波形顶板-UHPC组合桥面板优化设计

为解决正交异性钢桥面板的疲劳问题，从其根本原因和提高其抗疲劳性能的基本途径出发，提出一种新型波形顶板-UHPC（超高性能混凝土）组合桥面板结构体系.确定影响新型桥面板受力特性的主要参数及其合理取值范围，使用基于BP（back propagation）神经网络的优化设计模型对结构进行优化设计，就所优化的结构尺寸进行疲劳性能测试.研究结果表明:该结构能大幅减少桥面板结构中的几何构型不连续部位数量和焊缝数量，显著提高顶板局部刚度；波形钢板高度、顶部和底部水平段宽度是结构受力性能的重要影响参数；基于BP神经网络的优化设计模型适用于该类桥面板结构的优化设计，最大误差为4.4%；新的结构体系具有良好的疲劳性能，疲劳寿命超过200 a，为正交异性钢桥面板的疲劳问题提供了较好的综合解决方案. 

Optimal Design of Corrugated Steel Deck Plate-UHPC Layer Composite Deck

In order to solve the fatigue problem of orthotropic steel bridge decks, an innovative corrugated steel plate-UHPC (ultra-high performance concrete) layer composite deck structure is proposed based on the cause of the fatigue problems and the basic approaches used to improve the anti-fatigue performance. First, the major design parameters that significantly impact mechanical properties and the corresponding ranges of the parameter values were determined using parametric analysis. A model based on the BP artificial neural network was developed to determine the optimal design of the innovative structure system. Finally, the fatigue performance of the optimal structure was studied. The results show that the number of geometric discontinuity locations and weld joints are decreased, while the local stiffness of the deck plate is increased. According to the results of the parametric analysis, the height of the corrugated steel plate and the width of the top and bottom horizontal parts of the plate play important roles in structure mechanical characteristics. The proposed optimal design model based on the BP(back propagation) artificial neural network is suitable for the optimal design of innovative structure systems, and the maximum error is 4.4%. The innovative bridge deck has good fatigue performance, and its fatigue life is over 200 years, which provides a comprehensive solution to the fatigue problem and has good potential for further development and application.