Design/Build Services for the Reconstruction of Ramp MQ at the Robert F. Kennedy Bridge, RK-73, New York City
The $50-million project to reconstruct the RFK Bridge's Manhattan/Queens ramp exceeded original expectations when it finished four months ahead of schedule. Work, which included construction of temporary roadways and demolition of old structures, was done under live traffic conditions on a span that averages 170,000 vehicles a day.
Part of a nearly $1-billion capital improvement program, the 26-month project called for design and replacement of the existing 54,000-sq-ft, two-lane elevated ramp to meet currently accepted design load and seismic standards. Built in 1967, the existing span's spread-footing foundations had no capacity provision to resist seismic load.
Work involved removing the old concrete deck of the ramp, replacing the steel support stringers and building a new concrete deck that included galvanized reinforcement rebar.
The team and stakeholders negotiated a quick change order for unexpected surprises that were not part of the original scope, such as replacing seven of 18 cap beams due to the poor condition of the existing concrete. Work on this included designing new cap beams and ordering the formwork. During excavation to modify the existing footing, the team found that the column below ground was poured around an existing duct bank. It designed a new column and cap beam and installed temporary supports to maintain traffic.
Many of the 36 footings also needed to be upgraded to meet the new loading requirements. After discovery of many previously unknown utilities in the area, the design of some of the footings had to be modified to fit field conditions.
The judges called the team's work "impressive" and noted its success in finishing ahead of schedule with minimal impact to drivers.
Owner/Developer Triborough Bridge and Tunnel Authority
General Contractor Halmar International
Lead Designer/Structural/Civil/MEP Hardesty & Hanover
TBTA Construction Manager The Liro Group
Surveyor MJ Engineering & Land Surveying
Subcontractors Imperial Iron Works; Structal