Stability research on reservoir slope based on geomechanical parameters back-analysis and monitoring data: A case study in China

Abstract

Stability evaluation of reservoir slope is a key issue affecting the safe operation of water conservancy projects, especially the new unexpected slope deformable bodies caused by changes in the hydrodynamic environment during the reservoir operation. The present study investigated the slope stability evaluation based on geomechanical parameters back-analysis and monitoring data of the left bank deformed slope of Guandi reservoir in China, of which the soil mechanical parameters result of laboratory test do not match the actual operating. In order to accurately evaluate the stability of this slope under the complex external environment, the deformation characteristics and instability mode of the slope were analysed based on the systematic study of the relationship between monitoring data and reservoir water level as well as rainfall. The failure mode of deformed slope was proposed, and the geomechanical parameters were obtained through back-analysis according to monitoring data of slope deformation. Based on the back-analysis results, the detailed analysis of the slope stability was studied, and the stability sensitivity analysis of the deformed slope under the sudden drop of the reservoir water level was carried out combining with the reservoir dispatch requirements. The results show that the slope stability using the back-analysis parameters are objective and reasonable. The research results could provide scientific references for stability evaluation of similar slopes.