Numerical modelling of Val d’Arán landslide with Material Point Method

Abstract

Flow-like landslides in mountainous areas can cause extensive damages due to their high velocity and long run-out distance. This work presents a real case of landslide occurred on 11 May 2018 in Val d’Arán (Catalonia, Spain). It involved about 50.000 m3 of glacial and colluvial material, travelling about 250 m until the valley floor and climbing about 100 meters on the opposite hillside. With the aim to assess the capabilities of the Material Point Method (MPM) [1,2] plane strain analyses with the 2-phases 1-point formulation [3,4] are conducted on a representative section. First, the slope material is described with the Mohr-Coulomb criterion. Second, a constitutive model based on the critical state theory (Ta-Ger [5,6]), is adopted. The simulations results led to conclude that an advanced constitutive model, able to simulate the strength loss of the material during the movement, is required to reproduce flow-like landslides and to obtain realistic results in terms of long run-out distance.