To the joy of both road
and port officials, Georgia's longest cable-stayed bridge is
set to open in a matter of days. A fallen traveler truss, geometry
issues and high winds plagued the main span contract and contributed
to a two-year delay.
With a 1,250-ft main span and a
185-ft clearance over a channel that leads to the Port of
Brunswick, the new Sidney Lanier Bridge will allow larger
ships to make calls there. The lift span bridge it replaces
has a 139-ft clearance and allows a 250-ft channel width,
says Lisa Sikes, Georgia Dept. of Transportation project engineer.
Opelika, Ala.-based Scott Bridge Co. has just begun its $21-million
contract to remove the old bridge.
The longest cable-stayed bridge in Georgia was tough to
build. (Photo courtesy of Georgia Ports Authority)
Joint venture contractor Recchi/GLF,
Miami, originally was scheduled to open the 1.5-mile-long
bridge in December 2000. It now faces some $1 million in late
penalties on its $65.5-million contract. "We are working
to mitigate further accrual," says Brian West, project
manager for Recchi/GLF.
In 2001, a $1-million custom-made
form traveler from Europe being lowered with strand jacks
slipped loose and fell. "You'd be hard-pressed to find
a piece the size of a small car," says Craig Finley,
senior vice president for Pasadena, Calif.-based Parsons Transportation
Group, construction engineer for the team. Replacing the traveler
added at least six months to the project.
With 485-ft-high towers and a coastal
location, "you may have excellent working conditions
at ground level, but there may be 50-mph winds at the upper
tower elevations," says West. Tower crane work was suspended
when sustained winds hit 45 mph. "The wind factor was
not fully considered in the contract," he says.
The design by T.Y. Lin International,
San Francisco, is similar to that of the Talmadge Bridge in
Savannah and was spurred by the latter's popularity, says
Man-Chung Tang, T.Y. Lin chairman. "Having built one
cable-stayed bridge in Savannah, it was logical to use one
in Brunswick," says Glenn Durrence, GDOT director of
construction. But the Lanier bridge required marine-based
construction, so the contractor built 300,000-ton granite
islands in the 32-ft-deep channel.
Variations in the computer models
of the designer and construction engineer caused discrepancies
in wind load factors, traveler weight and camber and tie systems.
Extra rebar and post-tensioning were needed, as was "a
lot of ongoing discussion...to gain approvals borne out of
variations on assumptions found in the two separate models,"
The contractor is challenging a
$122,000 penalty proposed by the Occupational Safety and Health
Administration, says West. This was for fall protection and
other issues. There were no fatalities.
Half the cost of the new bridge
is financed through the Coast Guard, since the old bridge
constituted a "navigational hazard." Rosiek Construction,
Arlington, Texas, completed an initial $18.9-million contract
for the approach spans in 1998. "After this long battle,
having the end in sight is nice," says West.