Abstract:
To study the influencing factors and regularities of the torsional behavior of air-cooled concrete pipe columns under the press-bending-shear-torsion action, the torsional behavior of existing air-cold concrete tubular columns was studied in this paper. The finite element model was established and verified by the existing test results, The effects of wall-to-diameter ratio, stirrup reinforcement ratio, concrete strength, longitudinal reinforcement ratio and slenderness ratio on the torsional behavior of concrete tubular members under the press-bending-shear-torsion action were analyzed, and the response surface method was used to study the significance and interaction of the above five influencing factors. It is found that the torsional bearing capacity of concrete pipe string increases with the increase of wall diameter ratio, and concrete strength and longitudinal reinforcement ratio, and the torsional ductility increases with the increase of the wall diameter ratio and the longitudinal reinforcement ratio. The all single factor reactions are significant, the effect of slenderness ratio is the most significant. The interactions between wall diameter ratio and concrete strength, wall diameter ratio and slenderness ratio, and concrete strength and slenderness ratio are the most obvious. Finally, this paper suggested the important factors that need to be considered in the design of concrete pipe column.