Partnerships, Innovation Build a Bridge in South Carolina
In 1929, the first bridge over the Cooper River and Town Creek in Charleston,
South Carolina, opened with a 3-day gala celebration. The 4.36-km (2.71-mi)
bridge, later to be known as the Grace Memorial Bridge, was the fifth
largest structure of its type in the world at that time. The landmark
bridge was followed by construction of a second structure over the Cooper
River, the Pearman Bridge, which opened to traffic in 1966. In recent
years though, it became clear to the South Carolina Department of Transportation
(SCDOT) and the community that the two bridges had become functionally
obsolete. The Grace Memorial Bridge has only two 3-m (10-ft) lanes,
lacks shoulders, and has only a limited ability to carry vehicles weighing
more than 5 tons. The Pearman Bridge, meanwhile, provides two northbound
lanes and one southbound lane, but does not have emergency shoulders
or a median to separate opposing traffic. And neither bridge has enough
vertical or horizontal clearance to safely accommodate today’s
larger shipping vessels. “The two older bridges were congested
and in dire need of replacement,” says Charles Dwyer of the SCDOT.
Replacing the two bridges with a new Cooper River Bridge has required
the SCDOT and the Federal Highway Administration (FHWA) to identify
innovative sources of funding for the massive project and to work closely
with residents, city and town officials, and others in the surrounding
communities to choose a context-sensitive design that would fit in with
the historical aesthetic of the city and to minimize the impact of the
construction on the community.
A design/build contract for the new Cooper River Bridge was executed
in July 2001 with Palmetto Bridge Constructors (PBC). PBC is a joint
venture of Skanska USA and HBG Constructors. The lead designer is Parsons
Brinckerhoff. Construction of the bridge is required to be completed
by 2006. Construction has been accelerated, however, and the contractor
is now aiming to complete work early by having both directions of traffic
using the new bridge in the summer of 2005. As of August 2003, more
than 50 percent of the bridge’s concrete had been placed. The
use of the design-build concept has helped accelerate the completion
of the largest single infrastructure contract in SCDOT’s history.
 |
| This view of the new Cooper River Bridge under construction
in Charleston, SC, shows reinforcing steel in the bridge's Eastern
Tower. |
The new Cooper River Bridge will have the longest cable-stay span
in North America, stretching 471-m (1,546 ft) across the Cooper River.
The total length of the bridge is 4.02 km (2.5 mi). A diamond tower
design was chosen after several public hearings provided feedback on
various design options. “There was a lot of public input as to
what the structure would look like. The community involvement has been
an ongoing effort,” says Tad Kitowicz of FHWA’s South Carolina
Division Office. “We have held a lot of public hearings and worked
hard to involve residents. As Charleston is a historic city, we need
something that will fit with the surrounding area and become a landmark
of the city,” adds Dwyer. A 3.6-m (12-ft) bicycle and pedestrian
lane was added to the design at the urging of the local community. The
lane includes observation sites with benches. Additional interchange
ramps were also added after consultation with local officials. To encourage
public input and feedback on the project and provide information, a
Community Bridge Office was set up. A Web site (www.cooperriverbridge.org)
has also provided frequently updated news and information on the project.
|
| Large concrete girders for the new bridge
are set in place |
 |
| The first concrete girder is set into place
between two pier caps for the new bridge's Meeting Street off-ramp.
|
The new bridge’s cable-stayed span will be suspended by 128
cables from two diamond towers at each end of the span. The cables are
to be anchored on the bridge’s deck level and inside of the diamond
towers. To protect them from weather conditions, the bridge cables will
be enclosed in a high density polyethylene pipe. The diamond towers
will support an eight-lane road deck that is almost 61 m (200 ft) above
the median high tide mark. Platforms and tower elevators that can be
used for safety inspections and maintenance have been incorporated into
the design.
With a project budget of $677 million, SCDOT had to develop an innovative
financing plan that includes several partners. The South Carolina Infrastructure
Bank, which was established by the State in 1997 to provide loans and
other financial assistance for major projects, has contributed $325
million in funding. A $215 million Federal loan was provided under the
Transportation Infrastructure Finance and Innovation Act, which is being
repaid by SCDOT, Charleston County, and the South Carolina State Ports
Authority. Additional funding has come from FHWA.
To learn more about the Cooper River Bridge Project, visit the Cooper
River Bridge Web site at www.cooperriverbridge.org
or email the SCDOT at info@cooperriverbridge.org.
Back to top
..................................................
Articles in this issue:
Partnerships, Innovation Build a Bridge in South Carolina
Blue Ribbon Panel Issues Recommendations for Bridge and Tunnel Security
Value Engineering 2003: Conference Features Success Stories, Lessons Learned
Join the High-Performance Concrete Community
..................................................
