Geological disasters occurred frequently in the reservoir area since the Three Gorges reservoir was built up

which highlights the importance to study the stability and failure mode of reservoir bank under the condition of reservoir water level fluctuation. A method to evaluate the slope stability by centrifugal test is introduced with Liangshuijing landslide as a testing case. Soil slope models considering geological conditions of the Three Gorges are also constructed. Through the techniques of digital photography

laser displacement sensor

pore water and soil pressure sensor

controlling of drawdown and charging of reservoir is implemented in the test

and a series of important test data such as pore water pressure

displacement

pore water pressure and soil pressure is obtained. Results indicate that the model displacement is mainly in the vertical direction from the beginning to the end of the water adding stage

and the horizontal displacement is much larger than that in water falling stage. With the rising and plunging of the reservoir water level during the experiment

crack formation appears at the leading edge first

then gradually extends at the middle and trailing edge. In this process

large deformation is generated at the middle edge and localized slip appears. In general

failure pattern of the model shows the trend of retrogressive mode. At the end of the experiment

volumetric water content gradually increases from the trailing edge. During the rise of water level

model deformation is relatively small. The main deformation occurs during the decline of water level. Therefore

the landslide is a dynamic-water-pressure type. The deformation and failure are mainly due to the dynamic water pressure effect. The failure mode and the mechanism of deformation instability under the condition of reservoir water level fluctuation are revealed by the experiment

which provides an important basis for the prevention and control of landslide in the reservoir area.