基于模态挠度法的预应力连续箱梁桥状态评估  

Application of modal deflection method for condition assessment of prestressed concrete continuous box-girder bridges

作　　者：林贤坤[1,2] 张令弥[2] 郭勤涛[2] 张宇峰[3] 

机构地区：[1]广西工学院,广西柳州545006 [2]南京航空航天大学,江苏南京210016 [3]江苏省交通科学研究院,江苏南京210017

出　　处：《土木工程学报》2010年第10期83-90,共8页China Civil Engineering Journal

基　　金：国家自然科学基金资助(50575101);江苏省交通科学研究计划项目(06Y20);广西工学院博士基金(03081509)

摘　　要：以预应力混凝土连续梁桥的通扬运河大桥为研究对象,探讨基于运行试验模态分析的模态挠度法在桥梁状态评估中的应用。建立其有限元模型,通过环境激励振动试验获得其试验模态参数,基于柔度矩阵指标和挠度指标定义的两个目标函数,利用实数编码的加速遗传算法修正大桥的有限元模型,获得基本准确反映大桥实际静力行为的有限元模型。借助其有限元模型对试验模态振型质量归一化,利用振型已质量归一化的环境激励振动试验的试验模态参数,可获得桥梁结构已知载荷作用下的试验模态挠度,通过与静挠度实测值比较,可对桥梁的状态作出评估。结果说明基于运行试验模态分析的模态挠度法应用于桥梁状态评估的可行性与有效性。Application of modal deflection method based on operational modal analysis（OMA） for condition assessment of the Tongyang Canal Bridge,with a prestressed concrete continuous box-girder bridge,is presented.A static finite element model（FEM） is built and updated based on the results of ambient vibration testing（AVT） using a generic acceleration algorithm,with the objective function defined based on flexibility matrix index and deflection index,for evaluating the updated FEM.In virtue of the updated FEM,the mass-normalized mode shapes were obtained.Using the natural frequencies and mass-normalized mode shapes of the AVT,the experimental modal deflection values for the given loads were calculated.With a comparison between the experimental modal deflection values and the measured values of static deflection,the condition of the bridge is assessed.

关 键 词：预应力连续箱梁桥 环境振动试验 模型修正 遗传算法 模态挠度法 状态评估 

分 类 号：U447[建筑科学—桥梁与隧道工程] O327[交通运输工程—道路与铁道工程]