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.