中文摘要：

在三峡水库运行过程中,库水位周期性涨落引起库区内滑坡稳定性发生变化,渗透特征是滑坡的内在属性,滑坡因渗透性的不同而导致其稳定性对库水变化的响应不同。根据万州库段水位统计资料,以三峡库区万州区下坪滑坡为模型,分析在4种不同数量级的渗透系数条件下的渗流场特征,研究在不同渗透系数下的滑坡稳定性变化规律。分析结果表明：该类型滑坡的稳定性变化与库水位的变化呈现高度的正相关;滑坡稳定性最差出现在库水位下降到最低水位时,且水位降速越快,滑坡稳定性越差;不同渗透条件下的滑坡稳定性随时间的变化规律基本一致,其变化率处在一定的波动范围内,保持在-2%-2%之间;滑坡稳定性的最大值和最小值都是随着渗透性的变大而变大;稳定性最小值与渗透系数的对数值表现为近似指数关系,稳定性最大值与渗透系数的对数值表现为近似对数关系。

英文摘要：

During the operation of the Three Gorges Project, the reservoir water level changes according to the actual condition of water storage and hydrologic condition. Because of the correlation between the underground water level of landslides and the reservoir water level, water level cyclical fluctuation may have effects on the landslides in many ways. The effects cause the changes of the stability of landslide in the reservoir area. Permeability is the internal property of landslide. The permeability coefficient can be used to characterize the hydraulic conductivity of the soil. It is also the main factor influencing the characteristics of seepage field of the landslides on the reservoir bank. The stability of the landslides responds differently to the changes of the reservoir water level, due to different permeability of the landslides. According to the statistics of the reservoir water level of the Wanzhou, we take the Xiaping landslide in Wanzhou district of the Three Gorges Reservoir area as a model. We study the variation law of the stability of landslides with different permeability coefficients by analyzing the characteristics of seepage field under 4 different orders of magnitude of permeability coefficient. The results show that the variation of the stability of this type of landslides shows highly positive correlation with the variation of the reservoir water level. The worst stability of the landslide appears when the water level is dropped to the lowest level. And the faster water level drops, the worse the stability of landslide becomes. The regularities of the coefficients of landslide stability changed with the time are almost the same under different permeable conditions. The variation ratio of the coefficient fluctuates within a certain range between-2%to 2%.The maximum and minimum of the landslide stability go after the permeability. As the permeability of the landslide decreases, the response of the groundwater to the reservoir