强地震动幅值谱随机涨落特征的研究
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摘要
本文从工程应用的观点,将强地面运动幅值谱|A(f)|表示为强度受到调制的随机过程即其中,为随频率变化的确定性函数亦|A(f)|是的均值,η(f)为均值为零的随机过程。在随机过程η(f)为各态厉经的假定下,研究了η(f)的功率谱密度函数的特征及其衰减形式。根据地震学的有关理论,提出了用四个参数控制幅值谱的均值随频率变化的函数形式并对拟合这些参数的原则作了讨论。本文利用SMART—1台阵资料,对强地震动幅值谱及其随机涨落特征进行了定量分析,说明幅值谱的随机涨落对地震动峰值的影响大致在3％至12％之间,而对反应谱的影响大致在10％至33％之间。
For convenient engineering application this paper assumes that amplitude spectrum of strong ground motion is a random process with modulation intensity as follows
where is a mean value of or a deterministic function that changes with frequen is a random process with zero mean value. Under the assumption that the random process is ergodic attenuation properties of power spectra density function of (f) have been studied in detail. According to theory of seismology we have used four parameters to control mean value function of amplitude spectrum that changes with frequency and discussed the principle of fitting these parameters. Using SMART-1 array data this paper has analyzed quantitatively amplitude spectra and their random disturbance properties of strong ground motion. These results indicate that random disturbance of amplitude spectra leads to variation of acceleration peak ranged from 3 percent to 12 percent but great variation of response spectra from 10 percent to 33 percent.
For convenient engineering application this paper assumes that amplitude spectrum of strong ground motion is a random process with modulation intensity as follows
where is a mean value of or a deterministic function that changes with frequen is a random process with zero mean value. Under the assumption that the random process is ergodic attenuation properties of power spectra density function of (f) have been studied in detail. According to theory of seismology we have used four parameters to control mean value function of amplitude spectrum that changes with frequency and discussed the principle of fitting these parameters. Using SMART-1 array data this paper has analyzed quantitatively amplitude spectra and their random disturbance properties of strong ground motion. These results indicate that random disturbance of amplitude spectra leads to variation of acceleration peak ranged from 3 percent to 12 percent but great variation of response spectra from 10 percent to 33 percent.
引文
1． M. D.Trifunac,Preliminary Empirical Model for Scaling Fourier Amplitude Spectra of Strong Motion Acceleration in Terms of Earthquake Magnitude,Source to Station Distance and Recording Site Condition. B.S.S.A.,Vol.66,pp.1343-1373,1976．
2． 罗奇峰.近场加速度的半经验合成.博士学位论文.1989． 国家地震局工程力学研究所.
3． P.A.S,Papageorious,and K.Aki,A Specific Barrier Model of the Quantitative Description of Inhomogenous Faulting and the Quantitative of Strong Ground Motion, I.Description of the Model,B.S.S.A.,Vol.73, pp. 693-722． 1983．
4． 金星,廖振鹏.强地震相位谱的统计规律性.地震学报.Vol.17,No.1． 1994．
5． 金星,廖振鹏.地震动相位特征的研究.地震工程与工程振动.Vol.13,No.1． 1994．
6． 廖振鹏,金星.强地震动相位的一个随机模型.地震学报.Vol.17,No.4．
2． 罗奇峰.近场加速度的半经验合成.博士学位论文.1989． 国家地震局工程力学研究所.
3． P.A.S,Papageorious,and K.Aki,A Specific Barrier Model of the Quantitative Description of Inhomogenous Faulting and the Quantitative of Strong Ground Motion, I.Description of the Model,B.S.S.A.,Vol.73, pp. 693-722． 1983．
4． 金星,廖振鹏.强地震相位谱的统计规律性.地震学报.Vol.17,No.1． 1994．
5． 金星,廖振鹏.地震动相位特征的研究.地震工程与工程振动.Vol.13,No.1． 1994．
6． 廖振鹏,金星.强地震动相位的一个随机模型.地震学报.Vol.17,No.4．
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