Comparison Of Seismic Isolation Design Of Shear Wall Structure Based On Code For Seismic Design Of Buildings And Code Of Design For Seismic Isolated Buildings

In China seismic isolated buildings are increasing and isolation building design methods are constantly developing and improving.There are significant differences between Code for Seismic Design of Buildings and Code of Design for Seismic Isolated Buildings.This paper introduce a new direct design.And it is notable that significant differences are existed in terms of design methods and critical design indexes between these two codes.However,comparison on the seismic design of base-isolated structures using these two codes was rarely reported.In order to deeply analyze the impact of the two codes on the seismic isolation design of RC shear wall structure and promote the reasonable application of building isolation technology,this paper firstly carried out the isolation design of shear wall through two code respectively,and compared the design indexes of the superstructure and the seismic response.Furthermore,the elastic-plastic analysis under large earthquakes is carried out,the seismic performance and damage state of the two structures are investigated,and finally give an economic comparison.The main contents of this article are as follows:(1)The system compares the major differences between the fortification target,design response spectrum,design process,and important performance indicators(layer shear displacement angle)of the two codes.It mainly introduces the repair of large earthquakes,the design of medium earthquakes,the equivalent linearization method of the isolation layer,the long-period response spectrum and the complex vibration decomposition method.(2)The elasticity analysis of the middle and large earthquakes is carried out for the shear wall isolation structures designed by the two codes.Compare the design index and seismic response of its superstructure.The research shows that the control index for the design based on Code of Design for Seismic Isolated Buildings is the bottom shear ratio.Due to the long period of the reaction spectrum of Code of Design for Seismic Isolated Buildings decreases rapidly,compared with the design of Code for Seismic Design of Buildings,The base shear of the superstructure decreases by about 10%.And the cross-section and reinforcement of the superstructure are reduced to a certain extent;The interlayer displacement angle of the superstructure increases by about 20%;The displacement of isolation layer is reduced to more than 20%.(3)The Perform-3D software was applied to perform dynamic elastic-plastic analysis under the action of large earthquakes,and compare the damage state and energy dissipation distribution of the superstructure of the shear wall isolation structure based on two codes.The analysis shows that the interlayer displacement of the superstructure is significantly increased than that of the elastic analysis,and the increase can reach 30%-40%.Indicating that a certain degree of plastic damage has occurred to the isolated structure under the large earthquake,and the elastic analysis of the large earthquake underestimates the interlayer displacement.The energy dissipation of the isolation layer of the two structures is good,and the seismic energy is concentrated in the isolation layer,which greatly reduces the seismic effect of the superstructure.(4)Finally,based on the economic analysis of the shear wall structure designed with two codes.the life-cost evaluation from direct engineering cost,failure lost cost and maintenance cost,respectively.Compared with the Code for Seismic Design,the direct cost of Code of Design for Seismic Isolated Buildings is relatively low,a reduction of 16%,but due to the greater damage after the earthquake,the full life-cost has increased by 5.6%.