Analysis And Comparison Of Seismic Response Of Frame Structures With Different Isolation Schemes

With the vigorous development of the construction industry,China's basic isolation technology has been greatly improved.Basic isolation technology can also be called passive control technology,which consumes and reduces part of the seismic energy through the isolation device of the isolation layer.Compared with other isolation structures,the base isolation structure has wider application range,simple construction and maintenance and lower cost.However,with the complexity and diversity of isolation bearings,the isolation effect of its single isolation bearing will have certain limitations.In order to further improve the isolation effect of the isolation structure,the isolation bearings will be optimized.The basic isolation study is carried out compared with the bearing arrangement,so this paper mainly studies the influence of the optimized bearing combination and arrangement on the seismic effect.This article first introduces the concept of the seismic isolation structure and the mechanical characteristics of the support,derives the dynamic balance equation,and uses the finite element software SAP2000 to model an actual project.This actual project is a 6-story reinforced concrete frame structure teaching building of a school located in Juancheng,Shandong.According to the Regulations of the Shandong Province Construction Engineering Earthquake Protection Regulations,the seismic calculation level of the structure of this teaching building should be from the original 8 degrees(0.2 g)Raised to 8 degrees(0.3 g)for seismic calculations,the models are traditional seismic structures and three different isolation schemes.The three isolation schemes are supported by lead core isolation bearings and natural rubber The seat combination is arranged.Firstly,the four models are modal analyzed,and the finite element software is used to analyze the dynamic elastoplastic time history of the structure.The dynamic time history results of the fortification and rare conditions are analyzed and discussed respectively,and the layers of the four models are compared and analyzed.Inter-displacement,inter-layer shear and inter-layer acceleration,compare the performance changes before and after isolation and check whether the results are satisfied according to the specification,calculate whether the displacement and tensile and compressive stress of the isolation support meet the requirements of the specification,and obtain different isolation schemes Bearing force-displacement hysteresis curve.The results show that: Compared with the non-isolated structure,the isolation effect of the three basic isolation schemes is significantly enhanced,and the natural vibration period has been greatly improved,all extended to 3 to 4 times to stay away from the excellent cycle of the site,and the floor The seismic effects of inter-layer shear,inter-layer displacement and inter-layer acceleration are also reduced correspondingly.With the arrangement of natural rubber bearings,the isolation effect is significantly improved,and the force-displacement hysteresis curve of the isolation bearings is relatively full,indicating that the energy dissipation capacity of the isolation bearings is better.It is recommended to use lead-core isolation bearings It is arranged in the outer ring,and the natural rubber bearing is arranged in the inner ring,so as to ensure the torsional rigidity of the structure.Finally,predict the development prospects of isolation technology,and hope that this paper can provide a reference for similar isolation design.