Abstract: Taking Tibetan Nimu bridge as an object，and using the finite element soft，a mode and dynamic analysis was siren．By simulating the seismic responses，the characteristic of the bridge Was acquired and the TMD system was applyed to control the seismic responses of the bridge．The main vibration mode Was confirmed by the method of mod al mass ratio．The optimal param eters of TMD，when attained，were simulated into the finite element moda1．At last，the conclusion that fixing TMD in arch bridge is an efective passive vibration control method to reduce the seismic response of the structure，which is verified by the time-marching analysis result．

Key words: seismic response, mode analyse, parameter optimization, TMD, time-marching analysis, passive vibration control

摘要： 以西藏尼木大桥为研究对象，结合该桥型特点，采用大型通用软件对其进行了模态分析和动力计算．通过模拟 地震响应得到该桥的反应特性，由此采用调谐质量控制器(TMD)对该桥进行受控分析．采用振型贡献率确定受控模 态，在获取TMD系统的优化参数后将其模拟入有限元模型中，并最终通过时程分析验证了TMD运用于拱桥被动减 震控制的有效性。

关键词: 地震反应特性, 模态分析, 参数优化, TMD, 时程分析法, 被动减震控制