2012年5月28日河北唐山Ms4.7地震的数字强震动记录分析

摘要

Records of 87 stations from Capital Area Strong Motion Network from the May 28 th,2012 Ms4.7 Tangshan earthquake are processed and analyzed including baseline correction,digital filtering,computing velocities,displacements,PGA,acceleration response spectrum,Fourier spectrum,EPA and instrument seismic intensity.The results indicate that the recorded acceleration peak is 53.1 cm/s2,the effective peak acceleration is 20.9 cm/s2,the highest seismic intensity and instrument seismic intensity are both six.The frequency components of strong motion records produced by Tangshan Ms4.7 Earthquake are mainly 5～16 Hz and the predominant period is about 0.06 s.In conclusion,frequency components of seismic wave are mainly high frequency for earthquakes with magnitudes of 4～5 and the long-period seismic waves can be ignored.The higher frequency is,the sooner attenuation is.What is more,local site conditions have a strong effect on earthquake ground motion characteristics.%对2012年5月28日河北唐山MS4.7地震获取的数字强震动记录进行了处理和分析,包括基线校正、数字滤波、峰值加速度PGA的合成、速度和位移计算、傅里叶谱分析和加速度反应谱计算、有效加速度峰值的计算、仪器地震烈度的计算等.研究结果表明:记录到的峰值加速度PGA为53.1 cm/s2,最大有效峰值加速度EPA为20.9cm/s2,仪器记录最大地震烈度为Ⅵ度.唐山MS4.7地震的加速度记录频率成分主要为5～16 Hz,地震的卓越周期为0.06 s左右.因此,对于4.0～5.0级地震,频率成分主要为高频成分,且频率越高衰减越快,长周期频率成分基本不发育;另外,台站所处局部场地条件对地震动特征影响较大.