Preliminary Engineering, Final Design, and Construction Consultation
Erdman Anthony provided preliminary engineering, final design, and construction consultation for the replacement of a reinforced-concrete closed-spandrel arch bridge carrying PA Route 75 over Norfolk Southern's Pittsburgh Line in Port Royal (SR 0075/A03). The structure is the westernmost in a series of end-to-end bridges crossing the railroad, a local roadway, and the Juniata River. The structure is also adjoined to the First Street ramp bridge, also designed by Erdman Anthony, which ties in perpendicularly to SR 75.
The replacement structure is a 75-foot-long steel-plate girder bridge with an additional 26-foot-long reinforced-concrete slab span. The steel span is metalized for corrosion protection and long-term serviceability. Portions of the existing bridge foundations were maintained in the new construction. A seismic tomography investigation of the existing foundations was used to confirm the adequacy of the foundations for reuse.
The original arch bridge, constructed in 1910, was a contributing element to the Pennsylvania Railroad Main Line Historic District. To mitigate the loss of this historic resource, the southwest quadrant of the project area includes a parklet with bench seating, interpretive panels with historical photographs and text, and greenspace overlooking the rail lines.
The project required extensive coordination with Norfolk Southern to minimize disturbance to the rail lines, which carry nearly 70 trains each day. Despite numerous competitive bids received, there were minimal contractor questions on the bid package, indicating the quality of plans, specifications, and estimates delivered by Erdman Anthony.