Shuttle buses will replace the MBTA’s Red Line service between Broadway and Ashmont and North Quincy stations this weekend (Jan. 7-8) as repairs get underway to the JFK/UMass lobby and the pedestrian walkway above the Braintree platform.

The JFK/UMass MBTA station serves both the Ashmont and Braintree branches of the Red Line, as well as three commuter rail lines and several bus routes. The commuter rail section of the station will be unaffected by the repair work, according to the T.

The pedestrian walkway, which connects Columbia Road to the lobby, has been closed since November, blocking customers as they seek to enter the dilapidated station. An inspection led to a “critical structural finding” that spurred agency officials to close off the walkway. “After necessary repairs are completed, the MBTA will reopen the pedestrian ramp at Columbia Road,” the T said in a statement this week.

On a recent Friday, a Columbia Road door, located next to the closed walkway and typically used by commuters exiting the Ashmont platform, was propped open by a bag of rock salt.