Study on the spatial mechanical characteristics of welded turnout on the bridges for passenger dedicated lines

Abstract

In order to solve the problems of stress and deformation of welded turnout on Hongzuihe super large bridge for passenger dedicated lines,a spatial coupling model of welded turnout on bridge is set up according to the structures and arrangement forms of turnout and bridge.The spatial mechanical characteristics induced by temperature load,vertical load,transverse deformation of rail,etc.are analyzed.The results show that the maximum value of the rail additional expansion and contraction force appears at the movable end of girder body under temperature load,and it is influenced significantly by the distance between the fixed and movable bearings.The relative displacements between the switch rail and the nose rail,point of nose rail and wing rail are smaller,and within the expansion range of the external locking device.When applying load fully on the half of continuous beam,rail longitudinal displacement,additional deflection force and bridge vertical deflection reach maximum.When applying load fully on the straight single-track line of the beam,bridge transverse deflection and torsion value reach maximum.Rail transverse deformation induced by temperature load is relatively small,and has little influence on the reduction rate of wheel load and derailment coefficient.Because of all sorts of factors such as high standard of passenger dedicated line and complicated structure of turnout and bridge,the influence of rail transverse deformation should not be ignored.It is suggested that the spatial mechanical characteristics should be considered in designing the welded turnout on bridge for passenger dedicated lines.