Contrastive study on the granular avalanche dynamic process using the depth-integrated continuum and discrete element methods

This paper carried out simulations of a channel flow experiment and a case study of granular avalanche flow using two kinds of methods, depth-integrated continuum method and discrete element method. In the simulation of the channel flow experiment, we presented a method for calculating normal force and bending moment of the rigid wall based on the depth-integrated continuum method. Although the peak value of the normal force and bending moment cannot be obtained using the depth-integrated continuum method, the residual value can be obtained rapidly and accurately. Then, Frank landslide in Canada was simulated using the two methods. Calculation results of the extent and duration of the granular avalanche were in good agreement with actual situation, which validated the correctness and effectiveness of the two methods. The velocity process, energy process, and risk zoning of the granular avalanche were obtained. Calculation results showed that the maximum average velocity of the granular avalanche was about 68 m/s at 20 s. The computational efficiency of the depth-integrated continuum method was better than that of the discrete element method, while the energy process of the granular avalanche could be better traced using the discrete element method. Detailed comparison and discussion were carried out in the simulations of the experiment and the case study which can provide a scientific reference and basis for the simulation of the granular avalanche flow.