Material-oriented maintenance of railway track using under sleeper pads (USPs)

Under-sleeper pads (USPs) are an emerging technology that has demonstrated numerous advantages in infrastructures of railway transportation. This review study explores the innovative application of material-oriented maintenance using USPs to optimize railway track performance and minimize maintenance costs. Through the integration of USPs with elastic/viscoelastic properties between railway sleepers and the ballast layer, the dynamic and long-life characteristics of the track-train system are enhanced. Key factors such as track deterioration, geometric irregularities, structural defects, and operational conditions play a crucial role in determining the maintenance-oriented effectiveness of USP’s materials. USPs provide a wide array of benefits, including mitigating track degradation, enhancing lateral and longitudinal resistance, and extending the life of ballast. They address challenges like asymmetric settlements, track defects, and train-induced vibrations, resulting in extended tamping intervals and improved stress distribution. The implementation of USPs significantly extends track maintenance intervals, often doubling their duration. Moreover, these pads are instrumental in reducing railway track maintenance expenses and overall life cycle costs by approximately 10% and 30%, respectively. This research underscores the essential role of USPs in addressing track deterioration, geometric irregularities, structural defects, and operational conditions to ensure the safety, efficiency, and longevity of railway tracks through material-oriented maintenance practices, and to instigate a transformative evolution in maintenance methodologies. The current review study comprehensively explores the USP’s potential, emphasizing maintenance factors, in resiliency and enhancing the railway infrastructure sustainability and maintenance activities.