Restoring Force Drift Angle Relationship Models of Reinforced Concrete Columns with Side Walls

Experimental studies of reinforced concrete columns with sidewalls have been conducted recently, and evaluation methods of the strength and ultimate drift angle have been proposed by some researchers including the authors. The observed restoring force drift angle relationship of columns with side walls is characterized by initially high strength portion, which is mainly a contribution of side walls, followed by ductile behavior, which is mainly a contribution of columns after the failure of side walls. In this study, backbone curve models of restoring force drift angle relationships are proposed considering these characteristics. The accuracies of the models are examined using a variety of experimental data including those conducted by other researchers. It is concluded that the models can be used in earthquake response analysis as conservative models.