GROUTING HEATHROW'S NEW TUBE

This short article describes the stabilization of the sandy gravel above the new Piccadilly Line station tunnels at Heathrow Airport. The soil formation comprises 5m of water-bearing sandy gravel overlying clay, the crown of the twin 7.5 diameter tunnels coinciding approximately with the top of the clay. A series of 80 grout holes were drilled in a fan-shaped arc across the entire width of the twin tunnels. A multi-sleeved grout tube was fitted in each hole for the two-stage grouting operation, the tube being sealed into the ground with a bentonite/cement sleeve grout. Primary injections of a cement/bentonite grout were followed by a chemical-solution grout consisting of sodium silicate and mixed esters, which filled the remaining pores and provided an impermeable mass of high strength. /TRRL/

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  • Corporate Authors:

    IPC Building and Contract Journals Limited

    32 Southwark Bridge Road
    London SE1 9EX,   England 

    IPC Building and Contract Journals Limited

    32 Southwark Bridge Road
    London SE1 9EX,   England 
  • Publication Date: 1975-3-27

Media Info

  • Features: Figures;
  • Pagination: p. 35
  • Serial:
    • CONTRACT JOURNAL
    • Volume: 264
    • Issue Number: 4986
    • Publisher: Reed Business Information, Limited
    • ISSN: 0010-7859

Subject/Index Terms

Filing Info

  • Accession Number: 00126060
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Feb 19 1976 12:00AM