Resilient Element Attached Under the Concrete Sleepers to Improve the Rail Track Performances

Abstract

Heavier concrete sleepers used in most of the ballasted tracks are subjected to greater stresses and faster deterioration of track structures. Resilient elements such as Under Sleeper Pads (USPs) installed at the bottom surfaces of concrete sleepers are promising techniques to increase the degree of vertical elasticity in the track structure and also with the intention of enhancing sleeper–ballast interaction to minimize dynamic stresses and subsequent track deterioration. In this study, cyclic loads from fast and heavy haul trains have been simulated using a large-scale Process Simulation Prismoidal Triaxial Apparatus (PSPTA) to investigate the performance of ballast behaviours improved by the USPs. The laboratory results indicate that the inclusion of USP at the bottom face of the concrete sleeper significantly reduces the stresses transmitted and minimizes the amount of plastic deformation and degradation of ballast.