Dulles Corridor Metrorail Project, Phase I

The Dulles Corridor Metrorail project (unofficially called the Silver Line) is a 23-mile extension of the existing Metrorail system serving the Washington, D.C. metropolitan area. The extension runs from East Falls Church to Washington Dulles International Airport, and westward to Ashburn, Virginia. The Metropolitan Washington Airports Authority (WMATA) is responsible for its construction.

Schnabel provided geotechnical engineering services for the 11.6-mile, $1.1 billion first phase. To meet the accelerated 12-month design schedule, we mobilized a team of more than 50 engineers and support personnel, including seven drilling crews. This enabled us to mount a large-scale subsurface investigation that included 1,300 borings, in situ testing, and a comprehensive laboratory testing program. Our drilled shaft foundation design for the aerial guide eliminated the need for multiple drilled shafts at each column, and reduced the diameter of each shaft. The design incorporated a drilled shaft load testing program. Schnabel’s contributions dramatically reduced the foundation costs and the schedule for foundation construction.

For more information, click here to visit WMATA’s webpage.