岷县漳县6.6级地震及余震强震动记录特征分析

Characteristics of Strong Motion Records from Minxian-Zhangxian MS6.6 Earthquake and Aftershock

摘要:

对2013年7月22日甘肃岷县-漳县地震获取的273条主余震加速度记录进行格式转换、基线校正和滤波等常规处理，分析该地震主震（M_S6.6）和余震（M_S5.6）两次地震记录的幅值、持时以及反应谱特征，发现M_S6.6主震记录的PGA范围在0.728~177.5 gal间，M_S5.6余震记录的PGA范围在0.732~69.3 gal间；将观测数据与霍俊荣和第五代《中国地震动参数区划图》地震动衰减关系进行对比，发现霍俊荣衰减关系更吻合于此次地震的主余震加速度衰减；绘制主余震5%~95%重要持时分布图，并针对主震62MXT反应谱和本地设计谱以及近些年国内主要强震震中反应谱开展比较分析；最后研究土层台、基岩台、相同台站各个震级反应谱的特征。

Abstract:

On July 22, 2013, an M_S6.6 earthquake and its aftershock occurred at the border area between Minxian and Zhangxian Counties, Gansu Province. In this study, 273 items of acceleration records from the M_S6.6 mainshock and the M_S5.6 aftershock were processed, and the characteristics of the amplitudes, response spectra, and duration of the records were compared. The peak ground acceleration range of the main earthquake was 0.728-177.5 gal, and that of the aftershock was 0.732-69.3 gal. According to the comparison among observation data, the attenuation relationship of Huo Junrong, and the ground motion attenuation relationship in the fifth Chinese seismic zonation map, it was found that the attenuation relationship of Huo Junrong is more suitable for the acceleration attenuation of the two earthquakes; the 5%-95% significant duration distribution of the two earthquakes was calculated and plotted. The response spectrum of the main earthquake at 62 MXT was compared with the design spectrum and the response spectra of major strong earthquakes in China in recent years. Finally, the response spectrum characteristics of typical soil stations, bedrock stations, and the same station with different magnitudes were analyzed.