桥梁竖向变形引起的中低速磁浮轨道不平顺分析

Analysis on Track Irregularities of Medium-low Speed Maglev Transit Induced by Bridge Deformation

为了揭示桥梁竖向变形引起的中低速磁浮轨道不平顺问题,建立4跨磁浮轨道-桥梁结构有限元模型,计算分析单墩沉降、梁体竖向转角和梁体竖向错台引起的中低速磁浮轨道F轨竖向变形。结果表明,当单墩沉降量达到15 mm时,F轨轨面10 m弦矢高为2.95 mm,接近其容许限值3 mm,说明现有规范规定的相邻墩台沉降差限值5 mm过于严格;当梁体竖向转角为0.2‰rad时,转角附近F轨轨面高低差达到5.3 mm,建议梁体竖向转角控制在0.1‰rad以下;当梁体竖向错台为3 mm时,F轨轨面高低差达到3.32 mm,建议梁体竖向错台控制在2 mm以下。

In order to reveal track irregularities of the medium-low speed maglev track caused by the vertical deformation of bridge,a finite element model of the four span bridge with the span length of 25 m and the track is built.Then,the vertical deformations of the F-shaped rails induced by the single pier settlement,the vertical rotation and the stagger step of beam are calculated respectively.The results show that the rise of arch in the 40 m chord length reaches 2.95 mm,which is very close to the allowable limit 3.0 mm,when the settlement of the single pier is 15 mm.It indicates that the 5 mm allowable limit of differential settlement of both adjacent abutments specified by the existing design standard is too strict.The height difference between the F-shaped rails near the rotation angle arrives at 5.3 mm when the vertical rotation angle of beam is 0.2‰rad,so it is suggested that the vertical rotation angle of beam should be less than 0.1‰rad.In addition,the height difference between F-shaped rails is 3.32 mm when the stagger step of beam is 3 mm,thus it is suggested that the stagger step of beam should be less than 0.1‰rad.