Numerical modelling of a rock avalanche laboratory experiment in the framework of the "Rockslidetec" alpine project

This paper illustrates the results of a collaboration born among the authors, in the framework of the INTERREG IIIA ‘‘Rockslidetec’’ project, with the aim of studying rock avalanche propagation by means of physical and numerical modelling. The EPFL rock mechanics laboratory has carried out an experimental campaign. Tests consist in releasing unconstrained gravel flows on an inclined panel. One of the experiments has been simulated by the codes developed by the partners. The Cemagref code and RASH3D (Politecnico di Torino) are based on a continuum mechanics approach; EPAN3D (CETE) on a discrete approach. Cemagref results, although rather far from observations made on deposit morphology, reproduce quite well the travel distance, without any parameter calibration. RASH3D reproduces well the velocity of propagation of the rear and front of the mass, but less the final deposit shape. EPAN3D reproduces very well the final deposit but the calculations are based on the calibration of 11 parameters.