The City of Calgary has seen exponential growth over the past decade, and things don’t seem to be slowing down for the Stampede City. With more and more people and industry moving in, demands placed on infrastructure and services have never been greater.
A plane takes off at sunrise from the new runway at
the Calgary International Airport.
More than 600,000 cubic meters of earth and rock
was excavated (enough to fill 240 olympic-sized
swimming pools) to create the Airport Trail Tunnel,
which provides a thruway for Calgary’s commuters.
A Runway with a Difference
In response to an increase in airline and passenger volume, the Calgary Airport Authority moved ahead in 2011 with expansion plans that included the construction of a new 4,270-meter-long runway, associated taxiways, and underpasses. PCL, Parsons, and Dufferin (PPD) were awarded the Runway Development Project as a joint venture initiative for the Calgary Airport Authority.
Mother Nature, however, had her own plans for the progression of the runway. Calgary has notably long winters, and the city also saw two very wet springs in 2011 and 2012. Then, in June 2013, southern Alberta experienced the costliest flooding in Canada’s recorded history.
Consequently, most of the main construction work for the Runway Development Project, such as concrete paving, backfilling, and gravel work, could only be completed during six months of each year, and was constrained further by the unexpected weather interruptions.
As a workaround, the project team developed a schedule that enabled mass excavation to continue around the clock throughout the winter months. As a result, critical schedule items were delivered on time at no additional cost to the Calgary Airport Authority. The project team also mobilized specialty equipment to thaw frozen electrical conduit so electrical cable could be pulled and electrical fixtures installed all winter long. To mitigate the unseasonably wet spring weather, the project team used additional concrete paving equipment and manpower to place over 300,000 cubic meters of concrete during the few dry months of that summer.
This effort resulted in the completion of Canada’s longest runway, now welcoming flights at the Calgary International Airport (YYC).
Tunneling a Way Through
The City of Calgary was interested in developing an east-west connector tunnel under the planned runway area to minimize travel time for an increasingly large number of commuters and to enhance the movement of goods. The City recognized that for the 620-meter-long, cast-in-place tunnel to happen and remain affordable, it needed to be designed and built before construction of the new runway at YYC was completed. PCL, Parsons, and Dufferin (PPD) were also awarded the Airport Trail Tunnel project as a joint venture initiative for the City of Calgary.
The PPD team worked with the City and the consultant, CH2M Hill, to develop a construction plan and budget for the Airport Trail Tunnel that would meet the demanding two-and-a-half-year schedule. This aggressive schedule was precipitated by the need to complete the tunnel and backfill around it without affecting the Runway Development Project.
Excavation progressed 24 hours a day, seven days a week. The project team built the cast-in-place structure in double shifts through the winter. Four sets of tunnel forms on rails allowed for quick transitions between segment pours, and tents above the formwork protected the concrete while it was poured, and as it cured through all types of weather.
With six traffic lanes and two potential light rail transit (LRT) lanes to accommodate possible future LRT C-Train expansion, the tunnel provides a means for Calgarians to keep up with the vast growth of their city.
“YYC is extremely pleased at reaching our goal on time and under budget, and very appreciative of the efforts from the PCL, Parsons, and Dufferin team to work together with all trades, program manager, and design consultants to achieve that goal,” said Sig Undheim, director of the YYC Runway Development Project.