摘要
为解决抗震设防工作中强震观测资料不足的问题,提出一种设定地震场景下基于随机效应模型的基岩地震动合成方法。基于Peer-NGA强地震动数据库,利用随机回归技术建立设定地震场景参数(F,M,R,V)与地震动参数(I_(a),D_(5-95),t_(mid),ω_(mid),ω′,ζ_(f))的关联性,讨论其残差及参数相关性;根据地震动参数组反算伽马调制函数的参数组(α_(1),α_(2),α_(3)),并使用随机地震动模型合成设定地震场景下的地震动加速度波形。给出2017年8月8日九寨沟M_(S)7.0地震的应用范例,并与NGA地震动衰减关系进行比对,明确方法的有效范围。结果表明:①通过对C-B数据子集中观测波形进行拟合,根据概率密度分布的直方图选择拟合函数的形式,可知对数正态分布可以较好地对I_(a)进行拟合;D_(5-95)和ω_(mid)/2π的分布范围分别为5.4~41.3 s和1.31~21.6 Hz,其平均值分别约为17 s和5.87 Hz。②设定地震场景(F,M,R,V)下,参数v_(i)以及θ_(i)具有相关性,I_(a)和D_(5-95)之间的相关系数为-0.28,呈现出负相关特征;ω_(mid)和ω′的负相关特征与高频地震动分量随时间快速衰减的特征一致。③2017年九寨沟M_(S)7.0地震的设定场景下,在0.1~5.0 s的域范围内,九寨白河(51JZB)台处的模拟加速度反应谱簇对实际观测波形成了较好包络;预测结果在确保模型具备有效泛化能力的同时,与NGA地震动衰减关系具有较好一致性。
A method for bedrock ground motion synthesis based on random effects modelling in a set seismic scenario is proposed.Firstly,based on the strong ground-motion data from NGA database,the correlations between the parameters(F,M,R,V)of the set seismic scenario and the ground motion parameters(I_(a),D_(5-95),t_(mid),ω_(mid),ω′,ζ_(f))are established by using stochastic regression technique,and the residuals and the parameter correlations are discussed.Secondly,the parameter set(α1,α2,α3)of the gamma modulation function is back-calculated from the ground motion parameter set,and the ground motion acceleration waveforms in the set earthquake scenario are synthesized using the Sanaz stochastic ground motion model.Finally,an application example of the Jiuzhaigou M_(S)7.0 earthquake on Aug.8,2017 is given and the research results are compared with the NGA ground motion attenuation relations to decide the effective range of the method proposed in this paper.The results show that:①By fitting the observed waveforms in the C-B data subset and choosing the form of the fitting function based on the histogram of the probability density distribution,it is definite that I a can be better fit by the lognormal distribution;D_(5-95) lies between 5.4 s and 41.3 s,with a mean value of about 17 s;ω_(mid)/2πlies within the range from 1.31 Hz to 2.6 Hz,with a mean value of 5.87 Hz.②Parameter v_(i) is correlated with parameterθi in the set seismic scenario,and the correlation coefficient between I_(a) and D_(5-95) is-0.28,showing a negative correlation feature;the negative correlation feature ofω_(mid) andω′is consistent with the rapid attenuation with time of the high-frequency ground motion component.③In the set scenario of the 2017 Jiuzhaigou M_(S)7.0 earthquake,the simulated acceleration response spectral clusters at 51JZB station form a better envelope of the observed waves in the frequency domain from 0.1 s to 5.0 s.The prediction results are in good agreement with the NGA ground-motion attenuation relationship while ensuring that the model has effective generalization capability.
作者
张洁
曾金明
胡其志
王程程
张严方
ZHANG Jie;ZENG Jinming;HU Qizhi;WANG Chengcheng;ZHANG Yanfang(School of Urban Construction,Wuchang Institute of Technology,Wuhan 430065,Hubei,China;CCCC Second High way Consultants Co.,Ltd.,Wuhan 430056,Hubei,China;School of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan 430068,Hubei,China)
出处
《地震研究》
北大核心
2026年第1期120-131,共12页
Journal of Seismological Research
基金
湖北省教育厅科学技术研究计划项目(B2022363)
武昌工学院校级科学研究项目(2021KY10).
作者简介
第一作者:张洁(1986-),讲师,主要从事岩土地震工程等方面的研究.E-mail:249333256@qq.com;通信作者:胡其志(1969-),教授,主要从事岩土工程研究.E-mail:hqz0716@163.com.
