Study On The Regulation Of Internal Forces Of Frame-core Tube Structure Caused By Vertical Deformation Differece

Frame-core tube structure which can take full advantage of steel and concrete,and has good seismic performance,has been widely used in high-rise buildings.With the increase of the height of the building,because of the different vertical stress level of each bearing component and the time-varying characteristics of the concretematerial,the vertical deformation difference between the frame column and the core tube is more and more obvious,it will adversely affect the structural components and non structural components,and seriously,it will lead to beam and plate cracking,steel yield in advance.Therefore,it is necessary to study the influence of vertical deformation on the internal force of frame-core tube structure.In this paper,based on the review of the literature and research status of the vertical deformation of frame core tube structure and its vertical members,a typical actual frame-core tube structure in Guochuang Guanggu Shangcheng is selected as the object of study,construction simulation analysis on this object was carried out with ETABS.The analyses are as follows,firstly,analysising the influence of concrete shrinkage and creep on the vertical deformation and the internal force of structural members;then,calculating the example of the core of the construction of the reasonable number of layersanalysising the influence of the advanced construction of the core tube on the vertical deformation;next,on the basis of simulation calculation ofvertical deformation difference compensation,the paper puts forward the suggestion of vertical deformation difference compensation;finally,combined with the actual project,the measures to control the vertical deformation are put forward.The conclusions of this paper are as follows:considering the shrinkage and creep of concrete,when the structure is completed,the vertical deformation of the wall and column is about twice as much as that of the elastic deformation,and the verticaldeformation is most completed within 1 years and become stable after 3 years;the vertical deformation difference caused by shrinkage and creep is about 58% of total deformation,when the shrinkage and creep tend to be stable;considering the shrinkage and creep,the bending moment and shear force of the frame beam close to the column increase,while the bending moment and shear force of the frame beam close to the wall decrease,with the change of time,the shrinkage and creep can reduce the additional internal force of the frame beam which caused by the difference of vertical deformation;considering the shrinkage and creep,the axial force of the bottom column is increased about 3%,and the axial force of the core is reduced.The reduction of the outer wall is smaller,and the inner wall decreases greatly,which can reach up to 14%;the shrinkage and creep of concrete can lead to the redistribution of stress between concrete and steel bars,which results in a 227% increase in the steel stress in the column.