Topping out at 62-storeys and
278m-tall, Twentytwo located at
22 Bishopsgate will on completion
be the City of London’s highest
building, and second only to the Shard in
western Europe.
Being built on the plot of the previously
stalled Pinnacle scheme, the new
development incorporates the below-ground
elements of its predecessor, including three
floors of basement and a raft slab supported
on piled foundations.
From ground level upwards it is a
steel-framed structure surrounding a large
central core, with minimal internal columns
ensuring long clear spans of up to 17m.
Twentytwo will eventually offer an impressive
118,000m2 of flexible workspace for all sizes
of businesses.
The building will be the first of its kind
to house a food market, brimming with
fresh tastes and open kitchens, while other
amenities will include an innovation hub,
gym, well-being retreat and spa, a restaurant
and London’s highest free public viewing
gallery.
Constructing one of Europe’s tallest
structures on the site of a previous scheme
was always going to throw up a few snags.
“Reusing the foundations was the project’s
biggest challenge,” says WSP Project Engineer
Diego Padilla Philipps. “In the end, we
re-used 100% of the existing piles, although
some are not in the most convenient
positions for the new structure.”
In order to remedy this pile position
challenge, transfer structures have been
introduced at basement level and level two
to support columns that do not have a pile
directly below them.
The basement level transfer structure
supports one column that extends up to
the full height of the building. The transfer
structure is a 15m-long plate girder weighing
approximately 97t.
Meanwhile, the level two transfer structure
is another giant steel member that also
transfers loads from perimeter columns. This
Commercial
City’s
tallest
tower
Known as Twentytwo,
the City of London’s
latest signature
commercial building
will be head and
shoulders above all
others in the square
mile. Martin Cooper
reports on the
challenges that have
been overcome.
The steel frame will
top out by the end of
the year
18 NSC
Nov/Dec 18
FACT FILE
Twentytwo, 22
Bishopsgate, London
Main client:
AXA IM – Real Assets
and Lipton Rogers
Developments
Architect: PLP
Architecture
Main contractor:
Multiplex
Structural engineer:
WSP
Steelwork contractor:
Severfield
Steel tonnage:
17,000t
/The_Shard,_London
/Braced_frames
/Multi-storey_office_buildings#Flexibility_and_adaptability
/Steel_construction_products#Plate_girders