功率谱法在隔震桥梁抗震分析中的应用研究

Application of the Power Spectrum Method in Seismic Analysis of Seismic Isolation Bridges

隔震桥梁在地震作用下一般要求墩、梁保持弹性,主要通过非线性构件隔震支座耗散地震能量,属于典型的局部非线性问题,目前主要采用反应谱法和非线性时程法进行抗震分析.对功率谱法在隔震桥梁抗震分析中的应用开展研究,通过一具体实例,建立了结构三维动力有限元计算模型,并根据设计加速度反应谱生成与其匹配的设计加速度功率谱,借助虚拟激励法实施了抗震分析,同反应谱法和非线性时程法计算结果进行了对比分析,结果表明功率谱法和反应谱法以及非线性时程法计算结果具有较好的一致性.

The seismic performance of isolated bridges requires that the bridge piers should re- main elastic under seismic action. The system mainly dissipates earthquake energy through nonlinear isolation bearings, so presents a typical locally nonlinear problem for seismic analysis. At present, the response spectrum method and the nonlinear time-history method are normally used for seismic analysis of this kind of structures. In this paper, the application of the power spectrum method in seismic analysis of isolated bridges was studied. According to the design acceleration response spectrum, the compatible design acceleration power spectrum was generated at first, and then the seismic response analysis with the power spectrum method through an iteration process was carried out. The results show that the calculated seismic responses of the structure with the power spectrum method and the response spectrum method are in good agreement with each other.