Unified bearing capacity model of confined concrete column subjected to axial compression

To better study the behavior of confined concrete, this paper presents the basic hypothesis of uhimate equilibrium of confined concrete and the unified yield criteria of confining material. Based on the static equilibrium condition and yield criteria of components, a unified bearing capacity model of confined concrete column is proposed, and a simplified calculating equation of the model is also given. The model captures the character of confined concrete column. Effects of the confinement effect ratio, the lateral confinement ratio, unconfined concrete strength and the properties of confining material on the bearing capacity of confined concrete column are carefully considered. The model may be applicable to the calculation of bearing capacity of steel-confined concrete, concrete filled steel tube and FRP-confined concrete. The predictions of the model agree well with test data.