地震动相位差谱的统计规律

本文建立了地震动相位差谱的经验模型,并根据地震动加速度记录资料,对模型中的系数进行统计回归,建立了地震动相位差谱经验关系。结果表明,地震的震级和震源距对加速度时程相位差谱的均值曲线和方差都有重要影响,震源距相同震级不同时相位差谱的均值曲线近似平行;震级相同而震源距不同时相位差谱的均值曲线不仅上下移动而且形状如发生变化,震源距的增加将加大其低频处与高频处的差异。相位差谱的方差将随震级和震源距的增加而变大。

AN EMPIRICAL LAW FOR PHASE DIFFERENCE SPECTRUM OF EARTHQUAKE GROUND MOTION

An empirical model for phase difference spectral evaluation of earthquake ground motion is established and the coefficients in the model are regressed from the earthquake acceleration records. The results indicate that the mean smoothened curves and standard variance of phase difference spectrum are both magnitude and distance dependent. The curves are nearly parallel for different magnitudes but at same distance. The shape of the curve also changes with distance. Increase of distance causes obvious difference near two ends of the curve. The standard variance of phase difference spectrum becomes larger with the increase of magnitude and distance.