Abstract:

The Shibangou landslide was a rainfall-induced large-scale bedding bedrock landslide during the “9.18” floods in 2011 in Nanjiang county. Through field survey and detailed study on the geological environment and geological features of Shibangou landslide, we discussed its geological formation mechanism and deformation evolution in details. it’s found that the surrounding three channels provided a very large catchment, The hidden potential energy caused by super heavy rainfall, the high static water pressure, uplift pressure, and the liquefaction of sliding soil are main causes of the high-speed sliding of the landslide. The landslide experienced four phases the original jointed fissures in the bedrock filled with water and then opened, and troughs initiated in short ranges, then the trough valleys slowly expanded, and finally the water-filled trough valleys slid violently. It’s suggested that during the geological survey, investigation of the microrelief of slopes and the weathered unloading areas should be focused on, it is of great significance for the forecast of such potential bedding bedrock landslide.

Key words: smooth layer of bedrock landslide, landslide causes, evolution mechanism, rainfall-induced