Validation of a DEM granular flow model aimed at forecasting snow avalanche pressure

Structural design of passive-protection against snow avalanches is limitated because of the lack of knowledge about loading pressure on structures. Consequently, that design is based on rough estimas of the drag coefficient, considering a straightforward dependence on the obstacle's geometry. In this paper, we first assume a flowing snow avalanche as a granular flow and we study numerically and experimentally the impact of a dry granular flow against an obstacle. Small-scale laboratory experiments were conducted to validate a numerical model. Experimental velocity profiles and thicknesses are estimated and granular impact force is measured. A 3D numerical model, based on the discrete element method (DEM), was set-up to reproduce the experimental configuration. The contact law involved elastic and dissipative components. The model is validated by comparisons with both the experimental flow characteristics and the impact load history. Once validated, the model is used to investigate the contribution of the height of the obstacle on the drag coefficient. Finally, results are discussed and compared with other studies.