降雨诱发公路边坡失稳破坏机制研究

Study on Mechanism of Highway Slope Failure Induced by Rainfall

降雨是诱发公路边坡病害的重要原因之一,尤其在广东地区,连续性的强降雨给高速公路边坡带来极大的安全隐患。本文以广东省某高速公路沿线某高边坡为例,利用地勘数据并借助有限差分软件,考虑降雨强度和边坡后缘裂缝深度两个因素,分析其在诱发边坡破坏中所起的作用。结果表明,受降雨入渗和后缘裂缝影响最大的是第二级边坡;随着降雨强度的增加,一级边坡坡顶到后缘裂缝之间的位移增加最为明显;当后缘裂缝较深时,降雨对各级边坡的稳定性均会产生影响;边坡最大水平位移和降雨入渗深度成线性正相关关系,与后缘裂缝深度近似成二次函数关系;边坡安全系数和降雨入渗深度之间为线性负相关关系,后缘裂缝深度较浅时,对边坡的安全系数影响不大,当裂缝深度增加到一定阈值后,边坡的安全系数会大幅降低。

Rainfall is a major cause of highway slope damage,especially in Guangdong province,where continuous heavy rainfall poses great safety risks to highway slopes.Taking a highway slope in Guangdong province as an example,this study analyzed the role of rainfall intensity and slope back-edge crack depth in inducing slope failure by using geological exploration data and finite difference software.The results showed that the second-stage slope is mostly affected by rainfall infiltration and back-edge cracks.As the rainfall intensity increases,the displacement between the top of the first-stage slope and the back-edge cracks increases most significantly.When the back-edge cracks become deeper,rainfall affects the stability of all stages of slopes.The maximum horizontal displacement of the slope is positively linearly correlated with the depth of rainfall infiltration,and approximately quadratically correlated with the depth of back-edge cracks.There is a linear negative correlation between the rainfall infiltration depth and the slope safety factor.When the back-edge cracks are shallow,they have little effect on the slope safety factor.But as the crack depth increases beyond a certain threshold,the slope safety factor will decrease significantly.