Elimination of the Braddock Hump and other construction updates
As the Platform Improvement Project progresses, this week marked an important milestone: the official elimination of the “Braddock Hump.”
Since Braddock Rd Station opened in 1983, the platform at the south end was approximately two to four inches higher than the level of the train floor, creating a barrier for wheelchair users when exiting a train and posing a tripping hazard for all customers. Earlier this year, the cause of the hump was determined following extensive inspections and engineering analysis. The investigation found that the concrete piers that support the platform were actually built a few inches too tall when the station opened.
In order to officially eliminate the Braddock Hump and set the platform at the correct height, the construction team used hydraulic jacks to lift the 1.6-million-pound platform deck off the concrete piers that support it. The jacks supported the platform while crews adjusted the piers and the platform bearings were successfully rotated and lowered to the correct height. The southern end of the platform was lowered by 4 inches total, in 1/4 inch increments, and another section of platform was lowered 2 inches total, in 1/8 inch increments. The jacks will continue to hold the platform while crews rebuild the structural piers that support it.
Construction update (June 26, 2019)
- At Braddock Rd Station, in addition to the work on the Braddock Hump, crews have poured concrete along 60 percent of the platform (with the exception of platform section that was affected by the hump). Crews are now placing new granite along the platform edges and waterproofing the platform concrete before new paver tiles can be set. The platform canopy is being sandblasted and painted to prepare for the installation of new skylights.
- At Eisenhower Ave Station, work on the platform edges is in progress, with all concrete poured on both the inbound and outbound sides of the platforms. The next step at Eisenhower Ave will be to place the new granite edges. The process for waterproofing the platform deck is also underway.
- At Franconia-Springfield Station, all the concrete has been poured on both sides of the platform edge. Additionally, all of the existing skylights have been demolished above the platform before new ones are installed. Painting of the pedestrian bridge is ongoing.
- At Huntington Station, demolition of the inbound and outbound platform edge is complete, and the formwork and rebar are being installed. The first concrete pours for the inbound platform edge started this week and pours for the outbound side will begin next week. All platform paver tile has been demolished. In addition to the platform work, demolition of the south mezzanine skylights has begun.
- At King St-Old Town Station, crews have completely installed the formwork and rebar and poured out all of the concrete for the platform edges. Crews have started installing the granite edges this week.
- At Van Dorn St Station, crews have completed all the new concrete for the platform edges. In the coming weeks, crews will set granite slabs on platform edges, complete waterproofing and install new expansion joints.