In some railway bridges, it took a lot of time to recover from the damage of the concrete around embedded part of circular steel stopper caused by recent earthquakes. If the damage can be controlled, recovery will be easy. In this paper, experiments and analyzes focused on the effect of amount of reinforcing bars and edge distance on the failure mechanism are performed. It was clarified the shear failure is occurred when the shear strength of the concrete around embedded part of circular steel stopper is lower than the full plastic circular steel stopper strength, and the cover concrete failure is occurred when the cover concrete strength is lower than 80 persent of the full plastic circular steel stopper strength.
