An Experimental Evaluation of the Attenuation Effect of Rail Pad on Flexural Behaviour of Railway Concrete Sleeper under Severe Impact Loads

Interactions between the wheel of rolling stocks and the rail often generate interfacial impact forces to railway tracks. The dynamic impact loads are of very high magnitude but short duration, and are caused by either wheel or rail abnormalities such as flat wheels, dipped rails, etc. Although the possibility of the large impact loading to cause an extreme failure to an insitu concrete sleeper could be very low about once or twice in the design life cycle, the damage of track components especially for the concrete sleepers is often observed. The railway sleeper is a major component of railway tracks. Its role is to distribute the load from the rails to the underlying ballast bed. Up to current knowledge, the behaviour of the in-situ prestressed concrete sleepers under the impact loading has not yet been thoroughly comprehended. In order to evaluate the resistance of railway concrete sleepers to impact loads, a high-capacity drop-weight impact testing machine was thus constructed at the University of Wollongong. It is currently the largest one of its kind in Australia with the maximum drop height of 6m. This paper demonstrates the experimental investigations, in order to evaluate the attenuation effect of rail pads on the impact behaviour of railway concrete sleepers. The impact tests were carried out using the prestressed concrete sleepers manufactured in Australia. This study enables and enhances the methodology to analyse and design for the prestressed concrete sleepers at ultimate limit states.