High-Speed Ballasted Railway Track Lateral Resistance Characteristics and Reinforcements

Ballast flight commonly occurs in high speed ballasted railway tracks, and the probability of ballast flight increases with the decrease of shoulder height; thus, reduced shoulder heights or flat shoulders are used in some countries, which result in lateral resistance reduction. The influence of shoulder height on lateral resistance was analysed in this study. Further, two polyurethane reinforcement methods were proposed, including crib-ballast reinforcement and shoulder reinforcement, which increased the lateral resistances of flat shoulder ballasted tracks and met the demands of tamping. A series of in-situ lateral resistance tests were carried out in this research. The results show that compared to a shoulder height of 150 mm, a 30% reduction in lateral resistance occurs in flat shoulders. For polyurethane spraying depths of 200 mm and 300 mm, the corresponding changes observed were 31% and 41% increase in crib-ballast reinforcement, 41% and 60% increase in shoulder reinforcement, and 70% and 100% increase in synthetic reinforcement (both crib-ballast and shoulder).