Non-load Effect Study And Construction Monitoring On Super High-rise Concrete-filled Steel Tube Structure

The frame-core tube structure with concrete filled steel tube(CFST)column possesses the advantages of both steel and concrete,and is widely used in the high-rise buildings recently.The construction period of high-rise building is longer,and a greater temperature stress field on the surface of steel plate is produced by solar and environment radiation.Meanwhile,the mechanical property of CFST component is influenced by concrete shrinkage and creep during construction period.However,the non-load effect including the effects above is not taken seriously,so it is necessary to study intensively.In this paper,a finite element analysis is conducted to study into the influence on the level of components and structures caused by temperature field and concrete shrinkage and creep,and the construction monitoring is proceeded to study on the method to reduce the influence of temperate field.For CFST components,the effects of temperature and concrete shrinkage and creep are introduced respectively by ASHREA model and CEB-FIP(90)model.The result shows that the horizontal deformation is influenced by solar non-uniform temperature field.The horizontal deformation reduces with the section dimension increasing less than 900 mm,and increases rapidly with the rise of the column height.The vertical deformation difference is produced by concrete creep,and increases with section dimension increasing.Solar non-uniform temperature is multiplied based on concrete creep,which leads to the rise of vertical deformation difference increasing rate.As for the level of structure,a simplified calculating method is presented with size effect and nonlinear variation of temperature field along horizontal direction.The effect of concrete shrinkage and creep is considered through construction composite section.The analysis is based on Wan Plaza 9# building,and the results below are obtained.The influence of non-uniform temperature field is limited in local stress field,which is inability to influence the whole structure.The horizontal displacement of structure caused by solar radiation is about 16.6% of which caused by wind load,and the vertical displacement caused by concrete shrinkage and creep increases 0.6 times.The monitoring results of temperature and stress is analyzed in the paper,and the simulation analysis is verified.The maximum temperature of components is 6oC lower than the maximum air temperature due to the thick fireproofing coating.According to the parametric analysis,the construction progress of thick fireproofing coating should be over half of the building height so that the temperature effect can be ignored properly.