Since Project Inception
Since project inception, Parsons’ responsibilities for the Metrorail system have included the following deliverables:
- Preliminary engineering design of entire system
- Planning and route location
- Surveying and rights-of-way requirements
- Design criteria, standards, and directives
- Standard construction specifications
- Construction estimates and schedules
- Management of all final design contractors
- Construction management and start-up support for the first revenue section
We also managed the design of the following project components:
- Aerial, at-grade, and subway structures
- Trackwork
- Traction power
- Train control and communications
- System safety evaluation
- Noise and vibration control
- Corrosion control
- Tunnel ventilation
A significant portion of the system was constructed within heavily developed commercial and residential areas. The Metrorail network includes 50 underground transit stations and 48 miles of subways (22 miles of cut-and-cover tunnels, 11 miles of earth tunnels, and 15 miles of rock tunnels).
Because Parsons encountered virtually all possible soil conditions during underground construction, we developed techniques to underpin foundations for major buildings and introduced many tunneling innovations:
- Leader in U.S. application of the New Austrian Tunnel Method (NATM), developing NATM tunneling designs for both line sections and station caverns
- Applied techniques for gasketed and bolted segmental concrete lining
- Incorporated floating slabs to reduce ground-borne vibrations
- Designed single-pass and two-pass soft-ground tunnels
- Integrated benefits of incorporating a large-diameter earth pressure balance machine
In close association with WMATA staff, we developed the criteria and coordinated the design of the Metrorail automatic train control system. This system includes a dual, computer-based operations control center and vital control equipment installed throughout the transit system to provide safe, automatic systems for train protection, operations, and supervision.