Comparative Analysis of Track-Bridge Interaction of Sliding Slab Track and Rail Expansion Joint for Long-Span Railway Bridge

Sliding slab track system, which consists of low friction sliding layer between track slab and bridge deck, is recently devised to reduce track-bridge interaction effect of continuously welded rail(CWR) without applying special devices such as rail expansion joint(REJ).In this study, a series of track-bridge interaction analyses of a long-span bridge with sliding slab track and REJ are performed respectively and the results are compared.The bridge model includes PSC box girder bridge with 9 continuous spans, and steel-concrete composite girder bridge with 2 continuous spans.The total length of the bridge model is 1,205m, and the maximum spacing between the two fixed supports is 825m.Analyses results showed that the sliding slab track system is highly effective on interaction reduction since lower rail additional axial stress is resulted than REJ application.Additionally, horizontal reaction forces in fixed supports were also reduced compared to the results of REJ application.However, higher slab axial forces were developed in the sliding slab track due to the temperature load.Therefore, track slab section of the sliding slab track system should be carefully designed against slab axial forces.