以芦山地震震中距100km内的20个台站60条原始强震记录为依据,研究芦山地震动卓越周期、反应谱峰值周期、地震动持续时间和震源持续时间.研究发现:EW、SN和UD 3个方向卓越周期的变化范围为0.013～0.275s;5％阻尼比反应谱峰值周期变化范围为0.03～0.65s;芦山地震动90％持续时间变化范围为5.1 ～35.9s,震源持续时间在EW、SN和UD 3个方向的均值分别约为6.41s、6.05s和5.47s.以台站地震动持时为依据,回归地震动持续时间的空间变化曲线,并与Bommer(2009)地震动持时预测曲线进行比较,发现芦山地震动持续时间高于Bommer(2009)预测曲线,表明芦山地震中的震源作用时间大于目前的预测平均值.芦山地震动持时和震源持续时间在NE向有较明显的方向性,尤其是震源持续时间;而该方向上的余震分布弱于震中SW方向,表明发震构造在主震发生过程中NE方向能量释放较多,所以余震分布较弱.地震动持时和震源持时无上盘效应可能与隐伏发震构造相关.%Based on 60 records from the 20 stations within 100km to the epicenter of Lushan earthquake,the predominant period,period of peak response spectrum,duration of ground motion,and source duration are investigated.By the study,we conclude that within 100km to the epicenter,the scope of predominant period is 0.013 ～ 0.275s in EW,NS and UD direction;the scope of period of peak response spectrum for 5％ damping ratio is 0.03～0.65s;the scope of 90％ ground motion durations is 5.1～35.9s;the scope of averaging source duration is 6.41 (EW),6.05 (NS) and 5.47s (UD).Furthermore,based on the ground motion duration calculated by 20 stations dada,the predictive curve and equation of ground motion duration is regressed and compared with the recent equation of ground motion duration by Bommer(2009).We find that the ground motion durations of most stations are larger than predictively mean value by Bommer (2009),which means that the source effect of Lushan earthquake is relatively larger.Lastly,by the contour figure of ground motion duration and source duration,we conclude that the directivity character of duration is relatively apparent in NE direction.The relatively larger source duration and ground motion duration in NE direction indicate more energy release in the main shock of Lushan earthquake,which perhaps causes the relatively less aftershocks in this direction.The duration has no hanging wall effect,which perhaps results from the blind-reverse fault structure of Lushan earthquake.
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