This article reports that drill+blast is still used in a considerable proportion of tunnel construction projects, because of increasingly sophisticated drilling methods and use of explosives; sometimes, it can be used where other methods fail. The article reports on the activities of various companies here, and describes some of their equipment. Manufacturers and technical consultants have both been notably successful in meeting the technical challenges faced by drill+blast. These challenges include: (1) the maintenance of accurate profiles; (2) safer explosives use, especially in wet conditions; (3) increased advance rates; and (4) applications in difficult geology. For long tunnels, drill+blast competes with fully mechanised methods, especially the use of tunnel boring machines (TBMs). The large-capacity jumbos now generally available improve overall efficiency. The most important recent advances in blast-hole drilling have been in automation, including positioning, to enable more accurate removal of the ground at lower cost. Advance is the other major factor in drilling efficiency, and modern hydraulic drills have penetration rates about 50% higher than for earlier drill models. Blasting has become more accurate, but its use requires formal training for both safety and general security.

  • Availability:
  • Corporate Authors:

    Miller Freeman

    Calderwood Street
    London,   United Kingdom  SE18 6QH
  • Authors:
    • Jones, M
  • Publication Date: 1999-12


  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00788442
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Mar 3 2000 12:00AM