Louis-Hippolyte-La Fontaine Tunnel

Structural Expert covering the services of technical assistance, advice and due diligence to the design team for the retrofitting works of the following structral components Tunnel, Ventilation Tower, and Portal and Approaches in reinforced and prestressed concrete. The Pont-Tunnel Louis-Hippolyte-La Fontaine (TLHL) is a complex formed by a road tunnel and a road bridge that connect Longueuil (Le Vieux-Longueuil borough) to Montreal (Mercier–Hochelaga-Maisonneuve borough) passing under the river Saint-Laurent and on Île Charron.

It is the only road tunnel linking Montreal to its suburbs. The Lafontaine tunnel is a submerged tubular structure measuring 1,391 m in length. It follows Highway 25 and passes under the main navigation channel of the St. Lawrence River immediately downstream of the St. Lawrence Seaway. Its construction began in 1963 and it opened on March 11, 1967. The bridge-tunnel sees around 120,000 daily crossings, 13% of which are trucks.

The tunnel was built with prefabricated sections in drydock and then sunk into the river 24 meters below the water surface. Each of the seven (7) sections of the submerged tunnel weighs 32,000 t, is 110 meters long, 37 meters wide and rises to a height of 8 meters, constituting one of the largest prestressed concrete structures in the world, for a total bridge-tunnel distance of 1.8 km long.