This paper describes the Wilderness Viaducts, which were part of the improvements to the picturesque section of road overlooking the Kaaimans River mouth and wilderness beach on the coast of South Africa. For some years, this section of road had not been able to handle its increasing traffic volume adequately, and it had been troubled by localised slope instability. The upgrading of the road in this very sensitive and difficult environment was achieved by building a series of concrete viaducts, which blend inconspicuously into the landscape. The viaducts were selected as the most appropriate and flexible way of widening the road in a situation where conventional cut and fill would not have been feasible or acceptable. The structures used are actually "half viaducts" in the sense that they support only the outer half of the roadway, whose inner half runs on the remodelled original roadbed. An essential feature of the design is the longitudinal retaining wall, which runs on or near the centre line of the new road. The design used conventional piers on spread footings where the anticipated depth of loose material over the bedrock was less than about 6m, and hollow cylindrical piers elsewhere. During the construction, every pier foundation had to be appraised carefully, and two-way traffic flow had to be maintained along the existing road. (TRRL)

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  • Corporate Authors:

    Concrete Society of Southern Africa

    Portland Park, P.O. Box 168
    Halfway House,   South Africa 

    Brooke Pattrick (Pty) Limited

    P.O. Box 422
    Bedfordview,   South Africa 
  • Publication Date: 1988

Media Info

  • Pagination: p. 18-20
  • Serial:
    • Volume: 48
    • Issue Number: 48
    • Publisher: Concrete Society of Southern Africa
    • ISSN: 0379-9824

Subject/Index Terms

Filing Info

  • Accession Number: 00492757
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Mar 31 1990 12:00AM