Angelle Bergeron/ENR
Contractor placed the last of five main girders over the navigational channel of the U. S. Hwy. 90 Biloxi Bay Bridge on May 2.

The contractor for the new, $338 million U.S. Hwy. 90 bridge from Biloxi to Ocean Springs, Miss., placed the fifth and final girder on the main navigational channel span May 2. With that challenge out of the way and 35% of the decking already completed on the northern span of the east-west bridge, it seems the contractor is well ahead of schedule to meet the November 13 milestone to open two lanes of traffic and win a $5-million early completion bonus. “By the end of June, they will have 85% of the milestone decks in place,” says Kelly Castleberry, project manager for the Mississippi Dept. of Transportation. “You would almost be able to drive across it, but not quite.”

The contractor is not exercising bragging rights until the deadline is past. “Our opening date is November 13,” says Steve Underwood, project manager for GC Constructors, a joint venture of Massman Construction Co. of Kansas City, Traylor Bros. Inc. of Evansville, Ind., and Kiewit Southern Co. of Peachtree, Ga. MDOT issued a notice to proceed June 2006 on the fast-paced, design-build project to restore a vital artery knocked out by Hurricane Katrina’s storm surge. The time frame has definitely been the biggest challenge on the project, Underwood says. However, GC had the advantage of access to equipment and manpower resources from the three partners when both were in scarce supply for others in the aftermath of the hurricane. “All the equipment on the job, with the exception of a few barges, is the property of GC Constructors,” Underwood says. The contractor has about seven boats and 20 cranes on the job, including the 4100 ringer used to place the navigational channel girders, which weigh up to 105 tons, Underwood says.

Built in 1962, the old bridge featured two side-by-side structures, two lanes each and no shoulder, with about 21 ft of clearance between the water and the bridge, Castleberry says. It also included a bascule span bridge that was scheduled for an $11-million maintenance contract about two weeks before Katrina made landfall in August, 2005. “After initial service life, those draw spans require maintenance every year, not to mention the labor costs of having someone there 24 hours a day to operate it,” Castleberry says.

Angelle Bergeron/ENR
Workers use a jackhammer to remove a shear key from the Biloxi Bay Bridge.

The new bridge is pile footing, column cap and concrete girder construction and will also feature two side-by-side structures. Each will hold three lanes of traffic and two shoulders. The eastbound structure will have an additional 12-ft-wide pedestrian and bike path. To ensure the bridge’s future resilience against storm surge, Parsons Transportation Group, Inc. of Pasadena, Calif., designed the structure with three primary differences – height, shear keys and girder lengths, Castleberry says. Most of the 1.2-mile bridge is being constructed at elevation 28, beginning at elevation 7 on each end and rising to 95 ft. at the main navigational channel. The 120-ft-long spans (as opposed to the former 52-ft spans) will be locked into place by shear keys that are 1 to 1.5 ft. high.

The $338-million contract also includes construction of the CSX Rail overpass, a roughly ¼-mile length of bridge that connects to the Biloxi Bay Bridge on land at the Ocean Springs, or east end. The four-lane, shear pin steel girder construction bridge is being replaced with a pile footing column bridge with steel girders for two primary reasons, Castleberry says. “That shear pin construction can be a problem over the life of the bridge if the metal in one of those pins is fatigued,” he says. Like the bay bridge, the overpass was constructed in the early 60s. “Also, it didn’t have safety shoulders and was only four lanes, so we are trying to tie in with six to match the bay bridge and bring it up to current standards.” Although the Biloxi Bay Bridge is 100% federally funded, “once you get onto land on the Ocean Springs side, it’s an 80/20 match,” Castleberry says. The milestones are the same for construction of the overpass. “In order to get traffic on the Biloxi Bay Bridge, we have to have that finished as well,” he says.

With 14 subcontractors and 350 employees on the job, GC is almost at peak workforce, Underwood says. As hurricane season looms on the horizon and a $100,000-per-day penalty kicks in if the contractor doesn’t make the November 13 milestone, Underwood would rather not count his chickens at this stage of the game. “In this business, you never get a chance to get bored,” he says. “On occasion, a boring day is nice.”