A study was performed on a concept of using a focused high-power laser beam to cut a kerf at the gage of a hard-rock tunnel. Such a concept would eliminate mechanical gage cutters. Cutting tests were performed in a variety of hard rock types with a Contractor-owned five kilowatt CO2 laser. Test results were analyzed to allow approximation of power levels required for full-scale tunneling. A design and cost methodology was derived to allow estimation of laser costs in the size range of interest. Fenix and Scisson, Inc., acting as subcontractor to UARL, developed information on cost and performance of mechanical tunneling in hard rock, with emphasis on the gage cutting problem. It is concluded that this concept will work, and that cost benefits will be realized in large-size tunnels (20-ft-diameter of greater) in hard rock (30,000 psi or greater). Advances in laser technology will extend the economic desirability of this technique to smaller tunnels and softer rock. (Author)

  • Availability:
  • Corporate Authors:

    United Aircraft Corporation

    Research Laboratories
    East Hartford, CT  United States 
  • Authors:
    • Carstens, J P
    • Banas, C M
    • Biancardi, F R
    • Melikian, G
    • Peters, G T
  • Publication Date: 1972-11

Media Info

  • Pagination: 254 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00054328
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • ISBN: FRA-RT-73-12
  • Report/Paper Numbers: Final Rpt
  • Contract Numbers: DOT-FR-20021
  • Files: TRIS
  • Created Date: Jun 10 1974 12:00AM