Research For The Seismic Behavior Of The Structural System With Limited Stiffness Outrigger And With Rigid Outrigger

In the design of super high-rises, if the regular structural system can not control the structural horizontal displacement, outriggers will be adopted to restrain the displacement of outer columns and coordinate the distortion of outer columns as well as the core so that the stiffness of the structure is strengthened and structural horizontal displacement is decreased.However, for long the focus of the research of outriggers is how to maximize the effect of displacement control of rigid outriggers when the assumed outriggers are rigid. But insightful and thorough researches along with more effective solutions to the defects of outriggers are still absent. For instance, for the structural system with outriggers, the main structure will be influenced in various negative ways due to the concentrated rigidness of the rigid outriggers under the horizontal seismic force. Moreover, outriggers lead to weakness in a structure in terms of seismic behavior.Targeted at the problem, this thesis proposes that the negative influence of outriggers on a structural system can be relieved by setting several less rigid outriggers so that over concentrated rigidness can be separated and the structural system can also achieve displacement control to the same degree.Based on a concrete project analysis, the thesis adopts the recommended M.A.R.S. method in practice in our country and carries out elastic analysis of three different structural systems i.e. with outriggers, with rigid outriggers and with limited rigidness outriggers through static analysis theory of the structural System with outriggers as well as seismic design and analysis theory based on structural dynamics. Through detailed comparison and analysis of the results, the thesis proves that structural system with limited rigidness outriggers is superior to that with rigid outriggers in terms of seismic behavior, and displacement control can be achieved. Therefore, it shall be the premium structural system of the super-highrise design in the earthquake fortification zone.