Discrete element modeling of a rainfall-induced flowslide

The mass movements of flowslides are rarely monitored in field attributed to their sudden failure and rapid movement characteristics. Numerical modeling provides an alternative way to provide an insight into these mechanical behaviors. This paper presents an application of the discrete element method (DEM) for simulating the movement of an actual flowslide using a calibration-based approach. The effect of fluidization was simulated by calibrating the residual friction coefficient at the slip surface. The calibration results showed that the residual friction coefficient played an important role on the travel distance, height and surface of deposits, while the stiffness ratio ks/kn has a negligible effect on the simulation output. The use of the constant residual friction coefficient implies that only the undrained behavior of the flowslide was modeled. This simplification is suitable for the 2D simulation which neglects the lateral spreading effect. The geometry of slip surface has a great influence on the deformation of sliding mass, while the geometry of slip surface significantly affects the velocity of traveling mass.