关键词: 特大型多级滑坡;阶跃变形;地下水;降雨;库水位;三峡库区;藕塘滑坡;

Abstract: The deformation of super-large landslide is a complex dynamic process.Analyzing the deformation monitoring data is an effective way to understand the stability and deformation mechanism of landslide.Taking a typical super-large multi-stage rock landslide，Outang Landslide，in the Three Gorges Reservoir area as an example，based on the topographic characteristics of the landslide and GNSS professional monitoring data，combining with the changes of rainfall，reservoir water level and groundwater level，the deformation characteristics of different regions of the landslide and the deformation mechanism are analyzed.The results show that：① Rainfall is the main inducement of step deformation of Outang Landslide.The landslide is more sensitive to rainfall during the step period，and a small amount of rainfall may trigger the landslide and accelerate again.② The influence range of reservoir water level change is limited to the front edge of the first-stage sliding body.The water level fluctuation will change the local stability of the landslide but will not directly lead to step deformation of the landslide.③ The change of groundwater level in the landslide area is the direct cause of the step deformation of the landslide.Reducing the change of groundwater level in the landslide area is the key to controlling the Outang Landslide.

Key words: super-large multi-stage landslide；step deformation；groundwater；rainfall；reservoir water level；Three Gorges Reservoir area；Outang Landslide