降雨入渗对炭质页岩边坡稳定性的影响

Impact of Rainfall Infiltration on Carbonaceous Shale Slope Stability

在降雨影响下,边坡内渗流场会发生改变,雨水会与炭质页岩发生相关反应,最终使边坡发生滑坡等自然灾害。文章结合非饱和土体的抗剪强度理论,运用Geoslope有限元分析软件对不同降雨方案下炭质页岩边坡的稳定性进行研究。结果表明:当其他条件一定时,降雨强度越大,在开始一段时间内边坡的安全系数下降较快,随之下降速度又逐渐变缓,最终炭质页岩边坡已经处于不稳定状态;降雨历时越长,渗入量越大,炭质页岩边坡随时可能出现滑坡现象;当饱和渗透系数在小于降雨强度的范围内变化时,边坡安全系数变化敏感性强,在饱和渗透系数大于降雨强度的范围内变化时,边坡安全系数变化敏感性较弱。

Under the impact of rainfall,the seepage field in the slope will change,the rainwater will produce the related reactions with carbonaceous shale,and finally lead to the slope landslides and other natural disasters.Combining the shear strength of unsaturated soil,this article studied the stability of carbonaceous shale slope under different rainfall programs by using the Geo-slope finite element analysis software.The results showed that：under certain other conditions,when the rainfall intensity is greater,the safety factor of slopes shows the faster decline at the beginning period,followed by gradually slo-wing down of decline rate,and eventually the carbonaceous shale slope is already in the unstable state;the longer when the rain lasts,the greater the infiltration amount,and the carbonaceous shale slope landslides may occur at any time;when the saturated permeability coefficient varies within a range less than the rainfall intensity,the slope safety factor has strong sensitivity to changes,and when the saturat-ed permeability coefficient varies within the range greater than rainfall intensity,the slope safety factor has weaker sensitivity to changes.