Effect of Sleeper Interventions on Railway Track Performance

The sleeper/ballast interface is an essential stage in the transfer of train loads from a railway track structure into the ground. Generally, only a small number of ballast grains support the sleeper base. The resulting localized contact stresses can be very high, especially for modern concrete sleepers on hard igneous ballast. This may result in damage to both sleepers and ballast and reduce the stability of the interface. This paper presents results from cyclic loading tests carried out to explore the potential for performance improvement through the adoption of different sleeper types and modifications to the sleeper/ballast interface. Measurements of resilient performance, plastic settlement, sleeper/ballast contact number and area, shoulder movement, ballast breakage and attrition, and the development of ballast longitudinal pressure are used to explore and explain the effect of each intervention. It is shown that twin-block sleeper types and under-sleeper pads (USP) have the potential to reduce maintenance requirements and whole-life costs.