Dynamic Capacity Reduction of Railway Prestressed Concrete Sleepers Due to Surface Abrasions Considering the Effects of Strain Rate and Prestressing Losses
In reality, railway prestressed concrete sleepers frequently experience significant aggressive loading conditions and harsh environments. Especially in sharp curves, lateral loading of train wheels in combination with incompressible hydraulic pressure aggravates the lateral oscillation and abrades the surface of sleepers right underneath the rail seats. Many investigators in the past have proposed various material models to improve abrasive resistance characteristics, but those have been mostly applied to the new products using novel materials such as fiber-reinforced concrete. On the other hand, prestressed concrete sleepers have been used for over 50 years and they have become worn over time. This paper highlights the dynamic capacity evaluation of worn sleepers, which will lead to predictive models that could be realistically applied to asset management of railway lines. This paper presents an investigation into the structural capacity reduction in worn railway prestressed concrete sleepers considering the effects of strain rate and loss of prestressing steel. RESPONSE2000 has been used to evaluate the residual dynamic capacity based on the modified compression field theory. Unprecedented parametric studies have been carried out to determine the influences of uniform and gradient prestress losses on prestressed concrete capacity. The study results exhibit the level of wear and tear, which is critical to the dynamic integrity of sleepers required for immediate replacement. The outcome of this study will help improve the practical maintenance and monitoring technology in railway industry.