Italian ground specialist Trevi trialled its tunnel pre-cutter and liner machine on a difficult section of the Rome - Naples route, at a point where the line passes underneath a hill with the ruins of a medieval castle above.
This precludes drill and blast because of vibration and Trevi used the contract as a first site test for the machine made by sister company Soilmec.
Most pre-cut systems cut a slot up to about 3m in advance of the face but Trevi's goes much deeper. More importantly, the concrete filling is done as the machine cuts around a 270 arc. A special slipform mounted on the back of the cutter is used to inject fibre reinforced concrete through two or three nozzles.
The machine cuts and simultaneously concretes a 10m deep arch. It should greatly simplify the operational logistics of using pre-cut methods and Soilmec's developments could make the method more cost-effective.
The Piombinara castle site was Trevi's first chance to use the equipment on an actual contract under working conditions.
Trevi is now looking for new applications on the Bologna to Florence section.