When Mike Yeager was assigned to the Bridge of Lions Rehabilitation Project, he wasn’t too concerned about whether he would be restoring the historic St. Augustine, Fla., structure or building a new span.
Now, almost halfway through the five-year, $76.8 million project, Yeager has a whole new perspective on the bridge, which was built in 1927 to replace a wooden trolley bridge to Anastasia Island.
“When I was first hired to come to this project, if you would have asked me did I care whether it was a new or old bridge I would have said I just want to build a bridge,” said Yeager, senior project engineer for URS Construction Services, which oversees the project for the Florida Department of Transportation (FDOT). “I like building movable bridges. If it was a new one or an old one it was OK either way. But now that I’m here, I do believe it was the right decision to rehabilitate it.”
Reaching the decision to rehabilitate the 1,481-ft. (450 m) concrete and steel bridge was no easy task. During the 1980s, there was a lot of discussion about whether to rehabilitate or replace the bridge because it was rapidly deteriorating. The situation was so bad transportation officials had to reduce the load limit on the bridge to 15,000 lbs. (6,800 kg).
About 21,500 vehicles cross the bridge daily.
“There was a big debate in the community about replacing the bridge,” said Laurie Sanderson, FDOT public information officer. “The department of transportation did several studies and there were no safety issues. We could make it just as safe structurally and functionally, although the lanes will be a little narrower than if we built a new bridge.”
Sanderson said the community pushed strongly to rehabilitate the bridge and in 2003 the Federal Highway Administration issued the order to restore the bridge rather than build a new one.
“Part of the reason the community was so involved in trying to save the bridge was because St. Augustine, to a certain extent, identifies with the Bridge of Lions,” Yeager said. “It’s a source of identification for St. Augustine and because we’re rehabilitating it will remain a source of identification. This is a historic town. They try to save historic structures.”
St. Augustine, founded in 1565, is the oldest continuous European settlement in North America. The Bridge of Lions connects the historic downtown business district with Anastasia Island. In 1982, the bridge was listed on the National Register of Historic Places.
The bridge derives its name from two stone lion statues stationed at its west end. They were commissioned by local philanthropist Andrew Anderson and were based on a statue he had seen in Florence, Italy, to reflect St. Augustine’s Mediterranean heritage.
Skanska Civil USA’s Virginia Beach office was the low bidder for the contract, which was awarded in 2004 and includes constructing a temporary bridge, rehabilitating the Bridge of Lions, removing the temporary bridge and building parks on both ends. The rehab includes replacing two steel draw spans and installing 27 steel cofferdams around the bridge’s pilings.
In February 2005, Skanska began construction on a 2,211-ft. (674 m) temporary bridge a few yards north of the current bridge. The temporary bridge opened in May 2006, a little ahead of schedule. Currently, crews are working on the bridge’s new foundation and doing steel work.
“The first phase of the project was to build a temporary bridge,” Yeager said. “Since that time we’ve been doing demolition work on the existing bridge, taking the decks off. We’ve sent all the arch girders out for rehabilitation so they can be reinstalled.”
Yeager said one of the main challenges in rehabilitating the girders is maximizing the amount of historic steel that remains while making sure they are strong enough for modern load carrying.
Also ongoing is the drilling operation for the new bridge shafts.
“We are installing drill shafts and constructing the west approach substructure,” said John Birch, project manager of Skanska. “Most bridges are steel or precast concrete piles you drive into the ground.
These are drilled, basically sinking a big casing into the river bed, then going beyond the casing for some depth and placing a large rebar cage in it that you then fill with concrete.”
Birch, who has been with Skanska for 18 years and has worked on several bridge projects in Virginia and North Carolina, said one big problem is getting everything lined-up perfectly.
“You have a certain period of time between drilling the last five feet and placing the first concrete,” Birch said. “We are having a few coordination issues because what happens is when you get to the bottom it has to be inspected using a remote camera and you have to meet some very tight tolerance on cleanliness. Until you’re past that you cannot proceed to install the rebar cage and pump the concrete.”
Sanderson said materials left over from previous bridge construction projects has been another obstacle.
“One of the major challenges in rehabilitating a historic bridge over the Intracoastal Waterway is finding historical obstructions,” Sanderson said. “We’ve encountered other materials, leftover concrete that was left behind from other construction on the bridge. We’ve had to clear it out of the water. Some of it is allowed to remain, but we have to drill through it to get our drill shafts down.”
Though there have been a few cost overruns, Sanderson said, they are still within the total budget and the project is on schedule for completion in 2010.
While they have found plenty of construction material, no historical artifacts have been discovered.
“To my knowledge we haven’t found anything of historical value,” Birch said. “I’m not aware of anything like cannon balls or anything of that nature.”
Birch said they have a long list of equipment on-site, including several heavy American Triple H cranes, a fly drill, a land-based excavation drill, demolition equipment, sheet pile driving equipment and pile driving equipment. Skanska owns about 80 percent of the equipment and has rented several pieces from Moody Rentals, which Birch said “has provided good service and took care of everything we needed.”
There are more than 20 subcontractors on-site, including Coastal Taisson, the drill shaft subcontractors; Amber Construction; and Universal Concrete.
“We have about 50 of our own forces and including subs, there are about 75 to 100 people working each day,” said Birch, adding they’re working a day and night shift.
Birch said another concern is the limited work space around the bridge, “There’s only about 100 feet north and south and that becomes challenging for your tugboat and barge operations,” Birch said, “because when the tide runs here, it runs.”
Another challenge, Birch said, is the structural steel.
“The existing spans had to be saved when we took the deck off,” Birch said. “They were sent to steel fabricators, Florida Structural Steel out of Tampa, and they have to remove all the post-1927 steel that was put on to shore it up. All that steel is not deemed original so it has to come off.”
Birch said they’ll use approximately 18,000 cu. yds. (13,800 cu m) of concrete on the bridge. While the machinery and control rooms will be new, one of the goals is to restore the bridge to its original 1927 design.
“The lights and railings on the Bridge of Lions were changed in the 1970s,” Sanderson said. “We are replacing those lights and railings with replicas of the historic lights and railings from 1927 so it will actually look more like the original structure.”
Though the bridge is a major commuter route, because of the temporary bridge, traffic delays have been limited.
“No detours, delays,” Birch said. “Zero effect. I would say — and this is my opinion — they’re probably better off right now then they have been in the past with the temporary bridge. There are no weight limitations. We don’t shut that bridge down to road traffic.”
Birch said boaters have been the ones most impacted by the construction.
“Most of the commercial traffic picks their times quite carefully to come through here because of the tides,” Birch said. “They like to come through at slack tide. We work with the Coast Guard to be good neighbors about letting those guys through. When we have an all-night closure, there’s always three openings in the day to let the commercial people through.”
Sanderson said when the two-lane Bridge of Lions reopens, the temporary bridge will be dismantled.
“The bridge is an important economic and transportation link between downtown St. Augustine and Anastasia Island,” Sanderson said.
“Historical tourism is really the lifeblood of St. Augustine and many tourists come to St. Augustine to see the Bridge of Lions.”
Yeager has learned during his stay how much the bridge means to the community.
“We had a closing ceremony for the bridge when it was about to be rehabilitated instead of celebrating the opening of the temporary bridge,” Yeager said. “What they did was celebrate the closing and the wait for its reopening. This is a good job for a lot of reasons. Part of it is because we’re involved in saving the bridge.” CEG