Design Research On The Terminal Spine Of Crts Ⅱ Ballastless Track Slab On The Connecting Section Of Bridge And Tunel

Because ballastless track has advantage of high stability, less maintenance workload and relatively mature technique and so on, the wide use of ballastless track on the high-speed railway becomes the development trend in the worldwide, specially, it is general for the slab track.In china, the slab track is used in some passenger dedicated lines. But the researches relate to structure design, construction method and later maintenance, and specially the technique of the slab track used in the transition section and special sections are required to be further in-depth study, and gradually improve its economic efficiency.In this paper, CRTSⅡslab track used in the special section of Beam Bridge-Tunnel-Continuous Beam Bridge is the research object, a spatial model of line slab bridge is established to analyze and calculate the force and displacement of the bridge, the slab, and the rail under the action of temperature strength and braking force. The optimal design of the terminal spine can be obtained. Finally, the friction slabs of different length and different friction coefficients were analyzed in the paper, obtaining the reasonable value in the special section.The conclusion:By comparison of several programs, only one terminal spine is needed in the tunnel in the case of temperature force. Because of the impact of temperature change which results in transition section in rail in the entrance and exit of tunnel, where additional force will suddenly increase, the maximum displacement of the rail and the jointed slab occurred in the center of the tunnel. Therefore, the connection of the regions has to be re strengthened in the design, which can ensure that there is no larger alignment irregularity. However, in the case of braking force, it is necessary to design two terminal spines so that the longitudinal force of the whole structure can be distributed uniformly. Finally, the paper analyzes the magnitudes and distribution regularities of maximum longitudinal forces of the rail, track slab and piers changing some parameters such as the length and coefficient of friction slab and the stiffness of terminal spine, through which appropriate length of the friction slab is 50m. the friction coefficient is 0.8.