Traversing the Brunswick River, 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.
“There is no doubt the future is bright for Brunswick,” said Doug Marchand with the Georgia Port Authority. “More and more shippers, carriers, and international traders are choosing Brunswick, and we will continue to move this port forward in the years to come.” — T.Y. Lin International PROJECT PARTICIPANTS
- Owner: Georgia Department of Transportation, Atlanta
- Design Architect: T.Y. Lin International and Georgia Department of Transportation
- Structural Engineer: T.Y. Lin International, San Francisco
- General Contractor: Recci America (now Condotte America)—GLF, a joint venture, Miami, Fla.
- Ready-Mix Supplier: Cemex Concrete, Tampa, Fla.