Fatigue crack and its retrofitting method in a curved I girder bridge

In Korea, most of steel bridge have the shape of box type and have been mainly applied to curved section. However, there are some cases that I type girder were applied in curved bridges. Such I type girder has structural disadvantage compared to box type due to torsional forces, and potential of damage by fatigue is considered to become higher as time goes by. In this study, cause of fatigue cracks in a curved steel I girder bridge was investigated through visual inspection and stress and deflection measurement under actual traffic flow, and structural behavior characteristics of the bridge was examined by conducting detailed structural analysis. In addition, a retrofitting method was suggested for the cracks and its validity was confirmed through detailed finite element analysis.