Thermal performance of CRTS Ⅱ slab track-bridge structure under extreme temperatures: Numerical simulation

Abstract

Large thermal deformation of CRTS Ⅱ slab track due to thermal effect is harmful to the operational safety of the high-speed railway. In order to explore the thermal deformation of the CRTS Ⅱ slab track under extreme ambient temperatures, the parameters of two bilinear cohesive zone models (CZMs) of vertical interlayer and longitudinal slab interlayer are firstly deduced by the splitting and shearing modelling tests, respectively. Secondly, the transient heat transfer models of CRTS Ⅱ slab track-bridge structure incorporatedwith two CZMs are verified by our previous thermal experimental results. Finally, thermal responses (e.g. temperature distribution, stress, and displacement) of the track structure are calculated under two extreme high temperatures (i.e.50℃ and 60℃) and two low temperatures (i.e.-20℃ and −40℃), respectively. Results show that the heat transfer model could effectively reflect thermal performance of the CRTS II track-bridge structure under extreme high and low temperatures. The internal temperatures and stresses of the track slab rapidly change in two hours and then have a slow change rate, an obvious mutation is found in the stress and displacement response under extreme high temperatures. Furthermore, the maximum arching displacement change from the ends of the track slab under the 50℃ to the middle of the track slab under the 60℃, while both the maximum warping displacement occur at the ends of the track slab under the −20℃ and −40℃, respectively.