Modelling the Propagation of Debris Avalanches in Presence of Obstacles

Landslide propagation modelling is an important issue in engineering-based procedures for susceptibility and hazard analysis. The paper deals with debris avalanches, which develop along open slopes with nearly constant inclination and may propagate over large distances. In particular, the paper investigates the effect of different combinations of artificial obstacles on landslide run-out, deposition heights and thicknesses of soil eroded along the landslide path. Among the several numerical techniques available to this purpose, Smooth Particle Hydrodynamic (SPH) is used since it is a convenient tool for reasonable computational times and accurate description of the main kinematic quantities such as heights and velocities of the mobilised volumes. A frictional rheological model is used, and also the role of time-space variable pore water pressures is considered. The numerical results are discussed to individuate the changes induced by obstacles in landslide dynamics and to discuss the feasibility of such typology of intervention in steep slopes.