中文摘要：

柴湾滑坡是三峡库区结构复杂的大型老滑坡之一,三峡水库蓄水后,该滑坡出现明显复活迹象。本文基于滑坡结构和2007-2015年监测数据,分析了该滑坡活动对库水位变化的响应特征;采用数值模拟手段分析了库水位变化时滑体内渗流场及孔隙水压力变化特征。研究发现,该滑坡在平、剖面上分别呈现牵引式分块与浅、中层分层的缓慢活动特征;当库水位降速〉0.8 m/d时,滑坡活动呈现滞后的台阶式加剧趋势;越接近地表,滑坡活动对库水位变化愈敏感。柴湾滑坡活动特征受其复杂结构控制,滑坡中前部地下水与库水密切的水力联系以及中层、深层滑体良好的渗透性决定了滑坡的分块和分层活动特征。库水位上升时透水性较强滑体内的扬压力和库水位下降时透水性较弱滑体内的动水压力是造成滑坡分块分层活动的内在动力。

英文摘要：

The Chaiwan landslide is a large and complex landslide in the Three Gorges Reservoir area. The landslide is composed of three kinds of materials and develops three slip zones along the contacts among the materials and along the contact between the landslide and the bed rock. The materials of the landslide from top to bottom are very dense coarse soil with some silt and clay with low hydraulic conductivity, dense and coarse soil with higher hydraulic conductivity and very loose cataclastic rocks with the highest hydraulic conductivity, respectively. Reactivation of the landslide was observed since the operations of the Three Gorges Reservoir. Response of the Chaiwan landslide to water level fluctuation of the Three Gorges Reservoir is explored in this study based on the structure of the landslide and field monitoring data from 2007 to 2015. Variation in pore water pressure within the landslide during filling and drawdown of the reservoir was simulated using the Seep/ W code. The results show that the landslide is under a slow movement with about retrogressive movement pattern and along the upper and middle slip zones during both the constant rate and a filling and drawdown periods of the reservoir, while the movement rate of the landslide suddenly increases when the drawdown rate of the reservoir is greater than 0. 8 m/d. The upper and lower parts of the landslide are the most sensitive to the reservoir water fluctuation. The movement pattern of the landslide is due to itself complex structure and great difference in hydraulic conductivity of the materials. The continuously slow movement of the landslide during both the filling and drawdown periods of the reservoir is attributed to the uplift pressure during the filling period occurred within the middle and lower materials of the landslide where the hydraulic conductivity and seepage pressure is high to very high during the drawdown period generated within the upper and middle materials where hydraulic is lower than that of the lower material.