The Henry Hudson Bridge spans 1,540 feet over the Harlem River and carries approximately 23 million vehicles per year. When the multi-level roadway bridge opened in 1937, it was the longest plate girder arch and fixed arch bridge in the world. OHL North America company, Judlau Contracting, Inc. (Judlau), replaced the lower level, four-lane roadway and the entire north approach structure at the Bronx end of the bridge, provided seismic retrofitting, installed energy-efficient lighting, and refurbished the pedestrian walkway.
Judlau replaced the 77,000-square-foot, non-composite reinforced concrete bridge deck with prefabricated steel grid deck panels. The concrete-framed north approach structure was demolished, and the crews constructed a steel-framed concrete shell and deck structure. The scope of work also called for performing structural steel repairs, upgrades, and enhancements to the steel superstructure. More than 825 tons of structural steel were used on this project, with some 90 tons used to install maintenance and inspection platforms; 190 tons to replace tower truss members; 180 tons for component repairs to stringers, floor beams and fascia girders; and more than 365 tons for new stringers, floor beams, stringer to floor beam supports, and seismic retrofits to columns.
Judlau had to maintain the structural capacity of both levels of the bridge, while replacing the concrete-framed structure on the north approach. The complex sequence of operations involved partial installation of the new columns and floor beams inside the existing structure, a multi-step jack-and-load-transfer procedure to support the upper-level columns, and completion of the new structure and reinforced concrete deck in stages. Construction of the concrete shell and structure included placement of over 1,600 cubic yards of high- performance concrete for footings, retaining walls, curtain walls, and deck. The crews used a custom-designed gantry crane to perform all lifting on the lower level, to resolve issues related to deck’s reduced load - bearing capacity and overhead clearance. All loading and unloading had to be conducted within minimal windows for traffic shut downs.