【摘要】 由降雨引发的浅层黄土滑坡灾害具有致灾性强、范围广、影响面积大等特点,是黄土高原地区危害严重的地质灾害类型。经典算法采用安全系数描述坡体稳定性,难以对坡体变形破坏的起始位置和实际失效面加以识别,限制了滑坡变形过程的描述和滑坡有效预测。以非饱和土吸应力理论为指导,基于Hydrus中的Slope Cube模块,建立黄土斜坡水-力耦合模型,结合黄土地区易滑坡形态统计数据,针对凸型、凹型、直线型3种坡型与30°、40°、50°三种坡度组合,计算了不同降雨条件下的坡体稳定性响应。结果表明,不同坡型的黄土斜坡对降雨条件具有明显的响应。相同降雨量、相同坡度条件下直线型坡发生浅表层破坏的可能性最低,凹型坡次之、凸型坡的稳定性最差。与之相对应的,相同条件下凸型坡失稳时间最短、凹型坡次之、直线型坡最长。本研究可为浅层滑坡的早期识别和预报提供支撑。更多还原

【Abstract】 The shallow loess landslides triggered by precipitation has the characteristics of serious catastrophability wide range of influence and large impact area is one of the serious disaster in the Loess Plateau.It is difficult to identify the initial failure position and actual failure surface with the classical analysis method by using one safety factor to describe the slope stability which limits the description of the failure process of slopes and consequently influence the effective prediction of landslides. Guided by the theory of unsaturated soil matric suction the water-stress coupling model of loess slope was established based on the Slope Cube module with the Hydrus software.According to the statistics of slide-prone morphology of loess slopes the slope stability response to rainfall conditions was calculated under different conbinations of convex concave and linear and the three slope gradients of 30° 40° and 50°．The results show that different loess slopes have obvious responses to precipitation and its influence is controlled by the slope types.Under the condition of the same rainfall and the same slope the possibility of superficial surface damage occurs on the linear slope is the lowest followed by the concave slope and the convex slope.Correspondingly the time consuming of instability is the shortest for convex slopes the second for the concave slopes and the longest for the linear slopes under the same conditions.This study can provide support for early identification and prediction of shallow loess landslides.更多还原