The Structure System Optimization Of A Super High-rise Building

The super high-rise building is a 330 meter tall 75-story office building located in Tianjin, China. The main lateral force resisting system for the tower consists of a frame-shear wall system comprised of a perimeter ductile moment-resisting frame and an interior shear wall core linked together with outrigger and belt trusses. The application of Steel Plate Shear walls (SPSW) in high-rise buildings is rare in our country and China standard has not stipulated the height limit of this system. But a number of researches at home and abroad have shown SPSW with excellent performance. Based on this project, this paper established five different analysis models and compared each system's performance and economic effect. The main research contents and the results are as follows:Frist, the five models are established by ETABS based on this super high-rise building. They are SPSWs system, Hybrid structureⅠ, Hybrid structureⅡ, Concrete-filled steel tube column frame-support model and Spiral support-tube structure. In order to facilitate a more accurate analysis, structural members in the model have the geometries matched the structural drawings. Load combinations include all principle directions of earthquake and wind with all applicable load-case combinations per the china code.Second, run elastic analysis got related performance index. Such as Vibration model, Displacement of structure, Shear/Gravity Ratios, Frame Shear Ratios, Building Torsion Check, Story Stiffness. The results show that the model elastic properties can meet the relevant code specification.Third, with the compare of each model's performance and economic effect under the action of 7 degrees earthquake, some conclusions can be drawn, as the following: (1) SPSWs have a superior performance, its elastic stiffness is much higher than a brace structure, and they are much lighter compared to reinforced concrete shear walls;(2)the stiffness of the overall structure can be effectively increased by adding a large steel braces on the outer frame; (3)It's not suitable to use a single steel frame-support structure system in super high-rise building; (4) Spiral support-tube structure has good bearing ability and resisting lateral performance.