Lateral Resistance of Frictional Sleeper Ballast Bed

The Sichuan−Tibet railway is built under some difficult situations, including limited ballast bed profile, frequent earthquakes and large diurnal temperature variation. These difficulties cause insufficient lateral resistance of ballasted track, which is an urgent problem for the stability and resilience of the continuously welded rail (CWR). Aiming to improve and quantify the stability and resilience of CWR, the lateral resistance of frictional sleepers (designed as that normal sleeper with arrowhead shape groove) is evaluated with the single sleeper push test (SSPT). By performing SSPT, the increment of lateral resistance of ballast bed with frictional sleepers is measured. Shapes of sleeper grooves are properly designed and optimized (three groove shapes with the same size and volume but different arrowhead directions). Whether frictional sleeper applied to ballast bed (reduced ballast shoulder width) will provide enough lateral resistance for the ballast bed at Sichuan−Tibet railway line. Results show that frictional sleepers can increase the lateral resistance by minimum 7% and maximum 21%. Arrowhead directions significantly influence the lateral resistance, which is increased by 7% (same pushing direction) and 24% (opposite pushing direction), compared to normal sleepers. Therefore, strict attention should be paid to the laying direction when laying in curved sections of ballasted track. After reducing the ballast shoulder width from 50 cm to 30 cm, using the frictional sleeper (single arrowhead direction pushed in reversed direction) can still provide enough lateral resistance, which is the same value as a mono-block Type Ⅲ sleeper with 50 cm shoulder width.