Aftershock records have a considerable effect on the results of collapse assessments conducted on buildings. Thus, they should be selected cautiously. As the number of recorded aftershocks is not sufficient, mainshock records are often utilized instead. In order to increase the correlation between the aftershock time history and the seismic response of a structure, this research intends to investigate several Intensity Measures (IMs). For this study, three RC frames were considered. Forty-four far-field records from FEMAP-695 were selected as main and aftershock. Each building analysis was conducted under 44 mainshock–aftershock chains. According to the results, use of the summation of the first mode spectral acceleration value of aftershocks as the second part of a vector IM can lead to the sufficiency of the IM.

中文翻译：

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远场余震下地震塌陷评估矢量强度测量的研究

余震记录对建筑物倒塌评估的结果有相当大的影响。因此，应谨慎选择它们。由于记录的余震数量不足，通常使用主震记录来代替。为了增加余震时程与结构地震响应之间的相关性，本研究打算研究几种强度测量（IM）。在这项研究中，考虑了三个 RC 框架。来自 FEMAP-695 的 44 条远场记录被选为主震和余震。每个建筑物分析都是在 44 次主震-余震链下进行的。结果表明，利用余震一阶模态谱加速度值之和作为矢量IM的第二部分，可以得到IM的充分性。