杨浦大桥动力特性测试与评估

Dynamic Characteristic Testing and Assessment for Yangpu Bridge

上海杨浦大桥为主跨602m的双塔空间双索面钢-混结合梁斜拉桥,连续服役已有20年。在对大桥自振特性进行有限元分析的基础上,采用环境激励法进行现场实测,获取了包括索塔、主梁在内的全桥整体动力特性,实测结果与理论计算基本吻合;以竣工时结构完好状态下的实测动力特性为基准,通过历次模态试验结果比对分析,研究了大桥结构整体状况的变化程度及原因,结果表明该桥运营以来自振特性几乎没有发生变化,桥梁整体状态良好。

Shanghai Yangpu Bridge is a double towers cable-stayed bridge with steel-concrete composite girders and two-cable-plane, 602m in main span length. It is necessary to assess the bridge＇s global safety by dynamic characteristics testing while it has been in service for 20 years. Based on the FEA result of the bridge＇s self-vibration characteristics, the actual dynamic properties of towers and main spans for Yangpu Bridge are measured in the condition of ambient excitations. The field measured results can match with the theoretical calculation. The change of the bridge structure state is analyzed by comparing past modal test results, while the comparison basis is the dynamic characteristics which are measured at structural healthy conditions when the bridge was erected. The results show that the bridge＇s self-- vibration characteristics are almost unchanged after it has been put in service, and the whole bridge has good structural integrities.