2002 AIA Michigan Design Honor Award

 NORTHWEST WORLDGATEWAY
Romulus, MI

Jury Comment:
The steel roof structure provides a robust and readily identifiable form on the airport's skyline. The truss systems and joists provide an economical solution to the need for long spans and create interesting spatial qualities.

Project Description:
This new 2 million-gsf airport passenger terminal includes a four-level terminal building, a connecting link with a food court, retail shops and other passenger amenities, east and west concourses and an 800-foot underground tunnel linking the concourses. Combining domestic and international facilities under one roof, the terminal's east concourse (Concourse A) is up to 99 feet wide and nearly one mile long with 64 jet aircraft gates. The west concourse building (Concourses B and C) accommodates 8 jet gates and 25 commuter aircraft gates. An 11,500 space parking garage; energy plant; three level roadway system; 180 acres of apron and taxiways and support facilities are also included in the total project. The project is located on a 314-acre parcel surrounded by six active runways.

A large king post truss and framing system provide support for nearly all of the 650,000 square feet of roof of the terminal complex, creating strong diagonals that are expressed in the interior of complex. This system provides a column-free space for the entire width of the concourse and terminal buildings. Intermediate joists, in lengths up to 42 feet, frame into the criss-crossing king post trusses, completing the lightweight and economical roof system. The unique framing system is also used throughout the connecting link between the terminal building and the main concourse, allowing for a 70-foot clear story and providing an opportunity for a lively mall atmosphere. The terminal building is recognizable by asymmetrical and undulating curves formed by large curving steel trusses. Steel joists provide intermediate support for the roof as well.

Flexibility and openness were critical design objectives met by the use of this unique steel truss and joist framing system. Availability of the steel joists in varied lengths and capacities provided a highly cost efficient roof support system. The connection of the steel joists to the king post trusses facilitated installation. Typically, the joists are not aligned orthogonal to the king post trusses; the angles at which the joists frrame into the trusses would have made the installation very difficult had an alternate form of framing been used.

Additionally, the use of the steel truss and joist system enables the owner to easily reconfigure the interior spaces of the terminal complex as the needs and services of the airline industry change over time.

The use of the steel king post truss and joist roof support system provided an opportunity to erect the roof in sections approximately 300' long by 100' wide, including the insts,11of all the intermediate framing, piping, duct-work, and conduit on the ground and to hoist large sections into place. Although this method was only used for installation of a small portion of the entire truss system, construction time was minimized nevertheless by the highly uniform nature of the vast roof support system. The area of the roof is very large, however, the variation in framing is minimal.

The steel joist and truss system proved to be a valuable and cost-effective option that expresses the design intent. The steel joist intermediate framing is very lightweight, resulting in the savings of a large amount of steel. The availability of joists in varied lengths and configtuations further minimizes the steel tonnage.

The steel joists provide a very lightweight alternative to the intermediate framing of the roof. The lightweight steel joists provide a virtually invisible roof support system, providing a focus to the large king post trusses.

The roof support system selected for the budding provided the large, open, column-free spaces and clear height clearances that the client and the design team desired. The diagonal trusses eliminate the need for intermediate columns, while the open area created by the joists provides adequate space for mechanical and electrical equipment, as well as required clear height clearances.

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