Interface damage and arching mechanism of CRTS II slab track under temperature load

Abstract

To study the interface damage and the arching deformation of China railway track system (CRTS) II slab track under high-temperature conditions, a three-dimensional (3D) finite element model of the CRTS II slab track was developed. A cohesive zone model (CZM) with a non-linear constitutive law was utilized to simulate the interface damage between the precast slab and the cement asphalt (CA) mortar layer. The model was verified by comparing the simulation results with the experimental results. The effects of the overall temperature rise and positive temperature gradient on the interface damage and deformation of the track structure under the different damage levels of the joint concrete were studied. The analysis indicates that when the joint concrete is intact, the interface between the precast and the CA mortar layer does not appear damage under the effect of the overall temperature rise or the positive temperature gradient. The damage of the joint concrete is an inducement for the interface damage and the arching of the slab track under the action of high temperature. The interface damage area and the height of the interface gap increase with the increase of the damage degree of the joint concrete. Especially under the action of the overall temperature rise, the interface gap can reach more than 30 mm. More attention needs to be paid to the construction quality and maintenance of joint concrete.