Analysis of mechanical properties and deformation characteristics of debonding-repaired slab track

Abstract

ABSTRACT To investigate the influence of debonding-repair materials on interface damage and deformation characteristics in track structures, a finite element model was established to represent CRTS III prefabricated slab track with debonding repairment under various conditions. The mechanical properties and deformation law of the track structure under the combined loads of train and temperature gradient were analysed under intact interlayer, debonding without repairment, and debonding-repaired conditions. Results show that both the interface damage area and stress increase in line with the temperature gradient, and that positive temperature gradients have a greater effect on interface damage than negative temperature gradients. In addition, the interface damage area and stress increase can be effectively slowed down with debonding repairment materials. Specifically, under a temperature gradient of 90°C/m, the failure rate of interfacial bonds is 21.2%, 29.6%, and 2.1% for conditions of intact interlayer, debonding without repairment, and debonding with repairment, respectively. In debonding conditions, the maximum vertical displacements along the lateral and longit udinal direction increase about 1.1 times ~ 2.3 times under positive temperature gradients more than the intact interlayer condition. Further, the pattern and peak vertical deformation for track slab are basically the same between the intact interlayer and the repaired debonding conditions. The calculation results indicate that the repair measures can alleviate interfacial adhesive deterioration and reduce the deformation of the track structures.