基于矢量和法的库水位下降边坡稳定性研究

为了研究库水位的下降对高陡边坡稳定性及变形的影响,以锦屏一级水电站左岸边坡为例,基于饱和渗流理论,以左岸坝头滑移破坏模式为研究对象,利用矢量和稳定性评价方法研究不同库水位下降速度对锦屏一级电站左岸边坡的稳定性影响规律。研究表明:当库水位以1 m/d的速度由1 880 m高程下降至1 800 m高程时,左岸坝头滑移破坏模式的安全系数由1.214降低到1.147,且安全系随着库水位下降趋于稳定,而当库水位下降速度达到2 m/d时,安全系数的降低速度随着库水位的下降逐渐加剧,当库水位达到1 800 m高程时,安全系数降至1.052,左岸坝头滑移破坏模式接近临界状态;库水位下降条件下坡体最大位移处发生在坝头滑移破坏模式潜在滑动面的剪出口位置。

Study on slope stability of reservoir water level falling based on Vector-Sum FoS Method

This paper is to study the influence of reservoir water level changes on the stability and deformation of steep slopes. Taking the left-bank slope of Jinping hydropower station as an example, based on the saturated seepage theories, the seepage is calculated under the changes of water level. In addition, the factor of safety of the slope is worked out with the Vector-Sum FoS Method during the seepage. New findings are as follows:when the reservoir water level has a rate of 1m/d from the elevation1880m to 800m, the safety factor of dam on the left bank of the head slip failure mode is reduced from 1.214 to 1.147, and the safety factor approaches a determined value as the water level tends to be stable. When the drawdown speed reaches 2m/d, the safety factor decreases more quickly; The maximum displacement of the slope is located at the shear outlet position of the potential sliding surface of the slip failure mode at the dam.