The article traces the formation of chalk deposits as found in the upper Cretaceous rocks of western Europe and briefly mentions the variation of physical properties found in white and grey chalk. A feature of chalk deposits of significance in tunnel drilling is the presence of joints and fissures which increase in spacing with depth until they cease to exist in the lower chalk. While tunnelling through unfissured, reasonably dry chalk of medium strength presents little difficulty, problems arise where excavation is through a water-bearing layer of gravel before entering chalk. Tunnels driven through well-fissured upper chalk usually require some form of ground treatment such as freezing combined with compressed air working. Problems encountered in driving a number of tunnels through fissured upper chalk in the London area are discussed. /TRRL/

  • Availability:
  • Corporate Authors:

    Morgan-Grampian Limited

    30 Calderwood Street
    London SE18 6QH,   England 
  • Authors:
    • Haswell, C K
  • Publication Date: 1975-11

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00137506
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Oct 6 1976 12:00AM