摘要
地震动特性受到地震震源、地震波传播介质和局部场地条件等因素的综合影响,虽然地震动反应谱虽然具有统计意义上的共性,但其具体形状又各不相同,特别是部分加速度反应谱与统计平均值之间存在显著的规律性偏差。为了进一步探究加速度反应谱与统计平均值之间的规律性偏差,本文基于日本KiK-net台网获取的8万余条强震动记录,建立了考虑地震震级和震中距影响的地面峰值加速度归一化加速度反应谱,并以预测值+0.5倍方差为界将加速度反应谱分为有、无反应谱规律性偏差的两组。通过有反应谱规律性偏差的反应谱(观测值)与无反应谱规律性偏差的反应谱预测值之间的差值,析出了反应谱的规律性偏差,验证了反应谱规律性偏差的形状与高斯曲线高度吻合,并可用加速度反应谱规律性偏差曲线的中心周期、相对高度和相对宽度等参数进行表征。基于2万余条有反应谱规律性偏差记录的统计分析显示,加速度反应谱规律性偏差主要受控于剪切波速、覆盖层厚度等局部场地条件表征参数,受地震震级、震中距、地震动强度等参数的影响相对较小。基于此,利用多元线性回归建立了加速度反应谱规律性偏差表征参数的经验统计关系,并提出了有加速度反应谱规律性偏差的场地相关加速度反应谱的确定方法。虽有待改进,但本文提出的反应谱规律性偏差概念将有助于改进场地相关地震动反应谱的确定方法。
The main factors that affect ground motion include the earthquake source,the medium and path of seismic wave propagation and the local site condition.Although the spectral accelerations of ground motion have common characteristics in statistical sense,the specific shape of each spectral acceleration is unique,and some spectral accelerations have significant regular deviations from the statistical mean values.These deviations often appear in the form of a single-peak superimposed on the average spectral accelerations,which might be related to the earthquake parameters,such as earthquake magnitude and epicenter distance,and the site parameters,such as shear wave velocity and overburden thickness,and strong motion intensity.In this paper,based on 85976 strong earthquake records obtained by Japanese KiK-net network,the statistical relationship of the spectral accelerations normalized by peak ground acceleration(PGA)with magnitude and epicenter distance was obtained.Using predicted value plus 0.5 time of variances as the separatrix,the acceleration records were divided into two categories,that is,the records with or without regular deviations of spectral accelerations.By calculating the differences between the spectral accelerations of records with regular deviations and the predicted spectral accelerations without regular deviations,the regular deviations of the spectral accelerations were separated out,and the shapes of the regular deviations were verified to be highly consistent with the Gaussian curve.The regular deviations of spectral accelerations could be characterized by the central period,the relative height and the relative width of the fitted Gaussian curves.Based on the statistical analyses of 25229 acceleration records with regular deviations of spectral accelerations obtained by Japanese KiK-net network,the correlations between the characteristic parameters of regular deviations and earthquake parameters,local site conditions,and ground motion intensity were discussed.The results indicated that:1)The cen
作者
袁明明
李小军
王玉石
Yuan Mingming;Li Xiaojun;Wang Yushi(College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124,China;Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China;College of Civil Engineering,Institute of Disaster Prevention,Hebei Sanhe 065201,China)
出处
《地震学报》
CSCD
北大核心
2024年第5期877-892,共16页
Acta Seismologica Sinica
基金
国家重点研发计划课题(2022YFC3003503)
国家自然科学基金(52192675)
高等学校学科创新引智计划项目(D21001)共同资助.
