Numerical Investigations on Optimisation of EPS Geofoam-Infilled Vibration Barriers for High‑Speed Railway Tracks

Ground-borne railway vibrations emanating from High-Speed Trains (HST) on ballasted railway tracks cause significant damage to infrastructure in the vicinity and structural vibrations that distress the residents. This study investigates the potential application of Expanded Polystyrene (EPS) Geofoam-infilled ground trenches as a mitigation measure for high-frequency ground-borne railway vibrations associated with HSTs, using full-scale ballasted railway track numerical models with a key focus on high-speed railway loading conditions and track vibrations. Evaluation of the results demonstrates the exceptional efficiency of EPS vibration wave barriers in attenuating Peak Particle Velocities (PPV) and propagation of ground vibrations away from the railway tracks. The efficacy of various geofoam wave barrier configurations, including different EPS density grades, trench dimensions, and placement locations, is analysed across a broad range of high train speeds. Results demonstrate that optimised trench dimensions, particularly those with low-density EPS infill and placed close to the railway formation, significantly enhance vibration attenuation. Furthermore, geofoam-infilled wave barriers exhibit greater effectiveness at higher, supercritical train speeds, substantiating their suitability for deployment in ballasted high-speed rail corridors to mitigate ground-vibration impacts.