边坡在降雨及地震作用下的稳定性分析

Analysis on Stability of Gravel Slope under Rainfall and Earthquake

目的研究边坡在地震和降雨作用下稳定性的变化规律,得出导致边坡失稳的敏感因素.方法基于ABAQUS有限元软件模拟分析边坡稳定性的变化过程,采用拟静力法和强度折减的有限元法等方法对边坡进行数值模拟,将得到的安全系数与极限平衡法所得安全系数进行对比.结果在弱降雨20 mm/h条件下,边坡安全系数发生变化的几率特别小,可见一定强度的弱降雨不会对边坡安全构成威胁;在强降雨50 mm/h状态下,前期边坡安全系数变化不大,后期安全系数逐渐降低且变化明显,甚至在降雨大约34h后边坡发生失稳破坏,安全系数极具降低,强降雨会对边坡安全稳定性构成极大威胁.结论在边坡或者堤坝等岩土工程中降雨和地震对其稳定性和安全性的影响,相对于其他外界因素更为重要.

To analyze the slope stability under rainfall and earthquake conditions, and get sensitive factors that lead to slope unstability. The ABAQUS software is used to simulate the slope stability changes, and the slope is simulated with the quasi-static method and the strength reduction method. It compares the factor of safety with the safety factor obtained by the limit equilibrium method. The result shows that：the slope safety factor is very small at 20 mrn/h under weak rainfall, and weak rainfall with certain intensity will not pose a threat to slope safety. In the heavy rainfall at 50 mm/h, the early safety factor is not changed much, the late safety factor is gradually reduced and the change is obvious, even after about 34 hours of rainfall, the safety factor is greatly reduced, and it can be seen that the heavy rainfall will pose a great threat to the safety and stability of the slope. The conclusion shows that：the influence of rainfall and earthquake on its ability and safety is more important than other external factors in geotechnical engineering such as slope or dam.