The Park Avenue Viaduct is an elevated railroad structure which carries four (4) third-rail powered tracks along Park Avenue from East 97th Street (cut stone retaining walls and cut stone arches), then at East 110th transitions to a steel viaduct up to the Harlem River Lift Bridge. The Viaduct spans 21 city blocks and is approximately 1.2 miles long. All trains from the Hudson, Harlem, and New Haven Lines converge just north of the Viaduct and must cross it to enter Grand Central Terminal.
As a subconsultant, SI Engineering, P.C. (SIE) performed a “Type A” inspection, which included the in-depth inspection of both the underside of bridges and top of deck, for 17 bridges from HU 3.62 (East 115th Street) to HU 4.42 (mid-block of East 132nd Street). Each bridge is typically 4 spans and 1 city block in length. The undersides were typically accessed with a 35’ BT from the parking areas below, and the fascia girders using the same from a lane closure along Park Avenue. Some access was via ladder and rooftops. As part of the inspection, MNR required approximately 125 locations to have Magnetic Particle Testing performed by a third party, which SIE coordinated the locations and access for. In addition to the Magnetic Particle Testing, SIE also performed dye penetrant testing to verify existing structural flags and any changes to them in additional suspect areas.
SIE was also responsible for coordinating the daily access with tenants and contractors working in the area, as well as coordinating WZTC closures and bucket trucks to perform the fascia and NDT work. Inspection findings were included in report submissions, including flags reports which were separated into “blocks” as per MNR guidelines.
