Analysis of Factors Influencing Longitudinal Force of Welded Turnout on Simply Supported Beam Bridge

Based on the characteristic of longitudinal interaction of welded turnout on a bridge,a finite element model for welded turnout-bridge-platform was established.By taking No.18 welded turnout on a simply supported beam bridge as an example,factors influencing its longitudinal force and displacement were analyzed.These factors are the temperature of rail,the temperature of bridge,the length of beam,the layout of support,the stiffness of pier,the structure of frog heel,and the resistance of fastening and ballast.Calculational results show that the influence range of welded turnout on a simply supported beam bridge was within two spans.The arrangement of welded turnout on simply supported beam bridges should make the expansion displacement directions of the turnout lead rail and the beam be opposite.The longitudinal stiffness of piers under welded turnout should be increased,and spacer block should not be adopted as the frog heel of welded turnout on a simply supported beam bridge.The No.18 welded turnout is suitable for laying on a simply supported beam bridge with a span of 32 or 48 m.