The authors give the reasons for the selection of the site: width of the river reduced to 260m, presence of rock very near the surface, ease of construction of access roads, and details of the design: six-span metal deck orthotropic slab bridge, the total length of which between the outside bearings is 610m; length of spans: 60-65m, 110-200m, 110-65M (the 200m span being the longest in france for bridges of this type). Details are given of the soil Gneiss mass (the upper part of which was weathered), construction of foundations in the river (dry method of construction with the help of cofferdams), land bearings (abutments resting on four reinforced concrete wells). The river piers consisting of a reinforced concrete massive shaft, the stability of which against ship collision was calculated for horizontal stresses of 1000 t. Data are presented on the box girder bridge deck (metal sheets and cross bars). A new construction method was used for manufacture and erection; the deck was entirely precast in the factory per section. Launching was done by bringing the sections to the launching frame by means of a piece of equipment called diplodocus. Brief details are given of the structural stability, the deck having been designed as a continuous six span girder. The effect of the wind on the structure was studied for A 100m cantilever. Protection against corrosion was carried out in the workshop. The internal part of the box girder was sanded and coated with two layers of copon-met-1-pon, and one layer of epoxy-pitch. The external part was sanded, coated with zinc and 5 layers of glycerophaltic paint. The surfacing of the orthotropic slab is 6cm thick, and it was tested on a ring road in quimper. First, the surface of the slab was brushed and subjected to blowing with compressed air, then a waterproofed course was applied consisting of elastomer on which chippings were spread; the asphaltic concrete wearing course is 4cm thick. Further details are given of bearing devices, expansion joints, footpath edges, parapets, drainage, signalisation, ancillary structures and maintenance. /TRRL/

  • Authors:
    • Thouzeau, C
    • Leouzeau
  • Publication Date: 1972-8-19


  • French

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Filing Info

  • Accession Number: 00099601
  • Record Type: Publication
  • Source Agency: Laboratoire Central des Ponts et Chausees (LCPC)
  • Files: ITRD, TRIS
  • Created Date: Nov 18 1975 12:00AM