9th Avenue Deck Cover Structure (Manhattan West)
Manhattan, New York
Project Description
Brookfield Manhattan West at 9th Avenue and 33rd Street is a dramatic, environmentally sustainable addition to the Midtown Manhattan skyline. It is a five-acre site, with over five million square feet of office and mixed-use development.
One block west of Penn Station, Brookfield's development lies at the heart of Manhattan's new West Side. Offices, hotels and residences are planned for surrounding blocks, including redevelopment of the adjacent Farley Post Office as the new Moynihan Station. Brookfield Manhattan West's iconic towers, flanking a grand outdoor plaza, marks the centerpiece of Midtown West. The two office towers soar 62 stories above what is currently undeveloped property.
Railroad tracks leading in and out of New York’s Penn Station are located, partially uncovered, 65 feet below grade. McNary Bergeron utilized post-tensioned precast segmental bridge technology to design a deck over these tracks, allowing for the construction of the office towers without disrupting the passage of the trains.
The precast segments were erected with an overhead gantry using span-by-span method. The new structure included 16 girders aligned side by side, each girder approximately 240’ long with 39 precast segments with a total width of 16 girders side by side is approximately 573’. Total deck area of approximately 137,500 square feet.
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Our Role
Hatcher Technical assisted McNary Bergeron in the preparation of design drawings, performing constructability reviews and producing fully integrated shop drawings for construction.
Location
9th Avenue and 33rd Street
Manhattan, New York
Owner
Brookfield Office Properties Inc.
Contractor
Rizanni de Eccher, USA
Designer
McNary Bergeron & Associates
Total Contract Value
$100 Million
Timeline
2011 - 2014
Construction Method
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16 simple-span precast concrete segmental box girders set side-by-side
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Girders are 2100 tons, 240' long, 12' deep and 23' to 35' wide
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20 x 37-strand tendons and 14 x 31-strand tendons per girder
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Girders were fully assembled and post-tensioned over a temporary platform before being placed in their final location using the launching gantry
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Girder placement was done during a 3-hour work window to minimize disruption to Penn Station rail traffic
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Cast-in-place concrete diaphragms and 6" structural slab ensure load-sharing between adjacent girders
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Armored steel openings for future building columns, ventilation, etc.
