The Vibration Isolation Performance Analysis On Prefabricated Concrete Frame Cantilevered Structure

The prefabricated structure realizes the industrial production of buildings and the rapid assembly production on site.Compared with the cast-in-place monolithic structure,the advantages of the prefabricated structure lie in the low pollution,saving time and good quality.At present,many high-rise buildings have adopted the prefabricated structure,but the overall stability of this kind structure is low and there are many weak parts,thus the seismic performance is not as good as the cast-in-place integral structure.Seismic isolation and vibration reduction technology has been applied to high-rise prefabricated structures to enhance their stiffness and integrity,also the impact of earthquake is reduced.On the one hand,the damping device changes the damping of structure and reduces the earthquake effect.On the other hand,the damping device has relatively weak stiffness and elastic performance.It would enter plastic stage and dissipating energy before the main structure under the action of serves seismic to protect the main structure in the occurrence of serious damage.The isolation device is to rely on its own deformation to make the energy cannot be transmitted upward,the seismic energy in the horizontal direction of a certain dissipation,to ensure the safety and stability of the upper building.This technology fundamentally alters the vibration duration of the building itself,thereby separating the structure from the superstructure.Effective ensuring that energy cannot be uploaded directly to the superstructure.There are some prefabricated structures with cantilevered floors in engineering practice,but there are few researches on the application of vibration isolation and damping in such structures and their effect on seismic performance.In this paper,the seismic performance of five models,such as cast-in-place structure,assembled structure,additional rubber isolation support structure,additional buckling constrained support structure and combined structure with rubber isolation and buckling are analyzed by numerical method.Pushover analysis and dynamic time history analysis are used to discuss the influence of vibration isolation technology on internal force,deformation and internal force of each vibration isolation element.The influence of different concrete strength,stiffness of BRB and rubber isolation support on structure is considered.Finally,vulnerability analysis is used to evaluate the failure probability model of composite structures with addition and subtraction isolation at each performance state point,in order to provide some reference for the design of such structures and earthquake collapse assessment.