降雨强度对含软弱夹层边坡失稳破坏临界长度影响

The influence of rainfall intensity on the critical length of instability failure of slope with weak interlayer

为研究降雨强度对含软弱夹层岩质边坡滑移范围的影响,考虑含软岩边坡坡角与岩层倾角关系、裂隙所处位置,采用图解法推导降雨致灾含软弱夹层边坡的失稳临界长度公式,分析验证关键因素对边坡失稳临界长度的影响,确定不同情况下边坡失稳临界长度表达式,并进行实际工程验证。研究结果表明:边坡失稳临界长度与降雨强度函数关系受边坡坡角、岩层倾角、裂隙位置影响;在降雨致灾边坡中,岩层强度参数c、φ和边坡滑移临界长度成反比关系;裂隙积水深度和降雨强度的增加导致边坡滑移临界长度增加,且降雨强度增至裂隙最大容量后临界长度趋于稳定;工程验证表明,所推导公式计算值与实测值在合理误差范围之内。

For the study of rainfall intensity on the influence of the rock slope with weak interlayer sliding range,considering including soft rock slope inclination angle and strata relations and the location of joints,graphic method was used to deduce the rainfall instability of the slope with weak intercalated critical length formula,analyze the key factors on the slope instability critical length,the influence of different cases of slope instability critical length expression,and verify it through the actual engineering.The results show that the relationship between the critical length of slope failure and the rainfall intensity function is expressed in different ways under the influence of slope angle,rock stratum inclination angle and fracture location.In the rain-induced slope,the rock strength parameters c,φand the critical slip length of the slope show an inverse trend.The critical length of slope slip increases with the increase of water depth and rainfall intensity,and the critical length tends to be stable when the rainfall intensity increases to the maximum capacity of the fracture.The calculated value of the formula and the measured value are within the error range.