Grand Convergence

The Gaylord National Resort and Convention Center proves that good things come in large packages, too

By Jim Parsons

The 2.4-million-sq-ft Gaylord National Resort and Convention Center in Prince George’s County, Md., isn’t scheduled to welcome its first guests until next spring, but big things have been happening at the 41.7-acre site on the banks of the Potomac River since construction got under way in June 2005.

Statistics on Gaylord National cement its status as the largest current hotel construction project on the East Coast and the fourth largest in the world, according to Gaylord Hotels, the Nashville-based company that already operates three other meeting-focused resorts in the southeast United States. By the end of July, more than 200,000 cu yd of concrete and 2,500 tons of structural steel had been used to form the 20-story, 2,000-room hotel and its accompanying 470,000 sq ft of flexible convention, meeting, exhibition and prefunction space.

The hotel’s signature feature—a striking 18-story atrium topped with 13 steel trusses totaling 2.4 million lbs—will support approximately 2,000 4- by 9-in. glass panels, forming a 1.6-acre indoor garden bordered by shops and restaurants.

The Peterson Cos.’ National Harbor mixed-use development (see sidebar), Jeff Barber, principal-in-charge for the architecture firm Gensler of Washington, says the real focus for guests and visitors will be the river and its surrounding scenery.

“We took advantage of the site’s sloping topography to orient the large program elements toward the Potomac, making the outdoor spaces expansions of the indoor rooms,” Barber says. “Even the exhibit hall and prefunction areas, which are often enclosed boxes, have large windows facing the river.”

That strategy also ensures that Gaylord National’s size doesn’t overwhelm its surroundings. For example, the hotel’s 300-ft-long north façade is designed to give arriving guests the impression of three different buildings. “The pieces will hold your interest, and help bring the building’s scale back to a human level,” says Gensler project design director Raffael Scasserra.

From the bottom…

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Before Gaylord National could begin its majestic rise next to the Potomac, the construction team led by general contractor Perini/Tompkins JV had to contend with complicated soils underlying the steep, waterfront site.

The project team excavated more than 240,000 cu yd of dirt and constructed multiple retaining walls, including a 48,000-sq-ft mechanically stabilized earth structure to prevent destabilizing residential neighborhoods a few hundred feet away. The hotel’s foundation also required driving more than 2,800 14-in.-diameter, 150-ton precast piles 70 to 100 ft through an undulating stiff clay lens.

“Our original schedule was to have three teams each doing 10 piles a day,” says Mark Makary, Perini/Tompkins principal in charge. “Many days, we got only five in—two of which would break.”

That experience led the project team to adopt a different tact in preparing the site for what was to be a future 30,000-sq-ft, 500-room addition.

“We went to 100-ton piles, which made for more piles and larger caps, but were easier to drive,” says Rod Dornbusch, Gaylord Hotels’ executive director of construction for the project. “Only about 600 hits were needed to get each of them in, instead of 2,000 hits needed for each of the 150-ton piles.”

…to the top

In contrast to the brute force required for the Gaylord Nation’s foundation, installing the atrium truss system 230 ft above floor level demanded some construction artistry. The project team spent nine months planning and practicing the erection procedure for the 240-ft-long welded arched trusses, which range from 36 to 42 in. in diameter.

“It’s natural to be concerned about the technical requirements of a unique design such as this,” says Tobey Arnheim, vice president of construction for Gaylord Hotels. “We couldn’t do any work beneath the trusses until they are all in place. Our whole schedule depended on this one area.”

Makary admits to having a few butterflies about the procedure as well. The 340-ft cranes used to hoist and swing the top trusses into place would leave only 11 ft of clearance from the top of the building. The site’s typically windy conditions were also a worry, with memories of an 86-mph gust recorded during a spring 2007 storm still fresh.

“Fortunately, things were pretty calm when we started with the trusses,” Makary says. “The first one required about an hour to install. Others have taken as little as 40 minutes to install.”

While the north ends of the trusses are allowed to “free float” to accommodate heat expansion by the 1-in.-thick glass roof panels, the design team needed to address the potential for heat gain inside the atrium.

“We had to use clear glass panels in the continuous skylight due to the need for sunlight for the indoor plants,” Gensler’s Barber says. “A network of radiant cooling pipes beneath the footpaths and terrace levels will channel heat from the atrium, dramatically reducing the air-conditioning demands.”

Intensive infrastructure

Supporting the operations of such an expansive facility requires a substantial network of interior infrastructure. Fit-up of the Gaylord National’s ground-floor IT center was completed while work on the exterior envelope was still in progress so that crews could install and test the systems that will control the technology-intensive building’s environmental, equipment and telecommunications operations.

The Gaylord National is also unique in having its own three-feed 13 kVa high-voltage supply. “Without it, the voltage drops across the 800-ft-long building would have required prohibitively large conductors,” Dornbusch says.

Gaylord National’s most impressive accomplishment may well be meeting the target April 25 opening date. Several major meetings and more than 1 million room nights have already been booked for a hotel still shrouded by cranes and scaffolding.

“We’re already running multiple shifts and working within nighttime noise restrictions to prevent disturbing residents of the adjacent neighborhoods,” Arnheim says. “There is no ‘Plan B.’”