Research Of Outriggers On Steel Frame-rc Corewall Hybrid Structure

Over the last twenty years, steel frame-concretes core tube structure system with outriggers has been more and more applied in practice. Although the outriggers may reduce the horizontal moving of the structure under the wind load, under earthquake action it also can cause sudden partial variation of structure's stiffness and internal force, and will easily come into being weal story. Meanwhile, the structure's damaged mechanism can't present the ductile yielding mechanisms as "strong column, weak beam" and "strong in resistance of shear force, weak in resistance of bending", thus, it is very significant to study the designing of the structure system's outriggers.The optimum placement with one or two outriggers has been analyzed by many documents; therefore this thesis takes structure under the horizontal load with four outriggers as an example, it use the rotation coordinated distortion which is at the attachment points of the outriggers and the tube body to establish equation, and it has derived the theoretical optimum placement of the outriggers; Meanwhile, it also has obtained the optimum placement of multi-layer outriggers.This paper has researched the mechanical behavior of outriggers of steel frame-concrete core tube structure system combined with Qingdao Development Zone of International Trade Building project. This project has applied the design idea of outriggers limited rigidity; the story has adopted steel reinforced concrete beam form, and it used the continuous outriggers, its form is very unique, so it is necessary to research about it. Strengthening of the design concepts, and to enhance use of steel reinforced concrete beam form, and continuous strengthening of the outriggers forms is unique, it is necessary to study. The normal documents usually put one or two layers as the research object, but it is rare to thoroughly analyze the multi-layer structure; this paper has applied the finite element software SAP2000 to establish three-dimensional finite element model, and the model set up six models to analyze the different strengthened stories. Through the calculation about different schemes, it has obtained the effect about period, displacement and internal force of strengthened story with different positions and quantity; it has also obtained the influence about the structural mechanics performance of different layers based on the analysis and comparison.Because the structure of this project is complex, and the top floor which exist the whiplash effect is adducted, this paper has adopted the elastic time-history analysis to calculate the seismic action of Qingdao Development Zone of International Trade Building project. Through the establishment of four different outriggers, it has studied the influence of structural dynamic characteristics from establishment of different horizontal strengthened layers. It has studied the proper establishment of horizontal outriggers, and it also comparatively analyzed the vibration spectrum of decomposition method which has obtained the basically same conclusion.Finally, through analysis it got a conclusion that the outriggers establishment of Qingdao Development Zone of International Trade Building is reasonable which is in line with the design concept of "limited stiffness", and it also summed up the influence of different outriggers to mixed mechanical properties; It has proposed the designing suggestion about the outriggers' establishment of super-high-rise construction which can provide a strong basis and good reference to the strengthened layer's designing of the similar projects.