徐国林, 陈龙伟. 2019: 液化场地强震记录的频谱特征. 地震学报, 41(5): 671-679. DOI: 10.11939/jass.20190112
引用本文: 徐国林, 陈龙伟. 2019: 液化场地强震记录的频谱特征. 地震学报, 41(5): 671-679. DOI: 10.11939/jass.20190112
Xu Guolin, Chen Longwei. 2019: Frequency spectra characteristics of strong-motion acceleration recordings at liquefied sites. Acta Seismologica Sinica, 41(5): 671-679. DOI: 10.11939/jass.20190112
Citation: Xu Guolin, Chen Longwei. 2019: Frequency spectra characteristics of strong-motion acceleration recordings at liquefied sites. Acta Seismologica Sinica, 41(5): 671-679. DOI: 10.11939/jass.20190112

液化场地强震记录的频谱特征

Frequency spectra characteristics of strong-motion acceleration recordings at liquefied sites

  • 摘要: 为研究液化场地上建筑物承受地震作用的特性,本文利用11组液化场地实测记录,对液化场地的地震动特征进行了分析。结果显示,场地液化后,地表加速度幅值减小,长周期成分显著增多,记录中出现明显的 “尖刺” 。对比国内外抗震规范设计反应谱与液化场地实测加速度反应谱,分析得出:在短周期T<0.3 s,规范设计反应谱值与实测记录反应谱基本一致;在中长周期段0.3 s<T<1.5 s,规范反应谱值明显低于实测记录反应谱值;在长周期段T>1.5 s,规范设计谱较实测记录反应谱值略低。基于5种数值方法模拟的液化场地地震动结果显示:周期T<1.0 s时,数值计算的反应谱值基本高于液化场地实测反应谱值,或与之吻合;而周期T>1.0 s时,数值计算的反应谱值均低于液化场地实测反应谱值。

     

    Abstract: To understand the characteristics of earthquake action on buildings at potentially lique-fiable sites, 11 acceleration records from the selected liquefied sites were analyzed to discuss the characteristics of ground motion. The results showed that the acceleration amplitudes were remarkably reduced after initial site liquefaction and that the long-period components increased significantly with apparent " spikes” recorded. Comparison of the design spectra widely used in seismic design codes, both domestically and internationally, with the acceleration spectra obtained in this study shows that: in the short period range T<0.3 s, the design spectra were consistent with the recorded response spectra; in the medium and long period range 0.3 s<T<1.5 s, the design spectra were smaller significantly than the recorded response spectra; in the long period range T>1.5 s, the design spectra was a little smaller than the recorded spectra. Five typical numerical methods are used to simulate liquefaction acceleration, the results demonstrated that the numerical methods could satisfactorily predict response spectral values for the period range T<1.0 s, but generally lower than the spectral values for the long-period T>1.0 s.

     

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