Seismic Optimal Analysis Of A High-Rise Twin-Tower Connected Structure With Buckling Restraining Brace

With the high-speed development of economy and the rapid popularity of new building materials and technology,city landmarks’ height is continuously rising and the plane arrangement is getting more complex.Connecting structure is a new system of high-rise complex building,which is formed by two or more tower buildings joined with steel connected-structure.Connected-structure will bear very huge and complex internal force under the actions of earthquake and wind,which is the critical point in design.A great quantity of horizontal and diagonal braces need to be arranged to ensure the safety of the structure.Unlike common brace,buckling-restrained brace is an energy-consuming component,which can yield in both tension and compression without buckling under moderate and rare earthquakes.On the same loading condition,BRB has smaller sectional dimension and lower stiffness,which can effectively decrease the earthquake reaction.Its excellent energy dissipation capacity can insure the safety of major structures.In this paper,structure design softwares PKPM and MIDAS are used to take out elastic and elastic-plastic analysis of an actual high-rise twin-tower connected structure under different earthquake levels.By way of continuously adjusting structural arrangement,this building finally meets the established performance-based seismic design goals and the requirement of the ‘3-level,2 –stage’ design.In this paper,BRBs are designed to replace the common braces of primary structure.The contrastive analysis result indicates that the BRBs can dramatically decrease the shear and inter-story displacement mutation of the stories where braces are installed.The damage of shear walls in connected structure stories is substantially weakened.However,the integral seismic performance of the structure shows no significant improvements.Finite elements software ABAQUS is used to build the FE models of BRBs.Under the loading scheme according to relevant specification,the BRBs have got full and stable hysteretic curves.The key performance indicators of BRBs all meet the requirements of relevant specifications,which indicates the BRBs designed in this paper possess good ductility and energy dissipation.