不同设计参数下矮塔斜拉桥的抗震动力学分析

SEISMIC RESPONSE FOR AN EXTRADOSED CABLE-STAYED CURVED BRIDGE WITH DIFFERENT DESIGN PARAMETERS

针对矮塔斜拉桥所具有的低塔及索少的特点,结合龙井河大桥实际工程,建立了计算仿真模型,对不同设计参数下结构的动力特性进行了研究。该文选择桥梁设计半径和墩梁连接形式为参数,着重讨论了两种参数对曲线矮塔斜拉桥的动力特性的影响;基于Midas/civil三维有限元计算软件,参照国家08抗震规范提供的地震反应谱数据,采用CQC振型组合方法对多组模型进行了地震仿真分析,探索了不同设计参数下此类桥梁在地震下的结构反应机理。结果表明,该文所提出的两个设计参数均对曲线矮塔斜拉桥的动力特性有较大影响,甚至直接影响到全桥抗震性能。研究结论不但对于实际工程有重要参考,为此桥后续的抗震设计提供参数依据,同时还为类似的曲线矮塔斜拉桥的抗震设计与施工建造提供了重要的理论参考。

The extradosed cable-stayed bridge has low towers and small number of cables. To investigate the dynamic behavior of the extradosed cable-stayed bridge, the paper established numerical model of Longjing Large-span curved bridge with varying design parameters. The two design parameters mainly considered herein were the design radius and the connection form between pier and beam. The influence of design parameters on the dynamic behaviors of the bridge were studied in this paper. Using the earthquake response spectrum data provided by National Seismic Code in 2008, the seismic behaviors of bridge models with different design parameters were investigated in the platform of Midas/civil. The results show that the two design parameters have a great influence on dynamic behaviors of extradosed cable-stayed curved bridges, especially on the overall seismic performance. This investigation can provide important reference for practical engineering and theoretical basis for seismic design of similar extradosed cable-stayed curved bridges.