芯筒-刚臂结构体系地震损伤分析研究

Seismic Damage Analysis on Core-Outrigger Structures

芯筒-刚臂结构广泛应用于超高层建筑设计中,但由于其刚臂设置引起的刚度突变容易造成刚臂及附近所在楼层在地震作用下发生破坏。目前,被动耗能减震技术日趋成熟,其中屈曲约束支撑(简称BRB)在高层建筑中应用最为广泛。将BRB设置于刚臂和外柱连接处,作为屈曲约束柱(简称BRC),提出新的芯筒-刚臂结构减震体系(BRC between the outrigger and exterior columns of COS,简称BRCC-COS减震结构体系),并基于抗震性能设计方法完成BRC的设计。针对芯筒-刚臂结构的平面简化模型,利用弹塑性时程分析方法研究其在地震作用下的结构特性。最后,根据不同的地震损伤模型评估研究该减震结构体系的地震损伤程度,研究分析表明,该减震结构体系能够降低由于刚臂设置引起的附近楼层和核心筒在地震下的损伤程度,并为该类结构的耗能减震设计提供可靠的理论依据。

Core-outrigger structure(COS)has been widely applied in the design of super high-rise building.However,there is a concern on large variation of the vertical stiffness caused by outrigger and this might lead to severe damage to the neighboring stories under earthquake.Passive energy dissipation technology has become increasingly sophisticated in recent years,one of which was the buckling-restrained brace(BRB)technology and was also comprehensively used in the high-rise building.In this study,a new energy dissipating plan utilizing buckling restrained brace as columns(BRC) at the location where the outrigger and exterior columns connect,is adopted in core-outrigger structures,hereafter referred to as BRCC-COS,and the design of BRCs was completed using performance-based seismic design.Elastoplastic time-history analysis was applied to evaluate the seismic performance of a simplified 2D model of COS,and a few seismic damage evaluation models were used to estimate the seismic damage on buildings.The analysis results indicate that the proposed new structural system BRCC-COS can reduce the damage levels in earthquake,and this provides theoretical basis on the design of COSs.