This article describes the design and construction of the slip road retaining walls for the Stonebridge roundabout scheme near the junction of the M42 motorway with the A45 trunk road in the English Midlands. Due to the difference required between the old and new alignments, retaining walls to support the new flyover approaches were needed alongside two of the four slip roads. The original proposal by contractor Tilbury Douglas Construction, on a Design and Build contract, was to use a reinforced earth system for both retaining walls. It would have cross-shaped interlocking reinforced concrete panels, from which galvanised steel straps would run back horizontally into the frictional backfill. The construction of the two 200m long walls began early in the contract period. At an early stage in the works, the contractor proposed the Terratrel system as an alternative to the reinforced earth system for part of one of the walls. Terratrel has three major components: (1) a galvanised steel reinforcing mesh; (2) a geogrid fabric; and (3) a suitable frictional backfill material. Terratrel has the advantages of lower cost, time savings, and allowing the wall faces to be sown with grass seeds to provide a grass slope. The completed Terratrel wall has a pleasant appearance; it is being monitored to test its long-term suitability.

  • Availability:
  • Corporate Authors:

    Thomas Telford Limited

    London,   United Kingdom 
  • Authors:
    • GRAHAM, M
  • Publication Date: 1996-6


  • English

Media Info

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Filing Info

  • Accession Number: 00729176
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Dec 12 1996 12:00AM