NSC 23
March 18
grid changes, the project has a fair amount
of large plate girders acting as transfer
structures. One notable area that needed
transfer structures is a suspended service
yard, built above some ground floor retail
units.
In order to support the yard and take into
account the loadings that delivery trucks will
exert on this slab, a series of large transfer
girders has been installed.
Value engineering plays an important role
in most projects’ design and this scheme is
no exception. Having initially been designed
by project consultants Clarke Bond, Caunton
were employed to take on the project at
RIBA Stage 4.
“We increased the profile and gauge of
the metal decking to allow it to span further,
which then meant we required fewer beams
to support it. The beams we did install were
larger members but, even with a slightly
higher steel tonnage, the project saved
money as the fire protection requirement was
reduced,” explains Caunton’s Engineering
Manager Matthew Shimwell.
Planning and logistics have also played
an important role on this scheme as the
development is taking place adjacent to a
‘live’ shopping centre and in the middle of
the busy town.
Along one elevation, which will eventually
accommodate the link between the old
shopping centre and the extension, the
new build abuts the old with columns only
100mm apart.
New foundations could not be installed
close to the existing centre and so one
grid line of new columns is supported on
cantilevering footings.
Summing up, Kier Senior Project Manager
Alan Quigley says: “Ordinarily we would
have erected the steel frame and built our
way out of the site from the service yard and
then finished up nearest the site entrance.
“However, the two anchor flagship stores
have to open on time and need to be handedover
first for their fit-out. They have dictated
our programme and this has meant a lot of
on-site planning, as we had to erect them
first. The direction we had to take with the
steel erection means we will effectively box
ourselves in at the end, which means we’ll
have to use smaller cranes as there will be
very little room for equipment manoeuvring.”
Retail
As well as constructing the shopping centre’s
extension, Kier is also undertaking a number
of other phases of work for this scheme.
Initially the company built a new west entrance
to the mall and completed the remodelling
and refurbishment of the management suite.
In addition, it has also recently commenced the
remodelling of the east entrance, which is said to
be particularly challenging as it remains open to
the public throughout the works.
However, possibility the most challenging part
of its work consists of enlarging the mall’s existing
multi-storey car park. Although this work is being
done only a stone’s throw from the extension, it is a
separate site with its own access and delivery points.
The original six-storey concrete-framed car park
is having two extra levels added to its top. In order
to minimise the weight on the existing foundations,
a steel-framed solution supporting metal decking
is being used.
All of the 90-plus existing concrete columns
have been strengthened to allow the new steel
columns to be landed on top to form a replica grid
pattern for the new upper floors.
Working on behalf of Caunton Engineering,
Composite Profiles has been engaged to detail,
supply and install over 9,000m2 of composite metal
floor decking for the new floors.
Composite Profiles Senior Operations Manager
Mark Harley says: “Tata Steel’s ComFlor 80 profile
was the obvious choice with its long-spanning
capability. The profile is also available with Tata
Steel’s unique Colorcoat FD170 pre-finished
coating to the underside.
“This provides a light and airy feel which many
car parks find difficult to achieve.”
Parking solution
The main retail element
of the scheme takes
shape
/Steel_construction_products#Plate_girders
/Fire_protecting_structural_steelwork
/Retail_buildings#Shopping_centres
/Construction#Steel_erection
/Construction#Mobile_cranes
/Car_parks
/Braced_frames
/Steel_construction_products#Decking_for_floors
/Concept_design#Floor_grids
/Concept_design#Floor_grids