Modeling failure of jointed rock slope with two main joint sets using a novel DEM bond contact model

In order to investigate the failure processes and mechanisms of jointed rock slopes, Distinct Element Method (DEM) was applied with a novel bond contact model. The bond contact model is validated by a series of numerical direct shear tests on jointed models and the comparisons to laboratory test results. DEM jointed rock slope models were then generated and two arrangements of joint sets and two types of slope surface were chosen to test the capabilities of the bond contact model. The slope models were destabilized progressively by the critical gravity approach, and both the failure onset and the slope collapse process were analyzed. Microscopic information reveals that the initiation of slope failure can be divided into three phases and is induced from stress concentration within the rock bridges, occurrence of tension cracks, and their propagation and coalescence. The slope surface properties reflected by different damping affect both post-failure configuration and propagation distance of the rock slope. The study demonstrates that the novel bond contact model implemented in the DEM code is able to tackle the fundamental problems of jointed rock slope failure and helps to better understand the slope failure mechanisms from a macroscopic and microscopic level.