Two major infrastructure projects around the Calgary International Airport will increase access to the airport and air traffic capacity considerably.

Currently under construction, the new runway expansion will be 14,000 feet long. This makes it the longest civil aviation runway in Canada, surpassing the existing Calgary runway at 12,670 feet. For comparison, Denver’s runway, the longest runway in North America, reaches 16,000 feet.

Meanwhile, the 620-metre Airport Trail Tunnel project will allow vehicular traffic en route to the airport to pass underneath the new runway. Both of these projects are significant for Canada and Calgary, as the region continues to develop into a major player in the global market.

The tunnel will increase access to the airport for vehicles travelling from the south or east, allowing motorists to avoid the Deerfoot Trail, an inner-city expressway that is currently over capacity and therefore often at a standstill during peak periods.

The City of Calgary is making a $295-million investment in the Airport Trail tunnel. The road project, with CH2M Hill managing the engineering assignment, is one of the largest in the city.

The project scope has involved:

• Removing more than 600,000 cubic metres of rock and earth during the tunnel excavation.

• Installing underground utilities, such as water for firefighting purposes and a 1,000 cubic metre storm water tank and drainage system. It includes a lift station with pumps that direct water away from the tunnel and towards the city’s storm sewers.

• Installing communication and surveillance systems, a fire and smoke detection system, emergency egress accommodations, a ventilation system and an electrical system that includes power supply redundancy.

• Roadwork improvements and expansion leading to and from the tunnel.

Concrete work on the structure itself began with the installation of the footings, followed by forming and monolithic casting of the tunnel walls and roof in 50 segments. More than 65,000 cubic metres of concrete was used, along with more than 12,000 tonnes of reinforcing steel.

The project’s main challenge was time. The schedule forced this project to issue pieces of the work before the final design was complete. Coverage between contractors then became a significant management challenge.

Additional challenges were met in the high variability of the rock encountered in excavation for the tunnel, dealing with heat of hydration in the thick concrete sections of the tunnel roof, working through long cable pulls with the electrical contractor, and commissioning equipment procured, installed and connected by three different entities.

Engineering innovations included: using a set of concrete forms that were on rails for faster cycle time between sections being cast; remotely monitoring tunnel safety systems; using CCTV for incident detection; and incorporating an aspirating smoke and gas detection system. I

In addition, the integration of the traffic signals near the tunnel with safety systems was necessary to prevent additional vehicles from entering the tunnel during an emergency.

The second project, on which CH2M Hill is doing design as a sub-consultant to prime consultant Associated Engineering, is the Calgary Airport Authority’s runway expansion program. The longer runway and taxiways will travel directly over top of the tunnel.

Once complete, it will allow air traffic controllers to operate both runways simultaneously, increasing air traffic capacity considerably in and out of the city.

For cities that are considerably above sea level, extended runways are necessary to allow larger aircrafts like the Airbus A380 to take off and land. With the addition of this new runway and the latest in navigation aids, Calgary will have the ability to provide certainty of delivery for courier companies such as Purolator, FedEx and UPS. Additionally, commercial airlines will experience fewer delays and cancellations due to extreme weather conditions like dense fog.

Throughout tunnel construction and under a compressed timeline, milestones have been consistently met. The final objective is the public opening, which is projected to take place in May 2014.

Calgarians will not necessarily benefit from these developments immediately. However, as the city continues to grow at such a rapid pace, they may appreciate the proactive approach the City of Calgary has taken in constructing the tunnel in conjunction with the runway expansion.

Joost Bolderheij, P.Eng., has more than 30 years of experience in the design, engineering, and project management of urban and rural transportation projects. He is the operations manager for transportation with CH2M Hill in Calgary. He is also the consultant’s project manager for the Airport Trail Tunnel Project.