2021年5月22日玛多M_(S)7.4地震地震动特征  

Analysis of the ground motion characteristics of the Maduo M_(S)7.4 earthquake in Qinghai on 22 May 2021

作　　者：万秀红[1] 吴哲[1] 李智敏[1] 屠泓为[1] 李鑫 WAN Xiuhong;WU Zhe;LI Zhimin;TU Hongwei;LI Xin(Qinghai Earthquake Agency,Xining 810001,China)

机构地区：[1]青海省地震局,西宁810001

出　　处：《地震地磁观测与研究》2021年第5期42-50,共9页Seismological and Geomagnetic Observation and Research

基　　金：青海省科技计划“共和盆地干热岩周边区域历史强震位错反演及动力学构造模型研究”(项目编号:2020-ZJ-752)。

摘　　要：为了研究2021年5月22日玛多M_(S) 7.4地震地震动特征,收集16个强震台的峰值加速度和其中9个台的强震波形数据,利用峰值加速度衰减及反应谱等分析玛多M_(S) 7.4地震强震动特征。结果表明,多数台站的PGA值都随震中距的增大而平稳下降,PGA的衰减特征与青藏区衰减关系间有较好的一致性;土层台与基岩台的加速度反应谱明显不同,震中距越小,短周期高频成分越多,衰减越快,震中距越大,长周期高频成分越少,衰减越慢;加速度反应谱的水平向与竖向比值曲线在4 s内呈现两峰一谷的现象,初步认为,距发震断层较近的野马滩1号大桥所受到的破坏及水泥路面的明显错断受水平向地震动作用的影响更大。Peak acceleration data from 16 strong motion stations and the waveform data from 9 strong motion stations were collected to study the ground motion characteristics of the 2021 Maduo M_(S) 7.4 earthquake using the attenuation of the peak acceleration and the response spectrum method.The results show that the PGA values at most stations decrease steadily with the increase of epicentral distance;the PGA attenuation characteristics are in good agreement with the attenuation relationship in the Qinghai-Xizang region.The acceleration response spectrum analysis shows that the smaller epicentral distance,the larger short-period high-frequency energy,the faster attenuation;the larger epicentral distance,the smaller short-period high-frequency energy,the slower attenuation.The ratio of vertical and horizontal acceleration response spectra shows two peaks and one valley in 4 s.It is considered that the damage of the Yematan No.1 bridge,which is close to the earthquake,and the cement pavement are more influenced by the horizontal motion.

关 键 词：玛多M_(S)7.4地震 强震动记录 峰值加速度 反应谱 

分 类 号：P315[天文地球—地震学]