突然断索后双吊索形式自锚式悬索桥安全分析

吊索是决定悬索桥结构安全的关键构件,已建悬索桥的吊索普遍存在锈蚀的现象,在锈蚀与疲劳荷载作用下,吊索可能发生突然断裂.已有研究及工程实例均表明,单根吊索断裂后其余的吊索有连续断裂的危险,从而导致全桥的倒塌.使用双吊索可以改善断索对悬索桥结构安全的影响.为研究双吊索对悬索桥安全性的改善程度以及断索后悬索桥结构的动力响应,基于非线性静力和动力分析方法,以某200 m的混凝土自锚式悬索桥为例,进行了悬索桥断索后结构的响应研究.研究结果表明,双吊索能大幅度降低断索后悬索桥结构的响应,从而提高了全桥在运营维护阶段的安全性.研究结论可为悬索桥吊索的更换、维修和加固提供参考.

Safety analysis of self-anchored suspension bridge with dual-shaped hanger after sudden breakage of hanger

Hangers are essential security parts of the suspension bridge structure. It is a general phenomenon that hangers have serious corrosion problems, and the hangers may fail suddenly under fatigue and corrosion effect. Existing research and engineering examples show that the breakage of a hanger can lead to the successive breakage of other hangers and then result in the collapse of the whole bridge at worst. Dual-shaped hanger can improve the safety of the suspension bridge related to the hanger failure. To research into the safety improvement and dynamic response of the suspension bridge after the breakage of the dual-shaped hanger, the study on the response of suspension bridge after hanger breakage is carried out using nonlinear static and dynamic methods, based on a 200 m self-anchored suspension bridge with concrete girder. The analytical results show that the dual-shaped hanger can reduce the response of suspension bridge after hanger breakage and improve the safety of the whole bridge during the service and maintenance stage. The conclusion can also provide a reference for the replacement, maintenance and reinforcement of suspension bridge hangers.