Analysis Of Seismic Performance And Limited Stiffness For Frame-coretube Structure With Horizontal Outriggers

ultra-high-rise frame-coretube structures without outrigger in strong earthquake zones which subject horizontal loads (wind or seismic) often fail to meet the standard requirements owing to excessive displacement. Because excessive lateral deformation can lead to structural damage and endanger structural regular service, so it usually sets rigid outriggers to improve integral lateral stiffness. Because outriggers could cause wave of structural stiffness and internal force, even form weak layers subjected rare earthquake. Thereby, "strong column-weak beam" and "strong shear-weak-bend" seismic design philosophy is hardly to be guaranteed. Then the mechanism of outriggers now lack of quantitative analysis.So, the study about the load characteristics of ultra-high-rise frame-corewall structure with outrigger under horizontal loads and how to enhance lateral stiffness and capacity of horizontal resisting thrust is significant.In this paper, the actual works on the floor with a strengthening of the framework-the core tube structure system to the following research:1.The study of mechanism of outriggers, which explains the effect of outriggers in ultra-high-rise frame-corewall structure.2.Used ETABS software to calculate a simple model of ultra-high-rise frame-corewall structure with outriggers, analyzing the change of internal force, discussing the actual essence of outriggers.3.Used ETABS software and ANSYS software to analyzing the structural modal of Xindu & Longcheng respectively, and then the wave results of displacement, period and internal force under seismic are obtained.4. Mainly analyzing the concept design of "limited stiffness". This paper adopts structural top displacement as control index, then the relationship between stiffness of outriggers and top displacement is obtained.Research suggests that increasing the Stiffnes of strengthening Stories can effectively reduce the vertex displacement, but when the stiffness increased to a certain value, little effect on the structure displacement, then should be chose the limited stiffness of strengthening Stories.5. From the relationship between generalized stiffness of outriggers and generalized stiffness of core tube. suggests that Only when the level of strengthening layer of generalized stiffness and generalized rigidity of the core tube than in a certain range, will reduce the structural displacement; and when the core tube truss generalized stiffness and generalized stiffness ratio increases to a certain value, then the structure of the reduced Displacement effect is not significant.6. From the relationship between generalized stiffness of outriggers and generalized stiffness of framework. suggests that Only when the level of strengthening layer of generalized stiffness and generalized rigidity of column than in a certain range, will reduce the structural displacement; and when the truss framework of generalized stiffness and column generalized stiffness ratio increases to a certain value, then the structure of the reduced Displacement effect is not significant.