Seismic Performance Analysis Of Super High Rise Concrete Structure With Buckling-restrained Braces

With the development of economy and the progress of Architecture Science and technology,super high rise buildings have made remarkable achievements in all parts of the world since the birth of the high rise buildings.And,with the shortage of land resources,in order to meet the demand of high-rise building use function,in the future for a long period of time will still be one of society most in need of building type,concrete frame core wall structure due to its excellent seismic performance has been widely used in high-rise buildings.At present,there are two kinds of ideas for structural design.One is the traditional way of resisting earthquake by using self stiffness of structure,the other is the idea of energy dissipation.The advantage of "energy dissipation" is that energy dissipation components can be used to help the structure dissipate the seismic energy,so as to reduce the damage of the main structure under the action of earthquake.The buckling restrained braces have good hysteresis performance,which can improve the ductility of the structure and protect the main structure.Because of its excellent energy dissipation capacity,buckling restrained braces have been widely studied by scholars both at home and abroad.However,the application of buckling restrained braces in super high concrete structures is relatively small.The buckling restrained bracing is applied to the structure of the super high rise frame core tube,and the shear wall can be reduced to reduce the structural seismic response.On the premise of guaranteeing the seismic performance of the structure,the"energy dissipation" change from "rigid seismic" to appropriate "energy dissipation" is realized.According to the United States in a super high-rise building concrete frame core tube engineering,through the comparison of different buckling restrained brace layout,re design of the model,reduce part of the shear wall,and symmetry in the X direction and Y direction with buckling restrained brace structure analysis model built by Midas.Building,by using the vibration spectrum response calculation in case of structure under earthquake action on structure decomposition,comparison of the data structure period ratio,layer shear,the interlayer displacement angle etc..The structural response of the structure subjected to rare earthquake is calculated by using Pushover analysis method and dynamic time history analysis method.The seismic performance of the structure is evaluated from the overall level,the main stress component level and the damage distribution of the structure.The incremental dynamic analysis method is used to understand the change trend of the structure under the change of the vibration intensity.The percentile regression of the obtained IDA curve is carried out to determine the limit state point,and the IDA method is applied to the performance evaluation method of the structure.The research shows that the shear wall is the most important anti lateral force component in the super high-rise concrete structure,and the buckling restrained brace is more flexible than the shear wall,so that the shear wall and the outer frame can work together.Under the action of frequent earthquakes,the reasonable buckling restrained brace can effectively reduce the dead weight of the structure,reduce the seismic response of the structure,and improve the lateral stiffness and torsional rigidity of the structure.Under the action of rare earthquake,the buckling restrained brace transforms the energy absorbed by earthquake into structural damping,increases the damping ratio of the structure,has good energy dissipation capacity,and effectively reduces the damage of the structure.