Bridge to Mont-Saint-Michel , 2002, Mont-Saint-Michel, France

Architect Sophie Nguyen in collaboration with Lead Consultant Arup, were one of the five teams shortlisted for the competition to design a 2 km new access to the Mont-Saint-Michel, including a new causeway and a footbridge.

The bay of the Mont-Saint-Michel is characterized by long stretches of shores and meanders creating horizontal bands of sand, sediment and water currents modified by the tides. The main theme for our proposal for the new access to the Mont-Saint-Michel is to restore the maritime character of the monument.

We chose to intervene by creating an additional layer to the existing natural strata of shores and tides of the bay. The proposed access will constitute a new built layer superimposed to the natural continuum of the bay, creating a clear and contemporary intervention in the landscape.

The proposed bridge consists of three horizontal planes- for pedestrians and shuttles, positioned on slender columns reminiscent of pier structures. The slender structure reduces the effects that will alter the natural landscape and the horizontal planes are positioned such as to allow side views of the water, the banks and the “herbus”. As we approach the Mount, the different strata of the bridge come to rest on a dike maintaining the visual continuity of the new access. The arrival on the Mount is via a hold, “moored” at the end of the bridge and laid on the Median of the Mont-Saint-Michel.

Structure
The new bridge comprises a central deck for shuttles to operate and two decks on either side slightly elevated from the shuttle route, for the pedestrians and the shelter route. This configuration generates the structure of the bridge section. The side decks and the central deck become the top of two main beams spanning between the slender columns. Viewed from the side, the decks will appear as “floating” slabs, connected below by the web of the beams. The piles and piers of the bridge are designed as a single element, built to extend above the highest tide. This construction process prevents excavations and the installation of piles caps. It is both economical and has limited impact on the environment.

Materials
In order to maintain a harmonious relationship with its environment, the structure will be built with materials from the surrounding landscape. The decks and hold will be constructed of shale concrete. Shale is a local material, a beautiful hard grey stone. Mixed into the concrete, it will give the bridge, a silver-grey colour, whilst providing a resistant surface with low maintenance. The central road will be covered with grey coloured bitumen to avoid a black line that would be visible from the Mount, with the grey tone being slightly darker than the footpaths so as to highlight the difference in functions. Daily submerged, the new median will be covered by surrounding deposits, authentic textures of sands, tangues and its variations of granulometry, blending into the landscape.

City: Mont-Saint-Michel
Country: France
Completed: 2002
Client: Syndicat Mixte - Mission Mont Saint Michel - Direction
Area: 2 Km
Contract Value: 22,000,000 Euros
Structural Engineers: Lead Consultant ARUP