青川Ms6.4级地震加速度记录与衰减关系研究

四川汶川Ms8.0级地震后,甘肃省地震局在甘川交界地区布设了多个强震动流动观测站,2008年5月25日记录到了1次最大余震,震级为Ms6.4。27个强震动台站共获得了81条记录。这次强余震记录到的最近震中距为12 km,最远为485 km,其中最大加速度峰值为367.6 cm/s2,最小加速度峰值为0.8 cm/s2。相比较汶川地震的强震动记录,由于流动观测台站的布设使得本次地震的记录具有更好的线性分布,震中距也更为丰富,因而更利于研究这一地区的地震动衰减关系。利用统计方法获得了加速度峰值随震中距的衰减关系,基本服从幂函数衰减关系。这一结果对甘肃东南部地区震害研究和抗震设防具有重要的应用价值。

PRELIMINARY ANALYSIS ON GANSU STRONG MOTION RECORDS AND ATTENUATION Of QINGCHUAN Ms6.4 EARTHQUAKE

After Sichuan Wenchuan Ms8.0 earthquake,Earthquake Administation of Gansu Province had founded some mobile strong motions immediately.Soon,the biggest aftershock（Ms6.4） in Qingchuan on May 25,2008 after the mainshock was recorded,and the authors got 81 records in total through 27 strong motions.The nearest and the furthest epicentral distances of the records are 12 km and 485 km.And the maximum and the minimum peak acceleration is 367.6 cm/s2 and 0.8 cm/s2.This paper attempts to show that the authors have got the attenuation relationship of peak acceleration by means of the statistical method.They found that there is a better Log/Linear relationship between the peak acceleration and epicentral distance.It will be the important value in the research of seismic disaster and the fortification against earthquakes in Gansu Southeast area.