TUNNEL BORING MACHINE VS DRILL-AND-BLAST - SOME RECENT U.S. BUREAU OF RECLAMATION EXPERIENCE

Nast and Cunningham tunnels were both constructed in hard, high strength igneous and metamorphic rock masses in the Colorado Rocky mountains. The tunnels are arranged in series with the inlet to Nast located only 115 M downstream from the outlet of Cunningham. The two tunnels are of comparable cross sectional area and length. Nast tunnel was excavated with a tunnel boring machine whereas Cunningham was excavated by drill-blast methods. Nast tunnel experienced more problems in excavation, required more support and lining, utilized a larger work force and cost more per linear metre for construction. This does not necessarily indicate a superiority for drill-blast excavation. Greater frequency and intensity of shear zones and jointing in Nast tunnel contributed to the increased excavation difficulties and support requirements./TRRL/

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  • Corporate Authors:

    Swedish Council for Building Research

    St Goergansgatan 66, Box 27063
    S-11230 Stockholm,   Sweden 
  • Authors:
    • Misterek, D L
    • Schoeman, K D
  • Publication Date: 1977

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00174173
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Document D3:1977
  • Files: ITRD, TRIS
  • Created Date: Jun 28 1978 12:00AM