Dunbar-South Charleston Interstate Bridges

The Dunbar-South Charleston Interstate Bridges carry Interstate 64 over the Kanawha River, Wilson Island, three roads, and railroad tracks between Dunbar and South Charleston, West Virginia.

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History

The Dunbar-South Charleston Interstate Bridges carry Interstate 64 over the Kanawha River, Wilson Island, three roads, and railroad tracks between Dunbar and South Charleston, West Virginia. They include a deck plate girder structure built in 1974 and a parallel box girder structure completed in 2010.

In August 1968, the State Road Commission awarded Maxon Construction of Dayton, Ohio, a $976,950 contract to construct seven land and river piers for the Dunbar-South Charleston Interstate Bridge substructure. ⁷ In August 1971, the State Highway Department announced that Bristol Steel & Iron Works of Bristol, Virginia, was awarded the low bid of $6,447,227 for the steel and superstructure work. ^{6 8}

Governor Moore dedicated the new Dunbar-South Charleston Interstate Bridge on June 5, 1974. ⁵ The deck plate girder structure, which cost $19 million to construct, carried four lanes of traffic.

By the early 21st century, the Kanawha River crossing was increasingly burdened with heavy truck and commuter traffic. The Charleston Metropolitan Planning Organization (MPO) identified the need for a parallel bridge in its Long-Range Transportation Plan. ² The existing four-lane bridge was handling 78,000 vehicles daily, 15% of which were trucks. Preliminary design studies evaluated several alternatives to increase the river crossing’s capacity, including widening the existing bridge, complete bridge replacement, and constructing a new eastbound bridge. ⁴ The chosen alternative was to construct a new eastbound structure on an improved alignment with three travel lanes and one auxiliary lane. The existing bridge would be modified to maintain four lanes for westbound traffic.

Several designs for the new bridge were considered, including concrete or steel box girders, steel tied arch, concrete cable-stayed suspension, and steel truss. ¹

The project was advertised for construction in February 2007, featuring two alternatives: a segmental concrete box girder by T. Y. Lin International of Alexandria, Virginia, and a steel box girder superstructure by another consultant. ^{1 4} The concrete box girder was ultimately selected due to its lower bid of $82,864,247 compared to the steel box alternative’s $112,910,000.

The total estimated project cost, including design and engineering, right-of-way acquisition, and utilities, was $196.5 million. ² An additional $2.3 million was spent on widening Interstate 64 in Dunbar and South Charleston. Finley Engineering Group of Tallahassee, Florida, and the Michael Baker Corporation provided construction engineering support, ⁴ while Brayman Construction of Saxonburg, Pennsylvania, conducted the construction. ¹

The new bridge was constructed as a balanced cantilever concrete box girder using form travelers with 175 cast-in-place segments. ^{2 4} It included eight piers, totaling 2,950 feet in length, with a 760-foot main span, the longest concrete box girder span in the nation, along with 460-foot and 540-foot side spans, and five additional approach spans of 144, 247, 295, 295, and 209 feet. ^{3 4} The main span length was determined to keep the main piers outside the river’s main channel to avoid interfering with barge traffic. ^{1 4} This was the first long-span, segmental box girder structure in the state built using the balanced cantilever method.

Four 16-foot-long segments were cast per week using two pairs of form travelers during construction. ³ The final segment was cast during a ceremony on June 17, 2009.

The new bridge was completed in 2010 at a cost of $93.6 million. ¹ After its completion, the 1974 span was rehabilitated at a cost of $11 million. ²

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Gallery

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Details

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Sources

1. “I-64 Kanawha River Bridge.” TYLin.
2. “I-64 Dunbar/South Charleston Bridge.” West Virginia Department of Transportation.
3. “Kanawha River Bridge Main Span Complete.” Concrete Construction.
4. Rodriguez, Santiago. “A Record Segmental Span.” Aspire Bridge, Winter 2009.
5. “I-64 Span Open.” Charleston Daily Mail, 5 Jun. 1974, pp. 1A-7A.
6. “State Opens $34 Million of Road Bids.” Raleigh Register, 25 Aug. 1971, p. 7.
7. “State Awards 2 I-64 Contracts.” Raleigh Register, 7 Aug. 1968, p. 1.
8. “Bids Received On 2 Bridges.” Charleston Daily Mail, 25 Aug. 1971, p. 39.