宁波招宝山大桥基于模型修正的动力分析

Dynamic Analysis Based on Model Updating of Zhaobaoshan Bridge in Ningbo

宁波招宝山大桥是曾经严重事故、后经局部拆除加固重建的大型独塔不对称斜拉桥,目前成桥状态十分复杂。为了评估大桥的使用性能和建立桥梁健康监测系统,需要符合实际结构的有限元分析计算模型。在采用精细的有限元模型基础上,以实际测量的动态试验数据为依据,应用基于灵敏度分析为基础的模型修正法,对结构有限元模型进行了修正。基于振型的模态确认准则的相关性计算表明,修正后的有限元模型比较好的反映了结构的实际状态,由此计算分析了成桥状态的动力特性。相关结果可为后续结构健康检测、损伤评估与维修管理提供必要的技术支持。

Zhaobaoshan Bridge in Ningbe is a typical non-symmetrical long-span cable-stayed bridge with single-tower, with its main girder strengthened and rebuilt after an accident of buckling of the main girder of the main bridge in the process of construction. For evaluating the properties of the bridge and detecting the structural damage, the finite element model should be in accord with the real structure. Model updating methods based on structural vibration data are developed and applied. Firstly, the precise finite element model is built, and then the dynamic data measured in reality are utilized to update the previous model by method based on sensitivity analysis.The computation of the model assurance criterion （MAC） based on the current relative results indicate that the updated finite element model can provide a better mathematic model for the dynamic analysis of the structure.