Research On The Influence Of The Yield Ratio Of Isolated RC Frame-core Tube Tall Buildings In High Intensity Areas

As an important part of the future city,the RC frame-core tube tall buildings carrying the important functions of the structural resilience under seismic hazard and received extensive attention from the engineering and academic circles.The introduction of the isolation technology can effectively reduce the seismic action of the superstructure,improve the structural resilience under seismic hazard,and reduce the design difficulty of the superstructure.However,there are still relatively few cases of isolation design for such structures in high-intensity areas.The influence of key design parameters on key design indicators of structures is still unclear,and the recommended values of key design parameters are lacking and the efficient design methodestablished on this basis.In response to the above problems,this paper has carried out related research,the main research contents and conclusions are as follows:(1)Based on the team design of the series isolated RC frame-core tube tall buildings project case(10),considering different isolation schemes(partially basement-isolated scheme and conventional base-isolated scheme),taking one structure as an example The design difficulties of this type of high-rise isolated structure are comparatively analyzed.The seismic response characteristics of the two schemes are compared and the key design parameters affecting design efficiency and accuracy,the yield ratio,are identified.(2)Based on the case of two isolated RC frame-core tube tall buildings projects,28analysis cases with different yield ratios were designed considering the influence of different isolation design schemes.Based on the fine finite element model,the influence of the yield ratio on the key design indexes of the structure(including the horizontal seismic absorbing coefficient and the maximum bearing displacement under the maximum considered earthquake)is studied.The results show that the horizontal seismic absorbing coefficient and the size limit of the isolation groove are determined separately.The upper and lower limits of the yield ratio apply to the isolated RC frame-core tube tall buildings with a yield ratio of 2%to 3%.(3)combing the design process of the isolated RC frame-core tube tall buildings,and clarifying the key design difficulties:1)the superstructure design period T_f is difficult to determine;2)the compressive stress of each isolator under gravity load?~g assumed by the isolators at different positions is not easy to select;3)The recommended range of values for lack of key design parameters(yield ratio)guides the determination of the type of isolator.The above problems lead to the repeated iteration of the traditional isolated structure design,resulting in low design efficiency.In view of the above problems,the corresponding solutions are given in this study:1)the empirical calculation formula of the superstructure design period T_f is proposed;2)the range of the compressive stress of each isolator under gravity load?~g of the isolators at different locations is recommended;3)The reasonable range of yield ratio(2%~3%)and the principle of isolators arrangement.On this basis,a high-efficiency isolation design method that does not require iteration is formed.Based on this method,two isolated RC frame-core tube tall buildings are designed.The results show that the method does not need to be iterated,and the design results are accurate and efficient.