About this Project

The 41st Street Bridge reconstruction project restored a critical connection between Mantua Avenue and Poplar Street in West Philadelphia. The original bridge had been closed to vehicular traffic for 22 years due to deteriorating structural conditions. The new bridge, completed ahead of schedule, replaces the aging infrastructure with a two-span continuous composite steel plate girder bridge supported by concrete abutments and a central pier. The southern span crosses active Amtrak tracks and measures 120 feet, while the northern span crosses abandoned Norfolk Southern tracks and measures 112 feet. The project also included the replacement of adjacent retaining walls and catenary structures, with architectural concrete parapets and fencing added for both safety and aesthetic purposes.

AEG provided both preliminary and final design engineering services for the bridge and its supporting structures. During the preliminary design phase, our team conducted soil reconnaissance and geological investigations in accordance with PennDOT’s Design Manual, Part 1, Design Manual 4, and Publications 222 and 293. This included reviewing published and unpublished data, consulting with City and PennDOT personnel, performing visual site inspections, and developing a subsurface exploration program to identify potential geotechnical challenges.

In the final design phase, AEG executed the subsurface investigation and testing program, prepared the Structure Foundation Geotechnical Report (SFGR), and assisted in developing specifications and contract details. The recommended foundation type for all substructures was drilled shafts (also known as caissons), based on detailed geotechnical analyses. The drilling program encountered hazardous materials, necessitating specialized handling procedures during both the investigation and construction phases. AEG’s work ensured the structural integrity and safety of the bridge while supporting the City’s goal of reconnecting neighborhoods through resilient infrastructure.

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