Abstract: Collapse of granular soil often induces natural disasters such as debris flow and landslide. Existing studies lack the influence of particle shape on the collapse morphology of granular soils. In this paper, three-dimensional discrete element method is used to simulate the collapse failure mechanism of granular material cylinder specimens. Three typical particle shapes (spherical, tetrahedral and elongated) are considered in the numerical simulations. For each particle shape, cylinder specimens with the same size and the same grain size distribution are generated using the same method, and then collapse tests are performed. Based on experimental results, the final collapse height and runout distance of cylindrical specimens with different shapes of particles are analyzed and compared with the laboratory test. It can be concluded that the discrete element method can reproduce the collapse process of the granular columns very well. Compared with specimen of pure spherical particles, specimens composed of irregular shape particles can reduce the angular velocity of particles, maintain a larger final collapse height and reduce the final runout distance.

Key words: granular flow, discrete element method, sand, particle shape, micromechanics, particle contact