Comparison of Approaches to Reliability Verification of Existing Steel Railway Bridges

Many existing steel railway bridges are exposed to degradation and increasing traffic loads. Their reliability assessment may contribute to sustainability in construction particularly when these bridges are kept in service. The sustainability aspects mainly relate to reducing waste material and to unnecessary replacements of existing bridges. The key aspects of assessment include specification of the target reliability and selection of an appropriate assessment method. The most efficient verification methods are based on advanced probabilistic approaches. The application of the adjusted partial factor method seems to be reasonable as it provides the balance between demands on the input information, computational complexity, and achieved improvements in reliability assessment. In this contribution, the advanced reliability approach is illustrated by an example of the assessment of a 90-years old steel railway bridge. This case study demonstrates that advanced reliability approaches may significantly improve assessment and allow to increase the estimated load-bearing capacity of the bridge by 10 to 20%