To find out the influence of external loads on non-linear damage and service performance of slab track in severe cold regions, from the perspective of micro-damage mechanics, a refined model of CRTSⅢ slab track-subgrade was established, which considered concrete plasticity and structural reinforcement. The deformation of track structure and the damage law of concrete base under different frost heave conditions were analyzed. Besides, the influence of temperature and train load on track structure was discussed respectively. The results are as follows, the slab track will produce interlayer seam due to subgrade frost heave deformation. Compared with the frost heave amount, the frost heave wavelength is the main factor to control the generation and development of seam. When frost heave occurs in the middle of the slab, the seam value reaches the maximum, and when it occurs in the groove position of the concrete base, the concrete on the upper surface is most vulnerable to tensile crack damage. The whole cooling load will aggravate the damage of the concrete base. Considering the load combination of the negative temperature gradient and the frost heave, the seam between concrete base and subgrade will reach 20.8 mm. Train loads will aggravate the damage of concrete base and reduce the structural interlayer seam under the load position. The interlayer seam maximum value of composite plate at the symmetrical position of the load on frost heave peak increases by 55.5% compared with the single frost heave due to the lever effect. © 2019, Editorial Board of Journal of Huazhong University of Science and Technology. All right reserved.
