三峡库区滑坡稳定性评价研究

三峡水库蓄水后 ,库水位将在 14 5～ 175m范围内波动 ,动水压力和水的软化作用是滑坡失稳的主要因素。库区滑坡稳定性评价规范要求采用不平衡推力法 ,但在考虑库水位下降产生的渗透力时 ,对渗流浸润线的确定缺乏理论依据 ,更没有实测数据的支持。为此 ,笔者运用一维的布辛内斯克方程 ,研究三峡水库蓄水后库水位下降和暴雨作用下滑坡渗流浸润线的变化规律 ;建立了渗流作用下滑坡稳定性评价模型 ;分析降速、渗透系数、暴雨等对滑坡稳定性的影响。

Study on Landslide Stability Evaluation for the Three Gorges Reservoir

Since the Three Gorges reservoir began to impound in 2003, reservoir water table will fluctuate from altitude of 175 m to 145 m. Both water softening and drawdown of reservoir water table have become main factors affecting the stability of landslide. According to criteria, disequilibrium push method should be adopted to evaluate the landslide stability. However, there are no theoretical criteria and measured data that the seepage line could be determined. So, Boussinesq equation is used to calculate the seepage line due to descending of reservoir water table from 175～145 m and rainstorm infiltration. A model of landslide stability evaluation for seepage is established. Effects of different descending speed of reservoir water table, permeability coefficient and heavy rainfall are discussed.