大跨度特殊延性桁架式框架抗震性能分析  

Analysis on seismic performance of large-span special truss moment frame

作　　者：马敬友[1] 周冰 张晧 张建亮[1] MA Jingyou;ZHOU Bing;ZHANG Hao;ZHANG Jianliang(Beijing Institute of Architectural Design,Beijing 100045,China)

机构地区：[1]北京市建筑设计研究院有限公司,北京100045

出　　处：《建筑结构》2022年第2期92-97,70,共7页Building Structure

摘　　要：特殊延性桁架式框架(STMF)是美国规范采纳的一种高延性钢结构体系。首先分析其在国内鲜有应用的限制因素,推导出考虑轴力及次弯矩影响的消能段极限抗剪承载力,然后根据预设性能目标、极限状态下非消能段满足弹性验算的要求推导消能段长度L;选取的有效范围,最后根据我国抗震设计准则,对大跨度STMF案例进行弹性设计及静力推覆分析,探讨STMF体系应用于国内工程的设计方法,论证现有研究成果在超大跨度(L>20m)工程中的适用性。研究结果表明:根据推导结果可以快速确定合理的消能段长度,实现极限状态下塑性变形集中在消能段,而非消能段桁架和框架柱仍处于弹性状态的设计理念;美国规范规定消能段范围不得有显著竖向荷载布置、跨度L≤20m、上下弦应取相同截面,充分考虑消能段弦杆承受的轴力及次弯矩影响时,STMF结构可以适当突破上述限制,且其抗震性能依旧良好。Special truss moment frame(STMF) is a high ductility steel structural system adopted by norms of the United States. Firstly, by analyzing the factors limiting the use of STMF in China, the ultimate shear capacity of energy dissipation section was deduced considering the influence of axial force and secondary bending moment. Then, the effective range of selected length of energy dissipation section L;was deduced based on the preset performance targets and the elastic checking calculation requirement of non-energy dissipation section under limit state. Finally, according to the seismic design criteria of China, the elastic design and static push-over analysis of large-span STMF cases were carried out. The design methods of STMF system for domestic projects were discussed. The applicability of existing research results in large-long span(L > 20 m) projects was demonstrated. Research results show that the reasonable length of energy dissipation section can be determined quickly according to deduced the results to realize the design concept that plastic deformation is concentrated in the energy dissipating section in the limit state while the non-energy dissipating section truss and frame columns are still in an elastic state;norms of the United States stipulate that the range of energy dissipation section should not have the arrangement of obvious vertical load, the span L ≤ 20 m, and the upper and lower chords should have the same cross section. When the axial force and secondary bending moment of the chord in the energy dissipation section are fully considered, the STMF structure can appropriately break through the above limitations, and its seismic performance is still good.

关 键 词：特殊延性桁架式框架 空腹式消能段 抗震性能 极限抗剪承载力 

分 类 号：TU318[建筑科学—结构工程]