End of the road for Ohio’s tallest bridge

July 8, 2010 at 12:00a.m.

Associated Press

COLUMBUS

Construction begins Monday on an $88 million project to replace the tallest bridge in Ohio, an aging structure similar in design to the one that collapsed in Minnesota in 2007.

The Jeremiah Morrow Bridge on Interstate 71 near Lebanon in southwest Ohio is considered safe but has enough structural deterioration that it can no longer handle heavy loads. Oversize trucks carrying more than 120,000 pounds, such military or farm equipment, are prohibited.

Ohio began developing plans to replace the bridge around the time the Interstate 35W bridge collapsed in Minneapolis, killing 13 people and injuring 145. The project is now on a fast track as the structure reaches the end of its 50-year life span, said Stefan Spinosa, an engineer with the Ohio Department of Transportation.

The bridge is actually a set of twin two-lane spans supported by a steel truss underneath the deck. It opened for traffic in 1965, running a length of 2,224 feet — about half a mile — and rising 240 feet over the Little Miami River. It carries about 60,000 vehicles a day, serving as a major freight corridor between Columbus and Cincinnati.

But repairs are becoming more frequent, and a recent inspection revealed that 80 gusset plates, which hold beams together, need to be stiffened before allowing overweight trucks to use the bridge again.

The new Ohio bridge will be supported by a series of concrete piers, a design chosen because it is more economical than a steel-truss bridge, Spinosa said. Steel is more expensive and requires more maintenance; concrete segmental bridges have a longer life span of 75 years and with proper upkeep can reach 100 years, he said.