Optimal Analysis Of Seismic Performance Of Buckling Restraint Bracing In An Over-limit High-rise Structure

With the continuous rise of the height of urban buildings,the structure layout is more and more complex,and there are more and more oversized high-rise buildings in various cities.Earthquake damage to the structure has had a huge impact,the traditional "three levels,two stage" seismic design can not fully meet the needs of design,with the performance based seismic design method can control the damage degree of structure component to ensure the use function of structure after the earthquake and reduce the economic loss,therefore,in designing multiple transfinite analysis,How to adopt performance-based seismic design method has become the focus of research.The buckling bracing can not only be used as an energy dissipating member,but also as a lateral force resisting member to provide lateral stiffness and reduce seismic effect.The buckling braces can increase the stiffness of the structure without yielding under the action of small earthquakes,and can dissipate energy and yield without buckling under the action of medium earthquakes and large earthquakes,thus reducing the damage degree of other main structural components.In addition,the buckling restraint braces can not only be used in the column braces between frames,but also can be applied in the connecting beams to solve the problem that the connecting beams lose their functions due to the serious damage caused by insufficient bearing capacity.At present,the development in China is still in the exploratory stage.Based on the preliminary design of an over-limit high-rise building in Guangzhou,this paper makes a detailed seismic analysis of the structure by using performance-based seismic design method to demonstrate the safety of the structure,and the structure as a whole meets the requirements of grade C seismic performance.On the basis of the original structure,the buckling constraints deep beam support to replace the original structure of the framework,and narrow size of frame column structure,supported by constantly adjusting buckling constraint parameters and the size of the frame column,make the structure the design indexes meet the specification requirements,with the original structure under small and strong earthquakes performance contrast,study the buckling constraint support the optimization of structural seismic performance.By comparing the calculation result shows that the two structure after column section size optimization,with deep beam buckling constraint support instead of the original frame as the component to resist lateral force,models can effectively improve the structure of Y direction of the interlayer displacement Angle,even if the column after column section size to reduce the damage degree is still significantly improved,after optimizing the structure of the better seismic performance than the original structure.Finally,the application of steel coupled beams with buckling restraint braces in frame-shear wall structure is proposed.The steel coupled beams are in the form of trusses,and the trusses are in the form of buckling restraint braces.By comparing the seismic performance of concrete coupled beam structure and BRB coupled beam structure under small and large earthquakes,BRB steel coupled beam can solve the shortage of severe damage of reinforced concrete coupled beam under large earthquakes,and BRB coupled beam structure is better than the reinforced concrete structure in the displacement Angle between floors,the damage degree of shear wall and frame column.The BRB beam has good plasticity and energy dissipation capacity.In this paper,performance-based aseismic design method is used to analyze an engineering example in detail,which provides some reference for aseismic design method of high-rise buildings over limit.Compared with the deep frame beams,the buckling restraint braces in the structure can improve the seismic performance of the structure well,reduce the seismic response of the structure and improve the lateral stiffness and torsional stiffness of the structure,and have good energy dissipation capacity,and effectively reduce the damage of the structural members.In addition,the structural system of steel coupled beams with buckling restraints can not only solve the problem that the coupled beams are seriously damaged and lose their function under the action of large earthquakes,but also improve the energy dissipation capacity of the coupled beams.In this paper,an optimization scheme for the design of this kind of structure is proposed,which provides a new idea for seismic optimization measures.At the same time,some references are provided for the arrangement of buckling restraint braces and steel coupled beams with buckling restraint braces in this kind of engineering.