本文以漩门湾三桥为工程背景,采用以构件为单位,逐步逼近的多目标优化方式对钢桁架拱桥进行结构优化分析,利用Madis/civil有限元软件建立数学模型,以桥梁结构中最大轴向应力和最大竖向位移为状态变量,以结构的矢跨比、桁架高度、截面尺寸、支承类型为设计变量,以全桥用钢量为目标函数,对全桥进行结构优化分析,以达到减轻结构自重,从而降低工程造价。 Taking the Xuanmen Bay Third Bridge as the engineering background, the structural optimization of the steel truss arch bridge is carried out by using the multi-objective optimization method of unit-by-unit approximation, and the mathematical model is established by using Madis / civil finite element software. The maximum axis Taking the stress and the maximum vertical displacement as the state variables, the structural span ratio, the truss height, the section size and the bearing type are taken as the design variables, and the steel quantity in the full bridge is taken as the objective function to optimize the structure of the full bridge to achieve Reduce the weight of the structure, thus reducing the project cost.