基于加权扰动共生生物搜索算法桩网复合地基优化设计

Design optimization of pile-net composite foundation based on perturbation-weighted symbiotic organisms search (PWSOS) algorithm

通过分析桩体未打入硬土层和桩体打入硬土层两种情况下桩网复合地基的受力变形特性和设计计算方法,建立了以桩径、桩长、桩帽边长和厚度、桩间距为设计变量,以地基承载力、沉降、加筋体抗拉、桩帽抗弯抗剪为约束条件,以工程造价为目标函数的桩网复合地基优化设计数学模型;通过引入加权扰动策略和减少寄生操作改进共生生物搜索(SOS)算法,提出了加权扰动共生生物搜索(PWSOS)算法;采用PWSOS算法求解桩网复合地基优化数学模型,得到基于PWSOS算法桩网复合地基优化设计方法。工程实例计算结果表明,改进得到的PWSOS算法具有更好的寻优性能和收敛速度,并得到了更优的桩网复合地基优化设计方案。

The mechanical properties and design-calculation methods of pile-net composite foundation were analyzed, with the condition of pile’s end into and not into the hard soil layer. A mathematical model for the optimal design of pile-net composite foundation was established by taking pile diameter, pile length, pile cap length, pile cap thickness and pile spacing as design variables. The foundation bearing capacity, settlement, tensile strength of reinforced geotextile, bending capacity and shearing capacity of pile cap were constraint conditions, and engineering cost was the objective function to be optimized. By introducing the perturbation weighting and reducing parasitic operations, the perturbation-weighted symbiotic organisms search(PWSOS) algorithm was proposed to increase the convergence speed and accuracy of the symbiotic organisms search algorithm. Based on the perturbation-weighted symbiotic organisms search, the global optimization of the mathematical model of the pile-net composite foundation was carried out, and the optimal reinforcement scheme that meet the requirements was the output. The results show that the optimal design scheme has better economic benefit and the perturbation-weighted symbiotic organisms search algorithm has better performance.