超大跨径斜拉桥钢结构疲劳监测与评估

Fatigue Monitor and Evaluation of Steel Structure of Overlong-span Cable-stayed Bridge

该文以某斜拉桥为研究背景,基于钢箱梁疲劳监测结果,研究了超大跨径斜拉桥钢箱梁疲劳性能。结果表明:在车载的累积作用下,钢箱梁顶板和U肋腹板易出现疲劳裂纹;索梁锚固区钢锚箱各板件的应力幅均较小,但在长期交通荷载作用下,箱梁外腹板亦有可能出现疲劳裂纹。而底板、底板U肋、索塔钢锚箱的应力幅值较小,不会出现疲劳损伤。

Taking a cable-stayed bridge as the background and based on fatigue monitor result of steel box girder,the article studies the fatigue performance of steel box girder for the overlong-span cable-stayed bridge.The result shows that the top slab and U-rib web are easy appearing with the fatigue cracks under the accumulative effect of vehicle,the stress range of every slab component of steel anchor box in cable girder anchorage zone is smaller,and the web outside of box girder is possibly appearing with the fatigue crack under the long-term traffic load.The bedplate,bedplate U rib and cable pylon steel anchor box can not be appearing with the fatigue loss because of smaller stress range value.