If you’ve ever been to downtown Toronto, CIBC SQUARE is a structure that’s hard to miss.
Walters Group played a key role as the structural steel fabricators and erectors for CIBC SQUARE including the 54-storey tower and podium, overbuild park, pedestrian bridge to Scotiabank Arena as well as two more pedestrian bridges. In total, approximately 15,000 tons of structural steel and decking were fabricated and erected.
Structural Steel Construction of the CIBC SQUARE Tower
In high-rise construction, there’s a great level of coordination that needs to happen. And for CIBC SQUARE, planning started months before steel reached the site. Regular planning sessions, model reviews, sequencing plans, and trade coordination were all considered to make this project move smoothly. On top of that, the level of complexity was also present on a variety of pieces on this project.
From ground level all the way to the top of the CIBC SQUARE tower, there were intricate details were all around that make CIBC SQUARE the distinctive space that it is.
The Canopy
Designed to be striking from every angle, the Architecturally Exposed Structural Steel (AESS) canopy required specialized hidden connections to achieve its seamless lattice look. The ends of the canopy were also cantilevered, so the steel had to be cambered during fabrication to ensure it would settle into the correct elevation once installed. Due to its massive size, the canopy was fabricated and installed in three sections and trial-fit to ensure proper alignment and fit.
The Podium
The greatest complexity in the structural steel design of the podium was the integration of the new GO Bus Terminal. The area needed to be column-free so buses could move freely in and out. To accomplish this, Walters fabricated and erected massive, long-span steel trusses above the terminal, to support the structure while also accommodating the building’s mechanical systems overhead.
The Crown
At the very top of the CIBC SQUARE tower, the crown’s design was dramatic, continuing the same three-dimensional diamond pattern façade. With its distinctive angles and complex geometry, the team focused heavily on detailing and coordinating the steel framework to ensure the hundreds of connection points were accurately provided for the glass façade and other systems installed later.
Constructing the Overbuild, Above Active Rail Lines
Building above active rail requires a tremendous level of coordination, safety training and documentation. Before any work could begin, detailed work plans had to be submitted to outline the crane operations, rigging procedures, material unloading, safety protocols, and the exact sequence of activities for each shift. All documentation had to be signed off by Metrolinx, the governing authority responsible for rail operations.
When it came time for the structural steel installation, the Walters crews needed to erect during the overnight hours (between midnight and early morning) during rail shutdown windows. Within that limited timeframe, they had to mobilize equipment, unload steel, complete lifts, and fully clear the tracks before trains resumed service. Plus, working overnight also meant lighting had to be moved as work progressed, equipment had to be carefully coordinated, and everyone involved had to complete Metrolinx safety training before setting foot on site.
Scotiabank Arena Pedestrian Bridge
Known for its glass wall and C-shape design, the geometry of the Scotiabank Pedestrian Bridge created torsional forces within the steel structure. This could cause it to twist or rotate if not carefully engineered. Working closely with RJC Engineers, Walters incorporated torsional camber into the structural steel design so that it would naturally straighten under its own dead load once installed.
And solving the bridge’s complex geometry was only part of the challenge.
To position the bridge, the team had to set the crane on an existing rail bridge behind the installation area. But it was nearly 100 years old, could it safely support it?
Working with the engineer of record, the team developed a plan to distribute the crane loads as much as possible across the bridge deck. Sensors were installed to measure how much the bridge deflected under the weight of the crane. If it moved more than a few millimetres, the lift would have to stop immediately. The bridge segment was lifted as someone was watching a gauge in real time to see if the bridge was moving.
From Friday night to Saturday evening, the team had to install the bridge, complete all bolting, and remove the cranes so the area could reopen.
Union Station Pedestrian Bridge
Connecting CIBC SQUARE to the Union Station Bus Terminal and directly to Union Station, this 42-metre-long bridge was designed as a large, 220-ton steel box girder. It was fabricated entirely at the Walters’ Stoney Creek plant and delivered to site as a single piece. Portions of the Union Station Pedestrian Bridge was also classified as AESS 4, meaning the exposed steel had to meet a very high visual standard. To achieve this finish, the massive girder was moved into a temporary greenhouse structure for painting before being transported and installed.
Yonge Street Pedestrian Bridge
Due to the size of the bridge and the constraints of the site, Walters fabricated the structural steel for the Yonge Street Pedestrian Bridge in three segments. Each had to be transported through downtown Toronto and installed above active traffic, requiring carefully coordinated road closures to move the oversized loads safely. With very limited storage space on site, each segment also had to be delivered and installed within a narrow window when traffic was cleared and the roads were closed.
Walters worked closely with the City of Toronto, EllisDon, and transportation authorities to coordinate installation during approved overnight road closures. Transportation routes were carefully planned, oversized load permits were secured, and crane and rigging operations were fully coordinated in advance. Walters also installed a column and temporary shoring tower ahead of the lifts to support the first two girders. The first two segments, weighing 38 and 34 tons, were installed on the same day, followed by the final 62-ton girder two weeks later.
CIBC SQUARE: An Iconic Structural Steel Project in Toronto
Walters Group is honoured to have been the structural steel fabricator and partner on the CIBC SQUARE development alongside our partners EllisDon, Hines, Adamson Associates Architects, and RJC Engineers. It’s a project that has helped shape Toronto’s skyline and one we’re proud to have been a part of.
Visit https://www.waltersgroupinc.com/project/cibc-square/ to learn more about this project.
Editorial piece originally published by Jessica Ranalli on LinkedIn.
