NATM

The “New Austrian Tunnelling Method” comprises the steps excavating, mucking, protecting. Excavating: Fragmentation of rock/soil in different ways (traditional equipment as e.g. demolition hammers, excavators, heavy-duty milling cutters and drills, blasting). Mucking: Removal of the loosened rock/soil. Protecting: Shotcrete protection of the vault. If necessary, rock bolts, pipe umbrella injection, and other additional securing means are applied. If blasting is used for excavating (release of toxic gases, dust formation, etc.), a proper ventilation is compulsory. Only then, the work may be continued.