Stability analysis of slopes in soils with strain-softening behaviour

This paper presents a numerical approach to analyse the stability of slopes in soils with strain-softeningbehaviour. In these materials, a progressive failure can occur owing to a reduction of strength withincreasing strain. Such a phenomenon can be analysed using methods that are able to simulate the formationand development of the shear zones in which strain localises. From a computational point of view,this presents many difficulties because the numerical procedures currently used are often affected by alack of convergence, and the solution may depend strongly on the mesh adopted. In order to overcomethese numerical drawbacks, in the present study use is made of a non-local elasto-viscoplastic constitutivemodel within the framework of the finite element method. The Mohr–Coulomb yield function isadopted, and the strain-softening behaviour of the soil is simulated by reducing the strength parameterswith the increasing deviatoric plastic strain. To assess the reliability of the proposed approach, somecomparisons with the results obtained using other constitutive models for soils with strain-softeningbehaviour are presented. Finally, a slope subjected to a prescribed process of weathering is considered,and the effects of this process on the slope stability are discussed.