This article describes the construction of a single carriageway viaduct near Chirk in North Wales, using a large concrete 'cast-push' bridge deck instead of a conventional on-site structure. This 470m long reinforced concrete viaduct will carry the Chirk bypass, the latest section of the upgraded A483/A5 road, 30m above the deep valley of the River Ceiriog. The design using incremental launching was chosen because of its significant construction benefits, combined with financial savings. The bridge is being built in eight spans, resting on seven rectangular hollow reinforced concrete piers; its deck will be based on a trapezoidal prestressed hollow box girder of length 470m. The steel nose of this girder is gradually guiding and edging the concrete deck across the valley, as it is built. At each end of the bridge, there is a reinforced concrete abutment or viaduct retaining walls on the front and two sides, infilled with imported stone embankment material. Each concrete pier is founded on steel H-section piles driven up to 14m deep, until the underlying sandstone is reached. Temporary steel piers have been inserted midway between the permanent concrete columns for additional support, until the deck spans the whole valley. (TRRL)

  • Availability:
  • Corporate Authors:

    Thomas Telford Limited

    London,   United Kingdom 
  • Authors:
    • Alexander, D
  • Publication Date: 1990-10-4

Media Info

  • Pagination: p. 32-35
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00620078
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Mar 31 1992 12:00AM