基于北岭地震的洛杉矶盆地的地震动盆地效应研究  

Basin effects of the Los Angeles Basin under the Northridge earthquake

作　　者：张旭[1] 闫佳琦 韩春鹏[1] 马春龙 李明宝[1] ZHANG Xu;YAN Jiaqi;HAN Chunpeng;MA Chunlong;LI Mingbao(School of Civil Engineering and Transportation,Northeast Forestry University,Harbin 150040,China;Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;College of Shipbuilding Engineering,Harbin Engineering University,Harbin 150001,China;Science Park,Harbin Engineering University,Harbin 150000,China)

机构地区：[1]东北林业大学土木与交通学院,哈尔滨150040 [2]中国地震局工程力学研究所,哈尔滨150080 [3]哈尔滨工程大学船舶工程学院,哈尔滨150001 [4]哈尔滨工程大学国家级大学科技园,哈尔滨150000

出　　处：《振动与冲击》2025年第2期221-234,共14页Journal of Vibration and Shock

基　　金：中央高校基本科研业务费专项资金(2572023AW70);中国博士后科学基金第73批面上项目(2023M730833)。

摘　　要：盆地场地对于地震动的放大作用十分显著,盆地效应的研究对于估测地震动、工程选址及抗震设计有着重要的意义。为定量探究盆地对于不同地震动参数及震害的影响,利用洛杉矶盆地区域布设的30个岩土台站获取的北岭地震加速度记录,以盆地外西北侧基岩场地为参考场地研究盆地地形对于幅值、持时、仪器烈度及阿里亚斯烈度等地震动参数的影响,并基于考虑路径几何衰减效应的传统谱比法分析盆地不同区域的场地放大作用。结果表明:(1)地震动幅值与阿里亚斯烈度均随震中距增加而减小,但在盆地东南侧边缘又呈小幅回升趋势;(2)盆地东南侧边缘对于持时及地震动的放大作用最为显著,呈明显地震动异常区;(3)盆地西北侧边缘的仪器烈度及调查烈度均高于其他区域,呈明显烈度异常区;(4)盆地中部区域各场地的地震动参数不存在明显异常,此区域震害也并未被盆地场地放大;(5)造成盆地两侧边缘地震动参数及震害异常区的主要原因为体波与次生面波相长干涉造成的盆地边缘效应。研究结果可为我国部分盆地场地对地震动影响的相关研究提供一定借鉴,为我国防灾减灾工程提供科学依据。The amplifying effect of a basin on the ground motion is notably significant,rendering the study of basin effects critical for the quantitative estimation of ground motion,engineering site selection,and earthquake-resistant design.In order to quantitatively explore the influence of the basin on different ground motion parameters and earthquake damage,the influence of basin topography on ground motion parameters such as amplitude,duration,instrumental intensity and Arias intensity was studied by using the acceleration records of the Northridge earthquake obtained by 30 geotechnical arrays deployed in the Los Angeles Basin,and the bedrock site on the northwest side of the basin was used as the reference site.Based on the traditional spectral ratio method considering the geometric attenuation effect of the path,the site amplification effect in different regions of the basin was analyzed.The findings indicate that:①both the amplitude of ground motion and the Arias intensity decrease with increasing the epicenter distance,yet exhibit a slight rebound trend on the southeastern edge of the basin;②the southeastern edge of the basin is particularly pronounced in terms of its amplification effect on the duration and ground motions,manifesting as a distinct ground motion anomaly zone;③instrumental seismic intensity and surveyed seismic intensity on the northwestern edge of the basin are higher than those in other areas,presenting a clear intensity anomaly zone;④there is no obvious abnormality in the ground motion parameters of each site in the central region of the basin,and the earthquake damage in this area has not been amplified by the basin site;⑤the main reason for the abnormal ground motion parameters and earthquake damage anomaly areas on both sides of the basin is the basin edge effect caused by the constructive interference of body wave and secondary surface wave.The outcomes of this study provide references for related research on the impact of ground motion on certain basins in China and offer a scienti

关 键 词：北岭地震 洛杉矶盆地 地震动参数 盆地效应 放大作用 

分 类 号：P315.9[天文地球—地震学]