Quasi-static collapse of two-dimensional granular columns: insight from continuum modelling

We investigate numerically the mechanism governing the quasi-static collapse of two-dimensional granular columns using a recently proposed continuum approach, the particle finite element method (PFEM), which inherits both the solid mathematical foundation of the traditional finite element method and the flexibility of particle methods in simulating ultra-large deformation problems. The typical collapse patterns of granular columns are reproduced in the PFEM simulation and the physical mechanism behind the collapse phenomenon is provided. The collapse processes obtained from the PFEM simulation are compared to experimental observations and discrete element modeling, where a satisfactory agreement is achieved. The effects of the macro density and friction angle of the granular matter, as well as the roughness of the wall surfaces on the quasi-static collapse, are also investigated in this paper. Furthermore, our simulations reveal new quasi-static collapse patterns, as supplements to the ones already observed in the experimental tests, due to the change of the roughness of the basal surface.