大渡河三交坪滑坡形成演化机制分析及稳定性评价

三交坪滑坡位于四川首汉源县境内的流沙河左岸，分布面积约1km^3。由于该坡体存在层间错动带和局部变形碎裂体．且地表泉水点较多．造成坡体上游、中部及前缘出现了大量的拉裂缝，目前坡体局部已处于不稳定状态。因此，对该坡体的稳定性评价显得尤为重要。文章根据坡体的结构及形态特征详细分析了滑坡的形成演化机制，判定三交坪滑坡的破坏模式为蠕滑拉裂。同时采用岸坡岩体地质分析及量化评价方法对该滑坡的稳定性进行了分析，得出浅层计算滑面及基岩覆盖界面处的深部计算滑面在天然状态下稳定性良好；但在天然＋暴雨的条件下，浅部滑面的稳定性有少许弱化，处于临界不稳定状态。最后，根据以上分析提出合理的治理建议。

Analysis on formation-evolution mechanism and assessment of the stability for a landslide in Sanjiaoping beside Daduhe River

Sanjiaoping landslide locates in the left bank of Liushahe River, 800m from Yongdingqiao reservoir in Sichuan Province. Its area is about 1km~2. Because of the interformational disturbed belt and the localized deformation-fracture as well as lots of spring water dots on ground surface, there are many stretch cracks in front and middle of the slope, even in the upper part. Part of the slope is unstable. So assessment on the landslide becomes very important. This article analyses the formation-evolution mechanism of this landslide according to its structure and morphological character, and determined that the destructive pattern of the slope is creep-cracking. We calculate the stability with two methods:geologic analysis and quantized assessment, the result is that the stability of calculated slide face of superficial layer as well as deep-bedrock interface is well in natural situation, but when it comes to natural-storm, the stability of superficial slide face is a little weak and in critical instability situation. At last, the authors give the control suggestions based on above analysis.