Failure mechanism and simulation for long run-out of the catastrophic rock landslide in the Shanyang Vanadium Mine, China

On 12 th August 2015, a massive rapid long run-out rock landslide occurred in the Shanyang Vanadium Mine in Shaanxi Province, China, which claimed the lives of 65 miners. No heavy rainfalls, earthquakes, and mining blasts were recorded before the incident. Therefore, the failure mechanism and the cause of the long run-out movement are always in arguments. In this paper, we conducted a detailed field investigation, laboratory tests, block theory analysis, and numerical simulation to investigate the failure and long run-out mechanisms of the landslide. The field investigation results show that the source material of the rock landslide is a huge dolomite wedge block bedding on siliceous shale layers. Uniaxial compression tests indicate that the uniaxial compression strength of the intact dolomite is 130–140MPa and the dolomite shows a brittle failure mode. Due to the progressive downward erosion of the gully, the dolomite rock bridge at the slope toe became thinner. As the compression stress in the dolomite bridge increased to surpass its strength, the brittle failure of the bridge occurred. Then huge potential energy was released following the disintegration of the landslide, which led to the high acceleration of this rock landslide. The 3D discrete element simulation results suggest that the low intergranular friction contributes to the long run-out movement of this rock landslide.