Some sections of the M25 motorway and the M26 motorway were constructed almost entirely on the gault clay outcrop which is relatively sparsely inhabited. Hence recourse could generally be made to conventional cutting and embankment construction. However, at Dunton Green in Kent, where the M26 motorway passes under an existing road in a cutting with a maximum depth of approximately 8 m, it was necessary to construct retaining walls to limit both the landtake and the ground strains experienced by nearby buildings, including a church. Gault clay is a heavily overconsolidated clay, similar to London clay, but with more extreme properties. In particular it is notorious for high shrinkage/swelling movements with changes in moisture content. Also the properties of the near-surface layers of the gault clay in Kent have been significantly affected by cryoturbation and solifluxion during periglacial conditions. This paper describes the design of these retaining walls which were constructed between 1978 and 1980 using cantilever bored piles up to 1.5 m in diameter. It also compares the predicted and observed behaviour of the retaining walls and of the surrounding ground as measured by in situ tests and instrumentation both during the construction phase and Subsequently while in service. (TRRL)

Media Info

  • Features: Figures; Photos; References; Tables;
  • Pagination: p. 533-548
  • Serial:
    • Volume: 34
    • Issue Number: 7
    • Publisher: Thomas Telford Limited
    • ISSN: 0016-8505

Subject/Index Terms

Filing Info

  • Accession Number: 00395100
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Aug 31 1985 12:00AM