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Cable-stayed bridge

The cable-stayed section of the new Champlain Bridge is clearly one of the biggest design and construction challenges of the entire project. The cable-stayed concept was chosen for its elegance, but also because this type of structure allows for the necessary breadth to reach across the Saint Lawrence River without interfering with seaway traffic. The cable-stayed bridge will be supported in the middle by a main pylon, which will hold up the main and back  spans.

Main pylon: rising steadily

Last September, the first 44 prefabricated segments were installed in 34 days, forming the bulk of the lower pylon. In mid-October, the metal structure of the lower cross beam, whose width corresponds to the three traffic corridors, was positioned on the pylon’s two legs. The cross beam’s construction and concrete work as well as the installation of the final 22 prefabricated segments of the lower pylon were completed between November 2016 and March 2017. The upper cross beam, also known as the bow tie, was raised onto the bridge’s future superstructure during a first lifting in spring. It will be hoisted to its final position, linking the two legs of the pylon a during the summer. The upper pylon will be built in 16 concrete sections cast in place using climbing formwork. The pylon will reach its full height in spring 2018. The first cables are scheduled to be affixed in fall 2017.

Main span: over the seaway

Located between the main pylon, built up against the Seaway dike, and Île-de-la-Couvée, where the next pier will rise, the main span is 240 metres in length and vaults across the shipping channel. This span will be erected by connecting 15 segments preassembled at the base of the pylon. In order to install 15 segments weighing more than 800 metric tons each without disrupting marine navigation, a unique lifting system, including a mobile lift beam, carriers and a lifting derrick, was specially designed and built. The average installation cycle for each segment, including lifting, positioning, bolting, attachment of the cables and other finishing steps, is expected to take three to four weeks. These activities will require the closing of the bicycle path on the Seaway dike at times.

Back  span: toward the river

Visible from the existing bridge, the temporary supports—installed several months ago, with some taken from the Millau overpass—help support the construction of the back span, which extends to the two piers at the end of the cable-stayed jetty. This portion of the bridge will counterbalance the main span. Since the architect opted for an asymmetrical bridge design with a single pylon, the back  span is shorter than the main span. Its box girders will therefore be filled with concrete. Construction of the back  span will last until fall 2017.

Main pylon by the numbers

• Pylon height: 170 metres
• Weight of the lower cross beam: 3,400 metric tons
• Weight of the upper cross beam (bow tie): 350 metric tons
• Number of elevators: 2

Main span by the numbers

• Reinforced concrete: 3,000 m3
• Structural steel: 7,000 metric tons
• Number of segments: 15
• Number of cables: 15 pairs