GEOLOGICAL PARAMETERS AND FULLFACE BORING; COST PROGNOSES

GEOLOGISKE PARAMETRE OG FULLPROFILBORING; KOSTNADSPROGNOSE

The main elements in a prognosis model for calculations of penetration rates and costs for fullface-bored tunnels are presented. The model is based on drillability indexes originally developed for conventional drilling equipment. The indexes describe the rock properties important to drilling rate and bit wear. The distance between joints and discontinuities is taken into account, as this parameter has been found to be important for fullface boring. Serious stability problems such as rock spalling and crushed zones must be foreseen and avoided, eventually taken care of with efficient supporting systems immediately behind the boring head. In the conclusions the author points out areas where fullface-boring of tunnels seems favourable. The article gives an extract of a project report. /TRRL/

  • Availability:
  • Supplemental Notes:
    • Chapter from Norsk jord-og fjellteknisk forgung. Fjellspreningsteknikk bergmekanikk geoteknikk 1976.
  • Corporate Authors:

    Norwegian Institute of Technology

    N-7034 Trondheim,   Norway 
  • Authors:
    • Blindheim, O T
  • Publication Date: 1977-3

Language

  • Norwegian

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00184271
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jan 13 1979 12:00AM