Amtrak Susquehanna River Rail Bridge
To increase capacity, safety, and connectivity for passengers and freight, the Susquehanna River Rail Bridge project involves replacing the two-track century-old Amtrak railroad bridge connecting Havre de Grace and Perryville in Maryland. This critical transportation link is the longest moveable bridge on the Northeast Corridor. Schnabel was retained to provide preliminary geotechnical engineering for the project.
The project involves constructing twin two-track railroad bridges over the Susquehanna River in Harford and Cecil Counties. The existing 4,123-ft long historic bridge was built in 1906 and is used by Amtrak, the Maryland Area Regional Commuter (MARC) rail, and Norfolk Southern Railway. When completed, the new four-track thoroughfare will reduce the current rail traffic bottleneck.
The project study began in 2013 with the preliminary engineering work, and the National Environmental Policy Act (NEPA) process was completed in May 2017 with the release of a Finding of No Significant Impact (FONSI). Our geotechnical engineering tasks involved conducting a conceptual geotechnical and environmental study, followed by subsurface investigations, seismic studies, geophysical investigations on land and water, and environmental services. During this process, we dug eight test pits and took five high rail, 84 land, and 37 river borings with extensive rock coring up to 200-feet deep.
We found the subsurface conditions were highly variable, with shallow rock depths of 10 feet at the Havre de Grace approach and deeper rock depths of up to 200 feet (infilled with soft alluvium and boulders) near the Perryville approach. Bridge pier design includes drilled shafts socketed into rock to resist lateral forces imparted by seismic and rail-braking forces.