Elimination method of sliding blockage effect in discrete element simulation of rolling stone based on discrete fracture network and damping joint model

The particle essence of the discrete element method could prevent the rock block from sliding on the slope surface due to the stress concentration between the convex particles of the sliding block and the slope. To eliminate this sliding blockage effect and simulate more realistic rockfall, slope surface was transformed into a series of successive joints by the discrete fracture network technique, and a damping joint model was developed by adding a normal dashpot and a shear dashpot on the smooth joint model that does not have damping properties. The motion processes of sliding, rolling, and collision were simulated by the proposed method, and the damping and movement performances were investigated. The macroscopic sliding and rolling friction coefficients significantly increase with the microscopic friction coefficient and the shear damping ratio. The normal restitution coefficient of collision decreases with the normal damping ratio, while the shear restitution coefficient of collision decreases with both the shear damping ratio and the friction coefficient. Furthermore, the simulation of a rockfall case demonstrates the proposed method represented a more realistic movement process and more plentiful characteristics of collision, sliding and rolling, compared with the simulated results of Rocfall software.