The author considers the use of lasers in conjunction with pentaprisms for checking the aspect and build of tunnel rings. The linear nature of the laser allows it to be used for checking tunnel rings in two dimensions - line and level. For accuracy in tunnel driving the square, plumb and plane of tunnel rings have also to be monitored. For this purpose the use of the laser can be extended into the third dimension by the use of a pentaprism to deflect the laser beam through 90 deg. The article describes the accuracy of the laser-pentaprism unit and derives an offset equation which can be appplied to any ring on straight or curved tunnel alignments.

  • Availability:
  • Corporate Authors:

    Morgan-Grampian Limited

    30 Calderwood Street
    London SE18 6QH,   England 
  • Authors:
    • Irwin, K
  • Publication Date: 1979-9

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00310559
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Oct 27 1980 12:00AM