Project DetailsLocation: Montgomery County, Maryland
Owner: Maryland State Highway Administration
Contractor: Wagman Heavy Civil, Inc.
The new 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 new important part of the community’s infrastructure.
Aerial photo is courtesy of Wagman Heavy Civil, Inc. Visit Wagman’s page to see more about their award-winning project.