This paper reports on the evaluation method of the inelastic deformation capacity of reinforced concrete square columns confined by various reinforcement, subjected to shear force, flexural moment and high axial force. The concrete model was developed, taking into account the effects of the concrete strength, the diameter and spacing of hoops, the hoop strength, the hoop shape (hoop with hook or spiral) and the presence of interior ties. Moment-curvature relations calcu- lated using the concrete models with some modifications were compared with experiments and found to be useful to evaluate the ultimate deformation of the members.
