Birdsboro Bridge

PennDOT District 5-0 | Berks County, PA

Constructed in 1927, the existing bridge was a 1,123- foot-long, nine-span, concrete open-spandrel arch structure that crossed over both the Schuylkill River and the Norfolk Southern Railroad. The bridge was weight-restricted to 15 tons. Along the north bank of the river, the Bridge Street Ramp sloped up steeply to form a T-intersection with the upstream face of the bridge and was considered part of the bridge structure. PennDOT District 5-0 classified the existing bridge as Structurally Deficient and Functionally Obsolete and listed it as its number-one priority bridge.

The proposed replacement bridge was a 536-foot-long, four-span, composite prestressed concrete bulb-tee beam bridge that will allow all legal loads to traverse the river and will have an expected service life of 75 to 100 years. As part of this project, the Bridge Street Ramp will be reconstructed and placed on fill along the north bank of the river. A new, second bridge will be constructed over the Norfolk Southern Railroad.

AEG provided numerous engineering and design services for the replacement of the S.R. 345 Bridge over the Schuylkill River in the Borough of Birdsboro. Although this project was originally scoped as a replacement on existing alignment, it was determined that moving the bridge to a new upstream alignment would be more advantageous for traffic safety and detouring. However, the relocation alignment presented unique river impact challenges. As a cost saving measure, the area between the river and railroad bridges is to be placed on fill as opposed to an additional bridge structure. This fill is within the 100-year flood floodplain and immediately adjacent to the FEMA regulatory floodway. AEG coordinated with the prime design contractor to develop a bridge and fill design that resulted in no increase in flood hazards.

A unique aspect of this project was that the causeway designs, construction of the new bridge, and demolition of the old bridge needed to protect boaters on this popular stretch of the river. AEG assisted in coordinating with regulatory agencies including the PADEP, US Army Corps of Engineers, PA Fish and Boat Commission, and the Schuylkill River National and State Heritage Area to develop a consensus on a proposed bridge design, sequence of construction, and causeway design that has minimal hydraulic impacts while promoting uninterrupted boating traffic.

AEG administered the subsurface boring plan and contract. Soil and rock samples were collected from the borings to characterize soil/bedrock conditions and develop foundation recommendations.