Analysis of degradation process of a railway steel bridge in the final period of its operation

This paper presents the problem of assessing degradation process of a selected railway steel bridge in the final period of its operation. Changes in the technical condition of the analysed steel railway bridge in time on the basis of special inspections carried out in 2009-2014 are investigated. The methodology for conducting steel railway bridge assessment in an engineering approach is being presented taking into account conclusions and results from the subsequent special inspections. Moreover, the results of fatigue analysis and assessment of the steel railway bridge, which was put in service in 1933 are discussed. In order to conduct the fatigue analysis and assessment, the deflection of the structure under moving load is measured, as well as the geometry of the structural elements in the support zone is verified. The impact of rolling stock, in particular heavy freight transport, on the bridge degradation process is indicated. It is found that dynamic effects induced by the freight rolling stock reveal a big influence on the rate of fatigue damage process of the bridge. Additionally, the degradation of the considered railway bridge due to the effect of track misalignment is taken into account. Furthermore, the impact of corrosion damage and fatigue on the distribution of stresses in the bridge structure is also discussed.