More than a year has passed since Hurricane Katrina plowed through the Gulf Coast states, causing the death of hundreds of citizens and billions of dollars
More than a year has passed since Hurricane Katrina plowed through the Gulf Coast states, causing the death of hundreds of citizens and billions of dollars in property damage due to catastrophic flooding. Among the affected structures wiped out or made unfit for use by hurricane winds and storm surge were three significant bridges Û Mississippi Department of Transportation’s U.S. 90 Biloxi Bay and U.S. 90 St. Louis Bay, and Louisiana Department of Transportation and Development’s Interstate 10 Twin Span Bridge (New Orleans-Slidell) Û that are just now beginning to see signs of rebirth. A fourth bridge Û Florida Department of Transportation’s Interstate 10 Escambia Bay twin structure Û was actually damaged by 2004’s Hurricane Ivan, and is much further along in its rebuilding.
The resulting post-hurricane bridge construction boom that had been predicted shortly after Katrina is now on the fast track to becoming a reality, with more than $1.6 billion in new contracts being awarded for just these four projects. Since the damage to these structures was so severe, simply repairing them was not an option. What follows are profiles of the progress being made on each of these new bridges, and the elements and design changes meant to make them more structurally sound. (Refer to key below for bridge locations.)
I-10 Escambia Bay Bridges
Phase 1 of this three-phase, $243 million project is due to be completed by year’s end, with one eastbound and two westbound lanes open on the new bridge. Phase 2 (Dec. 2006 – Nov. 2007) will see the demolition of the old bridge and the opening of two lanes in each direction on the new structure. Phase 3 of the project focuses on approach lanes and ramps.
Casting for the 3.17-mile project began in June 2005, with both Gulf Coast Pre-Stress in Pass Christian, Miss., and Standard Concrete Products Port of Tampa plant splitting the precast contract. Each company is supplying 600, 36-in. square piles; 493 bulb tee girders, ranging in length from 119 to 136 ft., averaging 78-in. deep; and, 43 pier base components. Gulf Coast also is delivering 67, 85-ton precast caps.
Not that the Escambia Bay project wasn’t affected by Katrina: Gulf Coast’s plant suffered major losses due to storm surge but was able to resume limited production within a month. Water came in at 18 feet above sea level, which mean about 12 ft. in our yard, says Max Williams, Gulf Coast’s vice president of sales. Everything on the ground level was ruined or washed away, including trucks, straddle cranes, front-end loaders, engines. None of the actual product [in storage] was damaged, so delivery was never a problem. Many of our contractor customers were ready to go back to work four days after Katrina.
After moving equipment and generators from the company’s Houston location, establishing communication channels was the top priority. Our computers were on the second floor of our offices, so they weren’t damaged. But all our paperwork, tax stuff were ruined, Williams says. We set up all our operations in one office, we had a fax machine in one of the boss’s house. But it paid off. We had our first shipments out within a week, after the roads were cleared, and made our first pour 30 days after Katrina.
Gulf Coast has contracts with all four projects profiled here, but the biggest problem after Katrina was keeping enough labor on site to get the jobs supplied. None of our management left, but the hands-on laborers were gone, either to act as flagmen for a high wage or to work for FEMA, explains Williams. But, now we use a labor-finding firm that does all the hiring and handles the payroll. I’d guess we have about 100 of our own employees and 220 we’ve gotten through labor suppliers.
Generating bids for the new bridge work was a crucial part of bringing money into the operation. Both Mississippi jobs are design-build; each has different plans. The contractors asked us what we were able to produce. Fortunately, we had what they wanted, and it wouldn’t affect our supplies to Escambia, says Williams.
We had to borrow another batch plant, so now we have two full-time plants. We’re running six, 30-in. pile lines and two, 24-in. piles lines, and we’re ready to put in a third, he adds. We recently bought out a neighbor’s property that was washed out by the flood waters.
Gulf Coast Pre-Stress’ proximity to St. Louis Bay makes it by far the best-situated operator for the four bridges’ precast/prestressed contracts. Barge availability, however, has proved problematic. Barge shipping began about three months after Katrina, but they are still hard to get, even when you look all over the country, Williams says. We’ve had three or four tugboats parked here at one time.
I-10 Twin Span Bridge
Since the end of August, the first visible signs of construction were under way as Boh Bros. Construction Co. of New Orleans began driving test piles for the $803 million, 5.4-mile Twin Span Bridge over Lake Pontchartrain. By the end of the fall, the team will have driven 13, 36-in.-square test piles to depths ranging from 103 to 119 feet. Although not all of the contracts have been awarded, the Louisiana DOT recently announced a November 15 letting of the second-phase contract. Boh Bros. won the first $379 million contract to build the level section of the bridge as well as the eastbound approaches on each end, all of which are expected to be completed by December 2009.
While sections of the old bridge were sufficiently repaired to sustain limited traffic, the new bridge will be built 300 feet east of the current structure, and will be the largest public works project in the history of the state. The Twin Span will have an elevation of 30 feet, 21 feet higher than its devastated predecessor, and an 80-ft. high-rise section near the Slidell side to allow for marine traffic. The 60-ft. width on each span will include three 12-ft. lanes and two 12-ft. shoulders on each side.
This first phase of erection will allow traffic to cross the lake using a combination of the two new structures. Precast/prestressed is a major component in this project, a significant change from the old bridge’s 54-in. concrete cylinder piles. Span length has also been increased with the new structure. Nearly 2,000 square prestressed piles, averaging 102 ft. long, will be used, along with 1,900 BT-78(-in.-tall) girders, at about 135 ft. long. Seven different precast cap configurations will number about 372. Decks will be cast-in-place. Both Gulf Coast Pre-Stress and Lafarge Concrete are confirmed suppliers to Boh Bros.; Volkert Construction Services of New Orleans is providing engineering and inspection services in support of LaDOTD.
US-90 Biloxi Bay Bridge
In June, MDOT awarded a $338.6 million contract to GC Constructors, a joint venture composed of Massman Construction Co. of Kansas City, Mo., Kiewit Souther Co. of Peachtree, Ga., and Traylor Brothers, Inc., of Evansville, Ind., for bridge replacement of the Biloxi Bay Bridge, linking Biloxi and Ocean Springs and Harrison and Jackson counties. The design-build structure will be erected as a high-rise bridge with 95 feet of high-tide vertical clearance (up from the originally spec’d 85 feet) and will include six traffic lanes and a shared-use path of biking and pedestrian. MDOT expects two lanes open by mid-November 2007 with a completion date of April 2008.
Although the design phase of this bridge is not yet complete, Gulf Coast Pre-Stress will be the primary precast supplier with 418, 18-in.-sq. piles averaging 96-ft. deep; 750, 24-in.-sq. piles averaging 97-ft. deep; and 560, 30-in.-sq. piles averaging 92-ft. deep. Gulf Coast’s Max Williams is quick to point out that not all test piles have been completed, so these lengths may change. The company is also supplying 12-in.-thick sheet pile, sized 4 _ 30 feet. Caps for this job will be cast-in-place, as will the decks. Girder design and contract letting are forthcoming.
MDOT’s Kelly Castleberry points out that many design elements between the old and new bridges are changing. The old bridge has 50-ft. spans, but with the new one, the distance of spans is increased, he explains. Also the navigational channel on the old bridge was about 150 feet, which will expand to 250 feet. Plus the old bridge was slightly curved in the middle to allow for navigational traffic, but the new structure is definitely a high rise.
US-90 St. Louis Bay Bridge
With work having begun in February, Mississippi’s other design-build bridge project is a two-mile, four-lane structure designed by HNTB. Granite Construction Co., in a joint venture with Archer Western Contractors of Atlanta, holds a $266.8 million contract for this project near Gulfport. The scope of the project includes two lanes in each direction, plus the approaches. The first phase of the erection will have one lane open in each direction by mid-May 2007; six months later, the remaining two lane should be ready for traffic.
Gulf Coast Pre-Stress will supply piles and modified bulb tee girders. According to the company, 450, 30-in. prestressed piles (size 111 feet average) and 490, 36-in. piles (132 feet average) will be manufactured for the project. Although Standard Concrete Products will be doing the majority of the girders, Gulf Coast will be making 18, 115-ft.-long post-tensioned haunch girders; nine, 147-ft.-long drop-in segment girders; and 18, 133-ft. end-segment girders. In addition, F&S Prestress is supplying 143 Type 4 girders with slightly shorter span lengths of 110 feet.
One of the more interesting aspects of the St. Louis Bay bridge projects is the use of 47 precast caps, which are so large they are being cast as two pieces with a closure pour in the field.
The structure’s center span is 250 feet with a navigation clearance of 80 feet (35 feet at the approaches), a vast improvement over the 10 feet of clearance the original bridge maintained.