Scaling behavior of granular columns collapse on erodible-inclined surfaces

Abstract

This paper explores the effects of slope angle, initial column aspect ratio, and interparticle friction coefficient on the mobility and erodibility of granular columns collapsing on an erodible-inclined layer before spreading and depositing on a nonerodable-horizontal surface using Discrete Element Method. The numerical results showed that the column collapse with higher aspect ratio or smaller friction coefficient induces larger normalized kinetic energy, leading to larger granular masses out the inclined region and longer runout distance. The slope angle, on the other hand, shows trivial impacts on the kinetic energy and apparent friction coefficient. Remarkably, these physical quantities are nontrivially behaved by a new dimensionless number that incorporates the initial column aspect ratio, inclination angle, and interparticle friction coefficient. These findings may significantly complement the better understanding of the behavior of natural disaster events such as landslides, rock and snow avalanches, or pyroclastic flows on complex surfaces.