ABSTRACT
Number of bridges used long periods in Japan has increased and some damages for their members caused to heavy transportation become apparent. Therefore, design methods of bridges have often revised for lifetime improvement. However, there are some cases that a bridge constructed before the change need a reinforcement to adapt the new criterion. In this study, take up a deck type steel arch bridge and reveal its fatigue performance, furthermore, the effect and influence for fatigue of aseismic reinforcement that method is Strengthening the Arch rib using Concrete jacket by finite element analysis. As a result, the post member that connects an arch rib and a stiffening girder tends to occur fatigue damages, especially the shortest post is weakest member of the arch bridge. And the reinforcement produces an effect that reduces a displacement of whole structure or stress.
