ANALYSIS OF DEFORMATION AND FAILURE MECHANISM OF BANK SLOPES WITH DIFFERENT STRUCTURES UNDER RESERVOIR WATER LEVEL FLUCTUATION—TAKING QIANJIANGPING LANDSLIDE AND SHUPING LANDSLIDE AS EXAMPLES

Since the impoundment of the Three Gorges Reservoir in 2003, different types of landslides have taken place in the main stream and tributaries of Yangtze River. Based on the structure of reservoir bank slope, taking Qianjiangping landslide and Shuping landslide as examples, this paper attempts to analyze the deformation and failure mechanism of slopes with different structures under the condition of reservoir water level fluctuation through the field investigation, long-term observation and simple model tests. It aims to provide scientific insight for the prevention and control of landslide disasters in the operation process of reservoir area. The results show that the dip-structure slope is easy to lose its stability and cause rapid landsliding in the process of water level rising, while the loose structure slope is easy to produce obvious deformation in the process of water level drawn-down due to the influence of seepage force. The deformation rate is positively correlated with the speed of water level drawn-down.