Seismic Performance Analysis Of Damping And Seismic Isolation System Of CFST Special-shaped Column Frame Structure

With the introduction of the national policy on the development of prefabricated structure construction,various localities have implemented the follow-up,issued the local prefabricated policy,and actively promote prefabricated buildings.With the advantages of flexible spatial layout,standardized production,fast construction speed,superior seismic performance,green,energy saving and environmental protection,prefabricated steel structure residence has gradually entered the public vision.In October 2019,the Ministry of Justice issued the regulations on Seismic Management of Construction projects(draft for soliciting opinions),in which it is pointed out that "the state encourages the application of isolation and damping technology in prefabricated buildings to improve seismic performance".At present,in the prefabricated steel structure residence,most of the energy dissipation damper are used to improve the seismic performance of the structure,but there is little research on the combined design of damping and isolation,so the isolation technology is introduced into the concrete-filled steel tubular special-shaped column frame damping structure in this paper.The feasibility and advantages of combined seismic isolation design are analyzed.The main research contents are as follows:1)Based on ETABS structural design and analysis software,the model of prefabricated concrete filled steel tube damping special-shaped column high-rise building system is established.Through numerical simulation,the structural system is analyzed under the action of response spectrum,frequent earthquake and rare earthquake.The variation rules of parameters such as inter-layer displacement angle,inter-layer displacement,floor shear force,shear weight ratio,rigid weight ratio,anti-overturning and so on.2)The isolation design is carried out on the basis of the damping structure,and the type and layout scheme of the isolation bearing are finally determined after many trial calculations.The seismic analysis of the structural system under frequent earthquakes,fortification earthquakes and rare earthquakes is carried out,and the variation rules of parameters such as inter-story displacement angle,inter-story displacement,floor shear force,shear weight ratio,rigid-weight ratio,anti-overturning and energy dissipation of seismic isolation bearings are studied.3)The seismic performance of the damping structure and the isolation structure is compared.The results show that the damping structure and the isolation structure system meet the design requirements of the relevant codes,and the isolation structure is more "flexible" than the damping structure.The floor displacement under wind load is larger than that of damping structure,which shows that it is more sensitive to wind load,the isolation layer dissipates seismic energy and weakens the transfer of seismic energy to the upper floor under the action of seismic wave.The overall isolation effect is better when the seismic acceleration response of the structure is reduced.