Client: Pennsylvania Turnpike Commission
Construction Cost: $189M
Key Facts:
The new twin 2,350’ long structures were built on an alignment parallel to the existing turnpike. It is the first cast-in-place concrete segmental bridge in the Commonwealth and features a 532’ main span across the Allegheny River. Additionally, the bridge spans Freeport Road, active rail lines, the side channel of the river used by recreational boaters and Fourteen Mile Island, part of the Allegheny Island State Park.
The bridge accommodates six lanes of traffic, plus acceleration and deceleration lanes for the Allegheny Valley Interchange at the western end of the bridge. The project includes the bridge approaches, reconstruction of the toll plaza and associated ramps and three smaller bridges over the Turnpike.
Aesthetics features were developed in an owners’ charette. The design was inspired by the sites landscape features and includes a variable depth superstructure and a stone pattern on rectangular piers that have concave curves in the transverse direction. The superstructure and substructure are designed with similar parabolic curves that blend the two elements into an elegant form.
Construction occurred between the 2007 USGA Open and the 2010 LPGA Open, both held at the historic Oakmont Country Club, which is adjacent to the bridge site on the eastern side. Balanced cantilever construction took place above the river, maintaining Turnpike, highway, rail and river traffic at all times. GM2's Complex Bridge staff had a team on-site throughout construction providing construction engineering and inspection services.