| The steel has met the requirements of various industries for various indexes of steel products of the rapid development of output and quality in China recent years gradually.The needs of current traffic construction is obviously unable to meet the needs of current traffic construction for bridge structures,especially to long-span bridges,the concrete filled steel tube bridge emerges as the times require.Creep could not be avoided in considering the long-term effect of concrete filled steel tubular structures because of the existence of concrete.Long-span concrete filled steel tubular arch bridges of static and random seismic responses are studied in this paper aimed to figure out the influence of core concrete creep.The current research status and results of concrete creep of concrete filled steel tube summarized by this paper based on the creep theory and mathematical model of concrete,and introduces the method of random seismic response analysis.Specifications for Design of Highway Concrete-filled Steel Tube Arch Bridges(JTG/T D65-06-2015)is adopted to the calculation formula of the core concrete creep,large-scale finite element software ANSYS is applied to establish numerical analysis model of long-span CFST Arch Bridge,The creep coefficient of each core concrete unit is changed,and the appropriate acceleration power spectrum model is selected,The static and random seismic responses of the model are calculated by static analysis module,modal analysis module and spectrum analysis module aimed to calculate the static and random seismic response of long-span concrete filled steel tubular arch bridge creep.By comparing the static results of each time step within three years after completion of the bridge,and handling with the data of random seismic response with and without creep,it is known that The effect of core concrete creep on the static results of structure is becoming smaller and smaller,and the growth rate of internal forces tends to zero,and most of the internal force changes are completed about half a year.The stress of the concrete is decreasing and the stress of the steel pipe is increasing in arch rib with the increasing of time.The root mean square root of the vertical displacement,the steel tube and the bending moment are reduced,but the root mean square root of the steel tube and the bending moment of the core concrete in the steel pipe are increased by the effect of the core concrete creep of the arch rib,for the random seismic response.Some reference value of the analysis of the influence of creep of concrete filled steel tubes on the static and dynamic analysis of structures is provided by the research results in this paper,and that can carry out further research. |
