关键词: 钢桁梁, 梁端横向伸缩, 轨道, 横向位移

Abstract: In order to obtain influence of beam-end lateral expansion of steel truss girderon geometrical shape of track，finite element method was employed to establish the calculation model． The model was to analyze variation of geometrical shape of ballast track and its influence factors when relative subgrade of beam-end of steel truss girder had horizontal expansion under the action of the diurnal temperature range． Results indicated that lateral relative expansion between the steel truss girder and subgrade made larger lateral displacement of ballast track while it exerted little influence on track gauge; ballast and fastening lateral resistance had little effect on lateral displacement of track，and on the change rate of track alignment after its increase to normal value when beam-end of steel truss girder had horizontal expansion; the distance from lateral fixed support of steel truss girder to central line of the route was mainly responsible for variation of geometrical shape of track． If the distance could be controlled within 6． 7m，the maximal lateral displacement track would be less than 2mm and change rate of track alignment less than 1‰．

Key words: steel truss girder, beam-end lateral expansion, track, lateral displacement