雅砻江中游某滑坡形成机制及稳定分析

Formation mechanism and stability evaluation of a landslide in Yalong River

雅砻江右岸某滑坡位于拟建坝址区上游,木里县卡拉乡,该滑坡一旦失稳,威胁坡脚居民以及拟建水电站的安全运行。本文在野外工程地质测绘、钻探、室内试验基础上,采用三维有限差分软件FLAC3D对滑坡进行数值模拟分析,对滑坡基本特征、形成机制以及稳定性进行分析评价。结果表明:该滑坡为特大型岩质滑坡,形成演化经历了剪切蠕动-滑移弯曲-贯通破坏三个阶段,天然状态下滑坡整体上稳定性较好,暴雨状态下处于欠稳定状态,局部表层存在二次滑动可能。

A landslide lies in？ the upstream of dam site at the right bank of Yalong River. Once the landslide is damaged. It will have an import an impact on the local residents and safe operation of the preparing hydropower station. This paper based on the field engineering geological mapping,drilling and laboratory test,the stability is analyzed by the numerical simulation using three-dimensional finite difference software（ FLAC3D）. It analyzes the basic characteristics,formation mechanism and stability of the landslide. The result shows that the landslide is a oversize rock？ landslide. Its formation and evolution has passed three stages： shear peristalsis,flexural slumping？ and transfixion failure. The landslide is stable under natural state and lacked of stability in,but secondary sliding may occur on local surface.