The South Carolina Department of Transportation (SCDOT) provided the first media tour of the Cooper River Bridges replacement project in May, and Bobby Claire had some good news to report.
“We’re currently ahead of schedule,” said Clair, SCDOT’s director of Engineering Special Projects. “We’re working very hard to complete the project early.”
The contract for the single biggest project in SCDOT history was signed in July 2001 with completion scheduled for 2006. Currently, the bridgework is on such a good pace that it may be finished a year ahead of schedule.
“We’re all working together to make that happen,” Claire said. “Overall the project is going extremely well. We’re fortunate to have the team we have.”
Approximately 150 people are working 10-hour shifts day and night, with some weekend work on selected areas. This workforce will peak at 500.
On foot and by boat, a dozen Lowcountry journalists were led on a tour of the project by Clair, who is overseeing the project for the Department, SCDOT Project manager Charles Dwyer and Jack Liles, assistant project manager of Palmetto Bridge Constructors.
“It’s important for us to get information out to the public and educate the public," Dwyer said.
From the beginning, Clair said, the goal has been to keep the community involved as much as possible. That’s one reason why there will be periodic media tours so the community is kept informed every step of the way.
“There are just a lot of questions about what is happening on the project and where we are to date,” Clair said. “This gives the entire media an opportunity to look at what’s going on and what the schedule is in the next few months.”
The tour started out behind the Community Bridge office on Huger Street, where just a few feet away, workers are busy in the assembly yard. On this day, huge cranes lifted a 120-ft. (36.5 m) high steel cage and delicately lowered it into a drilled shaft. There will be more than 400 drilled shafts needed to support the new bridge.
Each shaft holds about 700 cu. yd. (535 cu m) of concrete. A conveyor system is used to help deliver the concrete to the drilled shafts.
Trucks arrive under the Pearman Bridge and discharge into a hopper on a conveyor that holds 125 cu. yd. (95.5 cu m) of concrete. One barge load goes out at a time, and the barges keep circulating as the cores are made in the river.
“On some projects, you put concrete plants on barges,” Clair said. “But it’s such a large volume here, we elected to do it this way to keep up the consistency and volume.”
Steel castings are used to form the shafts for the foundations. Once the concrete sets, the casings can be removed and recycled for the next shaft.
Engineers continuously sample steel and concrete materials used in this project.
“There’s a lot of quality control and assurance that goes into this project,” Dwyer said. “SCDOT has placed an emphasis on contractor quality control and is following up with SCDOT and consultant staff doing quality assurance. Plus, the SCDOT quality team comes down from Columbia to review our project.”
Clair said 90 percent of the workforce is from the Charleston area. Liles said the workforce includes 47 percent minorities and 10 percent women.
The new bridge must be able to withstand several forces for the next 100 years.
The Charleston area was the site of the biggest earthquake on the East Coast, in 1886, and the new bridge is being built to withstand an earthquake of that size. The bridge also is being built in a hurricane zone and must be able to handle ship traffic.
“The complexity of the design is one of the biggest challenges on the project,” Clair said.
Once the new bridge is finished, the existing bridges will be dismantled and sections used to create 84 acres (34 ha) of offshore fishing reefs. The Department of Natural Resources and the Army Corps of Engineers are studying possible locations.
Walking out on a newly built trestle toward Drum Island, the members of the media hopped on a PBC boat and got a close-up look at work in the Cooper River. There, workers were busy on a flotilla of barges where shafts are being drilled down into the bottom of the river and into a clay formation known as marl.
Since the tour, crews have completed the foundation for the bridge’s tower, according to Clair. The first of two ship loads of rock to go around the tower foundation have arrived on site. “Once the rock is placed, the next step is to construct the footing for the tower. Then, we will continue to place rock on the remaining portion of the island. That will take us up to January 2003,” Clair said.
As much work as is being done, the project will really get exciting when the new bridge’s shape begins to rise out of the Cooper River.
For more information, call 803/737-1270.
(Bob Kudelka is on the editorial board of SCDOT’s publication, The Connector. This article was reprinted with permission from SCDOT.)