To maintain safe aircraft access to and from gates through active construction zones, the team adopted an “airport operations come first” approach, establishing construction work areas only after determining the setbacks required for gate access, aircraft pushback and tug operations, says Robert Millar, aviation project director for lead design firm HNTB.

“HNTB coordinated closely with (terminal architect) HOK and airline stakeholders to align terminal and civil construction schedules, ensuring existing gates remained operational until replacement gates were available,” says Millar. “Special attention was given to maintaining widebody aircraft access to international arrival gates until new international-capable gates came online.”

The team also built detailed blueprints to prevent service outages. Millar says the jet fuel sequencing plans were “particularly detailed” and included coordination with specialty installers and testing contractors to facilitate overnight shutdowns for flushing, testing and tie-ins to the existing system to avoid disruptions to airline fueling operations.

Safe crane operations were another challenge, requiring coordination between HNTB, the FAA, airport stakeholders and the joint-venture team of Holder Construction and Big D Construction (HDJV). Millar says HNTB helped implement a range of strategies, including mapping and designing temporary “crane roads” around the concourses for the crawler cranes to use, and running evaluations to confirm that large construction cranes did not block the air traffic control tower's view.

Brent Christiansen, superintendent for HDJV, says to execute heavy crane maneuvers safely, field teams had to maintain a rigid regulatory schedule and adapt constantly to shifting visibility. "The FAA required a weekly 7460 meeting to coordinate the areas of impact, as well as setting a ceiling for lifting operations and hours," he says. "Bad weather was the biggest challenge due to ILS (Instrument Landing Systems) operations and its requirements. The team had to continually watch the weather and be ready to lower and move equipment at a moment’s notice so as to not interfere with ILS operations.”

A unique aspect of the program was extending an existing passenger tunnel that had been constructed years earlier and preserved as a future connection point. “When the tunnel was eventually excavated and extended to serve the new concourses, the team had to address several complex engineering considerations to seamlessly connect the new and existing structures," says Millar. 

To anchor the tie-in, the team designed temporary shoring to hold down the end of the existing tunnel after removing overlying soils. "The extension also required careful consideration of the joint design between existing and new structures to mitigate against differential settlement, as well as to provide waterproofing continuity between the new and existing tunnel sections," says Millar.

The project’s completion brings the airport’s total capacity to 94 gates. While a separate joint venture of Austin Commercial and Okland constructed the Concourse B facilities under a $545-million contract, the seamless completion of the phase successfully wraps up more than a decade of master plan expansion across four phases, updating the entire airfield footprint.