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Staying Behind the Scenes at AmericasMart
Technically Complex Project in Atlanta Requires Contractor to Maintain Low Profile
By Bruce Buckley
Putting on a major industry event requires tremendous behind-the-scenes work, so it’s fitting that expansion of the world’s largest wholesale showroom space of its kind requires more effort than meets the eye.
The $130 million, 860,600-sq-ft AmericasMart Building Two West Wing project is planned to blend seamlessly with the existing three-building, 6.2 million sq ft of space at Atlanta’s AmericasMart.
More than 567,000 buyers attend its markets annually to look for home furnishings, rugs, apparel and other products.
The new building probably won’t stand out among its neighbors, but its design and construction required the team to conquer significant logistical and structural challenges.
“From the outside it looks like a big square box, but inside it’s more intricate,” says Brett Oliver, development manager with Portman Holdings of Atlanta, the project’s program manager. Holder Construction Co. of Atlanta is leading the construction.
Construction
Holder broke ground on the project in September 2006 and is scheduled to complete it in August 2008.
The 10-story expansion will house exhibition space on the first four floors and leased showrooms on the upper floors. The temporary exhibition space requires an open floor plan with minimal columns, while the top floors will feature a more efficient column grid built around smaller rooms. In order to accommodate the differing column grids, six 10-ft-deep and 4-ft-wide transfer beams with 213 0.6-in. post-tensioning cables in each will take up the entire fifth floor of the building.
The building will have five freight elevators, three service/passenger elevators, eight passenger elevators and three sets of escalators.
The new structure abuts an existing 18-level building, and when completed, the new showroom floors will connect to showroom levels in the existing building. The new structure was also designed to allow for vertical expansion of an additional eight floors in the future—enabling it to match up with that neighboring building. Crews will construct pads on the roof to hold a tower crane for that future growth.
The building, which was designed by John Portman & Associates of Atlanta, will match the exterior of its neighbor with a mix of precast and glass on the exhibition floors and curtain wall on the upper floors.
One of the most complex elements of the project involves an existing loading dock along the side of the existing building. Crews are constructing the new building over the existing loading dock, keeping it operational during major markets held at AmericasMart in January and July.
Keeping business uninterrupted during those two shows was a top priority for the owners, says Greg Avitabile, vice president of development and construction at AmericasMart.
“We expressed to Holder at the beginning of the project that [these markets] are what we’re all here for,” Avitabile says. “It’s nonnegotiable to miss schedules or to interrupt the markets. They’ve taken that to heart and we’ve spent a lot of time planning and rehearsing how things will unfold.”
Early on, Holder was faced with its first challenge to the schedule. The site had been home to a Greyhound bus station, and its basement levels still remained. As a result, significant soil remediation was required, and that went on for nearly eight weeks past the date that Holder had been scheduled to take the site. Holder worked with the developer to come up with a compromise.
“We had to start the project while some of those soils were still being removed from certain areas,” says Randy Rager, project director at Holder. “It’s critical for everyone that this project stays on track. Any adjustments have to account for the fixed dates we’re being held to.”
The concrete frame structure rests on foundations split into approximately two-thirds caissons of 6 ft to 8 ft in diameter and one-third footings on rock. The building will have three levels of basement on the site – which slopes 30 ft from end to end – with only the deepest level completely underground.
At ground level, trucks delivering products to the building will be able to access the loading docks via Winship Way, a two-lane side street that runs along the loading dock area. The new loading docks will mirror the existing ones on the other side of Winship Way. The expanded AmericasMart will now extend over Winship Way.
The first task for Holder was to get sheeting and shoring in, complete foundations, do initial grading and build a temporary loading dock while the existing dock was shut down. In January, the team had to reopen the main dock for a market, turning that area back over to the owner for nearly two months while the market was set up, opened to the public and then taken down.
Holder then began the work above the loading dock. Crews constructed elevated concrete slabs over Winship Way and had to get re-shoring out in time for the July show.
“Our guys worked until 3 a.m. the day before the deadline to be able to remove that reshoring so the Mart could let trucks in and load in materials for the market,” Rager says.
Although that road was handed back over to the owner for most of July, the team coordinated times when construction trucks could pass through the site and not interrupt the market. As a result, Holder continued concrete pours while the market went on.
Each floor requires four pours—each with approximately 600 cu yd of 6,000 psi concrete, 90 lb of resteel and 13 mi of post-tension cables.
The columns are 12,000-psi concrete. Because of the tight site, concrete trucks drive into the building. Two trucks unload the 6,000-psi concrete, which is pumped up to placing booms, while another truck unloads 12,000-psi concrete that is brought up in a bucket. Up to five trucks are inside the building at any one time.
“Everything is being timed like a Swiss watch to get deliveries in here around times when people need to get into the show,” Rager adds.
Once the fourth floor is completed, crews will begin work on the massive transfer-beam floor. Each beam weighs 1,800 lb per sq ft—nearly 18 times a normal floor weight—so crews will have to reshore down to the basement.
Crews will also build eight enclosed pedestrian bridges between the new facility and an AmericasMart building across Harris Street. The bridge work will require some coordinated street closures.
Throughout the project, Holder has used a 298-ft-tall freestanding crane, one of the largest freestanding cranes currently on a jobsite in the United States. At that height, the crane is able to clear the neighboring 18-story building.
Future interior work will be limited in the exhibition space, which is being left open, while the showrooms will require several hundred thousand sq ft of glass corridors. The interiors will resemble those in the existing building with minor differences to indicate that it is a different area.
Once completed, the massive building will have used 45,000 cu yd of concrete, 3,841 tons of resteel and 450 tons of post tensioning.
Once the project is finished, the Atlanta International Gift & Home Furnishings market will take place in the new facility.
“People can’t appreciate the logistical challenges on this job,” Avitabile says. “We register huge numbers of folks coming in here during markets. People can’t believe or don’t even realize that we’re doing all of this construction in the middle of these markets. The goal is zero complaints, and so far, so good.” |
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