DualSPHysics uses an SPH and DC-DEM (Distributed Contact Discrete Element Method) formulations to model a real case of an experimental debris flow. Rocks are imported from scanned geometries and the sizes are random-generated to match the granulometric curve.
Initial details of the formulation in Canelas, R.B., et al 2013, A generalized SPH-DEM discretization for the modelling of complex multiphasic free surface flows, SPHERIC 2013, Trondheim.