2008年青川Ms6.4级强余震加速度衰减影响场
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摘要
利用2008年5月25日四川青川发生Ms6.4级强余震10个流动强震台获取的强震动记录资料,对甘肃省陇南地区强震动自由场、加速度衰减影响场和近场加速度频谱进行了分析。根据强震动流动台在黄土地面的实际观测数据,与相近的基岩山洞专业台站的观测值对比,黄土地面的自由场加速度较基岩台的记录放大4～5倍,而优势频率也向低端移动1倍。从地面加速度分析,6级左右中强地震的极度破坏区半径大约60 km。在地震灾后恢复重建工作的抗震设计时,应该考虑地形影响因素,适当提高典型山区场地工程或民房建筑抗震设防标准(峰值加速度增大50%)。
Using the records of 10 mobile strong motions from Sichuan Qingchuan aftershock on May 25,2008,the strong vibration free field,acceleration attenuation effect field and near field acceleration spectrum in south of Gansu are analyzed.According to the strong vibration flow units in the background based on the actual observation data,and compared with the observed value of the bedrock of the cave stations,free field acceleration is larger 4 ～ 5 times than the bedrock of the background,the dominant frequency moves to low-end 1 time.The extreme damage radius of the Ms≥6.0 earthquakes is about 60 km.The seismic design of recovery and reconstruction work should consider the terrain factors of increasing typical mountainous area engineering or building seismic fortification standards( peak ground acceleration( 50%).
Using the records of 10 mobile strong motions from Sichuan Qingchuan aftershock on May 25,2008,the strong vibration free field,acceleration attenuation effect field and near field acceleration spectrum in south of Gansu are analyzed.According to the strong vibration flow units in the background based on the actual observation data,and compared with the observed value of the bedrock of the cave stations,free field acceleration is larger 4 ～ 5 times than the bedrock of the background,the dominant frequency moves to low-end 1 time.The extreme damage radius of the Ms≥6.0 earthquakes is about 60 km.The seismic design of recovery and reconstruction work should consider the terrain factors of increasing typical mountainous area engineering or building seismic fortification standards( peak ground acceleration( 50%).
引文
[1]刘旭宙,姚凯.汶川8级地震甘肃强震动记录及初步分析[J].西北地震学报,2008,30(3):266-269.
[2]孙崇绍.陇南山区局部地形对地震动强度的影响[J].西北地震学报,2011,33(4):331-335.
[2]孙崇绍.陇南山区局部地形对地震动强度的影响[J].西北地震学报,2011,33(4):331-335.
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