As Toronto's condominiums reach impressive new heights, regulating internal resident comfort becomes a more critical priority. Tall buildings are susceptible to lateral movement caused by high winds—which we've seen plenty of lately—and earthquakes. While the latter isn't of much concern in Toronto, local engineering firm Kinetica has engineered a damping system that enhances both wind and seismic performance, and it's now being installed at Canderel Residential's YC Condos.
The 62-storey, 639-unit development designed by Graziani + Corazza Architects features a slender and rectilinear design. That means high winds can cause the upper floors of the building to sway a number of feet. In concrete frame structures like YC Condos, traditional countermeasures against lateral forces like high winds typically take the form of tuned mass dampers. These devices absorb vibration—often by means of springs, pendulums or water—but require the sacrifice of otherwise usable space.
With YC Condos, valuable real estate has been maximized by employing the Viscoelastic Coupling Damper, which replaces the need for an obstructive tuned mass damper. The system was developed over the past decade at the University of Toronto with industry including Toronto structural engineering consultants and VCD manufacturing partners Nippon Steel & Sumikin Engineering and 3M Japan. One of the structural engineers involved in the early development was Tibor Kokai, now Principal at RJC Engineers, who served as the Engineer of Record on the project. UrbanToronto was recently invited inside YC Condos, with Kinetica chief development officer Joel Foo, to visualize how the system has been integrated into the building's bones.
The innovation consists of a rubber-like viscoelastic polymer in between steel sheets, collectively absorbing vibrational energy and transforming it into heat. The VCDs replace 42 steel coupling beams that connect to the shear walls in the midsection of the building. As a result, Canderel was able to recover over 5,000 additional square feet of space at the penthouse and mechanical levels.
The construction process has proved to be simple and quick—the steel template that will eventually hold the VCD is hoisted and then lowered onto shoring and integrated into the rebar cages. Temporary steel channels that ensure the template's two I-beams are aligned as they are cast into the concrete walls are removed and replaced by the VCD panels, which are raised into position via forklift.
Doing that requires the use of a custom-built trolley, pictured below, which holds the VCD panels between its four upper bars.
After being fastened into place, the VCDs are then concealed behind drywall, leaving a bulkhead that hides the unique devices from residents' view.
Installation of the VCDs—two on each side of the 21 middle floors—began shortly after the application of cladding on the subject levels. The vast majority of the 84 modular VCDs had been installed at the time of our tour.
Viscoelastic material was the first damping technology used in tall building construction. In 1969, the original World Trade Center in New York City employed approximately 10,000 in each of the towers. Now possessing higher damping and durability properties, the VCD technology is finding application around the world, providing resiliency against both wind and earthquake loading. As developers seek to maximize sellable square footage in their buildings, the technology also provides the economical benefits that make it an attractive alternative to traditional coupling beams and mass dampers.
YC Condos is scheduled to top-out in June. Additional information and renderings of YC Condos can be found in our dataBase file for the project, linked below. Want to get involved in the discussion? Check out the associated Forum threads, or leave a comment in the field provided at the bottom of this page.
|Related Companies:||Devisubox, entro, Graziani + Corazza Architects, McIntosh Perry, RJC Engineers, Ryan Design International|