There exists the problem of landslide reactivation due to the seasonal fluctuation of rainfall and reservoir water level annually. Based on a large number of GPS monitoring data of the landslide mass after impoundment of the Three Gorges Reservoir in Shiliushubao landslide area, the relationship between the external trigger factors and slope stability could be obtained. A finite element calculation model has been established for the stability analysis of the Shiliushubao landslide after impoundment from January 2004 to October 2009. Through the deformation characteristics of the landslide, it is shown that the landslide exhibited a stepwise pattern on the whole, which developed faster after impoundment and slowed down in rainy seasons. The trend of the curve kept roughly opposite to the fluctuation of the safety factor. It suggested that the stability of the landslide mass was closely related to the seasonal fluctuation of the rainfall and the reservoir level, and the landslide deposits demonstrated to be reactive with them. The subject provides a certain reference value on the landslide stability analysis and the risk assessment within a similar engineering geological condition.

Aiming at the deformation characteristics of surrounding rocks in underground powerhouse area of a hydropower station in Western China, the finite difference method is used for numerical calculation, and a assistant modeling software is used to realize the refined modeling of complex surface, which effectively improves the simulation accuracy. The results show that the stress level of surrounding rocks is low, the deformation of surrounding rocks is small, and the surrounding rocks is basically stable. However, the plastic zone of surrounding rocks has the trend of transfixion, so it is necessary to adjust the spacing of powerhouse.

The geological conditions are complex in the Longnan mountain area, and the landslide disasters are widely distributed and numerous, among which the large accumulation layer landslide is especially developed. This kind of landslide is mostly distributed along the river basin and has the characteristics of multi-phase and multistage. The slide body is mostly in the state of creep plastic flow, and it is easy to revive. In this paper, the creep characteristics and evolution model of the secondary landslide were studied based on the field geological survey and the numerical calculation method, in order to provide reference for the monitoring and treatment of the landslide in this area. The results show that the shear stress and shear strain concentration zone is mainly located near the previous sliding surface of the landslide, and the creep type is deep creep; The deformation of the sliding body in zone D show that the deformation of the trailing edge and the middle front is relatively small, while the deformation of the middle and the leading edge is large; At the present stage, the overall deformation mode of the slide body in the D area of Qinyu landslide is a slow creeping deformation mode of traction from the front, down-shifting from the middle to the back.

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Using RMR surrounding rock classification method, the surrounding rock quality of underground main powerhouse of a hydropower station is evaluated with a small evaluation unit. The results of surrounding rock classification show that the surrounding rock of main powerhouse is mainly Grade III, and Grade II and IV surrounding rock develop intermittently with the depth of main powerhouse, and there is no Grade I or V surrounding rock distribution. Secondly, setting a smaller evaluation section is conducive to improve the accuracy of surrounding rock quality evaluation and better grasp the distribution of different grades of surrounding rock in the evaluation area.