Sidney Lanier Bridge

Location:

Brunswick, GA
 

Owner:

Georgia Department of Transportation, Atlanta, GA
 

Designer:

T.Y. Lin International
and Georgia Department of Transportation
 

Engineer:

T.Y. Lin International, San Francisco, CA
 

Contractor:

Recci America (now Condotte America)
and GLF Construction Company, Miami, FL
(Joint venture)
 

Project Scope

Length:

7,779 ft (2371 m)
 

Width:

79.5 ft (24 m)
 

Longest Span:

1,250 feet
 

Awards:

2005 American Segmental Bridge Institute (ASBI) Award
2005 Engineering Excellence Honor Award from the Consulting Engineers and Land Surveyors of California (CELSOC)
 

Resources

 
 
 
 
 
 
Sidney Lanier Bridge
Sidney Lanier Bridge
Sidney Lanier Bridge
Sidney Lanier Bridge
Sidney Lanier Bridge
Sidney Lanier Bridge
Sidney Lanier Bridge
 
 
 
 
 
 
 
 
 
 
 
 
 

Design Challenge:
To replace a a 43-year-old lift-span bridge which was twice struck by ships and deemed a navigational hazard by the U.S. Coast Guard. This aging bridge had deteriorated and needed to be replaced with a modern, sustainable bridge.

Design Solution:
The Sidney Lanier Bridge is a cable-stayed bridge that traversing the Brunswick River in Brunswick, Georgia and carries two traffic lanes in each direction of the U.S. Route 17. The new landmark structure is the tallest (480 feet), the largest and is currently the longest spanning bridge in the state of Georgia. The bridge has a main span of 1,250 feet, 185-foot vertical clearance and a 400-foot wide navigational channel – which provide smoother traveling, time savings and increased safety. It is also the seventy-sixth largest cable-stayed bridge in the world. It was named for poet Sidney Lanier.

Built from water level, the design and construction team was challenged to use innovative techniques to construct the islands, towers, support trusses and bridge deck. Additional complexities included seismic, aerodynamic, and environmental considerations.

The new 2500-foot-long Sidney Lanier Bridge is the longest and tallest cable-stayed bridge in Georgia. T.Y. Lin International designed the concrete alternative, which replaces a 1956 lift-span bridge. Jointly funded by the United States Coast Guard and the Georgia Department of Transportation, the new bridge represents a community landmark that not only ensures smoother, safer passage for motorists, but should also help revive maritime commerce.

The four-lane superstructure is an 11-inch-thick concrete slab supported by a 5×4½-foot concrete longitudinal girder at each edge and by intermediate transverse girders spaced at 27 feet 8 inches. The bridge's support system features two concrete pylons and two concrete anchor piers. At the pylon, the superstructure is elastically restrained in longitudinal, vertical and transverse directions. The concrete deck is cast monolithically with the two anchor piers. Each concrete pylon carries two planes of fan-shaped cables anchored to the edge girders.

Construction was like no other project in the state, built from water level—with towers and anchor piers in the water. Cranes had to be mounted on barges and floated in the middle of the river until land could be created to support them. Massive rock islands were built around the base of each tower to ensure safety and provide protection against ship collisions.

After one tower was completed, a section of the deck structure, the pier table, was poured on braced supports from the tower. Custom-made form travelers, weighing about 145 tons each, were erected on each end of the pier table and used for cast-in-place construction of the bridge deck. This construction method was advantageous because it eliminated the need for a casting yard, and there were never any heavy segments that needed to be lifted into place. Instead, concrete for each segment was poured into the form traveler where it was held in place until cured and, if necessary, prestressed. Then, form travelers were moved out to cast the next segment.

Special care was taken to minimize the impact on wildlife habitats during and after construction. Motorist and maritime safety concerns also played an influential role. To the delight of motorists, the new bridge means no more waiting for maritime traffic. Eliminating 20 or more bridge lifts a day ensures a significant reduction of air pollution.

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.

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.

The contractor is a joint venture of Recchi America and GLF Construction Corp. Construction engineering is by Finley Mcnary Engineers, and construction engineering inspection is being provided by Figg Bridge Inspection, Inc.

The approach spans were constructed by Rosiek Construction Company, Inc of Arlington, TX. The 180' long concrete beams set were the longest ever set in the US at the time. The main span was constructed by the Joint Venture of Recchi America, Inc. and GLF Construction Co. under JV Project Manager Brian West and General Superintendent Richard Broggi.

 
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