四川汉源县二道坪滑坡成因及稳定性分析

在人类工程活动影响下,持续的强降雨极大的加速了滑坡、崩塌等地质灾害的发生,二道坪在受到人类工程活动同时,受到强降雨影响,导致二道坪坡体处于欠稳定状态。为了对二道坪滑坡的成因及稳定性分析,在对现场进行详细勘察后,结合无人机、工程地质学以及土力学等手段,对其进行研究。结果表明:二道坪主滑方向为100°,纵向长约174 m,横向宽约92 m,滑坡体面积约1.50万m~2,滑体平均厚度约4.5 m,体积约6.75万m~3,属小型滑坡;滑坡体为浅地表为第四系松散体及含角砾粉质黏土层,滑带为易溶于水的含角砾粉质黏土层,为滑坡的启动提供了有利条件;根据定量分析结果,在持续强降雨条件下(饱和状态),稳定系数为1.05,在地震和暴雨共同作用下稳定性系数为0.85,滑坡启动。

Cause and Stability Analysis of Erdaoping Landslide in Hanyuan County, Sichuan Province

Under the influence of human engineering activities, continuous heavy rainfall greatly accelerates the occurrence of geological disasters such as landslide and collapse, and the erdaoping slope body is in an unstable state due to the influence of heavy rainfall while it is subject to human engineering activities.In order to analyze the cause of formation and stability of Erdaoping landslide, after a detailed investigation of the site, it was studied by means of UAV, engineering geology and soil mechanics.The results show that the main sliding direction of the two-lane flat is 100°, the longitudinal length is about 174m, the transverse width is about 92m, the landslide area is about 1.50×104m2, the average thickness of the landslide is about 4.5m, the volume is about 6.75×104m3, and it is a small landslide.The landslide is a quaternary loose body and breccia-containing silty clay layer on the shallow surface, and the slide zone is a water-soluble breccia-containing silty clay layer, which provides favorable conditions for the start of the landslide.According to the quantitative analysis results, the stability coefficient under the condition of continuous heavy rainfall (saturation state) is 1.05, and the stability coefficient under the combined action of earthquake and heavy rain is 0.85, and the landslide starts.