Reliability assessment of welded steel details in bridges using inspection

This paper presents a bilinear two-dimensional probabilistic fracture mechanics model for fatigue crack growth in welded steel details. The model takes besides membrane stresses also the influence of misalignments and bending stresses in the welded detail into account. The distribution of the membrane stresses are estimated using a generic bridge structure and traffic measurements. The optimal reliability level for a welded detail in a bridge subjected to fatigue are estimated by cost benefit-analysis taking into account the risk of human lives through the Life Quality Index. Since the optimal reliability level is higher than the estimated reliability level, it is investigated how planned and reliability-based inspections techniques can be used to update the reliability level