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武蓮霞1,2， 余志偉2， 孫飛飛1
（1 同濟大學(xué)，上海 200092；2 華東建筑設(shè)計研究院有限公司，上海 200002）[摘要] 在高層和超高層建筑結(jié)構(gòu)中，設(shè)置帶伸臂桁架的加強層是減少結(jié)果側(cè)移的有效方法，但在地震作用下，普通支撐受失穩(wěn)限制，截面剛度往往很大，這時加強層的設(shè)置將會引起結(jié)構(gòu)剛度、內(nèi)力突變，并易形成薄弱層，結(jié)構(gòu)的損壞機理難以呈現(xiàn)延性屈服機制。本文針對某工程實例探討屈曲約束支撐( BRB)在帶伸臂高層建筑結(jié)構(gòu)中的應(yīng)用，對普通支撐方案和耗能型BRB方案在多遇地震和罕遇地震下的結(jié)構(gòu)性能進行了分析和比較，并嘗試引入承載型BRB，使之與耗能型BRB在伸臂中混合布置，將混合布置方案與前兩種方案結(jié)構(gòu)性能進行了分析和對比。結(jié)果證明：BRB不受失穩(wěn)影響，截面選擇上更加靈活，調(diào)節(jié)加強層剛度更容易達到希望的性能目標(biāo)，并且在罕遇地震作用下，起到消能減震的作用；根據(jù)結(jié)構(gòu)性能目標(biāo)的設(shè)定，耗能型BRB和承載型BRB混合使用，可以使結(jié)構(gòu)剛度分布更加合理，解決結(jié)構(gòu)的扭轉(zhuǎn)問題。
[關(guān)鍵詞] 伸臂；屈曲約束支撐；耗能型BRB；承載型BRB
中圖分類號：TU971 文獻標(biāo)識碼：A 文章編號：1002-848X(2011) Sl-0120-05Application of buckling restrained braces in ahigh-rise structure with outriggers
Wu Lianxia1,2, 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
