考虑雾化雨条件下边坡的稳定性分析

Slope Stability Analysis in Consideration of Atomised Rain

以锦屏水电站边坡为例,将渗流理论引入边坡的稳定分析,结合数值分析软件SLIDE,研究了边坡在不同降雨入渗深度下动水压力、安全系数的变化情况及规律,提出了降雨入渗及排水加固后的边坡稳定性评价方法。分析结果表明:随着雾化雨的降雨入渗,动水压力有不断增大的趋势,安全系数有不断减小的趋势,降雨入渗雾化3 d后,坡体下部已达到完全饱和状态,持续的雾化雨作用对坡体下部地下水位的改变不大,形成了稳定水流,边坡的安全系数也没有太大变化;同时,采用固定的土性参数来计算边坡的稳定性还不能全面地评价边坡的稳定性,土体抗剪强度参数c和φ的变异性及其相关性是影响边坡可靠度指标的一个极其重要的因素。

With the side-slope of Jinping hydropower station as a example,the theory of fluid-solid coupling is introduced into slope stability analysis.The variation and regularity of hydrodynamic pressure and safety factor of side slope in the presence of different depths of rainfall infiltration are analyzed by using numerical analysis software SLIDE.A method of stability assessment for slopes undergone rainfall infiltration and drainage consolidation is put forward.Results show that：with the atomised rainfall infiltration,the hydrodynamic pressure shows a trend of increasing and the safety coefficient shows a trend of decreasing.After 3 days of rainfall infiltration,the lower part of the slope has reached a state of saturation.Continuous atomised rain has little influence on the groundwater level in the lower part of the slope,and a stable water flow is formed,so that the safety coefficient does not change too much.Moreover,the slope stability cannot be assessed comprehensively by using fixed soil parameters,because the variability and correlation of soil shear strength parameters c and φ are important factors of slope reliability index.