This article reports some of the difficulties experienced while attempting to add upper decks to two major urban highways in San Antonio, Texas, USA. Contracts for adding six elevated lanes to 15.8 km of these roads began slowly, and one of them is still unfinished two years after its scheduled completion. Factors contributing to the difficulties seem to have included: (1) design complexities; (2) disputes over drawings; (3) lack of experience with high technology precast concrete systems; (4) over-optimistic assessments of construction times; (5) the overall scale of the project; (6) an extremely keen construction market during the contract bidding period. One contractor proposed a cantilevered road, with narrow spines supported on single piers and with wing sections supporting the road. Another contractor proposed a glued segmental structure with match cast and stressed segments right across the structure including the spine. Some of the difficulties associated with these approaches are discussed. Consideration is now being given to the more conventional approach of using federally standardised precast concrete or steel AASHOo beams, between 25 m and 50 m in length; these beams are used extensively throughout the USA, and they allow experienced contractors to use virtually production line methods to achieve rapid construction.

  • Availability:
  • Corporate Authors:

    Thomas Telford Limited

    London,   United Kingdom 
  • Authors:
    • Greeman, A
  • Publication Date: 1989-6-1


  • English

Media Info

  • Pagination: p. 38-40
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00498995
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Sep 30 1990 12:00AM