Following extensive pile installation and other foundation work in the Hudson River over the past year, the first permanent, vertical elements of the New NY Bridge are beginning to take shape: Two 40-foot steel cage towers now stand near the Westchester shore. Soon—with the addition of high-strength concrete—the first pier for the westbound span will be created.
“Everything we’ve been doing to date has been below the surface. This new work is giving people the first opportunity to see the bridge rising above the water,” noted Thruway Authority Construction Compliance Engineer Tom McGuinness.
The columns—over 130 in total—eventually will support the steel girders and deck of the new bridge. The girders and decking will be lifted in place by the soon-to-arrive I Lift NY super crane.
The steel cage frameworks for the piers are pre-assembled at a site several miles upriver. The rebar cages are transported to the project site by barge and lifted into place by floating cranes.
After the steel cages are carefully inspected, they are filled with concrete produced by the project’sfloating batch plants. Enclosing forms are erected around the frameworks to enable the concrete to set in the shape of the piers that will hold up the new twin-span structure.
The floating concrete batch plants maneuver around the river, mixing the precise amount of concrete required and using an extending arm to apply the material directly into the frameworks. The concrete flows around the steel cages and eventually hardens to form steel-reinforced concrete. The composite material is remarkably strong and capable of supporting the new bridge for the next century or more.
The New NY Bridge project remains on schedule and on budget as it approaches the one-year anniversary of new bridge construction that began with permanent pile installation in October 2013. Local residents can expect to see more and more vertical pier structures rise out of the river in the coming months as construction progress continues.