PennDOT the latest agency to give prestressed U-girders the green light

Sources: Modjeski and Masters, Mechanicsburg, Pa.; CP staff

Bridge designer and engineer Modjeski and Masters cites Pennsylvania Department of Transportation approval of standards immediately affording spliced, post-tensioned concrete U-girder options to state practitioners and structure owners. The new standards can be used for Design-Build projects, or as an Alternate Bridge Type at PennDOT District Executive discretion.

“We’ve developed a set of standards that can help designers, contractors and project owners be more efficient, cost-effective and innovative,” says Greg Reese, P.E., president of Modjeski and Masters subsidiary Summit Engineering Group, who led the Pennsylvania U-girder drive following similar efforts in Colorado, Florida and Texas. “With the economies of concrete being what they are at the moment, these standards can help budget-conscious organizations do more with less. They also assist in accelerated construction, meaning less interruption to the general public. We know Pennsylvania will benefit from these new standards in the same ways we’ve seen across the country.”

PennDOT now permits spliced, post-tensioned concrete U-girders in continuous units either for tangent or horizontally curved structures. Beams are to be designed and analyzed to meet AASHTO, Design Manual, Part 4 criteria, and standards accompanied by details, erection alternates and grouting specifications. A Load Rating Table and Rating Procedure must be incorporated on the Contract Drawings based on both the actual post-tensioned tendon configuration and an equivalent number of single-strand configuration.