DC Transit Officials Face Concrete Concerns
Crumbling concrete is under scrutiny at one Washington, D.C., transit station this month.
Investigators recently discovered concrete damage in a bridge outside the Rhode Island Avenue Station on the Metro’s Red Line during an inspection of the structural integrity of the area.
The inspection was prompted following two other concrete incidents occurring in the same station earlier in the month, which resulted in successive temporary closures.
Falling Concrete, Structurally Sound
In early September, concrete became the focus of Washington Metropolitan Area Transit Authority (Metro) officials’ attention after chunks of the material reportedly fell in commuter areas at the station, sources said.
On Sept. 1, station personnel reported small pieces of concrete falling from the station ceiling, Metro said in a statement. Just one day earlier, a metal bracket and small pieces of concrete fell in a different area about 40 feet away, it added.
On Sept. 2 Metro said they had found that the metal bracket and concrete debris that fell were used to fill an approximate 6-inch gap between the beam that supports the platform and the escalator support frame.
“While the bracket does not serve as a primary structural support, the bolts that secured the bracket deteriorated likely due to exposure to environmental elements,” Metro said.
Metro Chief Operating Officer Joseph Leader told The Sentinel that, based on preliminary inspections, he suspects water damage as a contributing factor, but does not think the broken pieces suggest a structural issue.
Below-ground stations between Van Ness and Medical Center are said to be susceptible to water seepage because they were not sealed against water at the time they were built, but the Rhode Island Avenue Station is an elevated structure.
Crews at Rhode Island avenue station. Some riders still showing up unaware of station closure pic.twitter.com/XpVlAncW0k
— Bri Carter (@ABC7Bri) September 2, 2016
Still, Leader noted: “It would lead us to believe that there was probably some water that got behind [the concrete]… from years of freeze and thawing that take place, the concrete will separate [from] the structural membrane and then will eventually crack and fall.”
Although repairs were made immediately following both incidents, and the authority said they did not appear to be related to any structural deficiencies, Metro ordered a “top-to-bottom” inspection by a third-party expert to ensure the structure is sound and does not present a hazard to the riding public.
The station remained closed through the weekend during those inspection efforts in “the interest of safety and out of an abundance of caution.”
During the closure, crews performed complete inspections of the station mezzanine, platform overhangs, columns and beams; removed and replaced all loose concrete identified during third-party inspections; installed safety/debris netting along the entire length of the station; and installed safety/debris netting in the bus loop area of the station.
Core Testing, Speed Restrictions
The condition of the bridge serving the Rhode Island Avenue Station was discovered during the follow-up inspections after these incidents.
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| Washington Metropolitan Area Transit Authority |
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Metro Chief Operating Officer Joseph Leader noted that preliminary inspections of the station suggested water damage caused the concrete to crack and fail, sources said. |
A timeline for repairs is being considered for addressing damage found on the Red Line bridge, WTOP reported Friday (Sept. 9); however, before work begins, core samples from the structure have been sent for testing.
The area was already slated to for track repairs in a three-week period in October, the station noted, but the scope of the work has grown with the discovery of the poor concrete conditions on the bridge that holds up the outbound track.
Although the transit authority indicated the deteriorated concrete on the bridge is not a safety risk for commuters, it has issued speed restrictions on trains coming into the station.
Speed has been reduced to 15 mph in the area to reduce stress on the structure and ward off further damage until permanent repairs can be made.
The speed restrictions are expected to remain in place through the end of November while the concrete repairs cure, Metro said.
In the meantime, “Additional, more wide-ranging inspections will be conducted over the coming weeks to evaluate and recommend a long-term solution to remediate the concrete deterioration caused by environmental conditions,” Metro stated.
Adjusted repair plans based on these inspections for the station are expected within the next few weeks.
