三峡库区秭归县盐关滑坡变形特征及成因机制分析

Deformation Characteristics and Formation Analysis of Yanguan Landslide in Zigui County, Hubei Province, Three Gorges Reservoir Area

盐关滑坡位于湖北省秭归县归州镇,长江一级支流香溪河的右岸.由于香溪河右岸的构造原因,盐关滑坡是一个反向堆积层滑坡,其所在的区域地质构造复杂,是滑坡易发区,通过现场勘察确定滑坡滑体、滑带和滑床的岩土工程性质,结合现场调查的滑坡变形特征,综合滑坡所处的地形地貌以及区域地质构造情况,分析并确定滑坡失稳破坏的原因.经调查发现,库水位上涨并保持高位运行是滑坡破坏的诱发因素,连续降雨是滑坡的变形破坏触发因素,特别是在遇到连续降雨时,库区水位的强烈波动对滑坡的稳定性造成巨大影响,最终导致滑坡失稳破坏.

Yanguan landslide is located in Guizhou town,Zigui County,Hubei Province,on the right bank of the Xiangxi River,a tributary of the Yangtze River.It is a landslide-prone area with complex geological structure.The slip zone,slip band and slide bed are determined through prospecting.The causes of landslide instability and damage are determined by on-site investigation of the topography and geological structure of landslides.The investigation suggested that heavy,long-term rain and reservoir water level rising and maintain high position is the triggering factor of landslide.Continuous rainfall has a great impact on the deformation and failure of landslides,especially the large fluctuation of reservoir water level under the condition of continuous rainfall,it is huge threat for landslide stability.