摘要
强震下结构会进入弹塑性,现行规范给出的层剪力分布无法反映结构非弹性状态下的响应。基于性态的抗震设计方法需要预知结构弹塑性状态下的层剪力分布。介绍了现有的层剪力分布模式;给出了6个V形偏心支撑钢框架(VEBF)算例的基本信息及所选近场地震动记录;对6个算例结构进行了近场罕遇地震下的弹塑性时程分析,得到了各结构的层剪力分布;提出了近场罕遇地震下VEBF结构弹塑性层剪力分布模式;与时程分析结果对比表明所提出的模式有较好的精度,可为基于性态的抗震设计方法提供参考。
Structures will get into plastic state under strong earthquakes.However,the story shear distribution given by current seismic code is derived from elastic analysis and cannot reflect the inelastic behavior of structures.Firstly,the importance of story shear distribution under inelastic state in the performance-based seismic design is emphasized.Then the story shear distributions proposed previously are briefly described and information of six V-shaped eccentrically braced steel frames(VEBF)and the near-fault ground motions records with velocity pulse are introduced.Using nonlinear time-history analyses,the story shear distribution of six VEBFs under near-fault severe earthquakes are obtained.Based on the calculated results from nonlinear time-history analyses,a new story shear distribution pattern is proposed.The comparison between the proposed pattern and the nonlinear dynamic analysis results shows the proposed distribution pattern has reasonable accuracy which may provide some suggestions for the performance-based seismic design.
引文
[1]蒋建.基于性能抗震设计方法与基于承载力抗震设计方法比较研究[J].结构工程师,2008,24(4):52-57Jiang Jian.Comparative study on performance-based seismic design method and bearing capacity-based design method[J].Structural Engineers,2008,24(4):52-57(in Chinese)
[2]孙国华,顾强,何若全,等.钢框架钢板剪力墙结构弹塑性状态的层剪力分布研究[J].工程力学,2013,30(7):113-121Sun Guohua,Gu Qiang,He Ruoquan,et al.Distribution of horizontal seismic shear based on inelastic state of steel plate shear walls[J].Engineering Mechanics,2013,30(7):113-121(in Chinese)
[3]GB 50011—2010建筑抗震设计规范[S].北京:中国建筑工业出版社,2010GB 50011—2010Code for Seismic Design of Buildings[S].Beijing:China Architecture&Building Press,2010(in Chinese)
[4]Recommended lateral force requirements and commentary[R].California:Seismology Committee Structural Engineers Association of California,1996
[5]Uniform Building Code[S].USA:Thomson Learning,1997
[6]Eurocode 8:Design of Structures for Earthquake Resistance(Part 1:General Rules,Seismic Actions and Rules for Building)[S].Brussels:European Committee for Standardization,2003
[7]Shih-Ho Chao.Performance-based seismic design of EBF using target drift and yield mechanism as performance criteria[R].UMCEE 05-05.Ann Arbor:University of Michigan College of Engineering,2005:25-26
[8]GB 50017—2003钢结构设计规范[S].北京:中国计划出版社,2003GB 50017—2003 Code for Steel Structural Design[S].Beijing:China Planning Press,2003(in Chinese)
[9]李爽,谢礼立.近场问题的研究现状与发展方向[J].地震学报,2007,29(1):102-111Li Shuang,Xie Lili.Progress and tend on near-field problems in civil engineering[J].Acta Seismologica Sinica,2007,29(1):102-111(in Chinese)
[10]韦韬,赵凤新,张郁山.近断层速度脉冲的地震动特性研究[J].地震学报,2006,28(6):629-637Wei Tao,Zhao Fengxin,Zhang Yushan.Study on the characteristics of near fault pulse velocity pulse ground motions[J].Acta Seismologica Sinica,2006,28(6):629-637(in Chinese)
[11]高学奎.近场地震动输入问题的研究[J].华北科技学院学报,2005,2(3):80-83Gao Xuekui.Study on selecting inputting wave for seismic response analysis excited by near-fault earthquakes[J].Journal of North China Institute of Science and Technology,2005,2(3):80-83(in Chinese)
[12]刘衍军,顾强.V形偏心支撑钢框架滞回能需求层间分布[J].建筑钢结构进展,2014,16(2):23-31Liu Yanjun,Gu Qiang.Hysteresis energy demand inter-story distribution of V-type eccentrically braced steel frames[J].Progress in Steel Building Structures,2014,16(2):23-31(in Chinese)