Experimental Study on Improving the Frost Heave of Graded Gravel on Passenger-Dedicated Railway Line

Frost heave significantly affects the graded gravel used to construct passenger-dedicated railway lines. For safety reasons, such lines have strict demands on the amount of deformation that can occur to tracks. The aim of this study was to investigate the geotechnical properties of graded gravel that was grouted with slurry. After grouting, scanning electron microscopy showed that the slurry bound well to the gravel particles. With increasing iterations of freeze-thaw cycles, the frost heave ratio increased, but it did not change significantly after 20 freeze-thaw cycles. In addition, changes in the unconfined compression strength were also negligible after 20 freeze-thaw cycles, and they tended to stabilized after 10 dry-wet cycles. These results show that graded gravel samples stabilized with slurry exhibited high resistance to the effects of freeze-thaw cycles and dry-wet cycles. We concluded that slurry can be successfully used to improve frost heave associated with the graded gravel of passenger-dedicated railway line.