Energy evolution of gravitational-granular flows

Abstract

The catastrophe of natural disasters such as landslides, is a prevalent phenomenon in natural terrain conditions in high mountainous areas; however, the mobility of such landslides has not yet well understood due to the discrete nature of material and the coming to play of water. In this paper, we numerically study the mobility of an unsaturated gravitational-granular flow, occurring on a slope-break system that contains two regions: inclined-upstream and horizontal-downstream areas, by using three-dimensional discrete element simulations. A sliding volume composed of spherical grains collapses on the first region, then plunges and deposits on the second one. The upstream-plunging length and the cohesive stress exerted on grains affect differently on the energy evolution not only in the whole process but also in different regions and directions depending on the inclination angle. These findings provide a deep understanding of the mechanism and mobility of landslides, leading to good predictions about the potential impacts of the catastrophic landslides on buildings and human lives.