Abstract: The debris flow is a worldwide geological disaster, and has been widely and deeply investigated over the years. Most studies of the geomaterial are focused on the instability mechanisms before the failure and the fast propagation after the failure, separately. This paper attempts to simulate the consistent process of a debris, using a continuous approach. The initiation, propagation and deposit stages of the debris flow are modeled using a constitutive model. The visco-elastoplastic constitutive model with solid-fluid transition is briefly presented and used in the study; and the corresponding physical parameters are carefully calibrated. Two failure mechanisms induced by increasing gravity and decreasing suction are discussed; and the definition for the interface between viscous and elastoplastic layers is explained. Finally, the consistent simulation of the debris flow is performed; and the impact effect against a retaining wall is heuristically studied.

Key words: debris flow, numerical simulation, Bingham's model, unified model, retaining wall