基坑挡土结构的粒子群优化设计方法

为提高基坑支护结构设计的速度和精度,用模拟自然界鸟群觅食行为的进化算法———粒子群优化算法(PSO)来确定支护结构优化设计方案.研究了基于弹性抗力法的基坑挡土结构的粒子群优化技术:定义在搜索域中的一组可能的基坑设计参数为一个粒子;建立与挡土结构的结构优化设计参数相关联的适应度函数;通过粒子群位置的演变过程来搜索对应最优函数的结构设计参数方法;桩单元长度动态调整的编程技术等.通过工程算例证明了基坑挡土结构粒子群优化设计方法的可行性和适用性.

Particle Swarm Optimization Design Method for Retaining Structures in Excavation Engineering

In order to increase the efficiency and precision of optimum design of retaining structures of exavation engineering, a particle swarm optimization (PSO) method, which was a new kind of evolution computing technique simulating bird behaviour in searching for food in natural world, was developed for searching for the optimum design parameters of a retaining structure, based on elastic resistance method. The main techniques included: defining a set of design parameters in searching domain as a particle (a bird), setting up the fitness function that was associated with the cost of the retaining structure, an algorithm for searching for the optimization design (the food) corresponding to the minimum cost in the evolution process of the positions of a swarm of particles, and a coding technique for dynamically adjusting the element length of piles, etc. The feasibility and applicability of the particle swarm optimization design method are finally confirmed with the analyses of an engineering case.