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

摘要

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 Lambda-shaped cracks can make track slabs suffer an up-warp deformation with an angle at the apex, while v-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 degrees were found not to affect the vertical deformation, while penetrating cracks with an angle less than 35 degrees 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.