Field assessment of the performance of a ballasted rail track with and without geosynthetics

Understanding the complex mechanisms of stress transfer and strain accumulation in layers of track substructure under

repeated wheel loading is essential to predict the desirable track maintenance cycle as well as the design of the new track. Various finite

element and analytical techniques have been developed in the past to understand the behavior of composite track layers subjected to

repeated wheel loads. The mechanical behavior of ballast is influenced by several factors, including the track confining pressure, type of

aggregates, and the number of loading cycles. A field trial was conducted on an instrumented track at Bulli, New South Wales, Australia,

with the specific aims of studying the benefits of a geocomposite installed at the ballast-capping interface, and to evaluate the performance

of moderately graded recycled ballast in comparison to traditionally very uniform fresh ballast. It was found that recycled ballast can be

effectively reused if reinforced with a geocomposite. It was also found that geocomposite can effectively reduce vertical and lateral strains

of the ballast with obvious implications for improved track stability and reduced maintenance costs.