作　　者： ; ;

机构地区： 中国海洋大学工程学院

出　　处： 《地震学报》 2007年第5期512-520,共9页

摘　　要： 具有向前方向性效应特征的地震动与普通远场地震动存在明显差异.作者曾尝试结合简单脉冲和近断层地震动参数衰减关系提出此类地震动的设计谱模型.为进一步检验所提出设计谱的适用性,分析了53条典型近断层方向性效应地震动的伪速度谱、规准伪速度谱和双规准伪速度谱,发现方向性效应地震动的双规准伪速度谱在土层和岩石场地上具有差别明显,且离散性小的特点.考虑场地条件的影响,基于双规准伪速度谱预测了近断层方向性效应地震动的设计谱,并与此前的研究结果进行了对比.结果表明,场地条件对于近断层方向性效应地震动影响显著;位于近断层岩石场地的建筑结构,尤其是中、短振动周期结构,可能比土层场地更易于遭受破坏.最后,提出了用于近断层结构抗震分析的简单脉冲模型的建议. Ground motions with forward-directivity effect in the near-fault region are obviously different from ordinary far-field ground motions. Design spectral models for this kind of motions have been proposed by correlating simple pulses with parameters attenuation relationships in a previous study of the authors. To further test the applicability of the established design spectral model, we analyze ground motion pseudo-velocity response spectra （PVS）, normalized pseudo-velocity spectra （NPVS） and hi-normalized pseudo-velocity spectra （BNPVS） of 53 typical near-fault forward-directivity ground motions. It is found that BNPVS not only has more salient features to reflect the difference between soil and rock sites, but also has less scattering to reveal the nature of forward-directivity motions. And then, BNPVS is used for prediction of design spectra accounting for the influence of site conditions, and the constructed design spectra are compared with those spectra established previously. It is concluded that site condition can heavily affect ground motions, buildings on rock can be even more dangerous than those on soil sites, in particular for ordinary buildings with short to middle vibration periods. Finally, pulse models are also suggested for structural analyses in the near-fault region.

关 键 词： 近断层作用 方向性效应 脉冲 伪速度谱 设计谱

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