Deformation analysis and stability evaluation of landslide excavated in front: case of Darong Landslide in Cengong County of Guizhou Province

After Darong landslide in Cengong County occurred, a barrier lake was formed in front of the landslide. To dredge the river channel, staged excavation and rolling compaction were conducted and the monitoring measures were taken to master the landslide′s stability. The results of monitoring data analysis show that the sliding mass was still stable; the relative large deformation occurred under the strong rainfall and the landslide toe excavation, and in the following 2 to 3 months, the stress and stability state were in a large fluctuation. In a specified condition, the influence of strong rainfall or long-term continuous rainfall on soil moisture content is limited, so the soil water content would not rise infinitely along with the increase of rainfall intensity; but pore water level is related to rainfall intensity apparently, and it might be the main cause of the landslide. The monitoring data and analysis of limited equilibrium method show that the landslide is stable generally; however it might be unstable under strong rainfall condition.