Linear contact-stiffness model

sliding model and viscous damping contact model are built based on particle flow code

and a numerical experiment is conducted to simulate the motion process of collapse mass.An ideal method of simulation and parameters selection is obtained.It has certain reference value on studying the composite motion of collapse mass which includes several motion types.The whole moving process of collapsing rock is simulated combining a specific engineering and the results prove the efficiency of this simulation method.Sliding distance of collapse mass and the velocity at all position are obtained in this paper which can provide valuable guidance for reasonable prevention measures selection.