摘要
2008年"5·12"汶川特大地震发生后,固定及流动台站获得了数量可观的余震地震动数据,为地震危险性分析和地震动衰减规律研究提供了丰富的数据。通过Gutenberg-Richter关系分析得到汶川地震余震震级-频度分布(FMD),结合B?th定律预估得到逼近实际的最大预估余震震级,基于修正的Omori定律拟合得到余震发生率与主震后时间的关系。主余震统计特性显示M_s4.0～6.4范围内的余震记录震中距及震级分布相对均匀,可作为建立地震动衰减规律的依据。故针对土层地表及基岩地表分别进行了EW、NS和UD三个方向的统计回归分析,给出了2种地表情况下三向地震动峰值加速度的定量衰减关系表达式。
After the 2008 devastating Wenchuan Earthquake on May 12th, a considerable number of aftershock ground motion records were obtained by both the fixed and mobile stations, which provide abundant research data for seismic risk analysis and ground motion attenuation relationship investigation. In this paper, the frequency-magnitude distribution of the aftershocks of the Wenchuan Earthquake was established through the Gutenberg-Richter relation. With the Both law, the estimated maximum aftershock magnitude was predicted, which is close to the real value. The relationship between the aftershock occurrence rate and the time after the mainshock was fitted based on the modified Omori law. The statistical characteristics show that the distribution of the epicentral distances and the magnitudes of the aftershock records for the magnitudes ranging from 4.0 to 6.4 is relatively even, which can be used for establishing the ground motion attenuation relationships. The statistical regression analyses of the EW, NS, and UD ground motion components were carried out respectively for both the soil and bedrock surfaces, and the quantitative peak ground acceleration (PGA) attenuation relationships for the 3 components were obtained.
作者
韩建平
徐金玉
HAN Jianping;XU Jinyu(Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province, Lanzhou University of Technology,Lanzhou 730050, China;Western Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology, Lanzhou 730050, China)
出处
《世界地震工程》
CSCD
北大核心
2019年第1期9-16,共8页
World Earthquake Engineering
基金
国家自然科学基金项目(51578273)
教育部长江学者和创新团队发展计划(IRT_17R51)
关键词
强余震
最大余震震级预测
余震发生率
震中距
衰减规律
strong aftershocks
prediction of maximum aftershock magnitude
aftershock occurrence rate
epicentral distance
attenuation law
