Analysis And Research On Thermal Action Of Super-long Annular Structure In Sandu Stadium

The large stadium is formed by super-long annular structure due to the requirement no joints of architecture,water supply and drainage specialty and owner,thermal action and shrinkage may play a controlling function in structural design.Based on the study of creep and shrinkage of concrete,temperature value and the temperature effect of the regular super-long structures,combined with relevant literature,construction and meteorological data,the force and deformation characteristics of the super-long annular hybrid structure under the action of annual warming and cooling and sunshine are compared and analyzed by using Midas/Gen finite element software.Finally,summarize the problems that should be noted in the analysis of the temperature effect.In this paper,the main contents as follows:(1)Shrinkage and creep effects on concrete temperature are described and then determine the calculation method and calculation model suitable for this project.(2)The deformation and stress characteristics of common,regular and super-long straight-line frame structure and annular structure are compared and analyzed under annual cooling.(3)Combined with relevant literature and meteorological data,the thermal action value of the project is determined,and the temperature values in China's codes are compared and analyzed.(4)The stress and deformation characteristics of the Sandu stadium under the annual temperature and sunshine are analyzed emphatically,and the working conditions of the temperature are compared and analyzed.(5)The influence of steel structure on concrete structure temperature and the influence of foundation stiffness on concrete structure under annual cooling are compared and analyzed.Through analysis the following conclusions can be drawn:(1)Under the same cooling effect,the internal force of the straight frame structure with the same length is much smaller than that of a circular frame structure,it is unreasonable to determine the distance between the expansion joints of the non linear structure simply according to the standard.(2)As for the structures similar to hybrid stadium,it is not comprehensive and unsafe to consider the annual cooling effect in accordance with the conventional design,and the annual heating and sunshine may also play a control role in the structure.(3)Considering the special form of the structure and the stage of construction,the temperature difference between different structures is different,the deformation of the steel structure causes the great secondary stress in the concrete structure,and the overall effect of the structure should be considered as a whole.(4)Under the effect of annual and sunshine temperature,the internal force of the reinforced concrete structure is not attenuated with the floor under the action of various temperatures,it is unreasonable to consider the temperature effect of the two layers of the structure only in the structure analysis and design.(5)The foundation stiffness plays a great role in reducing the temperature of the structure,the beneficial effect of the foundation stiffness on reducing the temperature can be considered in practical engineering.