Abstract: By taking a 156m large-span simply-supported steel truss girder on the Huangling-Hancheng-Houma line as a case,the influence of adjacent bridges on the longitudinal force distribution in the continuously-welded rail (CWR) on the steel truss girder is analyzed,and some suggestions are presented for the selection of relevant pa- rameters.In the investigation,nonlinear spring is used to simulate the longitudinal resistance of CWR and the beam element with rigid arms is employed to simulate the steel truss bridge.Calculation results show that (1) when the longitudinal stiffness of the substructure has no obvious variation,the multi-span simply-supported beams at both sides of the steel truss girder can be simplified into a girder with 6 spans for analyzing the longitudinal force; (2) as compared with the standard span of 32m for simply-supported beams,a span of 24 m may result in a force de- crease at the fixed end by 9%,while a span of 40m may result in a force increase by 7%; (3) by taking the adja- cent large-span continuous beam into consideration,the longitudinal force at the fixed end of the steel truss girder increases by 2. 2 times and the maximum compressive stress of the full bridge increases by 12%; (4) the longitudi- nal force at the fixed end of the steel truss girder is significantly reduced when simply-supported beams with one or two spans are arranged between the continuous beam and the steel truss girder; and (5) fasteners with small resis- tance helps to reduce the maximum stress and the horizontal force loaded on the pier.

Key words: railway bridge, railway engineering, long-span steel truss girder, adjacent bridge, small-resistance fastener