Steel Construction Vol 40 no 6 - International Steel Structures | Page 18
SAISC PROJECTS
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A new re
MdeAS Architects
The original article was published in Modern
Steel Construction, the official journal of the
American Institute of Steel Construction.
We thank them for their kind permission to
reproduce the article.
A dramatic retail newcomer of cubic
proportions has come to Manhattan’s 42nd
Street commercial corridor.
Known as the Cubes, the project flanks
the western edge of a through-block plaza
at 120 West 42nd Street between Avenue
of the Americas and Broadway. Its design
employs several distinct boxes shifted in
relation to one another while maintaining
the uniformity of its grid, and contrasts with
the monolithic character of the adjacent
1095 Avenue of the Americas tower (also
known as 3 Bryant Park). Framed with
400 tons of structural steel, the 85-fttall structure comprises three occupied
floors, as well as a fourth-floor mechanical
penthouse, and contains approximately
23,000 sq. ft of above-grade retail space and
an additional 55,200 sq. ft below grade in
the cellar and sub-cellar. The protruding
blocks provide an additional 4,300 sq.
ft of accessible rooftop exterior space.
The design relocated the main entrance
to the 1095 tower from the Avenue to
the west side of the building (plaza-side)
where a new doubleheight lobby was
constructed. Relocating the entrance
allowed for additional retail space along the
Avenue. The existing subway entrance was
repositioned away from the plaza corner to
allow prime retail use of that space.
Jewel box
ABOVE: Joe Mugford [top]
([email protected]) is
an associate and Philip Murray
[below] (philip.murray@gmsllp.
com) is a partner, both with
Gilsanz Murray Steficek.
16 Steel Construction Vol. 40 No. 6 2016
Glass curtain walls, wide interiors spans and
lots of right angles make the interior spaces
light-filled and engaging. Across the plaza,
this approach is mimicked at the interior of
the existing 1095 tower. From the street, the
structure looks like two separate buildings,
but the two sides are actually united
underground.
The ground-up development required
demolition of a six-story 1940s building.
Additionally, part of an existing annex
building was demolished to grade, but its
substructure was preserved and engaged
by the new superstructure. Drawings
for the existing building lacked the
appropriate level of details and demanded
extensive field verification. The 1970s
design of the existing annex building,
which was partially demolished, assumed
subsequent addition of more floors. Thus,
the preserved substructure did not require
much reinforcement, as columns were
already oversized, and reserve capacity
was therefore available to support the new
design. However, the column grid of the
new superstructure does not align with
the grid of the substructure, so the design
employs W30×173 transfer girders at the
plaza level that distribute the load to the
foundation. The new foundation system
consists of spread footings on 20-ton rock.
The challenging excavation and foundation
work included digging 32 ft below street
level adjacent to the operational 42nd Street
MTA subway tunnel, with careful attention
to earthwork vibration. The dig took place
around existing W14 columns, which had to
be temporarily supported with drilled piles.
The open layout of the retail floor plates
above grade required a long-span column
grid, typically 25 ft by 45 ft. With 20-ft
floor-to-floor heights, careful consideration
of live loads and vibrations demanded
stiffer frames. The entire superstructure is
designed using moment frames to maintain