Research On Seismic Performance Of Steel Frame-concrete Core Structures With Huge-columns

The modeling of hybrid steel-concrete structure widely used in tall building at present in china comprises external steel frames and core concrete tube, for it carries both the merits of steel structure and concrete structure. But there is a main contradiction on the seismic performance of this structure system: whether it is a dual seismic resistant system or not. It is necessary to further investigate the seismic behavior of the structure for most parts of our country are in seismic zone.In this paper, steel frame-concrete core structure system is researched, because steel frame-concrete core .structure with core concrete tube absence of stiffness and ductility, having intensity more than needed, but external steel frames absence of intensity, having stiffness and ductility more than needed. For this reason, on rarely seen earthquake, some people feel anxious that concrete core tube because of bearing most part of earthquake load is firstly destroyed, after that steel frame because of absence of stiffness leads to excessively deform and rapidly wrecks. And steel-concrete core structure only has one line of defense of RC tube. So it is necessary to improve steel frame-concrete core structure system, which will perfect structure seismic Performance and reasonably share earthquake force or earthquake overthrow moment. The regular part of steel frame-concrete core structure system is made up of huge-columns, limit stiffness outrigger storey, concrete core tube, which takes shape tough and hard structure framework. So it may stand up to wind load and earthquake action, to such an extent as to lateral stiffness of external frame is agree with core tube, which improve the rationally distributed problem of earthquake shear force and overthrow moment .so it can become dual defense lateral force system ,which is advantage to earthquake and wind defense. On complicated architecture appearance and elevation, it may coordinate the contradiction of complex shape on architecture and regular texture on building structure.The main section of this paper focuses on the calculating and analyzing of effect that huge-columns, limit stiffness outrigger storey, concrete core structure to improved Steel frame-concrete core structureswith huge-columns seismic Performance with the finite element analysis software (ETABS). As the results of a large number of analyses and comparisons, seismic behavior of such three kinds of structures is presented in detail and some design concepts are suggested for reference in structural design of complicated tall buildings.The main seismic performance is introduced, including low level period, top displacement, maximum layer displacement angle, frame bearing horizontal shear, frame bearing earthquake overthrow moment...