Geological characteristics and control of the ChenjiagouLandslide in the Three Gorges Reservoir area

Chenjiagou landslide is located in Fengjie county, Chongqing City. Based on the study of engineering geological conditions and basic properties of the landslide, this paper describes the characteristics of structure and deformation of the landslide and analyses the causes of formation and the main factor to induce slope failure. The stability and comprehensive treatment of the landslide are also discussed. According to the test data of rock samples and the data of site investigation, we can get the stability parameter of the landslide and the anti-shearing strength parameters. Because of water storage in the Three Gorges Reservoir, we calculate the stability of the main landslide and the sub-landslide under the different operating conditions. The results show that the main landslide is stable under natural and the rain-storm circumstance while the sub-landslide is in critical creeping motion or at the unsteady state when the landslide body in saturation or after impoundment of reservoir. Therefore, it is necessary for the landslide to make reasonable evaluation, prediction and treatment. The backfill toe weight and drainage system are adopted to keep the slide mass stable. Some useful experiences for investigation and treatment of landslides in the Three Gorges Reservoir areas are presented in the paper.