摘要
针对近断层区结构抗震设计缺乏专门竖向抗震设计谱的现状,以近断层竖向地震动为研究对象,基于《建筑抗震设计规范》,开展近断层区竖向抗震设计谱的研究。选取198条近断层脉冲型地震动的竖向分量,分析得到实际近断层地震动竖向反应谱,将计算得到的反应谱与中国抗震规范中的近断层竖向设计谱进行了对比。研究结果表明,中国抗震规范未充分考虑近断层竖向地震动的特点,表现为部分周期段上规范设计谱的谱值小于实际近断层竖向地震动反应谱,难以保证近断层区结构具有足够的抗震安全性。根据近断层竖向地震动的分析结果,基于中国抗震规范设计谱的基本形式,提出了谱值放大系数取1.5、特征周期下限取0.40 s(多遇地震)和0.45 s(罕遇地震)及减小曲线下降段衰减系数的修正方法。该竖向抗震设计谱工程应用简便,可为近断层区的结构竖向抗震设计提供参考。
Due to the lack of vertical seismic design spectra for the structural design in near-fault regions,the near-fault vertical seismic design spectra are studied,which took the near-fault vertical ground motions as the research object and the format is compatible to the code for the building seismic design in China.The vertical components of 198 near-fault pulse-like ground motions are used to develop the near-fault response spectra.Results given by the comparison of the near-fault response spectra and code-specific near-fault design spectra in China show that the effects of near-fault vertical ground motion are not fully considered in Chinese seismic design code.What the amplitudes of the code-specific near-fault design spectra are smaller than that of the response one in some periods leads to difficulties in the safety of structures in near-fault regions.According to the results,a reasonable near-fault vertical seismic design spectrum,based on the code-specific seismic design spectra in China,is proposed with a spectral amplitude amplification coefficient of 1.5,restricted characteristic periods to no less than 0.40 s for frequent earthquake and 0.45 s for rare earthquake and a decreased attenuation coefficient.The proposed seismic design spectra are useful for the design of structures in near-fault regions.
作者
潘毅
包韵雷
刘永鑫
李爽
PAN Yi;BAO Yun-lei;LIU Yong-xin;LI Shuang(School of Civil Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Key Laboratory of Seismic Engineering of Sichuan Province,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Key Laboratory of Structure Dynamic Behavior and Control of the Ministry of Education,Harbin Institute of Technology,Harbin,Heilongjiang 150090,China)
出处
《工程力学》
EI
CSCD
北大核心
2021年第12期183-190,共8页
Engineering Mechanics
基金
国家自然科学基金项目(51878559)
科技部资助项目(KY201801005)。
关键词
近断层地震动
竖向抗震设计谱
谱值放大系数
特征周期
衰减系数
near-fault ground motion
vertical seismic design spectra
amplitude amplification coefficient
characteristic period
attenuation coefficient
