the dynamics of the motion characterised. In order to analyse the embankment behaviour, attention will focus on seven control MPs distributed along the slope at depths of 0.5 m, 1.7 m, and 3.5 m.
