The main girders in a steel I girder bridge are connected with the slab, sway bracings and cross frames behaving together as a system. These members do not behave independently but behave as a structural system and have high redundancy. In this study, the effect of corrosion damage on load carrying capacity was evaluated using an FEM model of the bridge system assuming one or a few girders are corroded. As a result, the effect of load carrying capacity to the different corrosion damage were clarified quantitatively and an evaluation index for the load carrying capacity has been found.
