The performance of rail track incorporating the effects of ballast breakage, confining pressure and geosynthetic reinforcement

Rail tracks are often placed on ballast which offers the desirable resiliency to cyclic loads. However ballasted beds need periodic maintenance due to deformation and degradation associated with breakage and fouling. A proper understanding of load transfer mechanisms and their effect on ballast breakage are prerequisites for minimizing maintenance costs. Recycled ballast is a cheaper and environmentally viable option but its strength characteristics need to be investigated beforehand. This paper demonstrates the analytical, numerical and laboratory investigations carried out to investigate the geotechnical behavior of ballast, including shear strength, ballast breakage, and confining pressure. The potential use of geosynthetics for improving the stability and drainage of railway tracks under high monotonic and cyclic loading is also studied. Field tests were carried out to measure the in-situ stresses of ballast on a section of instrumented track funded and built by RailCorp, Australia.