Mirvish+Gehry is Looking Up!
By Lucas on Jan 24, 2014
As the height of buildings rise, so does the complexity of building them. As towers get taller and more slender, construction poses different challenges than building closer to the ground, and over 60 floors, things start to get exponentially more difficult.
With greater intensification taking place in Toronto and limited space to build, tall towers are the rule rather than the exception.
The three proposed Mirvish+Gehry towers, each soaring over 80 storeys tall, will require not only outstanding architectural vision, but also an unparalleled technical response including, structural engineering and construction acumen.
One of the biggest factors when building up is the impact of micro climates, which comes into play around the 40th floor. This is a problem in both summer and winter. At that height, winds gust stronger and temperatures are extreme more often. These, and other weather related conditions, make construction work more difficult, and can result in a loss of productivity that wouldn’t happen closer to the ground.
Mirvish+Gehry Toronto. Images source is credited as Mirvish Enterprises, Gehry Partners and Projectcore Inc.
When you have people working at great heights in the sky, there’s more than climate to think about. The workers need washrooms, a place to eat lunch and a break area. These amenities must be provided - not at every storey, but on several floors of a tall building.
As well as protecting the welfare of workers high above the ground, the safety of those below is paramount and overhead protection provided to protect from objects that could fall from above. Even a pebble falling from above could pose a risk.
Projectcore and its team of technical experts must overcome numerous logistical and engineering challenges, such as how to pump vast amounts of high strength concrete to considerable heights. New technology has made this possible and pumping is much more efficient than using a crane or buckets. Vast amounts of building materials will also have to be hoisted into the sky and that’s when just-in-time delivery is crucial when there is limited space for staging. Having materials, such as rebar, pre-manufactured helps to overcome limited staging areas and crane hoisting capabilities.
Scheduling is a critical issue – not only must the productivity losses inherent with working on tall buildings be factored in, but also the timing constraints, as city bylaws that limit the hours construction can carry on. A vast amount of material moves vertically using only one crane making scheduling challenging and efficiency paramount. Additionally, vertical transportation of workers can only happen once per shift.
With the increasing number of sky-scraping buildings in the city, Toronto has become well versed in the complexities and challenges of constructing tall towers. Watch for more ingenuity and innovation as new projects soar even higher and present even greater challenges.
Nevertheless, despite the challenges, Mirvish+Gehry is looking up!
Peter Kofman
President, Projectcore Inc.
