正交异性组合桥面构造优化

Optimization of Orthotropic Composite Bridge Deck

摘要:

正交异性组合桥面由于其较好的抗疲劳性能和静力承载能力、相对较轻的自重近年来在实际工程中得到较多应用。正交异性组合桥面通常由正交异性钢板和混凝土层组成，在加入混凝土层后结构刚度发生较大变化，若正交异性板仍采用传统正交异性钢桥面的构造形式将会造成不必要的钢材用量和焊接量增加。采用遗传算法，以单位面积造价最小为目标，结合现有规范考虑了构造约束和承载能力约束两类约束条件，采用两种应力控制方案，对不同桥面板跨度和混凝土厚度的正交异性组合桥面的构造进行优化。同时解决了构造改变导致荷载分配改变对承载能力分析造成的影响。优化结果表明，桥面跨度4.5m时，与未优化组合桥面相比，优化方案用钢量可降低1.7%~10.1%，焊接量可降低16.5%~31.8%。

Abstract:

Orthotropic Composite Bridge Decks have gained increased practical application in recent years due to their excellent fatigue resistance, static load-bearing capacity, and relatively low self-weight. These decks typically consist of orthotropic steel decks (OSD) and concrete layers. Significant changes in structural stiffness occur after the addition of the concrete layer. If the orthotropic plates are still constructed in the traditional OSD manner, it will result in unnecessary increases in steel usage and welding volume. This paper employs a genetic algorithm with the objective of minimizing the cost per unit area while considering two types of constraints: constitution constraints and load-bearing capacity constraints, in accordance with existing standards. Two stress control strategies are applied to optimize the constitution of orthotropic composite bridge decks with varying spans and concrete thicknesses. Additionally, the paper addresses the impact of changes in constitution on load distribution and load-bearing capacity. The optimization results show that, for a bridge span of 4.5 meters, compared to the non-optimized composite bridge deck, the optimized solution reduces steel usage by 1.7%~10.1%, and welding volume by 16.5%~31.8%.