This article describes a visit to the Second Dartford tunnel site when the pilot tunnel was almost complete, and reports on the progress being made with the main drive. Current progress has reached the stage where the main 10.3M. diamter tunnel is now being driven from the Kent side of the Thames. Details are given of the air pressure specifications concerning the construction of the tunnel and how these specifications were met. The Kent side had been treated with grout at this stage and preparation was being made to treat the Essex side. The method used for treating the sands and gravels is outlined. This was carried out from the surface by means of special sleeved injection tubes placed into preformed holes and grouted into position. Grouts included both clay/cement and cementation's low viscosity with chemical grout. Grouting and water tests have shown that, apart from chemical grouts, neat cement grouts with high water/cement ratios are the most successful grouts. /TRRL/

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  • Corporate Authors:

    IPC Building and Contract Journals Limited

    32 Southwark Bridge Road
    London SE1 9EX,   England 
  • Publication Date: 0

Media Info

  • Features: Figures;
  • Pagination: p. 29
  • Serial:
    • Issue Number: 0
    • Publisher: Reed Business Information, Limited
    • ISSN: 0010-7859

Subject/Index Terms

Filing Info

  • Accession Number: 00127927
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: ANALYTIC
  • Files: ITRD, TRIS
  • Created Date: Dec 29 1975 12:00AM