中文摘要：

对三峡库区归州老滑坡在库水位从175m下降到145m过程的滑坡稳定性进行研究,通过黄金分割方法优化计算时步,利用MIDAS/GTS有限元软件分析了库水位下降时岸坡内孔隙水压力的变化及由此引起的岸坡稳定性变化,确定了库水位下降量与库岸斜坡稳定安全系数的关系,结果表明：将优化方法用到库岸斜坡稳定性分析中,可提高计算效率;在库水位下降过程中,斜坡的稳定安全系数不是单调降低,而存在一个极小值;三峡库区归州老滑坡基本稳定。

英文摘要：

The stability of the old landslide of Guizhou in the Three Gorges region during reservoir water level drawdown from 175 to 145m is studied. Using the Golden-Split method to optimize the calculating process, the stability of the old landslide of Guizhou during reservoir water level drawdown is analyzed in combination of the pore water pressures calculated from the transient seepage analyses by using the finite element software MIDAS/GTS. Through numerical calculation, the relationships between the landslide stability and the reservoir water level drawdown are obtained. The results show that the old landslide of Guizhou is stable during the reservoir water level drawdown from 175 to 145m. It is effective to apply Golden-Split method to the analysis of landslide stability on a reservoir region. A minimum value of the safety coefficient of landslide exists, which does not singly reduce with reservoir water level drawdown.