Allegheny River Bridge – Pennsylvania’s First Cast-In-Place Segmental Bridge

The Pennsylvania Turnpike Commission (PTC) is replacing the Allegheny River Bridge near Pittsburgh, PA. Twin 2,350’ cast-in-place concrete segmental structures will be constructed above the river, active rail lines, and a state highway, all vital links in the valley’s surface transportation network. The new bridge will be adjacent to the existing bridge and will span the navigable waterway with a 532’ main span. A low bid of $190 million was offered by Walsh Construction in May 2007 and construction has begun. The bridge will accommodate six lanes of traffic, plus acceleration/deceleration lanes for the interchange and toll collection facility. Gently curved piers, reflective of the parabolic box girder superstructure, utilize an inlaid stone pattern and were selected by the PTC in an owner’s charette. This paper focuses on the unique aspects of the bridge design, including the 532’ main span and aesthetics, which will be achieved economically.