Kanawha River Bridge main span completed

T.Y. Lin International (TYLI) announced completion of the closure segment on the 760-foot-long main span of the Kanawha River Bridge, a new segmental bridge over the Kanawha River between Dunbar and South Charleston, W.V. With the main span closure, this is now the longest box girder span in the United States.

TYLI designed the record segmental span for the West Virginia Department of Transportation, Division of Highways and is currently providing construction support services. The new bridge will carry I-64 eastbound traffic on an improved curved alignment as part of the widening of I 64 in Kanawha County, for which TYLI also provided civil design services. Westbound traffic will remain on the existing steel plate girder bridge.Transportation officials celebrated the historic moment during a ceremony on June 17 in which workers cast the final segment. Project Manager Santiago Rodriguez said that at the peak of the main span's construction, four 16-foot-long segments were cast per week, using two pairs of form travelers.

The challenge for Rodriguez, as the designer, was to design a bridge with expansion joints at the abutments only, resulting in a distance of 2,975 feet between expansion joints. Of the total superstructure, three cantilevers remain to be completed, along with the bridge parapets, overlay, and roadway—all due to be completed by October 2010.The new Kanawha River Bridge will have a total length of 2,975 feet, including the 760-foot river span, 460- and 540-foot side spans, and five additional approach spans, ranging from 144 to 295 feet. The 66-foot, 8-inch-wide deck will accommodate four lanes of traffic plus shoulders, all on a single cell box girder. The continuous girder has a varying depth of 16 to 38 feet at the main span and a constant 16-foot depth at the approaches. This low-cost design was selected instead of a steel alternative, saving $30 million and simplifying construction, according to TYLI. The final result is an elegant and distinct