Collapse of Granular Column : an Adequate Tool to Characterize Granular Matter

In spite of a large effort of the scientific community, a global description of the rheology of granular assembly remains largely elusive. To gain a better insight into the mechanical behavior of granular matter, we focus on a canonical set-up: the collapse of columns under gravity. We carried on 3D DEM numerical simulations and experiments for various granular columns on a frictional plane. Interestingly, this flow configuration is dictated by only two parameters : the aspect ratio of the initial column, a, and the friction. The dynamics and final shape of the pile can be rationalized through a modified BCRE scheme. The model only includes two parameters, the aspect ratio of the initial column and the dynamic or neutral angle. Interestingly, all the friction coefficients, grain-grain and grain-wall, are encoded in this single value.