三峡水库区陈家沟滑坡地质特征与防治措施

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

在研究了三峡水库区奉节县陈家沟滑坡的工程地质条件及滑坡体基本特征的基础上,介绍了该滑坡的结构及变形特征。从滑坡形成条件、诱发变形因素两方面分析了滑坡形成的原因及诱发坡体失稳的主要因素;据岩土样品的试验值、现场大剪值,结合地区经验值及反算值,确定计算滑坡稳定性及剩余滑坡推力的抗剪强度参数,考虑到未来三峡水库蓄水,在不同工况下对滑坡体进行稳定性计算。结果表明:在天然及暴雨情况下,滑坡整体均处于稳定状态;次级滑坡体在饱水及水库蓄水后,处于临界蠕滑或失稳状态。结合工程实际对滑坡治理进行初步研究,提出回填压脚支档为主、辅以排水的综合治理措施。

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.