连续梁桥无砟轨道标高控制研究

Study of Elevation Control of Ballastless Track on Continuous Beam Bridge

为提高连续梁桥无砟轨道的线路平顺性及行车舒适性,以某客运专线(70+125+70)m大跨度连续梁桥为工程背景,根据预拱度设置原则,对连续梁边跨活载预拱度进行修正,并针对收缩徐变、整体温度及梯度温度等影响铺轨标高的常见因素绘制修正曲线,给出连续梁桥标高控制的基本流程。结果表明:对连续梁边跨活载预拱度进行修正,可改善简支梁与连续梁连接处的转角平顺性;针对收缩徐变、整体温度和梯度温度等影响铺轨标高的常见因素进行修正,可使预拱度设置更加合理;以设计标高作为铺轨标高的做法会导致连续梁轨顶标高偏差较大,严重影响线路平顺性。

To improve the smoothness and riding comfort of the ballastless track laid on the continuous beam bridge,a long span continuous beam bridge with span arrangement(70+125+70)m on a passenger dedicated railway was taken as a case study.On the principle of setting of the pre-cambering,the live load pre-cambering of the side span of the bridge was modified and with reference to the common problems,such as the shrinkage,creep,general temperatures and gradient temperatures,having influences on the elevation of the track laying,the modification curves were plotted and the basic process flow of the elevation control of the track laying was accordingly given.The results indicate that the modification of the live load pre-cambering of the side span of the bridge can improve the smoothness of the rotation angle at the junction of the simply-supported beam and the continuous beam.The modification with reference to the common problems having influences on the elevation of the track laying can make the setting of the pre-cambering more reasonable.The way of taking the design elevation as the elevation for the track laying will lead to the great deviation of the track top elevation of the continuous beam bridge and will severely affect the smoothness of the track.