MWAA Railyard & Maintenance Facility


Dulles, Virginia


Metropolitan Washington Airports Authority


Hensel Phelps

Project Completion Date:

December 30, 2018

Project Overview:

Provided MSE Wall design and materials, select backfill, labor, equipment, supervision and incidentals to build one MSE Wall. Terra Constructs also provided design, supply of precast coping and cast in place coping.


As an important part of the Dulles Corridor Metrorail Project, the railyard and maintenance facility stores and maintains railcars and engines for WMATA. The railyard and maintenance buildings are being constructed on sloped land where much of it needed to be built up to become level and useful. At the lowest part of the property, a MSE retaining wall is required. Strict MWAA quality and safety standards proves to be a challenge in maintaining a smooth flow of construction and material handling.


Terra Constructs teamed with The Reinforced Earth Company in designing and installing an MSE retaining wall with leveling pad, coping, and cast-in-place coping. Thousands of cubic yards of select fill will be trucked in, leveled, and compacted behind the wall.


Terra completed the project within the awarded performance period.

Services Rendered:

  • Labor, supervision, equipment and incidentals to install:
    • MSE abutment, including leveling pads
    • Precast Coping on MSE wall, including leveling concrete on top of walls
  • Materials, labor, supervision, equipment and incidentals to install Cast-in-Place coping on top of MSE wall including concrete and corrosion resistant reinforcing bar
  • Placed and compacted #57 Backfill material required for the MSE wall


  • MSE wall including #57 backfill & Leveling Pads
  • Precast Coping Installation including leveling concrete
  • CIP Coping on MSE Wall