We sat down with Ian Washbrook, Kirk Haugrud, David Optyker, and Kris Dahl to talk about an interesting project they’ve been working on that involves innovation, planning for change, and preparing for evolving cities.
Ian, Kirk, David, Kris, thanks so much for sitting down with us. Can you tell us about this project?
Ian: This is a very unique and fantastic project. We knew from the language in Calgary Municipal Land Corporation’s RFP that this wasn’t going to be “just another parkade”. The innovative design and construction journey has certainly proved that it means much more to the community and to Calgary’s urban fabric than your average above-grade parking garage.
The Calgary Parking Authority’s 510-stall parkade, located on 9th Avenue SE, will go beyond its function to participate in the cultural landscape it services, supporting visitors to New Central Library and the National Music Centre, in addition to other East Village and downtown destinations. It will also serve as an innovation incubator space, in an interesting mixed-use scheme.
Flexibility is integral to the design so that amenity spaces and future occupancy changes can be facilitated. Should self-driving cars start to drive people around and parking garages slowly become extinct, the building can be converted to residential and/or commercial space.
Structurally we designed the slabs, beams, and columns for superimposed dead loads and live loads that are double what a conventional parkade is typically designed for. The floor-to-floor height is also designed to be higher than a typical parkade to allow for future floor and ceiling finishes, and mechanical and electrical services that would accompany future occupancies.
Wow, this really sounds like a parkade of the future. Were there any challenges in addition to the flexibility requirement?
Kirk: Absolutely. The site itself features several constraint challenges: the CP Rail corridor to the south; the existing LRT tunnel bisecting the site in a north/south orientation; a large water main and utility right of way corridor to the east and adjacent to the LRT tunnel; and access requirements from Enmax’s District Energy. Our designs had to take all this into consideration, including loading restrictions over the LRT tunnel, as well as complex thermal building strains due to mixed occupancy use and exposure.
David: In addition, since the site is right next the CP rail corridor, the columns nearest the train tracks had to be designed for the potential impact of a derailing train. And another quirky challenge is the high water table on site. In the event of a flood, the exterior sump pits had to have their base thickened up to add enough mass to prevent them from floating upward.
Can you tell us how you solved some of these unique challenges?
Kirk: Our team designed two trusses that are two-storeys tall, and three more trusses that are each one-storey tall to span across the LRT tunnel and the utility ROW. The structural steel trusses span 33 metres, and the four main trusses weigh roughly 59,000 kg each.
The trusses are the main solution to creating a functioning structure on a site bisected by the LRT tunnel (which is skewed in plan). The truss design accounted for a specific erection procedure that would keep construction loading over the LRT tunnel within the fairly restrictive acceptable limits.
Another challenge involved the fact that the second level of the parkade is actually commercial office space for Platform Innovation Centre. So, we had to design a long-flying vehicle ramp through the atrium of the parkade to allow cars to bypass the second level from the ground floor to get up to level three. Since the site is bisected by a significant water main, the ramp also needed to be high enough to allow emergency crews and equipment vertical clearance to maintain or repair the pipe. The structural design considered the potential damage caused by a water main failure.
In addition, we designed a vehicle guard system to address the potential impact of vehicular traffic. This prestressed cable system also helped keep costs down since it’s considerably more cost-effective than a traditional vehicle guard system.
David: Another unique aspect of the project is that the structure is split by expansion joints, so the building is really two separate horseshoe shapes. Since the ends of the building follow an elliptical curve, each wedge of slab between beams has varying span length. Rather than attempt to detail, fabricate, and place reinforcement perfectly engineered for the changing span lengths, reinforcement was grouped into standard lengths that could cover a range of spans.
It sounds like the team really came together to solve these various challenges with innovative thinking. These are exactly the kinds of projects Entuitive thrives on. Any final thoughts?
Ian: There are many details that make this project unique and constructability was one of the key considerations, especially the long spans overtop of the LRT tunnel and utility line. Entuitive brought forward our experience designing the encapsulation of New Central Library overtop of the same LRT line across the street. We worked closely with the construction manager to ensure that the sequence of erection of the mega trusses and concrete infill framing did not exceed a load threshold overtop of the tunnel.
Kris: During design, one of the goals was creating a repeatable and consistent design. The slab design remained consistent at all typical levels of the project and the concrete beams were narrowed down to only a handful of variations. This repeatability of the design made installation and construction extremely fast, virtually free of rebar errors, and greatly helped to reduce the coordination time required during construction.
Kirk: Much like with the neighboring central library, CMLC has developed a challenging and undesirable site into a meaningful and iconic structure that will serve the community. I believe the entire consultant team did a great job delivering on the unique demands of this project. I have to say, this is the first parkade I am excited to visit when it is completed.
Thanks so much for taking the time to tell us about this parkade of the future, guys. We really appreciate it and can’t wait for its completion.
If you’d like to learn more about the 9th Avenue Parkade & Platform Innovation Centre, reach out to Ian Washbrook.
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