Temperature Filed Experimental Study of Longitudinally Connected Ballastless Track On Bridge in One Year Period

摘要

There are about 4500 kilometers CRTSⅡ (longitudinal continuous slab ballastless track) in thernoperating high-speed railway in China now. The track plate surface cracks are easily caused onrnLongitudinal continuous track structure under the temperature load. To get the temperaturerndistribution in this structure, a continuous observation of CRTSⅡ(China Railway Track SystemⅡ)rnby using temperature sensors was taken in China. Based on one year’s observation the timedependentrndeformations of vertical temperature gradient in different kind of season were discussed.rnBased on statistics and curve-fitting, raised temperature load models which was fit for the typicalrnarea in China. The analysis results showed that: The unballasted track temperature field isrninfluenced by many environmental factors, and the temperature field is formed by collectiverncoupling, and one of the main factors is the solar radiation. The changing of the temperature in therntrack structure is fast, the temperature changing value of surface was 16℃ in maximum, 8℃ inrnaverage, the temperature changing value became small, and the time of maximum temperaturerncome late with the increase of distance to surface. Fitting curve of vertical temperature gradient inrnlongitudinally connected ballastless track on connected bridge can be exponential curve, and therndistribution law matched the provisions about the vertical temperature gradient of the code forrndesign of railway bridge and culvert in China.