Deformational characteristics of Donglinxin slope induced by reservoir fluctuation and rainfall

Abstract

Landslides induced by reservoir inundation and rainfall are very common in southwest China, adversely affecting the construction of hydropower plants in this area. In this study, a case of Donglingxin slope located at the Sanbanxi reservoir is reported, which developed into a large landslide. To understand deformation and conduct stabilization measurement, an in-depth study has been done based on monitoring the trigger events like reservoir fluctuation, rainfall and groundwater levels. It was revealed that the rainfall mainly affected deformation of the upper slope; reservoir fluctuation reduced the stability of the toes of the slope. The activity of groundwater between the bedrock and the soilrock mixture, geomaterials greatly controlled the global stability. An analysis of the comprehensive effects of these trigger events, indicated that the slope was unstable and would have slid into the reservoir. The evolution of slope deformation was simulated by particle flow code, the result showed that the landslide started from the head of the gully. This case study provides important geo-technical references for engineering the prevention of reservoir bank slopes.