Experimental and numerical investigations of secondary granular flow

Abstract

AbstractAmong the geological disasters in the form of granular flow, the secondary slide mass is often neglected, potentially leading to unexpected losses. Results indicate that under conditions of a certain sliding total mass, the secondary granular flow in the deposition area is significantly influenced by pre‐formed deposits when tested in a flow flume. When the initial sliding mass is small and the mass ratio of two slides is less than 12.5%, the secondary sliding mass expands the runout distance, thereby increasing potential harm. To elucidate the interaction between the secondary sliding mass and the previously formed deposition, DEM (the discrete element method) was employed based on experimental tests.. The numerical results show that the previous deposition effectively blocks the secondary granular flow. When the initial sliding mass is small, the front edge of the second slide may overtop the previous deposition, extending the runout distance by impact, extrusion, and pushing. The DEM proves to be a reliable and effective tool for studying the secondary granular flow, revealing complex phenomena and processes that complement experimental research. This study provides valuable references for a more in‐depth understanding of multi‐phase continuous disaster processes.