Australian railways offer an efficient and economic mode of transporting freight and passengers across all States. Rail tracks are normally positioned on ballast because it is economical (availability and abundance), and because drainage is rapid and the tracks have a high load bearing capacity. However, repeated train load-ing fouls the ballast as small fines from the surface or subgrade intrude and then impair drainage that can po-tentially lead to track instability. In addition, the recent increases in axle loads, speed and traffic volume, cou-pled with the need to improve passenger comfort and reduce the cost of track life cycles, means that track de-signs must be optimised. Moreover, given that current ballasted tracks in many parts of Australia cannot sup-port increasingly heavier and faster trains, the need to develop innovative and sustainable ballasted tracks is crucial for transport infrastructure.
This paper aims to demonstrate and discuss some major aspects related to stabilizing ballasted rail tracks over-lying soft soils using artificial inclusions such as geosynthetics, recycled rubber mats, and end-of-life tyres. The use of geocomposites (i.e., bonded geogrid-geotextile layers) to enhance the performance of ballast is de-scribed with the aim of reducing track settlement, increasing the resilient modulus, and decreasing ballast deg-radation. The effects of increasing the confining pressure on rail track behaviour, particularly with regard to particle breakage has been studied using large-scale laboratory tests. We are therefore presenting a novel solu-tion of confining the upper sub-ballast layer (capping) with energy-absorbing recycled rubber tyres to increase the stability and resiliency of track substructure. This study confirms that a sub-ballast layer confined by recy-cled rubber tyres can actively reduce ballast breakage within the track substructure. This study also carried out numerical simulations using finite element method (FEM) to examine how end-of-life tyres to improves track performance. The outcomes of this study will lead to a better understanding of how artificial inclusions-reinforced ballasted tracks perform, and then to a cost-effective track design with improved safety and pas-senger comfort.