Discussion On The Application Of Isolation Bearing In A Step-terrace Structure Engineering

China has a vast mountainous area where rising numbers of buildings have been built in recent years.Thus the Step-terrace structure has been widely used as a typical mountainous structure.Due to the presence of ground layers at different heights,there is a severe vertical irregularity effect in the Step-terrace structure,which is detrimental to the design of the structure and the safety of the building.Based on a practical project,this paper establishes the uncontrolled structure,the isolation on sill structures,the layer-isolated structure and the baseisolated structure.The macro indexes of these four types of solutions under frequent and rare earthquakes are compared.Based on the deformation of the components,the performance of the components under the action of frequent earthquakes,fortified earthquakes and rare earthquakes is discussed.The research contents and main conclusions are as follows:(1)Explain the current status of research on Step-terrace structure and introduce the development of seismic isolation design methods.(2)Introduce the engineering examples studied in this paper,design four types of solutions and use PERFORM 3D software for simulation.(3)Compare the interlayer shear force,overturning bending moment,interlayer displacement angle,interlayer torsion angle,floor acceleration and component energy consumption of the four types of solutions under the action of frequent earthquakes and rare earthquakes,and Relevant calculations and check calculations of seismic structures.(4)Introduce the definition of component performance status in the Guangdong Province Standard " Specification for Performance-based Seismic Design of Reinforced Concrete Building Structure ",and use this as a basis,the performance status of beams and columns are analyzed.At the same time,the hysteretic performance of the isolation bearings of the three types of isolation solutions is compared,and engineering suggestions are proposed for different design.(5)Overall,the ungrounded sill ground column is a relatively weak component in the uncontrolled structure,and attention should be paid to its performance status when designing the Step-terrace structure;the the isolation on sill structures slightly reduces the seismic response of the ungrounded floor,but it also enhances the seismic response of beneath floors,resulting in the poor isolation effect.The layer-isolated structure effectively reduces the seismic response of the upper floor,and the seismic response reduction effect of the beneath floors is relatively weaker,resulting in the good overall seismic reduction effect.The base-isolated structure can reduce the seismic response of the upper floors and the beneath floors at the same time.The horizontal damping coefficient of the base partition solution of this project is 0.492,which allows the superstructure to be designed according to a half degree reduction.