研究目的:为了明确梁轨纵向相互力学行为对无砟轨道路桥过渡段道床板翘曲的影响,建立路桥过渡段处双块式无砟轨道桥上无缝线路及道床板力学计算模型,研究桥梁及轨道结构约束作用、钢轨伸缩力、道床板温度梯度等对道床板翘曲变形的影响。研究结论:(1)考虑桥梁及轨道结构的约束作用时,道床板上拱量相对增大约28%,达到2.5 mm;考虑桥上无缝线路纵向附加力时,桥台附近的钢轨伸缩变形会降低道床板的上拱量约44%,降为1.4 mm,且随着钢轨伸缩力的增大,降低值越大;(2)正温度梯度作用下,道床板上拱量有所增加,增大约43%,达到2.1 mm,而负温度梯度作用下道床板上拱量有所减小,减小约14%;(3)桥梁升温幅度越大,道床板上拱量越小,且随着温度幅度的增加,降低趋势变缓;(4)对于大跨度桥梁梁缝处铺设伸缩调节器时,道床板上拱量较主桥铺设小阻力扣件工况增大约1.2倍,增大到7.8 mm;(5)该研究结论对无砟轨道路桥过渡段设计优化理论和工程实践具有一定指导意义。
Research purposes: In order to clarify the influence of longitudinal mechanical behavior between the bridge and the hallastless track on the warping of reinforced concrete slabs in the subgrade - bridge transition section, a mechanical model including CWR and slab on bridge is set up, so as to study the effects of the restriction of bridges and track structure, the rail additional expansion and contraction force, and the temperature gradient of the slab on the slab warping. Research conclusions: (1) When considering the restriction effect of bridge and rail, the upwarping increased by 28% reaching to 2. 5mm compared with no consideration of the bridge and track structure. When considering the rail longitudinal force, the upwarping of the slab decreased by 44% reaching to 1.4mm, and the stronger rail longitudinal force results in more reduction of the slab warping. (2)When considering the positive temperature gradient effect, the warping increased by about 43% reaching to 2. 1mm. The negative temperature gradient effect made the warping decrease by 14%. (3)The more increase of the bridge temperature led to the smaller upwarping, but the impact decreased gradually when the bridge temperature reached high enough. (4)The warping of the slab greatly increased by 1.2 times reaching to 7.8mm when laying the rail expansion joint (REJ) in the beam gap of large - span bridge compared with lay small resistance fasteners in main bridge. (5)The research conclusions have certain guiding significance for the optimization of the design theory and engineering practice in the subgrade - bridge transition section.