Simulation of a long-runout rock avalanche triggered by the Lushan earthquake in the Tangjia Valley, Tianquan, Sichuan, China

Only one long-runout rock avalanche was triggered by the 2013 Lushan earthquake in the Tangjia Valley, Tianquan, Sichuan, China. The rock avalanche involved the failure of similar to 530,000 m(3) of sandstone from the source area. The displaced material travelled a horizontal distance of similar to 1600 m with an elevation descent of similar to 480 m, equivalent to a fahrboschung of 16.7 degrees Based on a detailed field investigation, we introduce basic characteristics of the rock avalanche and find that the rock avalanche resulted in one run-up in the Chunwojian Valley, a super elevation in the Gangoutou Valley, and increase in volume due to the entrainment of path materials. A numerical model (DAN3D) was used to simulate the post-failure behavior of the rock avalanche. By means of trial and error, a combination of the frictional model and Voellmy model is found to provide the best performance in simulating this rock avalanche. The simulation results reveal that of the rock avalanche lasted approximately 160 s and an average velocity of 10 m/s. (C) 2017 Elsevier B.V. All rights reserved.