| Isolation technology is a building with the basement or some site setting isolation devices to isolate or dissipate seismic energy.The technology could avoid or reduce the earthquake energy transmitted to the upper structure,reduce the structural vibration response,and thus ensure the earthquake safety of buildings.In recent years,with the continuous development and improvement,as well as in-depth research of seismic isolation technology,the corresponding theoretical basis of the technology is formed and has been applied in some projects.However,compared with the United States,Japan,Europe and other countries,the numbers of isolated building in China are still relatively few.At this stage,the seismic isolation technology is actively promote to use in high seismic intensity regions in some cities,provinces even and the country.Based on the present situation,this paper conducts theoretical analysis of the seismic isolation effect,and carries out numerical simulation analysis of a practical project.The isolation performance,effect and economy of both analysis methods are compared.This paper first briefly describes the development and application of seismic isolation technology.Secondly,the classification of isolated structure,the principle of isolation,the characteristics of seismic isolation bearings and the problems existing in isolation are discussed.Moreover,the research aims to solve the current design personnel confusion whether the high intensity areas utilize isolation design or traditional anti-seismic structure.The mechanical property of isolation dynamic equilibrium equation is established,and a practical project of frame shear wall structure is analyzed as the research object with the finite element software.And then,the isolated and non-isolated structure design schemes are established to carry out dynamic time history analysis.The seismic isolation structure on the shear wall is optimized through reducing a majority of the shear wall.At the same time,the seismic responses,such as inter story shear force,bending moment,displacement,displacement angle,acceleration,etc.,are compared with corresponding responses of the traditional frame shear wall structure.A reasonable and economical seismic scheme is proposed through analyzing the differences between both in the seismic performance,theeffect,the project quantity and the reduced loss of the earthquake and etc.Finally,the corresponding measures are put forward to ensure the isolation layer deformation demand of isolated structure under rare earthquake.The results show that the acceleration of traditional seismic structure increases with the increase of the story under the rare earthquake.There is no obvious change in the floor acceleration of the isolated structure,whose acceleration value is only 1/20~1/8 than the corresponding value of the seismic structure.The performance of isolated structure is better than that of non-isolated structure,and the isolation structure has obvious damping effect,larger safety reserve and lower cost in contrast with the seismic structure.It is suggested to give priority to consider adopting the seismic structure in high seismic intensity region. |
