水平和竖向地震动相干函数的比较
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摘要
为明确水平和竖向地震动相干函数之间的关系,本文选取SMART-1台阵第5次地震和第40次地震记录,采用水平分量和竖向分量加速度记录作为研究数据,用FORTRAN程序计算台站间相干系数,台站对间距d选择200 m、1000 m和2000 m等3种不同的距离,分别计算得到对应的相干系数。选用Abrahamson模型对不同距离d计算得到的相干系数进行拟合,比较水平和竖向分量拟合结果发现:竖向分量相干函数离散性大于水平分量。随着频率的增加,不同台站距下水平和竖向相干系数的衰减曲线均趋于一致,短距离低频率下,水平和竖向相干系数值相差较大。随着频率和台站间距的增大,水平和竖向相干系数值差距逐渐变小并趋于一致。
In order to clarify the relationship between horizontal and vertical ground motion coherence functions, this paper selects the 5 th and 40 th seismic records of SMART-1 array, and uses horizontal component and vertical component acceleration records as research data, and calculates with FORTRAN program. For the coherence coefficient between stations,the station selects three different distances, such as 200 m, 1000 m and 2000 m for the spacing d, and calculates the corresponding coherence coefficients. The Abrahamson model is used to fit the coherence coefficients calculated by different distances d. The horizontal and vertical component fitting results are compared. It is found that the vertical component coherence function is more discrete than the horizontal component. With the increase of frequency, the attenuation curves of the horizontal and vertical coherence coefficients of different stations tend to be the same. At short distances and low frequencies, the horizontal and vertical coherence coefficients differ greatly. As the frequency and station spacing increase,the gap between the horizontal and vertical coherence coefficients becomes smaller and tends to be consistent.
In order to clarify the relationship between horizontal and vertical ground motion coherence functions, this paper selects the 5 th and 40 th seismic records of SMART-1 array, and uses horizontal component and vertical component acceleration records as research data, and calculates with FORTRAN program. For the coherence coefficient between stations,the station selects three different distances, such as 200 m, 1000 m and 2000 m for the spacing d, and calculates the corresponding coherence coefficients. The Abrahamson model is used to fit the coherence coefficients calculated by different distances d. The horizontal and vertical component fitting results are compared. It is found that the vertical component coherence function is more discrete than the horizontal component. With the increase of frequency, the attenuation curves of the horizontal and vertical coherence coefficients of different stations tend to be the same. At short distances and low frequencies, the horizontal and vertical coherence coefficients differ greatly. As the frequency and station spacing increase,the gap between the horizontal and vertical coherence coefficients becomes smaller and tends to be consistent.
引文
[1]胡聿贤.地震工程学[M].北京:地震出版社,2006
[2] Darragh RB. Analysis of near-source waves:separation of wave types using strong motion array recordings[M].University of California:Earthquake Engineering Research Center, College of Engineering, 1988
[3] Oldham RD. On the propagation of earthquake motion to great distances[J]. Proceedings of the royal society of london, 1900,66:2-3
[4] Oliveira CS. Variability of strong ground motion characteristics obtained in SMART-1 array[C]. Proceedings of the12th Regional Seminar on Earthquake Engineering, 1985
[5]刘先明,叶继红,李爱群.竖向地震动场的空间相干函数模型[J].工程力学,2004,21(2):140-144
[6] Ye JH, Pan JL, Liu XM. Vertical coherency function model of spatial ground motion[J]. Earthquake engineering and engineering vibration, 2011,10(3):403-415
[7]全伟.大跨桥梁多维多点地震反应分析研究[D].大连:大连理工大学,2008
[8] Papazoglou AJ, Elnashai AS. Analytical and field evidence of the dam aging effect of vertical earthquake ground motion[J]. Earthquake Engineering and Structural Dynamics, 1996,25(10):1109–1137
[9] Abrahamson NA, Bolt BA, Darragh RB, et al.“The SMART-1 accelerograph array(1980-1987):A review”[J].Earthquake Spectra, 1987,3:263-287
[10]丁海平,袁莉莉,刘成浩.窗函数和带宽对地震动相干函数的影响[J].自然灾害学报,2018,27(3):1-10
[2] Darragh RB. Analysis of near-source waves:separation of wave types using strong motion array recordings[M].University of California:Earthquake Engineering Research Center, College of Engineering, 1988
[3] Oldham RD. On the propagation of earthquake motion to great distances[J]. Proceedings of the royal society of london, 1900,66:2-3
[4] Oliveira CS. Variability of strong ground motion characteristics obtained in SMART-1 array[C]. Proceedings of the12th Regional Seminar on Earthquake Engineering, 1985
[5]刘先明,叶继红,李爱群.竖向地震动场的空间相干函数模型[J].工程力学,2004,21(2):140-144
[6] Ye JH, Pan JL, Liu XM. Vertical coherency function model of spatial ground motion[J]. Earthquake engineering and engineering vibration, 2011,10(3):403-415
[7]全伟.大跨桥梁多维多点地震反应分析研究[D].大连:大连理工大学,2008
[8] Papazoglou AJ, Elnashai AS. Analytical and field evidence of the dam aging effect of vertical earthquake ground motion[J]. Earthquake Engineering and Structural Dynamics, 1996,25(10):1109–1137
[9] Abrahamson NA, Bolt BA, Darragh RB, et al.“The SMART-1 accelerograph array(1980-1987):A review”[J].Earthquake Spectra, 1987,3:263-287
[10]丁海平,袁莉莉,刘成浩.窗函数和带宽对地震动相干函数的影响[J].自然灾害学报,2018,27(3):1-10