宝兴县陇东镇初旭山滑坡形成机制及稳定性分析  

The Formation Mechanism and Stability Analysis of Chuxu Mountain Landslide in Baoxing County

作　　者：杨敏[1] 胡伟[1] 杨栓成 

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《防灾科技学院学报》2016年第1期25-32,共8页Journal of Institute of Disaster Prevention

摘　　要：以宝兴县陇东镇老场村初旭山滑坡为例,通过分析地质条件、滑坡组成及结构特征,运用geo-studio软件对该滑坡在地震工况、暴雨工况稳定性进行分析。认为滑坡体三面山脊环绕,堆积体结构松散、强度低,为滑坡形成提供了有利的地形条件;在"4.20"芦山地震作用下,滑坡前缘垮塌,坡体内部形成拉张裂缝,为降雨入渗提供了良好的通道;在暴雨作用下,降雨沿裂缝入渗,在土岩接触面形成滞水,致使接触面力学参数降低,同时雨水在坡体流动形成顺坡下的渗透力加剧了滑坡的变形。数值分析表明,天然状况下坡体稳定;在峰值加速度为0.2g的地震情况下,坡体前缘垮塌,整体处于基本稳定状态;持续暴雨状态下坡体失稳;地震之后暴雨作用对滑坡的稳定性影响不利。This paper takes the example of Chuxu mountain landslide as the research object, and analyzes the geological conditions, landslide composition and the structure characteristics, uses Geo-Studio software to analyze the stability of the landslide under the earthquake and rainstorm condition. The cause of deformation and failure of the landslide is that the landslide is surrounded by three sides of the ridge, and the structure is loose and the strength is low, which provides favorable conditions for the formation of the landslide. In ＂4. 20＂ Lushan earthquake, the front of landslide collapsed, and the tensile cracks formed inside slope, providing a good channel for rainfall infiltration. Under the condition of rainstorm, the rainfall infiltrates the accumulation along the tensile cracks, and then there has formed perched water in the contact surfaces of soil and rock, which reduced the mechanical parameters of the contact surface, simultaneously, the infiltration of rain water intensified the deformation of the landslide. Numerical analysis indicates that the slope is stable under natural conditions ; while at the peak acceleration of the 0. 2g earthquake, the front of the slope collapsed, and the slope keeps the basic stability; the slope would be unstable in the condition of continuous rainstorm; heavy rain after the earthquake has an adverse effect on the stability of the landslide.

关 键 词：地震 降雨 滑坡 稳定性 形成机制 

分 类 号：P642.22[天文地球—工程地质学]