Two Control Works to Counteract the Inception of Debris Avalanches

Abstract

Debris avalanches develop along open slopes, with significant lateral spreading, bed entrainment and flow-like motion associated to large runout distances. Recent numerical methods enhanced the simulation of the inception and propagation mechanisms with reasonable computational times and accurate description of the main kinematic variables such as height and velocity of the mobilised volumes. In this paper, a Smooth Particle Hydrodynamic (SPH) approach is applied to the simulation of propagation scenarios of differently-triggered debris avalanches in presence of two types of engineered slopes. The first option is the installation of a series of baffles in different geometrical combinations; whereas, the second alternative is the implementation of non-erodible zones. Both intervention types are conceived for the hillslope areas, so that the inception of debris avalanche would be limited since the very early stages of the phenomenon. A frictional rheological model is used, and also the role of time-space variable pore water pressures is considered. The discussion of the numerical results focuses on the modifications in the landslide dynamics induced by the two control work options, aimed to discuss the feasibility of such types of interventions in steep slopes prone to debris avalanche triggering and propagation.