Track stabilisation with geosynthetics and geodrains, and performance verification through field monitoring and numerical modelling
Railway systems form the largest worldwide network, catering for quick and safe public and freight transportation. Rail ballast forms both the load bearing stratum and the drainage layer for the track. A proper understanding of load transfer mechanisms and their effects on track deformations are essential prerequisites for minimising maintenance costs [1,2]. The measurement of vertical displacements is an established practice in most conventional track monitoring systems. However, it is also important to monitor lateral deformations that may affect track stability arising from the loss of lateral confinement. Therefore, a field trial was conducted on a track section near the City of Wollongong, Australia, to measure the deformations and cyclic stresses. The field trial further showed that the moderately-graded recycled ballast, when used with a geocomposite (combination of biaxial geogrid and nonwoven polypropylene geotextile), could perform well in comparison with traditionally uniform fresh ballast . A geocomposite, when placed below the recycled ballast layer, would function as reinforcement, drainage and separation, thereby reducing the vertical and lateral deformations.