降雨入渗非饱和黏土边坡稳定性的极限平衡条分法研究

考虑非饱和黏土边坡的基质吸力和渗流力，根据水位线位于滑面上、下的临界平衡状态，分别建立了滑体条块极限平衡状态下力和力矩平衡式，获得了降雨条件下非饱和黏土边坡稳定性的极限平衡条分法计算式。通过试验、参量变换以及作用力的位置关系可以确定相关参量，并采用数值计算求解临界平衡状态下滑体条块的相互作用力系数和非饱和边坡安全系数。案例结果表明：考虑渗流力时的非饱和黏土边坡安全系数比不考虑渗流力的安全系数降低约13.8%，且考虑渗流力作用的条间力作用系数变化率明显大于不考虑渗流力的结果；当降雨强度超过一定值时，坡面径流很快形成，边坡出现不稳定的时间基本相同。

Limit equilibrium slice method for unsaturated clay slope under rainfall infiltration

Considering the matrix suction and seepage force of unsaturated clay slope, the limit equilibrium state is discussed according to the sliding surface over or under the water line. Then, the force and moment balance equations are established in the limit equilibrium state of the sliding slope respectively. The formulation of the limit equilibrium slice method is obtained for calculating the unsaturated clay slope stability under rainfall infiltration. The related parameters of the equation are obtained through test, parameter transformation and the position relationship of the sliding force. Then, the interaction force coefficients and the safety factor of the unsaturated clay slope are determined in the limit equilibrium state with numerical calculation method. The case study results show that the safety factor of the unsaturated clay slope is lower about 13.8% considering seepage force than without considering the seepage force, and the change rate of coefficient between slices considering seepage force is obviously larger than that of coefficient between slices without considering the seepage force. The instability time of slope is approximately the same when the rainfall intensity exceeds a threshold with the formation of slope runoff soon.