Features
 Current Features
 Past Features
 Louisiana Contractor
    Past Features


Feature Story - October 2005

Concrete fortress
MEMA building to provide safe haven from natural disasters, terrorists

By Angelle Bergeron

The Mississippi Emergency Management Agency's Emergency Operations Center was conceived about five years ago as a fortress that would withstand natural disasters and acts of terrorism, and one that would provide a safe haven for emergency and government agencies during any sort of crisis.

"This was before Sept. 11, but after the 1995 Oklahoma City bombing, so we knew there was a risk of domestic terrorism," said Robert Laitham, executive director of MEMA. That risk pushed designers to create a secure facility that could house government entities forced out of their individual points of operations during a disaster.

"Our current facility is small, antiquated and doesn't have the space or technology to sustain a long-term operation or the necessary staff should the need arise," Laitham said. "We wanted to design something that would be self-sustaining without any outside support. If everything else fails, this building needs to continue because you've got to make sure the seat of government operates."

advertisement

The resulting $13.8 million 72,000-sq.-ft. facility in Pearl is an impressive mass of poured-in-place concrete, nestled half underground and protected on all exposed surfaces by precast concrete panels. Even the glass entrance, which marks one of the few possible points of penetration on the building, is guarded by X-ray machines.

"We wanted it to have a sense of mystique about it, so people would have a little intimidation when approaching, like reverence for the building's purpose," said Bill Tompkins, principal architect with the Jackson firm of Tompkins and Barron. "As a visitor enters from the front, the sidewalk appears to float above the ground and there are decorative barriers to keep people from driving into the building. The whole design creates a sense of caution, like a secure government building, to make people feel like they are being watched when they enter."

The Mississippi Legislature appropriated funds to build an Emergency Operations Center and the Federal Emergency Management Agency awarded a $6.6 million grant for the project, Laitham said. In addition to the EOC, the building will normally house offices for Homeland Security and the Mississippi State Health Department. During an emergency, the building will be a central command for the governor, MEMA and FEMA and includes a media briefing room with a variety of communication capabilities.

Consequently, the state and federal government dictated stringent security requirements, Tompkins said.

"There was the need for the building to be self-sustaining in the event of major power and utility losses, but it also needed to be pleasant and provide a good work environment for the regular employees," Tompkins said.

Inside the building, the architect created a lot of interior open spaces with glass walls and bright colors and with offices facing open hallways. On the exterior, Thompkins opted for ribbed, precast panels for the protective cladding. The ribbing creates shadow lines.

"There's more concrete in the walls than in the slabs," said Brad Bradshaw, project manager for Jackson-based Harrell Contracting Group, the project's general contractor. Six-in. precast panels further protect the 12-in. walls, which are poured double the thickness of the slabs.

By the time the building is complete, ready-mix supplier MMC Materials Inc. of Jackson will have provided between 12,000 and 13,000 cu. yds. of concrete to Harrell and Jackson Precast, the Jackson company that is fabricating the exterior cladding.

Harrell received the notice to proceed in July 2004 and began with clearing the site's pine trees.

"Then we had to dig a big hole," Bradshaw said.

Delta Land Construction Co. of Ridgeland, Miss., excavated and removed 50,000 yds. of material to create the massive hole in which the first floor would be constructed.

"We had to haul off all of that Yazoo clay because it was unsuitable to use for fill in that area," said Bill Summers, an estimator for Delta Land.

Once the hole was dug, Harrell erected a tower crane in the center of the circle to drill the concrete pilings and pour the concrete. After the pilings and grade beams were complete, the contractor began construction of the first-floor structural slab and exterior walls.

"We poured about 10,000 sq. ft. of floors at a time, with some block-outs," Bradshaw said.

Creating circular impressions in the otherwise monotonous poured-in-place walls was probably the hardest part of the job, said Tommy Joseph, superintendent for Harrell.

"We had to set these little round (components) in the forms (to create the impressions), and trying to make the holds on the forms and put it all together to look right was a problem at first," Joseph said. The Harrell crew figured out a way to attach the components so workers could jump the forms on a long wall without having to reset them each time.

"We had to glue them and screw them in," Joseph added. "Sometimes they would pop off, but most of the time they wouldn't."

He said the walkway leading up to the main entrance of the building is an interesting feature.

"It wasn't that complicated, but it was the first sidewalk I've done that is sitting on pilings and grade beams," Joseph said.

Harrell back-built the whole structure using the tower crane until it was time to construct the roof and exterior panels, Bradshaw said.

Normally, Jackson Precast would use its own batching facilities, but due to the tremendous amount of exposed poured-in-place and precast concrete, maintaining uniformity in the mix was crucial.

"We have a plant in Jackson and we fabricated there, but we used MMC Materials and its self-compacting concrete mix design that was the same as used for the poured-in-place onsite," said Bob Fulcher, sales and marketing with Jackson Precast. "We wanted to make sure the panels matched the rest of the building."

For MMC, scheduling deliveries has been a challenge, "but it's good, consistent, everyday work," said Stewart Boone, commercial sales representative. "It's a very large concrete job and, when you add precast it makes it even that much more attractive."

Jackson fabricated approximately 160 ribbed panels, a third of which were identical, Fulcher said. The largest panel weighed in at 15,000 lbs., but the average size ranged from 10,000 to 11,000 lbs.

"These panels have .75-in. recessed ribs and are battered five degrees," Fulcher said. "That means the panels go up and slope away. It's an unusual design, which gives this building a very distinctive look."

The architect's specifications also called for sandblasting the ribbed areas of each panel, which created a contrasting border.

Harrell is setting six to 10 of the panels each day, at varying angles. The edges and corners of each panel must be flush with the adjacent panel, so the corners must meet in three dimensions, Fulcher said.

"The aesthetics of the building are just wonderful," said Fulcher, pointing to a where two angular panels meet at a corner.

"This is an unusual building and I like what the architect did with the sandblasted and non-sandblasted areas."

If the contractor continues at the current pace, MEMA officials hope to move in by the first of the year, Laitham said. That will be well ahead of the July deadline.

 Click here for more Features >>


Try 4 issues of ENR
for FREE!

 

Sponsors

© 2014 The McGraw-Hill Companies, Inc.
All Rights Reserved