The MAADI Group designed, manufactured, and installed a prefabricated aluminum bridge, which provides a walkway between the Alexandra Pier and the Iberville Passenger Terminal, at the Port of Montreal, Canada. The new structure (called a skywalk) was part of a $78 million restoration project, which was designed to help modernize and integrate the aging maritime structures into the urban fabric of Old Montreal. The aluminum skywalk was completed through a tight collaboration with Pomerleau, the construction company managing the project, as well as architectural firm Provencher_Roy and NCK Inc.
The bridge is made of plates of aluminum alloy 5083-H321 and extruded aluminum 6061-T6 that are joined together using fusion welding. The fusion welding process at MAADI complies with CSA Standard W47.2, which requires companies to be certified for Fusion Welding of Aluminum, and CSA Standard W59.2-M1991 (R2013) for Welded Aluminum Construction (an equivalent to AWS D1.2). The floor of the skywalk is made of fire-resistant planks of red cedar from western Canada that have a 64 mm (2.5 inch) finished thickness, and the guard rail is made of a stainless steel mesh reminiscent of fishing nets, which was inspired by the maritime location. Complying with Canadian Highway Bridge Design Code CAN/CSA-S6-14 (2014), the skywalk has the capacity to handle a 1 tonne (2,240 lb.) vehicle and pedestrian traffic of 4.8 kPa (100 psf).
The design and installation of the skywalk bridge faced some unique challenges. Because the foundations of the buildings dated from the early 1900s, the axes of the columns and pillars were not perfectly centered, so precise measurements on all aspects of the bridge were required. “What was very important for us regarding the skywalk,” said Marc Plamondon, Pomerleau’s project manager, “was the precision [measurement] of the concrete footings, the precision [measurement] of the axes.”
Furthermore, due to the structural irregularities of these old but very solidly constructed buildings, the skywalk extends about 2.4 m (7.9 ft) onto the buildings at either extremity. “The skywalk rests on the two existing buildings, and other things,” said Philippe Beaudoin, the engineer who is managing the structural aspects of the entire Iberville restoration project on behalf of NCK Inc. “We did not have to build new footings to support the skywalk.”
The completed skywalk measured 32 m (105 ft) in length and weighed 9.15 tonnes. As such, it required an extra-wide truck and a police escort to transport it through the narrow streets of Old Montreal.
“This renovation of the Iberville Passenger Terminal will make thousands of cruise tourists feel even more welcome in Montreal,” said Alexandre de la Chevrotière, CEO of MAADI Group. “The big advantage for the Port is that aluminum is corrosion-free, so it has a low cost of ownership compared to other materials such as steel, which always requires maintenance to prevent corrosion. We are proud to have one of our pedestrian bridges showcased in such an appealing setting.”