Comparison And Analysis Of Seismic Behavior Of Reinforced Concrete Frame-Core Tube And Tube-in-Tube Structures

Frame-core tube and tube-in-tube structures are widely used in high-rise buildings in recent years because of their flexible layout and high space utilization.Although both of them belong to tube structure,they differ from each other in terms of spatial synergy.At present,the comparative analysis of the two structures is less,and the experience of earthquake damage that can be used for reference in practical projects is less.I hope this study can provide some reference for practical projects.In this paper,YJK and ETABS are used to analyze the main indicators of the structure,verify the correctness of the results of ETABS analysis,and then elastic analysis and non-linear dynamic analysis of the two structures are carried out using ETABS software.Elastic analysis mainly does the following work:(1)Verify the rationality of structural indicators,and use YJK to select the seismic wave that meets the requirements;(2)Study the shear lag effect of two kinds of structures.From the law of shear lag value,it can be seen that both structures show the trend of decreasing gradually from lower to upper levels,and the reduction rate of tube-in-tube structure is faster.The results show that the spatial performance of the tube-in-tube structure is better than that of the frame-core tube structure;the shear lag phenomenon of the structure varies under different seismic waves,indicating that the selection of seismic waves will have a certain impact on the structural response.In the non-linear dynamic analysis,the inter-story displacement angle,the base shear,the vertex displacement and the shear lag effect of the structure are studied,and the development trend of the column hinges,the performance of the column hinges and the stress of the shear wall are compared and analyzed.From the analysis results,it can be concluded that:(1)the displacement index of tube-in-tube structure is more dominant,but its base shear force will be significantly larger than that of Frame-core tube;(2)the shear lag effect shows a similar trend with elastic analysis,and the shear lag value of tube-in-tube structure decreases faster;(3)the number of hinges in the core tube of frame is more,and the plastic development is faster;(4)the frame-core tube structure has all kinds of shear lag effects.Stories have performance requirements,while tube-in-tube structure has more performance requirements for middle and lower columns,which indicates that there is room for improvement in the performance of tube-in-tube structure for columns;(5)Core tube and inner tube shear wall have larger stress in the bottom layer,and the bottom concrete layer will be damaged first,but the reinforced layer of tube-in-tube structure has not yielded yet,indicating that its outer tube has obvious seismic resistance effect,and the structure performance is obvious.Better seismic performance.(6)Comprehensive comparison shows that the tube-in-tube structure has better seismic performance,but similar to the frame-core tube structure,the bottom layer will be damaged first under earthquake action and should be strengthened locally.