变坡角浅层粘土斜坡稳定敏感性分析

用地球物理方法确定了滑坡体的坡底滑移面,重建了斜坡体,并根据坡角的变化划分了块段,运用力的递推原理,计算了滑坡体块段的稳定性系数.对坡角、含水率、内摩擦角、内聚力、静水压力、地震力及列车荷载等因素进行了分析,讨论了敏感性分析中因子变化步长、范围及因子的相关性,获得了粘性土层容重、内摩擦角、内聚力与含水率之间以及内摩擦角与内聚力之间的耦合关系方程.在因子独立及关联作用下,分别对斜坡稳定性进行了单因素分析并确定了敏感性因子.结果表明,内摩擦角、内聚力、坡角及含水率是影响斜坡稳定性的主要敏感性因素.将滑坡因子作为独立变量和非耦合处理时,将弱化含水率及内聚力在稳定性分析中的影响.

Sensitivity of landslide stability in a shallow clay slope with multi-sloping angles

An unsaturated clay slope, with multi-sloping angles, successively consists of loose layers of unsatu-rated clay, strongly weathered sandstone intermingled by mudstone, moderately weathered sandstone as well as lightly weathered sandstone. The slide interfaces were determined by geophysical approaches and the original slope was reconstructed. The sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was used to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping, water content, cohesion, internal frictional angle, hydrostatic pressure, seismic force as well as train load were analyzed. The step length, range and correlation of the above-mentioned factors were discussed and coupling equations were established to reflect the relationships between density, cohesion, internal frictional angle and water content, as well as the relationship between internal frictional angle and cohesion. The sensitivity of the slope stability was analyzed and susceptive factors were determined when the above-mentioned factors were taken as independent and dependent respectively. The results show that internal frictional angle, cohesion, sloping and water content are the principal susceptive factors influencing the stability of the slope. It can fade the influencing extent of water content and cohesion to the slope stability if the above-mentioned factors are taken as independent variables without considering their correlation.