FALLACIES IN NATM/RSST SHOTCRETE SUPPORTED TUNNELLING

This paper is the first part of critique of the New Austrian Tunnelling Method (NATM). In the author's view, the acronym NATM obscures the fundamental requirements for the method's success, and allows its occasional traumatic failures to be exaggerated. He prefers to name NATM the 'rapid shotcrete supported tunnelling method' (RSST), as it is open to a more realistic diagnosis of primary versus secondary problems. He sees RSST's key selling point as its flexibility, both of primary lining, and of expert decisions based on site engineering. RSST emphasises the importance of speed on overcoming deficiencies in stand-up time and primary shotcrete. The author refers to the case history of the investigation of a not too serious failure in a road tunnel, excavated by drill+blast, with half-section sequential excavation. Despite satisfactory design and monitoring indications, the collapse occurred about 20 days after the section was passed and ten days after the tunnel was completed. The significance of convergence measurements is discussed. The principal conclusions for on-site engineering decisions are derived from three types of displacement measurements. Geological information and classifications should be taken into account. The role of computational models is discussed.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/0041414X
• Corporate Authors:

  Morgan-Grampian Limited

  30 Calderwood Street
  London SE18 6QH,   England 
• Authors:
  • de Mello, VFB
• Publication Date: 1996-7

Language

• English

Media Info

• Pagination: p. 38-41
• Serial:
  • Tunnels & Tunnelling International
  • Volume: 28
  • Issue Number: 7
  • Publisher: Progressive Media Markets, Ltd
  • ISSN: 0041-414X

Subject/Index Terms

• TRT Terms: Anchorages; Bolts; Calculation; Classification; Construction management; Design; Failure; Geology; Improvements; Mathematical models; Measurement; Motion; Shotcrete; Speed; Surveillance; Tunnel lining; Tunneling; Tunnels
• Identifier Terms: Austrian tunneling method
• ITRD Terms: 3420: Anchorage; 3386: Austrian tunnelling method; 3888: Bolt; 6464: Calculation; 8513: Classification; 3666: Construction method; 9011: Design (overall design); 5520: Failure; 4053: Geology; 9108: Improvement; 6473: Mathematical model; 6136: Measurement; 5483: Movement; 4730: Shotcrete; 5408: Speed; 9101: Surveillance; 3374: Tunnel; 3385: Tunnel lining
• Subject Areas: Bridges and other structures; Construction; Design; Geotechnology;

Filing Info

• Accession Number: 00729235
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Dec 12 1996 12:00AM