地球物理学进展 ›› 2018, Vol. 33 ›› Issue (5): 1807-1813.doi: 10.6038/pg2018BB0417

• 固体地球物理及空间物理学(大气、行星、地球动力学、重磁电及地震学、地热学) • 上一篇    下一篇

基于2014年云南景谷MW 6.0地震的中强震地震动的方向性特征分析

胡进军1,2(),孙健1,2   

  1. 1. 中国地震局工程力学研究所, 哈尔滨 150080
    2. 中国地震局地震工程与工程振动重点实验室, 哈尔滨 150080
  • 收稿日期:2017-12-04 修回日期:2018-08-22 出版日期:2018-10-20 发布日期:2019-01-11
  • 作者简介:第一作者简介 胡进军,男,1978年生,河北石家庄人,博士,研究员,主要从事地震动参数特性分析研究工作.
  • 基金资助:
    国家自然科学基金资助项目(51578516);国家自然科学基金资助项目(51238012);中国地震局工程力学研究所基本科研业务专项资助项目(2014B06);中国地震局工程力学研究所基本科研业务专项资助项目(2016A01)

Analysis of directivity effect on ground motion based on the 2014 MW 6.0 Jinggu moderate magnitude earthquake in Yunnan, China

HU Jin-jun1,2(),SUN Jian1,2   

  1. 1. Institute of Engineering Mechanics, China Earthquake Administration, Harbin 150080, China
    2. Key Laboratory of Earthquake Engineering and Engineering Vibration, Harbin 150080, China
  • Received:2017-12-04 Revised:2018-08-22 Online:2018-10-20 Published:2019-01-11

摘要:

一般认为大地震震源破裂传播过程会造成近断层地震动的方向性特征,为了验证中强地震是否存在方向性特征,本研究以2014年10月7日云南省景谷县MW 6.0级中强地震的强震记录为基础,选取获得的39组主震记录,按照台站相对于断层的位置及走向将其划分为西北向和东南向两类场点.分别对垂直于断层和平行于断层的地震动分量的峰值、反应谱和持时参数进行了定量对比和分析.研究结果表明:(1)在峰值方面,西北向场点的峰值明显大于东南向的峰值,而且西北和东南向的峰值差别随着断层距的增大而逐渐减小;(2)在反应谱方面,西北向的平均反应谱明显高于东南向平均反应谱,并且当周期在1.2~4.0 s之间时,西北向和东南向反应谱谱比最高可达到7倍以上;(3)在持时方面,在断层距小于80 km的区域内,东南向的持时要明显大于西北向的持时.研究结果表明景谷地震的地震动表现出了较为明显的方向性特征.本研究分析结果可以为研究中强地震的地震动工程参数的方向性特征提供参考.

关键词: 中强地震, 地震动, 方向性效应, 景谷地震

Abstract:

It is thought that direction of the great earthquake rupture propagation will lead to near-fault ground motion directional characteristics. In order to verify whether there is directional characteristics of moderate strong earthquakes, we study the directivity characteristics of the acceleration ground motion during the MW 6.0 Yunnan Jinggu earthquake. Totally 39 sets of ground motions recorded are analyzed in this study. Firstly, the recordings are classified into two groups according to the relative location to the epicenter and the rupture direction. Then, the amplitude, response spectra and duration are analyzed. Results indicate that: (1)In terms of peak,the peak of the northwest is significantly higher than the southeast and the peak value decreases with the increase of fault distance; (2)In terms of response spectra, the average response spectrum of northwest is obviously higher than southeast and when the period between 1.2~4.0 s, and the response spectrum ratio of the northwest and the southeast can reach more than 7 times; (3)In terms of duration, in the near field area with the fault distance less than 80 km, the duration of the southeast is obviously larger than the northwest. The results show that the Jinggu moderate magnitude earthquake shows more obvious directional characteristics. The results of this study can provide a reference for studying the directional characteristics of seismic engineering parameters of moderate magnitude earthquakes.

Key words: moderate magnitude earthquake, ground motion, directivity, Jinggu earthquake

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