(1 北京市建筑设计研究院有限公司， 北京 100045； 2 北京建筑大学土木与交通工程学院， 北京 100044)

［摘要］位于8度区某高度为280m超高层钢结构采用内外筒方钢管混凝土框架-中心钢支撑（部分防屈曲支撑BRB）-伸臂桁架-环带桁架结构体系，共设置了863根普通钢支撑，并在结构底部加强区部分斜撑处和伸臂桁架腹杆处一共设置了104根防屈曲支撑。通过有限元法对普通钢支撑拉压不对称进行分析模拟。结果表明初始几何缺陷对普通钢支撑轴力的影响较大，长细比越大受压承载力下降越显著。采用ABAQUS对该结构进行了动力弹塑性时程分析，对结构在罕遇地震作用下的抗震性能进行了论证分析。结果表明，该结构满足"大震不倒"的抗震设防目标。

［关键词］防屈曲支撑；伸臂桁架；超高层结构；钢结构；抗震性能

中图分类号：TU973-31文献标识码：A文章编号：1002-848X(2021)08-0037-06

Analysis on seismic performance of a super high-rise steel structure with outriggers using BRBs

CHEN Xi1, GE Dongdong1, SU Yukun1, XIE Linlin2, WU Lianhong1, LI Wenfeng1, MIAO Qisong1

(1 Beijing Institute of Architectural Design, Beijing 100045, China; 2 School of Civil and Transportation Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, China)

Abstract:A super high-rise steel structure with a height of 280m located in the 8-degree seismic fortification area adopts the structural system of concrete-filled steel tube frame with inner and outer tubes-central steel braces (including some bucking restrained braces(BRB) )-outriggers-ring belt trusses. A total of 863 ordinary steel braces are arranged, and a total of 104 BRBs are set up at the part of the diagonal braces in the reinforcement area at the bottom of the structure and the web members of the outriggers. Tension-compression asymmetry of common steel braces were simulated through finite element method. The results show that initial geometric imperfection has a greater influence impact on the axial force of common steel braces, and the greater the slenderness ratio, the more significant the reduction in compressive bearing capacity. ABAQUS software was used to conduct dynamic elastoplastic time-history analysis of the structure, and the seismic performance of the structure was demonstrated and analyzed under the action of rare earthquakes. The results show that the structure satisfies the seismic fortification goal of “not falling under the rare earthquake”.

Keywords:buckling restrained brace;outrigger;super high-rise structure;steel structure;seismic performance

*国家自然科学基金项目(51808029)。

作者简介：閤东东，博士，教授级高级工程师，一级注册结构工程师，Email：gddhust@163.com。