MODERN TIMBER BRIDGES IN NORWAY - A VIABLE ALTERNATIVE

This article describes the design of the first timber road bridge to be built for many years in Norway. It is the Evenstad Bridge across the River Glomma, which will be 180m long, with five 35.5m spans and a 6.5m wide carriageway. Alternative steel, concrete, and timber designs were considered during the design study. It was found that the costs and functionality of these alternatives would be about the same, but that the aesthetic challenge would be easier to handle with the timber design. The first main challenge for the bridge design is its glue-laminated timber truss girder, with a curved upper chord, for the superstructure, with joints of multi-section dowel type; this is new for bridges, though not for hall structures. The second main challenge is its stress-laminated timber deck with damp-proofing and asphalt. The top side of the deck will have a membrane with an asphalt layer on top, for which a preservation treatment will be used with MT Creosote with BAP less than 50ppm; this will greatly extend its service life. The bridge substructure will be three concrete piers on steel piles and two directly founded abutments. There will also be some constructive protection for specific parts of the bridge, which will be instrumented to monitor its moisture content and stresses.

Language

  • English

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Filing Info

  • Accession Number: 00729185
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Dec 12 1996 12:00AM