Skanska, as a member of a joint venture, was awarded the $220 million design-build contract to construct a 3.1 mile extension of Washington, D.C.’s Blue Line.
The Washington Metropolitan Area Transit Authority project, known as the Largo Extension, is located in Prince George's County, Md. The line expansion also provided for a new transit station.
The route begins approximately 1,000 feet east of the existing Addison Road Station platform with an at-grade, double track alignment that requires retained cut construction.
Most of the work on the extension involved below-grade, cut-and-cover tunnels. Because work was required in sensitive areas, environmental mitigation was conducted in strict compliance with standards that were outlined by the client.
The scope of the project included:
· installation of approximately 780 feet of tail track, extending under Arena Drive
· construction of elevated guideways
· installation of eight widened jet fan sections for tunnel air circulation
· installation of two crossover areas along the new line
· construction of auxiliary equipment rooms near the stations
· integration of system elements including track, traction power, automatic train control, communications and systems into the existing operating structure
