An　enhanced　fatigue　assessment　of　critical　welded　details　in　a　steel-concrete　composite　railway　bridge　was　carried　out　by　fatigue　crack　propagation　analysis　based　on　linear　elastic　fracture　mechanics　(LEFM).　The　most　fatigue　critical　connections　concerned　in　this　study　were　identified　by　the　preliminary　fatigue　assessment　based　on　the　S-N　method　in　the　previous　research　of　the　authors　Zhou　et　al.　(2013).　Three-dimensional　crack　models　of　the　critical　connections　were　incorporated　into　the　global-local　finite　element　model　of　the　bridge.　The　stress　intensity　factor　(SIF)　histories　of　the　cracks　were　calculated　through　dynamic　analysis　of　the　bridge　due　to　the　high-speed　train　passages,　which　validated　the　applicability　and　the　accuracy　of　the　empirical　SIF　formulas　for　the　concerned　bridge　details.　The　fatigue　crack　growth　curve,　represented　by　crack　size　versus　number　of　train　passages,　was　obtained　through　crack　propagation　analysis　based　on　the　Paris　law　and　LEFM,　and　fatigue　propagation　life　was　predicted　for　each　critical　connection.　The　proposed　crack　propagation　analysis　method　provides　a　general　and　alternative　approach　to　evaluate　the　fatigue　life　of　welded　details　in　steel　bridges.　(C)　2016　Elsevier　Ltd.　All　rights　reserved.