PIKE COUNTY – A photograph of the Pinson Family Bridge will be featured in a 2010 calendar published by the Mississippi Valley Conference of State Highway and Transportation Officials. Taken and copyrighted by professional photographer Bill Griffin, the image was one of several submitted to Transportation Cabinet officials in Frankfort for consideration.

The Mississippi Valley Conference includes 10 states — Ohio, Indiana, Kentucky, Michigan, Illinois, Wisconsin, Missouri, Iowa, Minnesota, and Kansas. This year the MVC celebrates its 100th anniversary during its annual conference set for July 15-17 in Grand Rapids, Michigan. Conference materials will include a 2010 calendar with one photograph from each member state. The photographs must showcase an important transportation project in that state. Miranda Thacker, Executive Staff Assistant in the Cabinet’s Office of Public Affairs, headed a team which reviewed photographs submitted from around Ken-tucky. The team chose the one of the Pinson Family Bridge, which crosses Raccoon Creek and Ky., 1441 in Pike County.

The bridge has won several design and engineering excellence awards, including the highest award given by the Kentucky Chapter, American Public Works Association and the Ken-tucky Chapter of the American Council of Engineering Companies’ Grand Conceptor Award. The structure was also recognized by ACEC as one of the top civil engineering projects in the world that was designed in the United States.

Each four-span structure is 1,275 feet long with a maximum 380-foot span. The twin structures begin in a curve with super-elevation, transition through a spiral, and end in a tangent section of roadway. The innovative design of the bridge includes the first use in Kentucky of steel box girders. Most bridges are built using I-beams, which would have caused noticeable deck rotation on this particular bridge. Instead, welded steel plate girders were specifically sized for the long, curved spans. The bridge not only curves horizontally, it slopes vertically as well. Steel box girders reduce differential deflections caused by the combination of span length and curvature.

Temporary girder supports called “angel wings” were attached to the 200-foot tall piers to create stable platforms for more efficient and safe beam installation. Complicated by long spans, tall piers, a crowded workspace, and the curved alignment, this project was complex from the beginning. Long spans and tall piers complicate construction because as the beams are lifted by cranes, they can twist and bend. Span lengths were minimized where possible, but were constrained by the obstacles on the valley floor (roads, railroads, etc.). These same conditions that forced the long spans also restricted the contractor’s placement of cranes. Combining the surface constraints with the 200-foot height of the bridge, and the weight of the box girder segments created a one-of-a-kind construction job. The owner (Kentucky Transportation Cabinet), the design consultant and engineer of record (Palmer Engineering of Winches-ter), and the contractor (Bush & Burchett of Allen, Floyd County) collaborated throughout the project. All work was done by Ken-tuckians working for Ken-tucky companies. Fuller Mossbarger Scott & May Engineers of Lexing-ton provided all geotechnical services for the project. American Consulting Engi-neers of Lexington design-ed the temporary girder supports.

“Not only is this bridge an example of engineering innovation and excellence,” said Chief District Engineer Kevin Damron, “people who drive this section of roadway say the curvature of the bridge allows a longer look at the area’s awe-inspiring scenery. Mr. Griffin’s photograph is spectacular, and shows the beauty of the mountains as well as the way that the Pinson Family Bridge is integrated into its natural surroundings.”