Research On Interaction Between Girder And Track On Modern Trams Bridge With The Structure Of Embedded Track

The application of CWR (continuously welded rail) on the embedded track paved on the bridge for the modern trams has improved the running performance of modern trams, reduced dynamic effect of tramcars and the work load of maintenance, extended the service life of track components and bridges. However, the interaction between girder and track, which not only produces the additional longitudinal force on rail, bearing and pier top, but also causes problems about CWR in terms of strength and stability, which affects the laying of CWR. Based on the domestic and international researches before, this paper has done some researches on the girder-track interaction between the CWR on the embedded track and the bridge for modern trams and the design method of stress-free rail temperature. The main research works are as follows:Firstly, the mechanism of the girder-track interaction between the CWR on the embedded track and the bridge for modern trams has been studied. The reason and process of contractility, force of flexion and braking force of CWR have been analyzed. The influencing factor on girder-track interaction has been discussed.Secondly, the function and the performance of each components of the embedded track have been analyzed. The calculation model of the girder-track interaction on the basis of the research results has been established. What’s more, the computing ideas and methods has been elaborated.Afterwards, the special railway line with the structure of the continuous beams and simply supported beams has been selected as the research object according to the actual project of the Golden Phoenix Avenue in Chengdu. Based on the calculation model established above, many points have been analyzed and researched, including the influence on additional longitudinal forces of CWR, the relative displacement of girder-track, the additional longitudinal forces of bearing and the pier top from longitudinal resistance of track, the stiffness of bearing shear, the longitudinal stiffness at pier top, braking ratio and so on.Finally, the model of stability has been established, and the allowable temperature rise range to reach stability has been calculated through analyzing the concept of stability, process of instability and influencing factors on CWR on the embedded track paved on the bridge for the modern trams. The dynamic bending stress from rail has been studied when tramcars pass by using quasi-static method. The allowable temperature rise range and allowable temperature drop range have been calculated respectively through strength condition. calculated and discussed on the calculation methods of the stress-free rail temperature of CWR on the bridge has been studied.