Effects of crack status on stability of longitudinally coupled prefabricated track slab

Through analysing the stress and deformation of a longitudinally coupled prefabricated track slab (LCPTS) with cracks at high temperature, an analysis model for the stability of LCPTS with cracks was established based on the finite-element method and was tested by a scale model on-site. The effects of crack status on the stability of track slabs under the action of a temperature rise were studied through simulations. The results showed that ∧-shaped cracks can make track slabs suffer an up-warp deformation with an angle at the apex, while ∨-shaped cracks will cause track slabs to have two peaks at both sides of the crack. Cracks of depth 15 cm are most likely to cause track slab up-warp. Oblique non-penetrating cracks with an angle less than 45° were found not to affect the vertical deformation, while penetrating cracks with an angle less than 35° did not lead to yielding of the reinforcing bars or affect the normal operation of track structures. For track slabs with a crack spacing of less than 5 m, the vertical displacement will be affected by adjacent cracks. Therefore, in order to ensure the stability of LCPTS at high temperature, the crack status should be closely monitored.