Construction Simulation Analysis Of Vertical Creep And Shrinkage Effect Of Super High Rise Frame Core Tube Structure

With the continuous development of China's economy and technology,super high-rise buildings have been widely applied.In the super high rise building structure,the structure of the frame core tube is widely used,and it has become one of the more structure systems used in the modern super high rise building.At present,the research of super high rise building mainly focuses on the design method of structure itself,anti tilt,wind resistance,earthquake resistance and so on,and the construction process of the structure is relatively less.With the increase of building height,the vertical deformation caused by shrinkage and creep effect in construction stage and operation stage has also become a problem worthy of consideration.Therefore,it is important to consider the construction process simulation under the time dependent effect and creep shrinkage effect of materials,and the daily trend is imperative.In this paper,a calculation model of shrinkage and creep is established on the background of practical engineering.The whole construction process of the structure is simulated and analyzed by Midas/gen finite element software.The rationalization proposal is put forward for the actual project,the displacement compensation value of the outer frame and core tube is given,and the displacement monitoring control points in the construction are put forward,the specific contents are as follows:(1)through the theoretical analysis and numerical simulation,the influence of the first loading method,the approximate construction process loading method and the exact construction process method on the construction phase calculation,as well as their errors in the construction stage simulation are qualitatively analyzed,and the structure vertical direction is calculated by the exact construction process loading method.The necessity of deformation.(2)taking the super high-rise frame core tube structure of the financial center as the calculation model,the influence of the concrete shrinkage and creep estimation methods of CEB-FIP(1990),China specification(JTGD62-2004)and PAC three different countries on the vertical deformation of the structure is compared and analyzed,which is helpful for the designers to choose the rational selection stage.(3)the factors that affect the vertical deformation of the structure during the construction process are calculated by the finite element model.The construction speed,the relative humidity of the environment,the ratio of the reinforcement in the column and the number of the leading outer frame layers of the cylinder are analyzed quantitatively,and the effect of them on the vertical deformation of the structure and the shrinkage of the structures under these four factors are analyzed.The deformation effect caused by the variable effect is analyzed,and the problems needing attention in the construction are analyzed.(4)based on the engineering practice,the effect of the shrinkage and creep effect on the vertical deformation of the structure is calculated and analyzed in the construction stage and the use stage(1-5 years after completion).(5)finally,it puts forward compensation proposals and monitoring control points for the core tube and outer frame elevation of the financial center project,so as to provide reference for the actual project.From three aspects of material selection,structural design and construction stage,the rationalization proposals and Countermeasures for reducing the deformation difference of the frame core tube structure are put forward.