地震动频谱特性和持时对IDA结果影响的研究

Influence of spectral characteristics and duration of ground motions on results of IDA

地震动记录的选择是增量动力分析的基础性工作。为了研究地震动记录的频谱特性和持时对增量动力分析结果的影响,总结了四种常用的计算地震动记录特征周期方法,建立了地震记录分组,进行了反应谱比较,以建立的地震记录分组为地震输入,结合算例进行了IDA分析,比较了IDA曲线和地震易损性曲线的差异。在此基础上,按两种地震持时原则输入进行IDA分析,分析了地震记录持时对IDA结果的影响。研究结果表明,地震记录频谱特性对IDA的数值大小和离散程度存在较大影响,足够的持时输入有助于获得稳定性好的IDA结果。

The selection of ground motion records is the basis of incremental dynamic analysis （IDA ）.In order to study the influence of spectral characteristics and duration of ground motions on results of IDA,four conventional methods to calculate the characteristic period of ground motions were introduced,with these methods the record groups of ground motions were selected,and their response spectra were compared.IDA was performed taking the selected ground motions as imputs,then the IDA curves and the fragility curves of earthquake were compared.On this basis,the influnece of earthquake duration on IDA was analysed according to two duration principles.It was shown from the results that the spectral characteristics of ground motions influence evidently not only the magnitudes but also the level of dispersion of IDA,and sufficient duration time is good for the stability of results of IDA.