Red Line Tunnel Work Keeps Damaging Water Out – 4Washington
Work on keeping a Red Line Metro tunnel safe and dry is progressing ahead of schedule, according to the transit agency.
Metro said the track between the Medical Center and Friendship Heights stations are getting a treatment to keep water out of the track area. The tunnel in that area is below the water table, and hydrostatic pressure from the groundwater presses on the tunnel walls.
A company called J-Track was brought in to provide a solution. The company has had success in waterproofing coal mines and worked on the South Ferry/Whitehall Street subway station in New York City after Hurricane Sandy.
The company drills two holes in the ceiling of the tunnel and injects a polymer-based grout that reacts with water and solidifies. The new impervious membrane becomes like tires on a car and channels water away from the outside of the tunnel.
Metro said they have noticed a huge difference during the torrential rains in the area over the past couple of days. The work is ahead of schedule, but the Red Line will be closed this coming weekend for the company to finish their process.