|
Concrete Bridge Case Study
Bridges Home >
Featured Bridges
Sidney Lanier Bridge, Brunswick, Georgia
An Environmentally
Friendly Bridge
 |
| The Sidney Lanier Bridge (Photo courtesy of T.Y. Lin International) |
The 7,780-ft long Sidney Lanier bridge provides an
elegant cable-stayed crossing of the Brunswick River, and also
interacts well with the wildlife in its environment. The original
bridge that it replaced was deemed a navigational hazard by the
Coast Guard after ships collided with the bridge. The 1250-ft long
main span provides a 400-ft wide and 185-ft high navigational channel
to accommodate the large cargo vessels on the river heading to
and from the Port of Brunswick. The two cable-stayed side spans
are each 625-ft long.
 |
Each tower soars 467 feet into the sky.
(Photo courtesy of
T.Y. Lin International) |
The concrete deck is supported by two edge girders
and a system of transverse floor beams. The concrete edge girders
are 4-ft-9-in wide and 5-ft deep. They were designed as reinforced
concrete girders but employed longitudinal prestressing to limit
axial tensile stresses. The prestressed concrete floor beams are
spaced at just over 27 feet. Each of the two concrete towers are
467-feet high and are supported by 6-ft diameter drilled shafts.
 |
View of the Sidney Lanier Bridge from the top of a tower.
(Photo courtesy of T.Y. Lin International) |
The Brunswick River and four islands near the bridge
(Sea Island, Jekyll Island, St. Simons island, and Little St. Simon
Island) are home to federally endangered loggerhead sea turtles.
The adult turtles lay their eggs on the beaches of these islands,
and once the eggs hatch, the newborn turtles have to make their
way to the water. There were concerns that the lights on the bridge
would disorient both the adult turtles and the hatchlings. Therefore
special shielded low-sodium, low-wattage lights were used on the
bridge and the approach, and the number of lights was greatly reduced.
 |
| Approach to Sidney Lanier Bridge. (Photo courtesy of T.Y.
Lin International) |
Manatees were also frequent swimmers
in the river and care was taken to protect the manatees. The contractor
provided
a “manatee watcher” at all times, and the Georgia Department
of Natural Resources taught construction workers how to spot the
manatees and how to accommodate the manatees once spotted.
The Sidney Lanier Bridge garnered a 2005 American Segmental Bridge
Institute (ASBI) Award, and a 2005 Engineering Excellence Honor
Award from the Consulting Engineers and Land Surveyors of California
(CELSOC).
Project Principals:
Owner: Georgia Department of Transportation
Bridge Design Engineer- main span: T.Y. Lin International
Bridge design engineer—approach spans: Georgia
Department of Transportation
Contractor: Joint Venture—Condotte America, Inc.
and GLF Corporation
Construction Engineering:Finley McNary Engineers
Construction engineering inspection:Figg Bridge Inspection,
Inc.
References:
“Bridge Hits Take Their Toll,” Government Engineering, March-April
2007, pp. 34-37.
“Sidney Lanier Bridge Receives Honor Award,” Segments,
American Segmental Bridge Institute, Volume 46, Spring 2005, pp.
4-5.
Tang, Man-Chung, “Poetic Crossing,” Civil Engineering, American Society of Civil Engineers, August 2004, pp. 36-43, 83.
|