The Long Bridge project is an expansion of the existing Long Bridge, which carries two rail lines over the Potomac River. The project involves the construction of a 1.8-mile railroad corridor that runs from Arlington, VA to Washington, DC between the existing Long Bridge and the Washington Metropolitan Area Transit Authority Yellow Line bridge. This Design-Build project adds two additional tracks running over an additional railroad bridge, as well as a 16-foot-wide bicycle and pedestrian bridge across the Potomac River adjacent to the existing bridge. This expansion doubles the passenger rail capacity between Virginia and D.C., thus significantly relieving one of the worst commuter rail traffic bottlenecks on the East Coast. The new bridge is being constructed north of the existing structure and will intersect with the existing span on the District of Columbia (DC) side of the Potomac River. The bridge is expected to open in 2030.

F&R is providing ongoing drilling services for the environmental and geotechnical engineering consultant. The F&R team is providing drill rigs on two barges for a section of the subsurface investigation across the Potomac River. The drilling involves 21 SPT borings to depths of 25 to 110 feet. The F&R team will also assist with CPT soundings to depths of 50 feet at 23 locations.

In addition to ongoing activities noted above, F&R previously provided specialty drilling and laboratory services to support the 30% design drawings for the Design-Build contract. The drilling services provided by F&R included 18 land borings along highways, existing rail lines, public parks, and sidewalks. The land drilling required teams to work alongside active roadways and sidewalks. Additionally, F&R drilled 16 water borings in the Potomac River using two barges to complete the work – one for deepwater drilling and the other for shallow water borings. The borings were typically 100 to 150 feet deep, with rock coring and/or environmental sampling occurring in approximately 60 percent of the borings. Portions of the river are under the jurisdiction of the National Park Service and the District of Columbia, requiring multiple permits to proceed with aquatic drilling operations. Overall, the fieldwork required the cooperation of the National Park Service, the D.C. Department of Transportation, the D.C. Department of Energy and Environment, the D.C. Building Department, and the U.S. Coast Guard.

The F&R team’s laboratory services included soil classification testing, consolidation testing (to assess the settlement of the structures), triaxial testing (to determine strength parameters), and corrosion potential testing (to evaluate whether steel and concrete could corrode due to soil-structure interactions).