研究目的:大跨度桥上铺设单元板式无砟轨道所诱发的梁轨相互作用问题较之普通桥上无缝线路更为复杂,其纵向变形控制在既有规范和工程实践应用中存在不足。本文采用有限元方法建立线-板-桥-墩一体化计算模型,研究连续梁桥墩纵向水平刚度对单元板式无砟轨道无缝线路各部件受力及变形的影响,并提出无砟轨道纵向变形控制指标,为桥上铺设单元板式无砟轨道无缝线路提供理论依据。研究结论:(1)桥梁伸缩荷载下,通过铺设小阻力扣件可显著降低凸台周围树脂变形;列车制动荷载下,铺设小阻力扣件并不能有效降低树脂变形;(2)在伸缩荷载或断轨作用下,增大桥墩刚度并不能降低树脂变形量,但对于制动荷载,增大桥墩刚度可以显著降低树脂变形量,为确保树脂层变形低于3 mm,树脂层刚度最小值为70 kN/mm;(3)对于(60+100+60)m连续梁,铺设常阻力扣件时,轨温变化幅度高于40℃时需要铺设钢轨伸缩调节器,轨温变化幅度为30℃时满足无砟轨道强度和纵向变形要求的桥墩刚度限值为1 800 kN/cm;(4)该研究结论可为桥上无砟轨道设计提供一定的理论依据。
Research purposes: When the large span bridge lay unit slab non - ballast track, the problems of interaction between beam and rail become more complicate than the ordinary CWR, and the longitudinal deformation control is insufficient in the existing norms and application of engineering practice. The line - bridge - pier integration model of continuous welded rail is established to research the influence of the longitudinal horizontal stiffness of continuous beam bridge pier on the force and deformation of unit slab non - ballast, and put forward the non - ballast track longitudinal deformation controlling index, which can provide the theory basis for laying unit slab non -ballast track on the bridge. Research conclusions: ( 1 ) Under bridge expansion load, laying out the small resistance fasteners can significantly reduce resin deformation around the boss. Under train braking load, laying out the small resistance fasteners cannot reduce resin deformation effectively. (2) Increasing the stiffness of pier cannot reduce resin deformation under bridge expansion or rail breaking load, but can obviously reduce resin deformation under train braking deformation lower than 3 mm, the resin stiffness limit is 70 kN/mm. (3) For (60 + 100 +60) m load, to ensure resin continuous beam and laying out constant resistance fasteners, it is required to lay rail 40 ℃. When rail temperature range is 30 ℃, the pier stiffness and longitudinal deformation requirement. (4) The research bridge. expansion joint when rail temperature range is high than limit is 1 800 kN/cm to meet non -ballast track results are helpful to design of non -ballast strength track on