环境激励下双层中承式连续刚桁架拱桥模态参数识别研究

Research on Modal Parameter Identification of Double Deck Half-through Continuous Rigid Truss Arch Bridge Under Environmental Excitation

以大湾区核心地带地标式桥梁--明珠湾大桥为工程背景,该桥为双层中承式六跨连续钢桁架拱桥,主跨436m,为大湾区交通核心要道。本文开展基于环境振动激励下的明珠湾大桥模态测试试验研究。基于现场试验,精确识别明珠湾大桥的桥梁结构动态特性参数,通过实测值与midas/Civil有限元软件理论值计算值的对比,综合评估明珠湾大桥的实际动力特性。测试结果表明:明珠湾大桥实际动态特性与理论计算结果吻合程度较好,且桥梁实测刚度大于理论值,满足设计要求。本次试验对桥梁的后续运营提供了坚实的基础,也为今后同类型桥梁的验收提供有益借鉴。

Taking the landmark bridge in the core area of the Greater Bay Area-Mingzhu Bay Bridge as the engineering background,the bridge is a double-layer half-through six-span continuous steel truss arch bridge with a main span of 436 m,which is the core road of traffic in the Greater Bay Area.In this paper,the modal test of Mingzhuwan Bridge based on environmental vibration excitation is carried out.Based on the field test,the dynamic characteristic parameters of the bridge structure of Mingzhuwan Bridge are accurately identified.The actual dynamic characteristics of Mingzhuwan Bridge are comprehensively evaluated by comparing the measured values with the theoretical values of midas/Civil finite element software.The test results show that the actual dynamic characteristics of Mingzhuwan Bridge are in good agreement with the theoretical calculation results,and the measured stiffness of the bridge is greater than the theoretical value,which meets the design requirements.This test provides a solid foundation for the subsequent operation of the bridge,and also provides a useful reference for the acceptance of the same type of bridge in the future.