About this Project

This work provided preliminary and final design engineering services for reconstructing the 41st Street Bridge, retaining wall, and catenary structures in the City of Philadelphia.

The proposed bridge structure was a two-span continuous composite steel plate girder bridge supported by two concrete abutments and one pier. The southern span, from the South Abutment over the Amtrak tracks, is 120 feet long, and the northern span, over the abandoned Norfolk Southern tracks, is 112 feet long. The recommended foundation type for all substructures on the bridge was drilled shafts (caissons). Detailed geotechnical analyses were performed, and foundation recommendations were provided for the foundations for the proposed catenary structures and a new retaining wall adjacent to the proposed bridge.

During preliminary design, soil reconnaissance and a geological investigation were performed for the final design structure in accordance with PennDOT’s Design Manual Part 1, Design Manual 4, and Publications 222 and 293. Reconnaissance consisted of searching published and unpublished information, consulting with City and PennDOT personnel, performing a visual site inspection, developing a subsurface exploration program to identify and summarize potential problem areas, and discussing subsurface exploration requirements.

During the final design, AEG performed the subsurface investigation and testing program, prepared the Structure Foundation Geotechnical Report (SFGR), and assisted in preparing specifications and details related to the final contract documents. The drilling program encountered hazardous materials and required unique treatments for handling purposes during the investigation and construction activities.