Dynamic Response of Non-Ballasted Slab Tracks With CAM and SFRC Under High-Speed Rail Loading

Abstract

This study presents a comprehensive numerical investigation of the dynamic thermo-mechanical behavior of non-ballasted slab track systems incorporating Cement Asphalt Mortar (CAM) and Steel Fiber Reinforced Concrete (SFRC) under high-speed rail (HSR) loading conditions. A three-dimensional finite element framework is developed to simulate coupled effects of moving wheel loads, thermal gradients, and material nonlinearity. The fatigue life of the CAM layer and the structural performance of SFRC-based slab tracks are systematically evaluated.
Results indicate that the CAM layer experiences a maximum compressive stress of 0.31 MPa under dynamic loading, corresponding to an exceptionally high fatigue life of 167.21 million axle repetitions, significantly exceeding the design requirement. Incorporation of SFRC reduces the peak compressive stress in CAM to 0.22 MPa and limits long-term plastic deformation to 0.138 mm, compared to 0.187 mm in conventional reinforced slabs. The maximum vertical and lateral displacements are 0.114 mm and 0.283 mm, respectively, which are well within the permissible limits specified by HSR standards. Furthermore, SFRC exhibits improved damage resistance, with substantial reductions in tensile and compressive damage in the slab.