The joint-venture contractors charged with delivering in only 18 months a new U.S. Highway 90 bridge across St. Louis Bay in Mississippi are on track to meet their first milestone and win a $5-million incentive.

Despite competing for labor against region-wide contracts for debris removal and emergency work—and coping with a jobsite death—Granite Construction Inc., Watsonville, Calif., and Archer Western Contractors, Atlanta, or GAW, plan to open the first two lanes of traffic on the 1.9-mile-long, $268-million precast concrete girder bridge on May 16.

The Mississippi Dept. of Transportation awarded the contract early last year. GAW has completed 100% of pilings, caps and columns, 97.5% of the girders and 64% of the decks for the first milestone, says Allan Nelson, GAW project manager. The contractor faces a $50,000-per-day penalty for each day after the Nov. 30 milestone to deliver the remaining two lanes. GAW has completed all of the pilings and caps, 15% of the footings and 22% of the girders for that deadline.

Hurricane Katrina destroyed the bridge when it made landfall Aug. 29, 2005 (ENR 9/9/05 p. 18). Katrina also destroyed Mississippi’s U.S. 90 bridge over Biloxi Bay and I-10 twin spans over Lake Pontchartrain near New Orleans.

A storm surge completely submerged the St. Louis bridge, lifting decks and bents off of pile caps and leaving the 54-year-old structure in a pile of rubble. “About 99.5% of the bridge decks were gone,” says David Seyfarth, MDOT project engineer. “The only decks remaining in place were around the bascule span.”

The old bridge was built at ground level, but the new bridge rises to 85 ft. Span lengths are 120 ft, compared to the former bridge’s 52-ft-long spans. The shear keys are 1 ft to 1.5 ft, so a surge would have to uplift at least that high the longer, heavier spans to dismantle one.

"We knew the bridge would be design-build, so we put together a team with [Kansas City-based] HNTB, put together a design proposal, and we were short-listed by MDOT," Nelson says. "Since we were the initial ones out here, we were able to get our equipment and people mobilized," Nelson says. That timing gave Nelson''s team the jump on other projects gearing up in the Gulf Coast bridge construction environment. The St. Louis Bay Bridge is paced about six months ahead of the $338-million Biloxi Bay Bridge, which is being built by another team.

The bridge construction itself is relatively straightforward, Nelson says. “It was just a really tight schedule.” GAW did struggle to maintain morale after a March 20 fatality when a superintendent drove a workboat into a barge and was killed. Until then, there were 400,000 man-hours without a lost time incident.

To supply the 300 employees for the project, GAW established a work camp, paid twice the minimum wage and up to 20% higher than standard for some crafts, Nelson says. GAW also guaranteed an incentive of an added $1 per hour, to be deposited in a lump-sum amount in bank accounts of employees who stay for the duration of the contract. “With all these other projects, it’s hard to keep them, but when they start getting $1,000 to $2,000, they don’t want to leave,” Nelson says.