近场数字强震仪记录误差分析与零线校正方法  

Baseline correction of digital strong-motion records in near-field

作　　者：于海英[1] 江汶乡[1] 解全才[1] 杨永强[1] 程翔[1] 杨剑[1] 

机构地区：[1]中国地震局工程力学研究所,黑龙江哈尔滨150080

出　　处：《地震工程与工程振动》2009年第6期1-12,共12页Earthquake Engineering and Engineering Dynamics

基　　金：中国地震局公益性行业科研专项(200708010)

摘　　要：本文对数字强震仪记录进行了误差分析,并对国家强震动台网入网的5种型号数字强震仪系统作了振动台对比试验,分析了该系统加速度记录积分后速度和位移时程零线漂移的原因。本文提出了加速度记录的零线漂移校正方法和校正准则。为了印证零线校正方法的可靠性,对振动台试验中强震仪记录到的加速度两次积分得出位移时程与试验时记录到的绝对位移进行比较,计算位移和振动台绝对位移完全一致;对2008年5.12汶川8.0级大地震和1999年台湾9.21集集7.6级地震现场加速度记录两次积分后得出永久位移与两次大地震的GPS同震位移进行比较。结果表明,该方法对大地震近场仪器墩会发生倾斜或产生永久位移时加速度记录的零线校正有明显效果,可以给出加速度积分后的速度和位移并符合校正准则。本文方法解决了对大地震近场地面运动的研究停留在对峰值加速度和反应谱的研究阶段的困惑,满足了结构抗震对地面永久位移的需求。This paper analyzes the system error in digital strong-motion acceleration.In order to uncover the reason of baseline drifting of velocity and displacement integrated from acceleration,a shaking-table experiment was conducted.All the five kinds of accelerographs deployed in China Strong-Motion Networks were taken on the table,and the records were compared.This paper proposes a method of correcting the acceleration records.We compare the displacement integrated from corrected acceleration with the displacement directly measured in the shaking-table experiment.The results verify the credibility of the proposed method.And we compare the displacements integrated from acceleration records in Wenchuan（2008,Ms 8.0） and Chi Chi（1999,Ms 7.6） earthquakes with co-seismic displacements of the corresponding GPS stations.The GPS displacement and displacement integrated from corrected acceleration are identical in direction and value.All the results indicate that the proposed method has ideal effect on records from accelerographs with tilted platform in near-field.This paper not only studies the peak acceleration and the response spectrum of the near-field movement,but also meets the needs of getting the permanent displacements for the earthquake resistance of struetures.

关 键 词：数字强震仪 近场加速度记录 零线校正 永久位移 

分 类 号：P315.916[天文地球—地震学]