Abstract
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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.