Analytical study on geometrical irregularity and internal loads of railways with CRTS I ballastless tracks on arch bridges subject to thermal effects

Temperature variation causes geometrical irregularity and additional internal loads in railway systems. The geometrical irregularity and additional internal loads can adversely influence the dynamic behaviors of trains, therefore compromising the safety and ride comfort of trains. This paper presents an analytical study on the deformations and internal loads of railways with CRTS I ballastless tracks on an arch bridge. The bridge is located in the Sichuan-Tibet Railway Line within a high-altitude mountainous terrain exposed to significant temperature variations. This research derives analytical formulae to analyze the deformations and internal loads of railways under various temperatures and thermal gradients. The formulae are utilized to evaluate the effects of the stiffness of fasteners and the stiffness of isolation layers of CRTS I ballastless tracks. The results show that temperature changes cause significant vertical deformations and rotations of rails, and reducing the stiffness of fasteners and isolation layers is effective in mitigating rail deformations under the thermal effects.