雅砻江甲西滑坡成因机制及其稳定性分析

甲西滑坡位于雅砻江中游某大型水电站水库库尾,是该区典型的一种滑坡类型。研究该滑坡的形成机制,对认识该区斜坡的变形破坏规律,评价库区斜坡的稳定性具有重要意义。该滑坡发育于由中薄层状砂岩与薄层状板岩互层组成的中陡倾角反向层状结构斜坡中,其变形破坏机制为倾倒弯曲-拉裂型。地质分析及简化毕肖普法稳定性计算结果表明,滑坡堆积体在自然状态下处于潜在不稳定状态,在特大暴雨和洪水作用下滑坡前缘有较大规模滑塌失稳的可能,但水库2 870 m蓄水位对滑坡的稳定性不起主导作用。

ANALYSIS OF FORMATION MECHANISM AND STABILITY OF JIAXI LANDSLIDE OF YALONG RIVER

The Jiaxi Landslide is located in the end of a reservoir of a large hydroelectric station in the middle water of Yalong River.It is a typical landslide in this area.It has vital significance to analyze the formation mechanism of the Jiaxi Landslide with realizing the law for deformation of some acclivity in this area and evaluating the acclivity stability in the reservoir area.The Landslide happened in a reversal laminated structure slope with middle-high angle,which is made up of a alternating layers by median lamina sandstone and thin laminated slate.Its deformation and failure mechanism was bent-fracture.The geological analysis and the simplification Bishop stability computed result indicate that the talus slide is on non-stable condition in the natural state,and it predestined affinity has the big scale under the especially big rainstorm and the flood role slippery to collapse loses the steady possibility,but the 2870m store water level of this reservoir does not play the leading role to the landslide stability.