I-270 Watkins Mill Road

The interchange at Watkins Mill Road near Gaithersburg, MD opened in 2020. It relieves congestion on I‑270 — one of the DC area’s busiest corridors — while also providing a new link to the surrounding residential and commercial developments. A new four‑lane bridge over the highway includes bicycle and pedestrian access to cross I‑270.

Over 61,000 square feet of Reinforced Earth® MSE wall facing area was installed for the project, split into five structures.

The longest of the MSE walls (835 ft) was installed at a lower elevation at the edge of a tributary of Seneca Creek. The wall reaches about 33 feet tall and was designed to accommodate a 100‑year flood level to about mid‑height. It was part of the many environmental considerations by Wagman to reconstruct the tributary.

The tallest of the MSE walls (47 ft) is part of a 700‑ft long ramp for the new bridge. The walls are back‑to‑back and join a cast‑in‑place abutment with special design for soil reinforcement locations to avoid pile and drainage obstructions within the wall volume.

The concrete facing panels were cast with a stacked stone finish. Along with the slip joint columns every 30 feet, the architectural treatment adds a nice look to this important part of the community’s infrastructure.

Visit Wagman’s page to see more about their award-winning project.