【作者】 王新岐；

【导师】 余建星；

【作者基本信息】 天津大学 ， 结构工程， 2003， 博士

【摘要】 针对钢筋腐蚀、疲劳、预应力松弛、桥梁整体倾斜或变形所引起的斜拉桥局部破损，本文以使用15年后的永和斜拉桥为研究对象，对大型斜拉桥破损诊断技术进行研究，对永和斜拉桥破损位置进行定位、对其破损程度进行评价。建立了双索面通过刚臂与主梁及边梁相连的三梁式力学模型，采用ANSYS结构分析程序对永和斜拉桥进行动力分析，对其振动模态参数（频率、振型及阻尼）进行识别，以此作为斜拉桥完好状态下的动力“指纹”；采用自由交通流作为环境振源，对永和斜拉桥动力特性进行测试，识别出永和斜拉桥使用15年后的模态参数，确立了破损状态下的动力“指纹”；利用有限元分析、现场振动测试，对破损前后的模态参数进行分析，提取对破损状况较敏感的模态曲率作为斜拉桥破损诊断的参数；并从模态参数中选取部分点的分量，导出可以指示斜拉桥桥面（主梁）大概损伤位置的Index损伤指标，识别出斜拉桥发生破损的区段及破损程度；考虑大型斜拉桥在线监测要求识别破损的具体位置，从另一角度提出采用最优矢量法具体确定破损发生的位置及程度；为验证本文研究成果，对永和斜拉桥进行静力分析及静力测试，对其健康状况提出可靠的评价。本文研究成果使破损定位技术真正运用于实桥状态，为永和斜拉桥养护维修方案提供了技术支持，具有理论与实用价值。更多还原

【Abstract】 Considered local damage due to steels corrosion, fatigue, prestressing loses, whole bridge incline and distortion, this paper studies damage diagnosis technique of the cable-stayed bridge and determines the location and size of damages for Yonghe cable-stayed bridge, which has been used after 15 years. First, this paper presents three girders model with double cable planes which main girder and side girder is connected by rigid arms, analyzes the dynamic characteristic of Yonghe cable-stayed bridge and obtains its natural vibration modes (i.e., frequency, damping values and the mode shapes ) by ANLSIS structural analysis program and uses these parameters as dynamic dactylogram of the intact case of cable-stayed bridge. Using the passage of random as the ambient vibration ,the dynamic properties of Yonghe Bridge is measured and the modal parameter of its 15 years after is identified and used as dynamic dactylogram of the damaged case. By the finite element analysis and locale vibration test, damaged and undamaged modal parameter is analyzed and curvature mode shape, which is sensitive to damage state, is introduced as possible candidate for identifying and locating damage in the cable-stayed bridge. Selecting the branch of part measured point from modal parameter, this paper deduces the damaged index which can detect the possible damaged location of the cable-stayed bridge deck and identifies the damaged region and degree for Yonghe Bridge. For the purpose of structural condition monitoring in in-situ , from another viewpoint, this paper introduces the method called the best optimization vector to detect damaged location and degree. The accuracy and reliability of the method presented in this paper are demonstrated by static analysis and test and the healthy state of Yonghe Bridge can be evaluated. By the proposed method , damage diagnosis technique can be successfully applied in an in-service bridge and provides the help for rehabilitation program of Yonghe Bridge. The potential of its future application is also discussed.更多还原