Key factors influencing the mechanism of rapid and long runout landslides triggered by the 2008 Wenchuan earthquake, China

Background: The 2008 Wenchuan earthquake triggered many rapid and long runout landslides, which directly caused great loss of property and human lives and were responsible for a large percentage of total damages caused by the earthquake. It is very important for the purposes of landslide disaster prevention and mitigation to understand the earthquake triggered mechanism of initiation and motion of rapid and long runout landslides, which can potentially be the deadliest of ground failures. Results: In this paper, field investigations of some highly damaging landslides caused by the Wenchuan earthquake are introduced first, and followed by data from ring shear tests used to simulate the initiation and motion of one landslide in particular, the Donghekou complex landslide. Conclusions: It was found that groundwater and valley water played key roles in the rapid motion and long runout process of this landslide during the great earthquake.