Mesoscale modelling of CRTS II slab tracks subjected to thermal action and vehicle loads

Abstract

Evaluation of the damage and deformation of cast-in-situ concrete joints between the precast concrete track slabs of the China Railway Track System (CRTS) II is crucial to the safe operation of high-speed railways. To investigate the damage and deformation evolution of concrete joints under thermal action (caused by the natural meteorological environment) and vehicle loads, a two-dimensional thermal–mechanical coupled numerical model of concrete joints at the mesoscale was developed. This model analyses the influence of three factors – concrete strength, maximum diameter of the joint concrete aggregate and vehicle speed. First, meteorology and heat transfer theory were used in thermal simulations. Then, the non-linear characteristics of the joint concrete were modelled as a two-phase composite material based on the random aggregate algorithm and strain-based elastic damage theory at the mesoscale. The cohesive zone model was used to simulate the interfaces between precast slabs. The reliability of the proposed model was assessed using field measurements. The results of a numerical example showed that the maximum aggregate diameter of the joint concrete significantly affected damage evolution in the joint concrete and concrete strength has a slight effect on joint uplift.