A Study on Separation and Lifting Management in Urban Railway Precast Slab Tracks

In precast concrete tracks using cement-emulsified asphalt (CA) mortar as the filling material, separation between slab panels and filling layers frequently occurs. This study conducted field measurements at sites with observed separation. The analysis revealed that, compared to intact areas, locations with separation experienced over a fivefold increase in rail stress, slab panel displacement, and vibration acceleration. Additionally, finite element analysis (FEA) was employed to examine the effects of parameters such as the extent of separation, uplift height, and temperature loads. For B2S tracks, it was determined that an uplift height of 0.3 mm should be set as an observation threshold to prevent shear and tensile failure of the filling material. To maintain operational safety, an uplift height of 1.0 mm was recommended as the criterion for planned maintenance. Furthermore, the study revealed that sub-zero temperatures significantly intensified tensile and shear failure of the filling material.