Arthur Ravenel Jr. Bridge (Cooper River Bridge)

Location:

Charleston, SC
 

Owner:

South Carolina Department of Transportation,
Charleston, SC
 

Engineer:

PB (Parsons Brinckerhoff), New York, NY
 

Contractor:

Palmetto Bridge Constructors, Charleston, SC
(Joint venture — Tidewater Skanska of Norfolk,
Virginia and Flatiron Constructors of Longmont, Colorado)
 

Project Scope

Length:

• 1,546-ft main span length
• 3,296 ft cable-supported length
 

Structural Precast Elements:

• 54-in., 72-in. and 79-in. modified precast bulb-tee girders
• AASHTO Type III girders
• Post-tensioned and reinforced deck panels
• Mechanically stabilized earth walls
 

Costs:

$540 million
 

Awards:

2007 PCI Design Award Co-Winner,
Best Bridge with Spans Greater than 150 feet
 

Resources

 
 
 
 
 
 
Arthur Ravenel Jr. Bridge (Cooper River Bridge)
Arthur Ravenel Jr. Bridge (Cooper River Bridge)
Arthur Ravenel Jr. Bridge (Cooper River Bridge)
Arthur Ravenel Jr. Bridge (Cooper River Bridge)
Arthur Ravenel Jr. Bridge (Cooper River Bridge)
Arthur Ravenel Jr. Bridge (Cooper River Bridge)
Arthur Ravenel Jr. Bridge (Cooper River Bridge)
Arthur Ravenel Jr. Bridge (Cooper River Bridge)
Arthur Ravenel Jr. Bridge (Cooper River Bridge)
 
 
 
 
 
 
 
 
 
 
 
 
 

Design Challenge:
The Cooper River Bridge, South Carolina, U.S.A., was constructed to replace two obsolete bridges over the Cooper River that had deteriorated due to poor maintenance and strived to benefit surrounding communities, the local economy, and protect and enhance wetland environments.

Precast Solution:
The Arthur Ravenel Jr. Bridge, also known as the New Cooper River Bridge, is a cable-stayed bridge over the Cooper River in South Carolina, connecting downtown Charleston to Mount Pleasant. The eight lane bridge satisfied the capacity of U.S. Route 17 when it opened in 2005 to replace two obsolete cantilever truss bridges.

The Palmetto Bridge Constructors consortium (PBC), which consisted of Tidewater Skanska of Norfolk, Virginia and Flatiron Constructors of Longmont, Colorado, was awarded the design and construction contract by the South Carolina Department of Transport (SCDOT) in 2001. The construction joint venture hired Parsons Brinckerhoff (PB) to complete the design. For the sake of simplifying labor and equipment resources, Palmetto Bridge Constructors actually managed the building of the bridge as five separate projects (the two highway interchanges at either end of the bridge, the two approach spans, and the cable-stayed span) going on simultaneously.

Charleston’s new bridge over the Cooper River is a cable-stayed suspension design with two diamond-shaped towers, each soaring to a height of 575 feet (175 m). The total length of the structure is 13,200 feet (4.0 km), with the main span stretching 1,546 feet (471 m) between the towers. 128 individual cables anchored to the inside of the diamond towers suspend the deck 186 feet (57 m) above the river. The roadway consists of eight 12-foot (3.7 m) lanes, four in each direction. A campaign by locals eventually led to the addition of a 12-foot (3.7 m) bicycle and pedestrian path to the design, which runs along the entire south edge of the bridge overlooking Charleston Harbor and the Atlantic Ocean.

Precast concrete components, including three types of bulb-tee girders and AASHTO Type III girders, post-tensioned deck panels and mechanically stabilized earth walls, helped complete the project cost effectively and one year early.

The low-level approaches and interchanges include 118 spans of composite bulb-tee girders. The spans vary in length from 57 to 146 ft and in width from 30 to 116 ft. The girders feature 11,000-psi strength and a 7-in. web to provide longer spans and the needed concrete cover.

The 126-ft-wide bridge deck and cantilevered walkway were covered with 8,000-psi precast panels, with closure strips over the girders and floorbeams. The main span contains 918 full-depth precast concrete panels with a 2-in. nonstructural latex concrete overlay. The concrete mix allowed the use of black bars for reinforcement and was designed to provide the required 100-year service life for the bridge.

Designed For Hurricane Strength Winds
The bridge superstructure is designed to withstand shipping accidents and the natural disasters that have plagued Charleston’s history. The span is designed to endure wind gusts in excess of 300 mph (480 km/h), far stronger than those of the worst storm in Charleston's history, Hurricane Hugo in 1989. Engineers also had to be mindful of the 1886 earthquake that nearly leveled Charleston. The Ravenel Bridge is designed to withstand an earthquake to approximately 7.4 on the Richter scale without total failure. To protect the bridge from uncontrolled ships, the towers are flanked by one-acre rock islands. Any ship will run aground on the islands before it can collide with the towers.

The $540 million bridge project carries Highway 17 over the Cooper River and consists of a 4km eight- lane highway, bicycle and pedestrian path and two interchanges. The bridge is North America’s longest cable-stay bridge with a span of 471m and was constructed using the design-build approach, meaning that construction progressed before the complete design had been finalized. PBC completed the bridge one year ahead of schedule and approximately $150 million under budget.

“This cable-stayed bridge made extensive and commendable use of precast concrete deck panels. Using this approach on the longest cable-stayed bridge in North America will attract attention to this type of design, helping to inform designers of this new solution to recurring challenges. It shows that such a significant design can incorporate precast concrete elements effectively for both the superstructure and the approaches. It also is notable that the structure was designed for a 100-year life and used a design-build approach that greatly reduced costs and construction time.”
 
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