强降雨诱发平缓滑坡复活变形与稳定性演化分析

Analysis of Reactivated Deformation and Stability Evolution of Gentle Landslide Induced by Heavy Rainfall

平缓滑坡因地形坡度小易受强降雨影响而发生变形破坏.为深入研究强降雨对滑坡复活变形及稳定性的影响,以湖北省秭归县土地岭滑坡为例,进行强降雨条件下的滑坡渗流-应力耦合模拟,分析不同降雨条件下的滑坡复活变形过程中的孔隙水压力、位移场变化和稳定性演化.研究表明,平缓的土地岭滑坡的阶跃变形与集中强降雨密切相关,降雨导致滑坡体内孔隙水压力从后部到前部逐渐增加,前部响应最快;滑坡稳定性系数随降雨过程逐渐降低,在24 h内降幅最显著.这对强降雨引发滑坡的变形机制与预警具有一定的参考价值.

Gentle landslides are easily affected by heavy rainfall due to small terrain angles and resulted in landslide deformation and failure.In order to study the influence of heavy rainfall on landslide reactivated deformation and stability,the Tudiling landslide in Zigui County,Hubei Province is chosen for case study.A seepage-stress coupling simulation was carried out under heavy rainfall conditions.The pore water pressure,displacement field,and stability evolution were analyzed during the landslide reactivation under different rainfall conditions.The results show that the step deformation of the gentle landslide is closely related to heavy rainfall,which causes the pore water pressure in the landslide to gradually increase from the head to the toe,and it responds rapidly in the front part.The factor of stability gradually decreases with the rainfall process and decreases significantly within 24 hours.It provides a useful guideline for the deformation mechanism and early warning of landslides caused by heavy rainfall.