近年来的强震地震观测资料研究显示,近断层地面运动具有区别于远场地震动的显著特征。在收集世界范围内近断层观测记录的基础上,按场地和震级进行分类,采用统计分析的方法研究了近断层地震动的峰值、反应谱谱值和持时特征。研究结果表明,由于方向性效应的影响,两个水平分量的峰值存在显著差异,反应谱的谱值更显著,震级对地震动持时的影响比断层距的影响要大得多,在此基础上,建立了近断层地震动水平向和竖向分量持时的回归关系式,并与其他研究者进行对比,说明了其合理性,为进一步研究提供参考。
By studying the near-fault ground motions recorded in several strong earthquakes, the remarkable characteristics of near-fault ground motions are different from the far-from-fault records. The world wide free-site records of near-fault earthquake ground motions classified by earthquake magnitude and site condition are collected and discussed. The peak value, response spectral value and duration of near-fault ground motions are analyzed. The research results show that the peak values of two horizontal components are markedly different because of the directivity effect, and the response spectral values greatly increase, the duration of near-fault ground motions is greater affected by the earthquake magnitude than by the fault distance. Based on this, the regressive relationships for the horizontal and vertical component durations are established, and are proved to be reasonable when comparing to other researchers' conclusions.