A numerical study of the onset of granular avalanches

Granular media can either exist in a jammed state, in which their behaviour can be seen as solid-like, or they can exist in a dilute state and flow as a fluid would. In this contribution, we are interested in the mechanisms prevailing in the transition between solid-like and fluid-like behaviour, specifically in the case of the onset of granular avalanches. Therefore, discrete numerical simulations of granular flows are carried out. The focus is set on the analysis of the stick-slip dynamics preceeding the trigger of the avalanche; the existence of precursors to the flow, and their distribution in space and time will be investigated.