Behavior and Performance of Ballastless Track with Damaged Cracks under Train Load

Recent development trend of high speed railway is more and more focused towards ballastless track due to its advantages of low maintenance, high availability, low structure height and low weight. However, damage cracks of ballastless track superstructure, which is built of reinforcement concrete, are not avoidable. Also, damage cracks may have effect on the behavior and performance of ballastless track. In this paper, in order to study the effect of concrete slab cracks on the mechanics of ballastless track, a spatial finite element model of ballastless track with damaged cracks was established, based on cracking characters of concrete slab, in which the singularity of crack tip was simulated by 20-node hexahedron isoparametric singular element using the theory of elastic fracture mechanics. The mechanics of ballastless track under train load was analyzed and the results show that the crack has little effect on the global stress and deformation of the track. Besides, bar stress at the crack has a sudden increase, and the crack width has little increase under train load. In addition, both bar stress at the crack and stress intensity factor (SIF) increase with the increase in the crack depth, and the crack is not likely to propagate only by general train load.