Research On The Applicability Of The Ballastless Track Structure System Of The Main Span 400m Dual-purpose Cable-stayed Bridge

This paper takes the steel truss cable-stayed bridge with a span of(112+175+400+197+108)m in the north branch of the Yangtze River along the high-speed railway as the background project.Based on its construction requirements for laying ballastless tracks,the Numerical analysis method is used to analyze the structural deformation characteristics of the background engineering cable-stayed bridgeballastless track,and to discuss the feasibility and related technical indicators of the background engineering to lay the ballastless track.The main work and achievements are as follows:1)Based on ANSYS software,a refined finite element analysis model of the cable-stayed bridge for both highway and railway in the north branch of the Yangtze River was established,and the Midas model was used to verify it.The calculation results of the two finite element models were compared and checked with the design results.In this paper,ANSYS finely analyzes the correctness of the model.2)Discussed the rationality and feasibility of laying ballastless track on a cable-stayed bridge with a main span of 400 m.The overall deformation characteristics of the bridge,such as the vertical stiffness of the beam end,the angle of the beam end,the equivalent vertical curve radius,the local deformation characteristics of the internodes,the deformation curvature of each structural layer of the ballastless track,and the stress condition analysis of the rail;considering the interlayer of the ballastless track isolation layer The compression amount,the longitudinal deformation of the track slab and the base slab,and the longitudinal relative displacement of the beam and rail are analyzed to analyze the compatibility of the cable-stayed bridge for road and rail-ballastless track deformation;based on the static acceptance standard of 60 m chord length,the track height irregularity and torsion are analyzed.The results show that the bridge can be laid with CRTS III ballastless track with rubber isolation layer.3)Comparative study on the follow-up of ballastless track with rubber isolation layer and geotextile isolation layer under various load conditions,the results show that the deformation follow-up performance under the geotextile isolation layer is poor,while the deformation coordination between the layers can be improved under the rubber isolation layer sex.4)The local flexural deformation characteristics and the interlayer effect of the isolation layer under different ballastless track layouts are compared and analyzed for non-span inter-node layout and inter-node layout,inter-node 2-plate and inter-node 3-plate layout.The results show that the flexural deformation rate of the local upper arch and the maximum void volume between layers of the track slab in the way of laying across the internodes are slightly twice as high as those in the way of not spanning the internodes.The beam-ballastless track deformation coordination.Based on comprehensive comparison and selection,suggestions on the structure selection and design parameters of ballastless track laying in the background project are given: rubber isolation layer CRTSⅢ type slab ballastless track is used,no slabs are laid across the internodes,and two6170 mm slabs are used for the 12.5m internode.,12m-long internodes use2 pieces of 5920 mm board length.The thesis includes 78 figures,30 tables,and 90 references.