武莲霞^1,2，  余志伟²，  孙飞飞¹
    （1 同济大学，上海 200092；2 华东建筑设计研究院有限公司，上海 200002）

[摘要] 在高层和超高层建筑结构中，设置带伸臂桁架的加强层是减少结果侧移的有效方法，但在地震作用下，普通支撑受失稳限制，截面刚度往往很大，这时加强层的设置将会引起结构刚度、内力突变，并易形成薄弱层，结构的损坏机理难以呈现延性屈服机制。本文针对某工程实例探讨屈曲约束支撑( BRB)在带伸臂高层建筑结构中的应用，对普通支撑方案和耗能型BRB方案在多遇地震和罕遇地震下的结构性能进行了分析和比较，并尝试引入承载型BRB，使之与耗能型BRB在伸臂中混合布置，将混合布置方案与前两种方案结构性能进行了分析和对比。结果证明：BRB不受失稳影响，截面选择上更加灵活，调节加强层刚度更容易达到希望的性能目标，并且在罕遇地震作用下，起到消能减震的作用；根据结构性能目标的设定，耗能型BRB和承载型BRB混合使用，可以使结构刚度分布更加合理，解决结构的扭转问题。
[关键词] 伸臂；屈曲约束支撑；耗能型BRB；承载型BRB
中图分类号：TU971    文献标识码：A  文章编号：1002-848X(2011) Sl-0120-05

Application of buckling restrained braces in ahigh-rise structure with outriggers
Wu Lianxia^1,2, Yu zhiwei²,  Sun Feifei¹
(1 Tongji University, Shanghai 200092, China; 2 East China Architectural Design & Research Institute Co., Ltd., Shanghai 200002, China)

Abstract: Outrigger truss is an effective way to reduce the lateral displacement in high-rise and super high-rise structures. However extremely large axial stiffness of ordinary steel braces in the outngger truss would lead to sharp change in story stiffness and internal force, which would result in weak story and make it difficult to realize ductile yield mechanism subjected to seismic loads. This paper aims at the application of buckling restrained braces in a high-rise structure with outriggers. The structural behavior of a structural design with ordinary braces and another one with energy dissipative BRB under frequent earthquake and rare earthquake is compared, then a design mixed with load bearing BRB and energy dissipation BRB  (the mixed case) is further conceived. Analytical results indicated that: it is easier to satisfy the performance objectives by adjusting the stiffness distribution with BRB which could yield and get energy dissipated under rare earthquake; the mix arrangement of energy dissipative BRB and load bearing BRB can get more reasonable stiffness distribution and hence avoid
torsion of the whole structure.
Keywords: outriggers; buckling restrained brace; energy dissipative BRB; load bearing BRB