PRELIMINARY PHASES TO THE DESIGN OF A LARGE BRIDGE IN DEVELOPING COUNTRIES - THE EXAMPLE OF A BRIDGE IN GAMBIA

LES PHASES PRELIMINAIRES A LA CONCEPTION D'UN GRAND PONT DANS LES PAYS EN VOIE DE DEVELOPPEMENT - L'EXEMPLE DU PONT SUR LA GAMBIE

The construction of a large bridge is costly and has far-reaching consequences: it must therefore be based on detailed technical and economic studies. For selecting the location of the bridge and defining its geometric characteristics, the following questions must be answered: (1) Is the construction of the bridge necessary? The cost-benefit analysis will compare the advantages (new link, improvement of an existing link, savings in time and money for the users) with the investment cost; (2) Where should the bridge be built? The selection of the site depends on technical and economic criteria: characteristics and behaviour of the river to span, nature of foundation soils, type of road to be constructed; (3) What should the width of the bridge be? As regards fairly lightly-trafficked bridges, should a single-lane or two-lane carriageway be envisaged? Which width to select? Should it comprise a footway? The final solution selected depends not only on the traffic, but on the length of the bridge, its profile (linear or convex). Following the selection of the site, geotechnical studies must be conducted: site investigation, sampling, in-situ tests, use of pressiometers and penetrometers. The example of the crossing of the Gambia river between Kaolak and Ziquinchor is given. (TRRL)

  • Availability:
  • Corporate Authors:

    BCEOM

    15 Square Max-Hymans
    Paris Cedex 15,   France 
  • Authors:
    • Lombard, P
  • Publication Date: 1978-7-8

Language

  • French

Media Info

  • Features: Figures;
  • Pagination: p. 19-25
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00310040
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jul 22 1980 12:00AM