Mechanical behavior and track geometry evaluation of long-span cable-stayed bridges with ballastless tracks

Abstract

Ballastless tracks have been widely used in China’s high-speed railways; however, they have only recently been laid on 300 m-class cable-stayed bridges. For cable-stayed bridges with a longer span, the mechanical behavior of ballastless tracks is unclear, and the track construction acceptance method is incomplete, restricting the development of cable-stayed bridges with ballastless tracks. Taking four 300–1000 m-class cable-stayed bridges as research objects, this study established static track–bridge interaction models and dynamic vehicle–bridge coupled models. By evaluating static and dynamic indices, the feasibility of laying ballastless tracks and operating high-speed trains at 350 km/h on cable-stayed bridges was analyzed. Based on the results of dynamic analysis and track geometry evaluation, a 40 m chord was proposed for track geometry acceptance on cable-stayed bridges. The accuracy of the simulation results was verified through the measured data from the Xi-Cheng Railway. The numerical results showed that the 300–1000 m-class cable-stayed bridges with ballastless tracks had good static and dynamic characteristics. The 300 m baseline was unsuitable for the long-wave irregularity evaluation of tracks on cable-stayed bridges, and the 60 m chord was easily affected by wavelengths above 200 m, leading to misjudgment of the evaluation results. The 5 mm limits of the 40 m chord could be used for track geometry acceptance on cable-stayed bridges. Finally, a comprehensive evaluation method for track geometry, namely 10 m chord, 40 m chord, and minimum vertical curve radius, was formed.

Keywords:

• Ballastless track
• cable-stayed bridge
• high-speed railways
• track–bridge interaction
• track geometry
• vehicle–bridge coupling vibration

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study is supported by the National Natural Science Foundation of China (Grant No. 52078498; 52308223), Natural Science Foundation of Hunan Province of China (Grant number: 2022JJ30745), Hunan Provincial Science and Technology Promotion Talent Project (Grant number: 2020TJ-Q19), Frontier Cross Research Project of Central South University (Grant number: 2023QYJC006), Science and Technology Research and Development Program Project of China Railway Group Limited (Major Special Project, No. 2021-Special-04-2), Natural Science Foundation of Hunan (Grant number: 2022JJ40628), and Scientific Research Project of Hunan Provincial Department of Education (Grant number: 21A0010).