Failure mechanism and dynamic processes of rock avalanche occurrence in Chengkun railway, China, on August 14, 2019

Abstract

Rock avalanches are unpredictable due to their complex geological conditions and dynamics and such features have been regarded as important reasons for property damage and fatalities. The Ganluo rock avalanche of August 14, 2019 in China provides an outstanding case to evaluate the failure mechanism and dynamic process of long-runout rock avalanches. To understand the failure mechanism and dynamics of such events, a combination of in situ investigation, remote sensing data study, and simulation is performed. The result shows that the Ganluo rock avalanche released a rock mass volume of approximately 5.20 × 104 m3 that detached from the slope, and 1.52 × 104 m3 of unstable rock mass is still in the source zone. The analysis indicated that the prerequisite for the rock avalanche was continuous heavy rainfall, which occurred in the preceding months. The simulation shows the maximum sliding velocity is approximately 22 m/s. Additionally, the potential destructive zone of the unstable rock mass is evaluated, which can provide a reference for secondary disaster prediction.