Long, arching spans and tall, slender piers create an elegant concrete structure across the Monongahela River. This 3,200’ long bridge consists of seven spans, including a 518’ main span, built using balanced cantilever segmental construction to cross the river, two active rail lines and local roads. Cast-in-place concrete construction was used to form the 89’ wide, dual-cell box girders in this mountainous terrain where piers reach over 200’. The bridge includes over seven million pounds of reinforcing steel, 3,324 linear feet of drilled shafts, 51 thousand cubic yards of concrete and three million pounds of post-tensioning. The impact of tall piers, limited access, and river, road, and railroad crossings on the construction was minimized by using balanced cantilever concrete segmental construction.

GM2’s Complex Bridge staff worked with the contractor to provide a Contractor Alternate Design-Build solution that was bid competitively against an owner’s as-designed project. The Contractor Alternate design resulted in significant savings for the Pennsylvania Turnpike Commission over a steel plate-girder design. The contractor’s low bid of $95 million, which included design costs, was $8.6 million less than the price bid for the owner’s as-designed structural steel bridge contract documents.

The bridge was opened to traffic in July 2012. GM2’s Complex Bridge staff provided on-site construction engineering and inspection services during critical construction activities and provided home office support and construction engineering to the contractor.