桥上单元板式无砟轨道无缝线路的适应性

为研究适应连续梁桥上单元板式无砟轨道的最大温度跨度，采用有限元方法建立了线-板-桥-墩一体化计算模型，分析了在不同轨温变化幅度下，桥梁伸缩、墩顶水平位移及列车制动荷载对桥上单元板式无砟轨道无缝线路温度跨度限值的影响.研究结果表明:温度跨度限值随轨温变化幅度的增加而降低；为保证钢轨强度、横向压弯变形及钢轨与轨道板相对位移等满足要求，当考虑桥梁伸缩时，以轨温变化40 ℃为例，其适应的温度跨度限值为271 m；随着墩顶水平位移的增加，桥梁温度跨度限值显著降低，当墩顶位移为30 mm时，温度跨度为237 m，当高墩桥梁墩顶位移超过30 mm时，应结合实际墩顶位移计算温度跨度限值；制动荷载下线路坡度对温度跨度限值影响较小，当线路坡度为20‰时，桥梁温度跨度限值为258 m. 

Adaptability of Continuous Welded Rail of Unit Slab Non-ballast Track on Bridges

To investigate the reasonable limit value of the distance between two fixed bearings of a continuous beam bridge on which unit slab non-ballast track was layed, a rail-slab-bridge-pier integrated model was established by the finite element method. In conditions of different rail temperatures, the influence of bridge temperature change, the lateral displacement at the top of pier, and train braking on the limit value of the distance between two fixed bearings of the continuous beam bridge was analyzed. The results show that the limit value decreases with an increase in the amplitude of rail temperature variation. Taking the rail temperature variation of 40 ℃ for example, the limit value is 271 m due to the requirements of rail strength, transverse bending deformation, and the relative displacement between rail and slab. With the increase of the lateral displacement at the top of pier, the limit value decreases significantly. When the displacement is 30 mm, the limit value is 237 m. When the displacement is more than 30 mm, the limit value should be calculated in dependence on the actual displacement at the top of pier. In addition, the track gradient has little influence on the limit value under braking load condition: When the track gradient is 20‰, the limit value is 258 m.