摘要
为研究2013年芦山Mw6.8地震Newmark位移的方向性特征,使用震源区近场22个台站的强震动记录,利用Boore的改进方法对地震动进行投影,分析Newmark位移随方向性变化、最大值与最小值比值(Dn max/Dn min)和卓越方向(θmax)等特征。得出以下结论:(1)Newmark位移随方向的变化存在明显的波峰和波谷,其最大值方向与最小值方向夹角在多数情况下处于近似垂直的关系。(2)Dn max/Dn min随着临界加速度(a c)的增大而增大;a c较大时,Dn max/Dn min随断层距的增大逐渐增大;此外,场地类型对Dn max/Dn min也有一定影响。(3)θmax在断层两侧和同震位移方向存在较强的相关性,在断层两端与同震位移方向相关性较弱;θmax与断层走向垂直方向(FN)的相关性不强;此外,θmax不随a c发生显著变化。(4)基于Arias烈度和考虑地震震级的Newmark位移经验模型对考虑方向性的Newmark位移的预测效果最好。
Using the strong motion records from 22 near-field stations in the focal area,the directionality of Newmark displacement during the 2013 Lushan MW6.8 earthquake was investigated.The ground motions were projected using the modified Boore method to analyze the characteristics of Newmark displacement,including changes in directionality,the predominant direction(θmax),and the ratio of maximum to minimum displacement values(Dn max/Dn min).Results show the following:(1)Newmark displacement exhibits distinct peaks and valleys as it changes with direction,and in most cases,the angle between the maximum and minimum directions is generally vertical.(2)Dn max/Dn min increases with critical acceleration(a c);when a c is large,Dn max/Dn min gradually increases with fault distance.In addition,the site type has a certain influence on Dn max/Dn min.(3)A strong correlation exists betweenθmax and the direction of coseismic displacement on both sides of the fault,but a weak correlation is observed on both ends of the fault.The correlation betweenθmax and the vertical direction of the fault strike is weak,andθmax does not notably change with a c.(4)The empirical model of Newmark displacement,which considers Arias intensity and earthquake magnitude,yields the best prediction effect of Newmark displacement when considering directionality.
作者
刘平
刘川
陈兴周
王海
魏长刚
范依仁
陈凡
吴煜心
LIU Ping;LIU Chuan;CHEN Xingzhou;WANG Hai;WEI Changgang;FAN Yiren;CHEN Fan;WU Yuxin(Xi'an University of Science and Technology,Xi'an 710054,Shaanxi,China;Shanxi Transportation Survey&Design Institute Co.,Ltd.,Taiyuan 030032,Shanxi,China;China Jikan Research Institute of Engineering Investigations and Design Co.,Ltd.,Xi'an 710054,Shaanxi,China;Wenzhou Geotechnical Investigation&Surveying Research Institute Co.,Ltd.,Wenzhou 325000,Zhejiang,China)
出处
《地震工程学报》
北大核心
2025年第2期437-447,共11页
China Earthquake Engineering Journal
基金
国家自然科学基金(51808444,51979218,U1965107)。
关键词
芦山地震
Newmark位移
方向性
地震动参数
Lushan earthquake
Newmark displacement
directionality
ground motion parameters
