水位涨落引起分层边坡滑坡的机理分析

基于分层边坡在水位涨落时发生滑坡的模拟实验，简要描述了实验中的主要现象，计算了实验模拟的分层坡体内与水位变化直接相关的动态渗流场、孔隙水压力场与渗透速度场分布。根据计算结果，对水位变化导致坡体变形失稳的机理进行了分析，为这类分层边坡滑坡的治理提供了依据。

Mechanism analysis of landslide of a layeredslope induced by drawdown of water lever

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.