Comparative Analysis Study On Isolated Design Of Damping Coefficient Method With Direct Design Method

With the continuous maturity and deepening of theoretical research on seismic isolation technology,more and more infrastructures such as buildings,bridges and tunnels are designed with isolation.Different from the traditional non-isolated design method,the isolation technology extends the self-vibration period of the structure by adding a vibration isolation device in the structure,increasing the damping ratio of the structure,thereby avoiding the excellent week of the site to weaken the upward transfer of seismic energy.And improve the seismic performance of the structure.However,most of the current isolation design methods adopt the damping coefficient method proposed in the Code for Seismic Design of Buildings.In essence,a non-isolated design method has obvious defects and shortcomings.This paper will introduce a new direct design isolation analysis method proposed in the Code for Design of Building Isolation,compare it with the damping coefficient method,and compare the similarities and differences between the two design methods to provide reference for engineering designers.Advice on the revision of the isolation specifications.The main contents of this paper include:(1)A brief overview of the development of isolation technology,the basic principles and applications of isolation technology,the latest research progress of isolation bearings and the research status of isolation technology in China,and the purpose and content of this paper.(2)The shock isolation coefficient method is introduced to design the basic isolation and the basic principle and design flow of the damping coefficient method.The principle of selection and arrangement of seismic isolation bearings is introduced through engineering examples.The principle of seismic wave selection and the damping coefficient are solved during dynamic time history analysis,and the verification is carried out under rare earthquakes.(3)Introduced the direct design method for seismic isolation design.The direct design method is the method proposed in the forthcoming Code for Design of Building Isolation.It is designed with response coefficient method in the design of response spectrum,calculation method and inter-layer displacement angle.Limitations and other aspects are different.In this paper,the equivalent stiffness and equivalent damping ratio of the isolation layer are determined by iteration.The performance-based design method is used to reinforce the upper structure according to the modified response spectrum under the fortification intensity,and the structure under the fortification earthquake is analyzed.The isolation effect.(4)Contrasting and analyzing the isolation effect of the damping coefficient method and the direct design method under the action of fortification earthquake.The damping coefficient method is designed according to the step-by-step structure under multiple earthquakes.The direct design method is based on the fortification intensity.Direct isolation design.Through the comparison of the interlayer displacement angle,the floor shear force,the overturning moment and the displacement of the isolation layer,the isolation effect of the two is analyzed,and the non-isolated structure,the damping coefficient method structure,and the steel area per unit area of the direct design method are analyzed.The economics of the design after isolation.(5)The material mechanics model determined by ABAQUS for dynamic elastoplastic analysis,the selected element type and the established finite element model are introduced.By comparing and analyzing the rare earthquake and the rare earthquake,the non-isolated design structure,the damping coefficient method structure and the direct design method structure floor shear force,the isolation layer displacement,the interlayer displacement angle,and the isolation bearing The tensile stress and hysteresis curve,the plastic damage of the structure,etc.,to analyze the isolation effect of the structure,thereby judging the safety of the structure.