地震动场地放大效应的时频特性分析

发布时间：2018-03-15 05:31

本文选题：复杂非均质场地　切入点：放大效应　出处：《岩土力学》2017年03期 　论文类型：期刊论文

【摘要】：为了详细研究均质及复杂非均质场地中地震动的放大效应,通过大型振动台试验获得原始试验数据,再采用傅立叶变换、时频分析与分段时频分析相结合的手段,对试验数据进行分析和处理。通过对试验结果的对比分析,发现当地震动沿竖直方向传播时,不仅地震动时程曲线的峰值会随场地高度的增加而逐步放大,其频率成分含量、主频段的频谱形状,以及整体地震动能量在时频平面上的分布,均会随着场地高度及各分层介质的不同而发生较大变化。与此同时,场地表面的倾斜程度、软弱夹层的厚度等因素也均对地震动的放大效应具有显著影响。通过以上研究,得到了一系列与地震动竖向传播放大效应相关的研究规律(包括PGA峰值特性、频谱特性、时频面上能量谱的分布特性等)。
[Abstract]:In order to study the amplification effect of ground motion in homogeneous and complex heterogeneous sites in detail, the original test data were obtained by large-scale shaking table test, and then the Fourier transform, time-frequency analysis and segmented time-frequency analysis were combined. Through the comparison and analysis of the test results, it is found that when the local vibration propagates along the vertical direction, not only the peak value of the time-history curve of the ground motion will be enlarged gradually with the increase of the height of the site, but also the frequency component content. The frequency spectrum shape of the main frequency band and the distribution of the whole ground motion energy in the time-frequency plane will vary greatly with the height of the site and the different layers of media. At the same time, the slope degree of the site surface, The thickness of weak intercalation also has a significant effect on the amplification effect of ground motion. Based on the above studies, a series of laws related to the vertical propagation and amplification of ground motion are obtained, including the peak value of PGA, the spectrum characteristics, and so on. The distribution characteristics of energy spectrum on time-frequency surface.
【作者单位】：四川省建筑科学研究院;西南交通大学土木工程学院;中国电建集团华东勘测设计研究院有限公司;
【基金】：国防基础科研计划(No.B0220133003) 中国水电顾问集团公司重大科技项目(No.GW-KJ-2011-18) supported by the National Defense Basic Scientific Research Program(B0220133003) the Major Science and Technology Project of China Hydropower Consulting Group(GW-KJ-2011-18)
【分类号】：P315.9

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