Assessment of Railway Bridge Reliability Using Load Measurement Data

A methodology is introduced that allows to determine the reliability of railway bridges subject to freight trains and which comply with code based assessment according to the Swiss structural code SIA 269. The methodology uses probabilistic models for section forces from freight trains. These models are based on a large database of wheel load measurements. A case study demonstrates how the methodology is applied to determine the reliability of generic bridges and subsequently allows the assessment of the reliability for a portfolio of railway bridges. The results show that the target reliability is achieved according to SIA 269 considering the code format and current set of partial safety factors. The study identifies potential load bearing reserves for bridges with longer spans.