基于块体元的塑性极限下限法在拱坝坝肩稳定分析中的应用

Application of plastic limit lower bound method to stability analysis of arch dam abutment based on block elements

将块体单元法与极限分析下限法相结合,提出了拱坝坝肩稳定的块体单元极限分析下限法.借助于块体单元法离散计算区域,通过块体系统静力场在结构面上满足Mohr-Coulomb屈服条件、应力边界条件以及在块体单元上的力矢力矩平衡原理,构成求解拱坝坝肩强度储备安全系数下限解的数学规划模型,模型的求解采用内点法.最后研究了一个楔形体算例和青龙拱坝左岸坝肩实例,通过比较块体单元下限法计算结果与刚体极限平衡法计算结果,验证了该方法的可行性.

A block element lower bound limit analysis method for the stability of arch dam abutment is presented through combining block element method with lower bound limit analysis method.By utilizing block element method to disperse calculation areas,and satisfying some conditions for the block system static field in structure surface such as Mohr-Coulomb yield conditions,stress boundary conditions and the force vector and moment balance principle in block elements,a mathematical programming model solving lower bound solution of arch dam abutment strength reserve coefficient can be constituted.The interior point algorithm is employed to solve the model.Finally,a wedge example and a test of Qinglong arch dam left abutment are researched.The calculated results obtained by block element lower bound method are compared with rigid body limit equilibrium method;it is shown that the proposed method is feasible.