PROJECT CASE STUDY III 152 ELIZABETH STREET
THE FOCUS OF THIS CASE STUDY WILL BE ON A REAL JOB SITE CHARACTERIZED BY OLD EXISTING BUILDING CONDITIONS THAT HAD TO BE RETAINED, TIGHT CONFINES, AND ITS LOCATION ON TOP OF A SUBWAY TUNNEL. THE STUDY WILL EXAMINE THE SPECIFICS OF 152 ELIZABETH STREET - A GROUND-UP CONDOMINIUM PROJECT DESIGNED BY TADAO ANDO - TO CONVEY FOUNDATIONS GROUP’S CONSTRUCTION METHODS AT SUCH COMPLEX BUILDING SITES.
COMPANY Foundations Group is an established Building + Construction Management firm formed in 1993 by Cooper Union School of Architecture trained architects. Comprised primarily of architects and engineers, our team is keenly aware of the design needs of each project, and we run all projects in a very collaborative effort with developers, clients, and architects. Over the last two decades, Foundations Group has built over 1.5 million sqft of construction in New York City ranging from ground-up buildings to building additions, conversions, gut rehabilitations, high-end residential, commercial fit outs, and museum exhibits. As one of the premier non-union Construction Management firms in New York City dedicated to building very high-end projects, we pride ourselves on our track record. We work with world renowned architects and designers such as Enrique Norten, Tadao Ando, Morris Adjmi, Soo Chan Khian/SCDA, Michael Gabellini, Shigeru Ban, and BKSK among others. We were selected by Tim Lynch and the NYC Department of Buildings as one of the select construction managers to help the DOB with their study on how to keep buildings and sites safe - High Risk Construction Oversight (HRCO). Our work has been published in numerous publications including The New York Times, Interior Design, and Architectural Record.
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MAIN CHARACTERISTICS OF THE EXISTING BUILDING Old brick parking building set above an MTA subway tunnel. First floor slab and support beams in very bad condition. Tight headroom for foundation work (approx. 8’ - 10’).
PRE CONSTRUCTION
ANALYSIS + SOLUTION THE CHALLENGE Retaining the existing ground floor and portion of the existing building exterior walls and construct a new foundation within the confines of an existing tight space.
EXCAVATION / FOUNDATION CANTILEVER: We were positioned above an MTA subway tunnel, meaning the new building foundation had to be executed as a cantilever. This was supervised by a TA at all times. PILE-WORK: Since the first floor slab of the existing building was kept, the headroom for working on the foundation was very tight (approx. 8’-10’). We ultimately completed 114 80’ deep friction piles within this headroom, and used 3.2’ long casings (about 25 casings per pile) all carried by hand. BEAM SUPPORT: The beams that were supporting the existing first floor slab were in extremely bad condition, forcing us to provide additional support to the slab and beams during all our moves. During excavation some of the columns were replaced with new temporary columns on top of the friction piles. All extra precautions were essential in ensuring that we did not lose any portion of the existing slab.
CONSTRUCTION METHODS
NEW BUILDING FOUNDATION
[ EXISTING STRUCTURE DEMOLISHED FOR NEW BUILDING ]
[ GROUND LEVEL ] [ TIGHT UNDERGROUND SPACE EXCAVATED FOR NEW FOUNDATION ] [ MASSIVE FOUNDATION CANTILEVERED OVER SUBWAY TUNNEL ]
[ UNDERGROUND SUBWAY TUNNEL W/ DRILLED SUPPORT PILES FOR FOUNDATION ]
*GRAPHIC NOT TO SCALE
EXCAVATION + SUPPORT
RETROFIT DRILLRIG
PILE-WORK
NEW FOUNDATION
NEW BUILDING
FOUNDATIONS GROUP / WWW.FOUNDATIONSGROUP.COM 520 W27TH ST., SUITE 302, NEW YORK, NY 10001 / TEL. 212 924 1724