兰渝铁路盖家阴山滑坡稳定系数水敏性分析

以兰渝铁路盖家阴山滑坡为例,进行了滑带土大型直剪试验,讨论了滑带土的c,φ值随含水率变化规律.通过传递系数法进行了滑坡稳定系数对强度参数c,φ值和地下水位变幅的敏感性分析,结果表明:随着含水率的增加,内摩擦角φ基本呈线性减小,黏聚力c呈现先增加而后又逐渐变小的特征;滑带土黏聚力c每降低1 kPa,稳定性系数将减小0.01~0.02;内摩擦角φ每降低1°,稳定性系数将减小0.07~0.09;在降水和地震条件下,当水位变幅系数δ大于0.53时,滑坡体将会发生蠕滑变形,甚至是失稳滑动.

Water Sensitivity Analysis for Stability Coefficient of Gaijiayinshan Landslide along Lanzhou-Chongqing Railway

Taking Gaijiayinshan Landslide along Lanzhou-Chongqing Railway as an example,large-scale direct shear test on sliding soil was conducted,in relation to which the law of the c,φ values of the sliding soil changing with the water content was discussed; then the analysis on the sensitivity of landslide stability coefficient to the strength parameters,i.e.c,φ values,and the variation of groundwater level was carried out by transfer coefficient method.The results show that,as the water content increases,the internal friction angle φ presents linear decrease substantially and the cohesion force c has a feature of increasing first and decreasing gradually then; the stability coefficient is lowered by 0.01 - 0.02 once when the sliding soil＇s cohesion force c decreases by 1 kPa,or lowered by 0.07 - 0.09 once when the internal friction angle φ decreases by 1 o; on the condition of precipitation and earthquake,when the water level variation factor δ is more than 0.53,the landslide will present creeping deformation,even instable sliding,thus required to be controlled.