Analysis Of Seismic Behaviour Of Super High-rise Steel Frame With Buckling-restrained Braces

With the improvement of our country’s economy level, the innovation of structure design technology,and the vigorous development of commercial real estate, besides, the requirement of building height from pcoplc,it result that high-rise building were widely spread.High-rise buildings has advantages of high land utilization,large volume rate,wide-range in application and so on. The steel structure has the advantage of light dead weight, high strength, short construction period, energy conservation and environmental protection and so on. High-rise steel structure system can take good use of the advantages of the two,but its maximum height is limited by type of fortification intensity and structure, the reason is that the structure’s dynamic response is too big under the action of strong earthquake, it easy cause structural damage or even collapse. So set up support is an effective measures to improve the lateral stiffness in the steel structure framework.This article is taking a proposed super-tall steel frame structure in kunming(structure body main height is 206.4 m) as research background, it put forward the supporting scheme for the structure to solve the security hidden danger,and to improve the structural lateral stiffness and seismic performance,its to meet the requirements of building height and the safety of the structure.Establishing dirrerent kinds of unbraced structure,two different common support arrangement of structure and Buckling-restrained Braces structure model, making modal analysis for four kinds of structure;Then making spectrum analysis for no support structure and the common support structure and Buckling-restrained Braces structure. As well as making the elastic time history analysis under the action of the frequent earthquake;Finally making elastic-plastic time-history analysis with common support structure and the Buckling-restrained Braces structure under under the action of strong earthquake.Taking comparison with analysis results:,we can know that common support structure with Layout symmetry, span is moderate,closed and continuous V common support structure’s dynamic performance and the damping effect is better, It shows that Optimize the layout is more effective to improve the lateral stiffness of the structure;Structure under the elastic stage, the support structure’s seismic response decreased obviously,and absorbing ability were improved remarkably, the reason is that support provides a larger lateral stiffness to the structure, but there is less difference between common support structure and Buckling-restrained Braces structure, both of them is provide additional lateral stiffness to structure;when structure under elastic-plastic phase, Buckling-restrained Braces structure taking the obvious advantage of hysteretic energy dissipation, its seismic response decreased significantly, its seismic performance is greatly ascend, and its seismic response values (interlayer displacement Angle, etc.) to be able to meet the specification requirements,it can guarantee the safety of structure.