Study And Optimazation On The Structural Scheme Selection Of Ultra High-rise Building

The height or regularity are beyond the Code requirements in a ultra high-risebuilding,so performance on the structure nust be specially analyzed to make sure reliabilityand security of the ultra high-rise structure. In particular, the reasonable selection of schemeand optimization of the structure is extremely important to the structural safety and overallcost-effect of whole building.An ultra high-rise building located in the northern suburb of Xi’an city was taken as theresearch background.The problems about scheme selection of the ultra high-rise buildingstructure were mainly researched. And then, the seismic performance of three structuralschemes were analyzed. Also, the preferred frame-core tube structure system with concretefilled steel tubular columns was optimized.The main contents and conclusions are as follows:Firstly, using the software SAP2000to finite element modeling of the reinforcedconcrete columns frame-core tube structure, steel reinforced concrete columns frame-coretube structure and concrete filled steel tubular columns frame-core tube structure andcomparative modal analysis respectively. The lateral displacement of the three structuresunder the action of wind load and earthquake were respectively calculated and compared.Theresults showthat the lateral deformation of the frame-core tube structure with the concretefilled steel tubular columns is minimal, while the lateral deformation of the frame-core tubestructure with the reinforced concrete columns is greatest.Then,elastic time-history analysisand elastoplastic time-history analysis of reinforced concrete frame-core tube structure wereconducted by inputing El-Centro wave,Taft wave and one artificial fitting seismic wave.Results showed that although the deformation of the frame-core tube structure usedreinforced concrete columns structure meet seismic code requirements, the deformation wassignificantly larger than other schemes, the structure also has weak underpinnings in partiallayer.Then, Pushover analysis of the three frame-core tube structures were carried out, thestory drift angle value of the three structures under the action of frequent earthquake and rare earthquake were obtained respectively. Through the comparative analysis found that: thelateral deformation of the frame-core tube structure used reinforced concrete columns isgreatest, there are obvious weak links, the lateral deformation of the frame-core tubestructure used steel reinforced concrete is among the three structural schemes and the lateraldeformation of the frame-core tube structure used concrete filled steel tubular columns isminimal, its seismic performance is optimum.Finally, the adoption of the preferred frame-core tube structure used concrete filled steeltubular columns was optimization studied by concept of performance-based seismic design, tooptimize the design of frame-core tube structure used CFST columns and the elastic-plasticdeformation of optimized structure was also checked by static and dynamic analysis softwareEPDA&PUSH, the results showed that the optimized structure could reduce cross-sectionaldimension significantly, cost reduction and good seismic performance, meet the goals ofstructural performance design.The results of this study could not only provide important theoretical basis for thestructural design of this ultra high-rise building structure, but also be useful reference for thescheme of similar ultra high-rise building structure.