The frequent drawdown of water level of the Yangtse River will greatly influence the stability of the widely existing slopes in the Three Gorges Reservoir zone

especially those layered ones. Apart from the fluctuating speed of water level

the different geological materials will also play important roles in the failure of slopes. Thus

it needs firstly study the mechanism of such a landslide caused by drawdown of water level. A new experimental setup has been designed to study the performance of a layered slope under the drawdown of water level. The pattern of sliding of a layered slope induced by drawdown of water level has been explored by means of simulating experiments. The influence of fluctuating speed of water level on the stability of the layered slope was probed

especially on the whole process of deformation and evolution of landslide of the slope. The experimental results showed that the slope is stable during the water level being rising

and the sliding body occurred in the upper layer of the slope under certain drawdown speed of water level. In the process of slope failure

some new small sliding bodies developed on the main sliding body

and these small sliding bodies could speed up the disassembly of the whole slope.Based on the simulating experiment about landslide of a layered slope under drawdown of water level

the whole process of the seepage velocity

the pore water pressure

and the gradient of pore water head within the slope body were calculated. The computational results were in good agreement with the experimental results. Accordingly

the mechanism of deformation and landslide of the layered slope induced by drawdown of water level was analyzed

which may provide basis for treating this kind of layered slopes in practical engineering.