Study on temperature field and thermal stress of CRTS Ⅲ slab track on simply supported beam bridge

ZHANG Pengfei; LIU Shuyu; JIANG Haoyu; YU Lu; YANG Aochuang

doi:10.11860/j.issn.1673-0291.20240142

Abstract：To investigate the variation patterns of the temperature field and thermal stress in seamless CRTS Ⅲ slab tracks on simply supported beam bridges under high-temperature conditions,an indi-rect heat-stress coupling analysis method is employed.A finite element model of the coupled structural system of the heat-ballastless track is established to analyze the distribution and evolution of the tempera-ture field,as well as the longitudinal force,stress,and displacement distribution between track structure layers under high temperatures.The results indicate that the temperature of each structural layer of the bal-lastless track exhibits a wave-like variation with ambient temperature.Over the course of a day,the maxi-mum and minimum temperatures,53.1℃and 26.4℃,respectively,occur at the top of the track slab.The amplitude of the temperature time-history curves decreases with increasing vertical depth of the track struc-ture,and the peak temperature shows a time lag.In summer high-temperature conditions,the temperature gradient of the track slab approaches zero around 11:00 and 21:00;the positive gradient peaks at 85.5℃/m at 15:00,while the negative gradient peaks at-43.8℃/m at 03:00.As the depth of the track structure in-creases,the temperature gradient gradually decreases.Under single-day high-temperature conditions,the rail longitudinal force and track structure displacement reach their maximum around 18:00 every day,repre-senting the most unfavorable state,while the longitudinal stress in the track slab and self-compacting con-crete layer peaks between 14:00 and 16:00.These findings provide a t theoretical reference for monitoring and maintenance of track structures in high temperature regions during summer.