Tactical and strategic changes had to be made to overcome unexpected problems on a 275 m long, 1.3 m diameter sewer contract to alleviate flooding in Stratford High Street in the London borough of Newham. The design was for the installation of a shield driven bolted segmental concrete primary lining with a 75 mm thick secondary concrete lining. The water bearing cohesionless soils were to be stabilised with chemicals and compressed air. Surface chemical treatment included the injection of a bentonite cement mixture to fill the larger interstices followed by a silicate bicarbonate grout to tighten up the ground. However, it was soon evident that surface chemical treatment had not been as effective as expected due to the presence of hydrocarbons and the layering of materials. The process was changed so that tunnelling used compressed air with chemical treatment at the tunnel face as a standby. Greater efficiency was achieved by injecting chemicals from the shield only when the initial clay cement surface treatment was insufficient to keep air consumption to safe levels. (TRRL)

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  • Corporate Authors:

    Specialist and Professional Press

    Surrey House, 1 Throwley Way
    Sutton, Surrey SM1 4QQ,   England 
  • Publication Date: 1984-8

Media Info

  • Features: Photos;
  • Pagination: p. 14-15
  • Serial:
    • Volume: 164
    • Issue Number: 4805
    • Publisher: Hemming Group, Limited
    • ISSN: 0039-6303

Subject/Index Terms

Filing Info

  • Accession Number: 00392493
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Apr 29 1985 12:00AM