考虑多目标的钢管混凝土拱桥拱肋参数设计优化

Optimization of Arch Rib Parameters Design for Concrete Filled Steel Tubular Arch Bridges Considering Multiple Objectives

为解决大跨度钢管混凝土拱桥拱肋参数设计优化问题,提出了一种考虑多目标的拱肋参数优化方法。以钢管混凝土拱桥主拱应变能和竖向线形挠度为目标函数,钢材用料成本为约束条件建立了考虑多目标的拱肋参数数学优化模型,采用基于改进惯性权重的多目标粒子群算法,联合有限元模型对大跨度钢管混凝土拱桥拱肋参数优化问题进行了寻优求解。结果表明:改进惯性权重的多目标粒子群算法可以有效求解拱肋参数优化问题;优化后拱肋参数变化范围在5%以内,腹杆直径、壁厚和横撑直径小幅增加,横撑壁厚存在略微减小;优化后设计荷载下主拱竖向挠度得到了改善,结构一阶弹性稳定特征值小幅增加。

To solve the optimization problem of arch rib parameters design for large-span steel tube concrete arch bridges,a multi-objective optimization method for arch rib parameters is proposed.A multi-objective mathematical optimization model for arch rib parameters was established with the strain energy and vertical linear deflection of the main arch of a steel tube concrete arch bridge as the objective functions,and the cost of steel materials as the constraint conditions.A multi-objective particle swarm optimization algorithm based on improved inertia weight was used to jointly solve the optimization problem of arch rib parameters of a large-span steel tube concrete arch bridge using a finite element model.The results show that the multi-objective particle swarm optimization algorithm with improved inertia weight can effectively solve the optimization problem of arch rib parameters;After optimization,the variation range of arch rib parameters is within 5%,with a slight increase in web diameter,wall thickness,and transverse brace diameter,while a slight decrease in transverse brace wall thickness;After optimization,the vertical deflection of the main arch under the design load has been improved,and the first-order elastic stability eigenvalue of the structure has slightly increased.