基于移动平均分解的近断层地震动弹性反应谱研究-《郑州大学学报(工学版)》

文章信息/Info

Title:: Study on Elastie Response of Structures to Near.fault GroundMotions Through Record Decomposition

作者:: 赵志航; 车伟; 冯群.; 中国地质大学(北京)工程技术学院,北京,100083, 中国地质大学(北京)工程技术学院,北京,100083, 中国地质大学(北京)工程技术学院,北京,100083

Author(s):: ZHAO Zhihang; CHE Wei; FENG Qun; School of Engineering & Technology , China University of Geosciences, Beijing 100083 , China

Keywords:: near-fault ground motion; low-frequency pulse ; high-frequency component; moving average filter; elastic response spectra

摘要:: 抗震设计规范中的设计反应谱是通过对大量的中、远场地震记录统计回归分析的结果,而近场地震记录因观测资料缺乏,导致对近场地震动的频谱特性考虑不够.近断层地震动有一些显著区别于远场地震动的特点,其中之一就是近断层地震动包含高频部分和低频脉冲部分.采用一种移动平均滤波器将近断层地震动分解为低频脉冲部分和高频部分,并采用这个方法分解了一些近断层地震动记录,同时研究了近断层地震动弹性反应谱的特性.结果表明,对于单脉冲记录,采用脉冲部分基本可以代表采用原始记录对结构的响应;对于多脉冲记录,因存在一个或多个次高峰,其脉冲部分不能有效代表原始记录对结构的响应,若仅考虑脉冲部分而忽略高频部分将对短周期结构相当不利.

Abstract:: The design response spectrum in seismic design code is the result of a large number of midfield andfar-field seismic records statistical regression analysis. As a result of the lack of observation data , the percent olnear-field seismie records is small , which lcads to the insufficient consideration of the frequency spectrumcharacteristic of near field ground motions. Near-fault ground motions have some important characteristie thatmake them different from far-fault ground motions. High-frequency components and low-frequency pulses ofnear-fault ground motions are among notable specifications. In this paper, a moving average filtering has beerdesigned to decompose the near-fault ground molions into two components having different frequeney contents:low-frequency pulses component and high-frequency component, The method is applied to decompose a few selected near-fault records and the elastie response of structure is examined through their response to the decomposed parts. The results emphasizes that for single pulse record the pulse component can effectively representhe response of the structure under the original records . But for multi-pulse record, owing to the existence ofone or more peaks, the pulse component can not efectively represent the structure response under the originalrecords, The sole consideration of the pulse component and ignoring the high frequency component is very badfor short cycle structure.