LATEST DEVELOPMENTS IN TUNNELLING PRACTICE

The article discusses developments in tunnelling techniques such as that of jacking a tunnel into place which although not a new method, has resulted in a project to thrust a 11X 7M road tunnel full face. The development of ground injection for nearly all forms of unstable ground conditions has enabled tunnelling to take place in ground previously thought unsafe or uneconomic. Tunnelling in non-cohesive ground conditions has been made more economic by the development of the bentonite tunnelling machine which stabilises the tunnel face by circulating bentonite, a thixotropic slurry. Rock cutting developments have been aimed at the mechanisation of the rock cutting process such as in the robbins tunnelling machine. Another innovation in rock tunnelling is the rotary boom road header machine which can be turned more quickly than the full-face machine to avoid obstacles. Developments in tunnel lining have been in the use of spheroidal graphite (sg) or nodular iron which gives steel-like mechanical properties to cast sections. The use of sprayed concrete linings to stabilise the rock surface offers the possibility of including steel fibres for added strength although the economic advantages are not yet fully proved. Another form of tunnel lining uses perforated, interlocking plates sprayed with concrete. In conclusion the article states that world-wide research is being directed towards improving tunnelling methods and reducing costs. /TRRL/

  • Corporate Authors:

    Foundation Publications Limited

    7 Ongar Road
    Brentwood CM15 9AU, Essex,   England 
  • Authors:
    • Tough, S J
  • Publication Date: 1975

Media Info

  • Features: Photos;
  • Pagination: p. 14-17
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00134388
  • Record Type: Publication
  • Source Agency: ARRB Group Limited
  • Files: ITRD, TRIS
  • Created Date: Dec 15 1976 12:00AM