Fatigue Life Evaluation of Welded Railway Bridges Based on Field Measurements

Fatigue life evaluation of existing bridges is an important task especially for bridges reaching design life or subjected to increasing traffic volume. This paper presents probabilistic fatigue life assessment of welded railway bridge based on field measurement and numerical methods which can be applied to any fatigue sensitive structure. Due to the unavailability of details for setting up measuring devices, scope of the measurements etc., it is not always possible conduct measurements for all critical details. Field measurements in some critical details in the structure can give the basis for reliability analyses and fatigue life assessment in all critical details. In this paper fatigue life is defined as time when critical detail in structure reaches target reliability level. Fatigue reliability analysis is based on S-N concept and Miner’s linear damage hypothesis taking into account model uncertainties and different probability density functions of stress ranges.