Modeling the Impact of a Falling Rock Cluster on Rigid Structures

Abstract

Rockfall is a common geological hazard in mountainous areas and can pose great danger to people and properties. Understanding the impact forces induced by a single rock or a rock cluster on retaining structures is considered key in the analysis and design of protection barriers. This study presents the results of small-scale laboratory experiments conducted to measure the impact forces induced by a group of rocks moving down a rough slope on a barrier wall. The effect of slope inclination angle and wall location on the impact pressure acting on the wall was examined. A three-dimensional discrete element model was then proposed and used to study the behavior of the rock cluster under different geometric conditions. Rocks were modeled using polydisperse clumps in which each clump consisted of several overlapping spherical particles to account for the shape effect of the falling rocks. First, the model was validated by comparing the measured and calculated forces, and then, it was used to investigate the role of different material and geometric parameters on the impact behavior. Conclusions were made regarding the role of modeling the irregular rock shapes and the roughness of the slope surface on the behavior impacted by the travel mode for different slope angles.