• Competition

    Competition

  • Competition

    Project

  • Competition

    Execution

  • Competition

    Construction

The Grand Pont in Lausanne, designed by the visionary engineer Adrien Pichard, spans the Flon Valley from east to west. It is a 170-meter-long multi-span, rubble masonry arch bridge comprising two superimposed arcades that was commissioned in 1844. The lower level was buried when the Flon Valley was backfilled in 1873. The upper level, which is comprised of 19 arches, is still visible and in use. The deck had already been widened once in 1891 using a metal frame in order to allow trams to cross over it, and then again in 1933 using concrete free cantilever structures.

In 2011, a plan to widen the deck was drawn up in connection with changes to the tram system, but this was blocked as a result of objections and never came to fruition. After several years in limbo, an inspection and investigation campaign was undertaken in 2020 which revealed deterioration of the concrete free cantilever structures (corrosion of the framework and cracks in the concrete). In addition, it was found that the entire slab was insufficiently waterproof and that the bridge was therefore full of water, which was dissolving the mortar joints and causing pieces of rubble to come away. Static inspections of the free cantilevers and the railings also found evidence of major structural non-conformities.

Consequently, a reconstruction plan was drawn up for the Grand Pont that involved replacing the concrete free cantilever structures with a new slab made of pre-stressed concrete. The slab is designed to ‘float’ above and protect the masonry arches without impairing the view of them or interrupting the flow of the bridge. The slab is therefore completely free of struts, is of a constant thickness, and is covered in a UHPFRC mineral waterproof coating and finished off with slim UHPFRC side edges.

Since the structure is listed as a historical monument, the project was carried out under the guidance of the Heritage Departments of the City of Lausanne and the Canton of Vaud. These consultations resulted in the existing railings, which date back to 1891, being partially retained. This involved disassembling all of the railing panels, sanding them down, reinforcing them, and returning them to their original position. As for the uprights, these were recast using a better-quality gray cast iron. Organically shaped lighting columns, each with two arms culminating in a bowl, are mounted atop the railing uprights anchored to the piers in order to lend the Grand Pont its own unique style of illumination.

  • Owner

    Road Department of the City of Lausanne
    TL – Lausanne Region Public Transport

  • Civil Engineer

    IG Grand Pont Civil Engineers Group:
    INGPHI SA, Lausanne
    Bächtold & Moor AG, Bern

  • Provided Services

    Detailed inspection
    Planning and monitoring of investigations
    Preliminary design
    Final design
    Tender documents
    Detailed design
    Supervision of construction works

  • Technical Characteristics

    Length: 170 m
    Breadth: 15.30 m
    Corniche: 62 m
    Walls: 30 m

  • Period

    2011 -2022

Project Team

  • Guillaume Fargier-INGPHI

    Guillaume

    Fargier

    Project Manager - Civil Engineer

  • hugo-crespo-equipe-ingphi

    Hugo

    Crespo

    Work Planning Technician

  • jonathan-krebs-equipe-ingphi

    Jonathan

    Krebs

    Associate - Project Manager - Civil Engineer

  • Kushtrim Bajrami

    Kushtrim

    Bajrami

    Draftsman

  • Philippe Menétrey-INGPHI

    Philippe

    Menétrey

    Manager - Project Manager - Civil Engineer

  • Sophie Tschumy-INGPHI

    Sophie

    Tschumy

    Civil Engineer

  • Tamás

    Szabó

    Draftsman

estacade-epesses-ingphiEpesses Corniche
modelisation-hotel-des-horlogers-ingphiHotel des Horlogers