Abstract: The 3D simulation model was established for the analysis of dynamic response of Taizhou Yangtze River Bridge to determine the most unfavorable fatigue damage section. The fatigue stress test was conducted on the deck and U-rib joint weld of the most unfavorable section, and the fatigue damage characteristics were analyzed. In addition, the fatigue test was carried out and the fatigue strength of the detail was evaluated by the nominal stress method. The results show that the most unfavorable section of Taizhou Yangtze Bridge lies in the mid-span of the steel box girder. Under the current traffic volume, the maximum stress amplitude of the measuring points of deck and U-rib weld in the mid-span section is much lower than the fatigue threshold recommended by the BS5400 standard. The fatigue strength of deck and U-rib weld of Taizhou Yangtze River Bridge conforms to the specifications.

Key words: bridge engineering, steel box girder, deck and U-rib, fatigue section, strain time history, fatigue strength

摘要： 通过三维仿真模型进行泰州大桥全桥动力响应分析，确定主梁最不利疲劳损伤截面。针对最不利截面的顶板与U肋连接细节进行疲劳应力测试，分析其疲劳损伤特征，并开展疲劳试验，采用名义应力法评价该细节疲劳强度。研究表明：泰州大桥钢箱梁跨中截面为疲劳损伤不利截面。在目前的交通流量下，跨中截面顶板与U肋焊缝处顶板测点的最大应力幅值远低于BS5400规范推荐的疲劳极限值。泰州大桥顶板与U肋构造细节的疲劳强度满足规范的规定要求。

关键词: 桥梁工程, 钢箱梁, 顶板与U肋, 疲劳截面, 应变时程, 疲劳强度