Experimental and numerical analysis of impact forces on structures due to a granular flow

The paper presents the results of an experimental and numerical analysis aimed to clarify some aspects regarding the impact of a granular flow on structures. The experimental set-up comprises a flume equipped with a system of differently sized model obstacles, which are placed along the run-out trajectory to measure the impact force. The soil used for the small-scale model is a mono-granular medium sand, which was revealed to be particularly suitable the simulation of flows like debris or rock avalanches. The numerical analysis deals with the capability of a DEM code of predicting the experimental evidences. The most significant results of the measured impact forces versus time have been numerically reproduced by a Distinct Element Model (DEM), after the numerical model of the granular flow had been calibrated on the basis of the displacement measurements, obtained through a photogrammetric technique.