An Evaluation Method for the Remaining Strength of a Plate Girder with Local Corrosion under Sleepers

Abstract There is a lot of local corrosion damage on the upper flanges under rail sleepers in the plate girder railway bridges. Since the sleepers are put on the upper flanges directly, the corrosion at the boundary progresses faster and causes a lack of the flange thickness through erosion, wet conditions among others due to contact of sleepers. Consequently, the strength of the plate girder decreases. Since the local corrosion often occurs on the upper flange under the sleepers, evaluation of the remaining strength of the plate girder with such corrosion damage is a very important problem for the maintenance. This paper presents an evaluation method for the remaining strength of a plate girder with local corrosion on the upper flange under sleepers, in which the remaining strength can be derived easily based on the buckling stress of the upper flange with lack of thickness due to corrosion. The ultimate behavior of the plate girder with corrosion is analyzed using the non-linear finite element method, and also some loading tests are conducted. In order to discuss the applicability of the evaluation formula, a comparison of the remaining strengths with the experimental and FEM results is made and it is concluded that the remaining strength can be accurately evaluated by the presented method.