降雨入渗对边坡浅层稳定性的影响

为研究降雨入渗对边坡浅层滑动面稳定性的影响,基于非饱和渗流理论,分析浅层滑动面在降雨期和停雨期的渗透系数和孔隙水压力,得出了边坡浅层滑动面稳定性的变化规律。结果表明降雨期间,坡脚处孔隙水压力增大至饱和,坡顶处孔隙水压力持续增大接近饱和,停雨后坡顶处孔隙水压力降幅大于坡脚处;降雨前期各滑动面稳定性均持续减小,降雨后期坡顶滑动面安全系数趋于收敛,但坡脚滑动面安全系数仍持续减小;停雨后浅层滑动面安全系数均增大,深层滑动面则呈波动状态。

Influence of Rainfall Infiltration on Slope Stability at Shallow Layer

In the aim of investigating the influence of rainfall infiltration on slope stability at shallow surface,the permeability coefficient and pore water pressure of slip surface of shallow layer in rainy period and non-rainy period were analyzed based on unsaturated seepage theory.The rule of slope stability variation in shallow layer was also researched.Results showed that in rainy period pore water pressure at slope toe increased to saturation,and at slope top increased until approaching saturation.After rainfall stopped,the decline margin of pore water pressure at slope top was larger than that at slope toe.In the early stage of rainfall,the stability of slip surfaces decreased continuously,and in the later stage of rainfall the safety factor of slip surface at slope top tended to convergence;whereas the safety factor at slope toe kept decreasing.After rainfall stopped,the safety factors of slip surfaces in shallow layer all increased;while the safety factor of deep layer fluctuated.