Potomac Yard Metrorail Station
Alexandria, Va.
BEST PROJECT
Submitted by: Halmar International
Owner: Washington Metropolitan Area Transit Authority (WMATA)
Lead Design Firm | MEP Engineer: Arup
Construction Manager: Potomac Yard Constructors JV (Halmar International LLC and Schiavone Construction Co.)
The station will be key to catalyzing development of the surrounding area into a walkable urban hub while also substantially reducing vehicle traffic, according to the project team. Sandwiched between wetlands and existing rail tracks, the $274-million station features two 800-ft-long platforms, an entry pavilion, a landscaped approach to a residential neighborhood and a pedestrian/bicycle bridge that provides a seamless link to adjacent recreational trails.
To mitigate a protracted permitting process that resulted in a six-month delay, the team used a grid of 1,400 concrete modulus columns in lieu of the original plan of employing wick drains and surcharging to achieve soil consolidation. The approach restored the project to its original five-year schedule at no additional cost.
Besides coordinating construction to prevent disruption of traffic along the existing rail lines, the team needed to avoid an 8-ft-dia jet fuel line that feeds nearby Ronald Reagan National Airport.
Photo by Session Studios/Potomac Yard Constructors
The pavilion and a connecting bridge were added to the project scope after construction started and had to be completed within the same time frame. The extra work was seamlessly integrated into the project thanks to communication among stakeholders. The south entrance pavilion was oriented to improve accessibility for sight-impaired riders traveling to and from the adjacent National Industries for the Blind.
To inform the community about project activities, including trucking 80,000 tons of material through the area, the team regularly met with city leaders and community groups. Extensive home surveys for more than 250 residences combined with vibration and settlement monitoring of adjacent bridge structures minimized construction-related impacts.
The team also implemented modified traffic patterns to preserve half of a neighborhood park that was expected to be affected by construction and worked with local educational organizations to provide summer internship programs to local students. The station is seeking LEED Gold certification under the U.S. Green Building Council’s new LEED for Transit Stations pilot program.