Simulation of quasi-static collapse of cylindrical granular columns, insight from continuum and discrete frameworks

Collapse of granular columns subjected to different flow conditions has recently been the topic of numerous experimental and numerical studies. The quasi-static collapse of cylindrical granular columns is an interesting case of granular flow relevant to the active deformation of retaining structures. In this study, this type of collapse is investigated using Smoothed Particle Hydrodynamics (SPH) method in the continuum framework and Discrete Element Method (DEM) in the discrete framework. Three-dimensional (3D) SPH and DEM models are developed to study the dependency of collapse pattern, final deposit profile (e.g., height, runout distance), and energy dissipation on the initial aspect ratio of cylindrical granular columns. Results demonstrate that by using appropriate constitutive models or contact behaviors, both SPH and DEM models are qualitatively and quantitatively capable of capturing different aspects of quasi-static granular column collapse. However, where the particle-level behaviors dominate (e.g., at flow front and sharp edges of free surface, tracing frictional loss at contact), DEM can be considered as the method of choice.