Classification of common geotechnical failure types occurring in Queensland’s heavy haul rail network

A well-maintained railway system is an essential requirement in the successful running of heavy haul coal railway networks. To minimise whole of life costs incurred in such a rail network, infrastructure assets must be effectively managed. Incurred costs clearly include the maintenance cost of failures and the resulting delays and cancellations. A well-functioning and healthy track foundation consisting of ballast, capping and subgrade layers may face gradual deterioration due to dynamic wheel loads, coal fouling, etc. Therefore, identification of ongoing issue(s) under or adjacent to the rail track is the primary duty of the geotechnical engineer. In this article, common failure types investigated in Queensland’s heavy haul coal rail network are presented followed by an explanation of associated signs and causes. A shear failure case study is also presented.