In this paper, the experiments were carried out to investigate the bearing strength of H-section columns with wing-plate. It was shown that the experimental values can be evaluated accurately by the previous equations. Then the specimens that a column was embedded in a pile head was used for the investigation into the friction strength and superposed strength. The effective area for friction was grasped by the experiment, and the ultimate friction stress was shown. Also, it was shown that the superposed strength of the experiment tended to be lower than the previously proposed calculated value.
