水城县尖山营滑坡成因及稳定性分析

在人类工程活动影响下,持续的强降雨极大地加大了滑坡、崩塌等地质灾害发生的可能性和风险.在受到长期人类工程活动同时,2020年9月强降雨后,导致尖山营在2020年9月15日发生滑坡.为了分析尖山营滑坡的成因及稳定性,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:尖山营滑坡体纵长约650 m,前缘横宽410 m,坡度上陡下缓,平均为20°,滑坡区面积约0.14 km2,厚度2～8 m不等,平均约6 m,体积约8.4×105 m3;滑坡体为浅地表为第四系松散体及全(强)风化泥岩层,滑带为易溶于水的粉砂质泥岩层,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0.724,尖山营坡体处于不稳定状态.

Causes and Stability Analysis of Jianshanying landslide in Shuicheng County

Under the influence of human engineering activities, continuous heavy rainfall greatly increased the occurrence of landslide, collapse and other address disasters. At the same time, Jianshanying suffers from long-term human engineering activities, and after heavy rainfall in September 2020, the landslide occurred in Jianshanying on September 15, 2020.In order to analyze the cause and stability of Jianshanying landslide, after a detailed investigation of the site, it is studied by means of UAV, engineering geology and soil mechanics.The results show that the slope length of jianshanying landslide is about 650m, the leading edge width is 410 m, the slope rises steeply and falls slowly with an average of 20°, the landslide area is about 0.14 km2, the thickness varies from 2 ~ 8 m, the average is about 6m, and the volume is about 8.4×105 m3.The landslide body is a quaternary loose body and a completely (strongly) weathered mudstone layer on the shallow surface, and the slide zone is a water-soluble silty mudstone layer, which provides favorable conditions for the start of the landslide.According to the quantitative analysis results, under the condition of continuous heavy rainfall (saturation state), the stability coefficient is 0.724, and the slope body of Jianshanying is in an unstable state.