考虑孔隙水压力的土坡稳定性的刚体有限元上限分析

采用一种结合刚体有限元与极限分析上限法来求解边坡稳定性问题的新方法。借助刚体有限单元离散计算区域并构造运动许可速度场 ,利用传统的安全系数作为评价边坡稳定的定量指标。水对边坡的影响作用可通过虚功方程表现出来 ,将孔隙水压力当作外力荷载做功。在满足屈服条件、流动法则、虚功方程以及相应的边界条件的基础上 ,引入非线性数学规划方法求解最小安全系数

A rigid finite element method for upper bound limit analysis of soil slopes subjected to pore water pressure

An upper bound limit analysis method using rigid finite elements is developed. Rigid finite elements are used to discretize the slope media. Kinematically admissible velocity discontinuities are permitted to occur at all inter element boundaries. The traditional definition of factor of safety is adopted in the present method so that the results from the limit analysis can be directly compared with those from methods of slices. The presence of water can be considered through work terms in the energy work balance equation. To do this effectively, the pore water pressure is considered as an external force, similar to gravity and surface tractions. The proposed method formulates the slope stability problem as a non linear optimization problem with constraints based on the yield criterion, flow rule, boundary conditions, and the energy work balance equation. The optimization problem is solved by a sequential quadratic algorithm.