The Wambo Rail Spur located near Singleton, New South Wales, Australia, runs
for 14 km linking the Mt Thorley rail loop and running north-west alongside
Jerrys Plain Road to the Wambo Coal Mine at Warkworth. A portion of the project
is a 260 m long tunnel located where the rail line passes under Jerrys Plain
Road. The tunnel has a low cover and is mostly within highly weathered to fresh
laminated siltstone interbedded with coal seams, sandstone and conglomerate.
This paper presents the design basis and construction methods used to achieve
the 100 year design life of the tunnel required by Wambo Coal while also
satisfying settlement and vibration limits imposed on Jerrys Plain Road.