Feasibility study on the solution of replacing track slab with lateral pushing rail in one maintenance window time

Abstract

The slab ballastless track is the primary type of high-speed railway. When the track slab in the ballastless track is severely damaged, the typical way to replace it requires cutting the jointless rail above the damaged track slabs. This paper discusses a solution of pushing the rail in the lateral direction (i.e., without cutting the rail) to replace the track slab. To study the feasibility and reliability of this solution, a finite element model for simulating the construction process of rail pushing is established. The necessary spacing of the support slides and the capability of the pushing device are analyzed. The influence of parameters such as the rail release length and the construction temperature on the mechanical state of the rail after being pushed is discussed. In practice, the repair time is limited to one maintenance window (i.e., 4 h). The control of the stress is critical in repairing progress. The corresponding relationship between the deformation curvature of the rail and the stress is studied, and the number of unlocking fasteners is reduced by optimizing the spacing of the rail support slides, which can effectively reduce the fine-adjustment range of the rail after changing the slab. By calculation and design, a “16 + 8 + 16 m” optimization plan is proposed, which can meet the needs of replacing the track slab in the four-hour maintenance window time of high-speed railway. Finally, the feasibility of the finite element model is verified through the comparative analysis of the monitoring data of the lateral pushing of the rail and the simulation analysis results.