Probabilistic fatigue life prognosis for steel railway bridges after local inspection and repair

Steel railway bridges are exposed to repeated train loads which often cause fatigue failure. To guarantee the target fatigue life, bridge maintenance such as local inspection and repair should be properly provided based on accurate fatigue life prognosis, but it is a challenging task because there are various sources of uncertainty associated with bridges, train loads, environment, and maintenance work. For the optimal risk-based maintenance, it is thus essential to predict the probabilistic fatigue life of a steel railway bridge and update the life prognosis information based on the results of local inspection and repair. In this research, a probabilistic approach is proposed to estimate the fatigue failure risk of steel railway bridges and update the prior information of fatigue life prognosis after bridges are inspected and repaired. The proposed method is applied to a generic steel railway bridge, and the effects of local inspection and repair on the probabilistic fatigue life prognosis is discussed through parametric studies