An Economic Study of Oscillating Disc Cutter Technology

This thesis considers the economic benefits of the Oscillating Disc Cutter (ODC) for use in tunnel development machines in hard rock. Mechanical excavation machines have the potential to significantly reduce direct and indirect tunnel development costs over drill and blast.The Oscillating Disc Cutter (ODC) excavates rock using a disc similar to those found on a Tunnel Boring Machine (TBM). However unlike TBMs, the ODC applies the cutting disc at an angle to the rock face such that the rock is undercut. This causes the rock to fail in tension rather than in compression, and therefore much less force needs to be applied to the cutter. These lower cutting forces allow harder, more brittle and more wear resistant materials to be used as cutting discs without the danger disc fracture caused by mechanical overload. In addition, the lower cutting forces allow the use of smaller more manoeuvrable machines, as the supporting machine does not need to impart the high reaction forces necessary to fracture the rock in compression.