超大跨度双跨钢桁梁悬索桥动力特性分析和模态试验

以跨径布置460 m+1480 m+491 m的一座双跨钢桁梁悬索桥结构为工程背景,充分考虑结构几何非线性效应、大位移非线性效应等因素的影响,建立了算例桥梁的MIDAS空间有限元分析模型,对基本动力特性进行了仿真分析和结构振动试验测试;对成桥结构进行动力特征参数测试,并与理论计算值进行了对比分析,该桥实测动力特征参数与对应理论计算值基本吻合,且测试值大于理论计算值,这表明成桥结构实测刚度大于理论设计目标值。

Dynamic Characteristics Analysis and Dynamic Test of the As-built Two-span Suspension Bridges with Steel Truss Girder

A double-span steel truss girder suspension bridge with the span layout of 460 m+1480 m+491 m was selected as the engineering background.The MIDAS CIVIL finite element analysis model of the bridge was established by considering the influence of geometric nonlinear effect,large displacement nonlinear effect and other factors.The simulated analysis and dynamic simulation of its basic dynamic characteristics were carried out.The modal and basic dynamic characteristics of the actual bridge structure were tested and compared with the results of finite element analysis after completion of the bridge.The results show that the theoretical analysis results are basically consistent with the measured results.In addition,the field dynamic test results are slightly larger than the theoretical results,which indicates that the bridge stiffness of the actual suspension bridge structure is larger than the design value.