The article describes the problems involved in the construction of an underpass in a city centre and of a tunnel under the River Thames. The first scheme described forms part of the Birmingham Middle Ring Road. The article sets out the way in which the problems of working space, services diversions, and maintenance of traffic were overcome during the excavation of about 2000 ft of cutting. The problems of supporting the sides of the excavation are described together with the solution adopted. The underpass is in the form of a water-tight trough and the article mentions the way in which flotation of the trough is prevented. The second work described is the duplication of the Dartford Tunnel. The article explains how cut-and-cover and machine boring methods are being used. Pre-grouting has greatly reduced the compressed air working pressures needed in the pilot tunnel. The article describes how the approaches to the tunnel are excavated between diaphragm walls. The main tunnel, to be bored later, will be lined with precast concrete segments. The total length will be 1820M and the diameter will be 9.6M. /TRRL/

  • Corporate Authors:

    Morgan-Grampian Limited

    30 Calderwood Street
    London SE18 6QH,   England 
  • Publication Date: 1973-10

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00082780
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Sep 30 1975 12:00AM