A New Tunnel System Underneath Virginia Avenue
Clark Construction, C3M, and joint venture partner Parsons Transportation will construct a new tunnel system underneath Virginia Avenue, between 2nd Street SE and 12th Street SE. The two-track tunnel will replace the current single-track tunnel and allow double-stack trains to pass through. This reconstruction will eliminate a key pinch point on the heavily-traveled I-95 corridor railroad route.
The scope of work will occur in two phases with no interruption to train operations. During the first phase, the project team will demolish approximately 300 feet of the tunnel’s south wall and roof to accommodate the new south track. The team will then construct a secant pile wall system adjacent to the tunnel’s remaining section of the south wall. This wall will act as a part of the support of excavation system for the first phase of construction and will be the dividing wall between the two new tunnels for more than half the tunnel’s length. The team also will install a drilled soldier pile and lagging support of excavation system offset south to the existing tunnel to allow excavation adjacent to the existing tunnel.
Once demolition, the secant pile wall system, and support of excavation are complete, the team will construct the 4,100 foot cut and cover south tunnel, in a trench up to 50 feet deep, adjacent to the existing active tunnel. The team also will construct six temporary bridges over the tunnel excavation to ensure that north-south vehicular and pedestrian traffic are not affected. At the end of Phase I, trains will be diverted into the new south tunnel. Construction operations will be separated from train traffic for the majority of the project’s length, except outside of each portal and for approximately 300 feet east of the west portal, where the tunnels merge together.
During the second phase, the team will demolish the remaining sections of the existing tunnel’s roof and south wall and construct the new 4,100 foot cut and cover north tunnel. At the end of this phase, they will backfill the trench, remove temporary bridges, and fully restore traffic to Virginia Avenue on a modified alignment that will return it closer to the historic L’Enfant Plan.
Additionally, the team will permanently relocate numerous water, sewer, electric, communications, and gas utilities, as well as temporarily relocate a number of driveways on Virginia Avenue. A new concrete arch bridge also will be constructed over an existing masonry sewer tunnel to protect it under the new railroad tunnel.
Clark Foundations, Clark Concrete, C3M, and Metro Earthworks are part of the project team.