摘要：研究目的：桥隧过渡段处钢轨在梯度温度力作用下将发生纵向爬行，影响无缝线路稳定性。本文以轨温过渡区钢轨为研究对 象，建立钢轨位移微分方程，推导轨温分布与钢轨纵向位移的映射关系，从而揭示影响无砟轨道钢轨爬行的规律 。研究结论： (1)考虑扣件阻力非线性的钢轨纵向位移量和变形范围均远大于线性阻力模型；对钢轨最大位移量而言，轨温非 线性分布相较于线性分布高出5.3%~38.6%，建议同时考虑轨温和纵向阻力非线性以准确获得过渡段钢轨爬行位移 ；(2)轨温差一定时，随着最大温度力梯度倍数k从1.5变化至3.5，轨温过渡区长度为10 m时，钢轨最大纵向 位移增加了7%，而过渡区长度为40 m和50 m时分别增加了26.7%和32.8%，因此对于轨温差大、轨温过渡区长 的过渡段，更应关注轨温非线性分布；(3)扣件极限阻力增大将使钢轨爬行量显著降低，但影响程度有限，极限 阻力从6.5 kN/(m·轨)增加至12 kN/(m·轨)，钢轨位移量下降40.8%~49.2%，而从24 kN/(m·轨)增加至30 kN/ (m·轨)，仅下降12.8%~24.4%；(4)推导的解析表达式能够准确描述各参数与钢轨纵向位移的映射关系，对于进 一步研究过渡段钢轨受力特性以及改善无缝线路稳定性具有参考价值。

Abstract：Research purposes： The rails at the transition between bridge and tunnel will crawl longitudinally under the effect of temperature gradient, which influences the stability of CWR. Taking the rail at the temperature transition zone as the research object, the differential equation of rail displacement was established, the mapping relationship between rail temperature distribution and longitudinal displacement was deduced, and the law of influencing rail crawl of ballastless track was revealed in this paper.  Research conclusions： (1) The longitudinal deformation and its range of nonlinear resistance model is much larger than the linear resistance model; for the rail maximum displacement, the non-linear distribution of rail temperature is 5.3%~38.6% higher than that of the linear distribution. It is suggested to consider the non-linearity of rail temperature and longitudinal resistance to accurately obtain the rail displacement at the transition. (2) When the rail temperature difference is constant, with the maximum temperature force gradient ratio k varying from 1.5 to 3.5, the largest rail longitudinal displacement increases only 7% when the transition zone length is 10 m but it increases 26.7% and 32.8% respectively when the length is 40 m and 50 m. Thus, more attention should be paid to the nonlinear rail temperature distribution for the transition with high rail temperature difference and long rail temperature transition zone. (3) The increase of limit resistance of fasteners will reduce the rail crawl significantly, but the influence degree is limited. The rail displacement decreases 40.8%~49.2% with the limit resistance varying from 6.5 kN/(m·rail) to 12 kN/(m·rail), but when the resistance changes from 24 kN/(m·rail) to 30 kN/(m ·rail), the slippage only is only 12.8%~24.4%. (4) The analytical expressions can accurately describe the mapping relationship between the parameters and the rail longitudinal displacement and provide useful references for further study of force characteristics of rail at the transition and improving the stability of CWR. 