Cost effective strategies for railway batter erosion control

Cost… effective strategies for Railway Batter Erosion Control are presented. Plot scale field trials were set up on a railway embankment batter on the Laleham branch near Blackwater as part of HEFRAIL Project. The embankment at this site exhibited considerable tunnel (piping) erosion on the top access road and the batters as a result of the formation being strongly sodic and moderately saline. Hence the shoulder of the embankment had to be reconstructed. The erosion control strategies on the plots were centred on control (doing nothing after surface preparation), limited use of erosion control blankets and waste ballast as mulch on seeded plots. It has been demonstrated that with a cost effective irrigation system, 100 % grass cover establishment on railway batters is achievable within 12 weeks. 100 % grass cover reduces erosion by over 90 % compared with the bare scenario. The cost of the 25 different treatments imposed at this site varied $2.621m² and $4.11/m², including an irrigation cost of $1.68/m². The shoulder reconstruction cost of $3.27/m² is additional. It is estimated that current conventional civil engineering remediation measures related to erosion on railway batters within Central Queensland coal network cost on average $11.73/m² Therefore, the treatments imposed are cost effective. The irrigation unit cost is expected to decrease with the larger scale of irrigated batter area and the refinement of the technologies, and installation procedures.