How to rebuild an operational airport Technical

Technical
EASTERN CAMPUS LAYOUT – PHASE 1 – NOVEMBER 2013
How to rebuild an
operational airport
eastern campus layout - phase 1 - november 2013
Height restrictions mean crawler rather
than tower cranes must be used on T2A
1
Terminal 2A Phase 1 when
complete
2
Car Park East operational
7
Terminal 2B pier Phase 2 open
8
Potential for station box for
Track Transit System (TTS)
to be built and Lima taxiway
TTS tunnels to be safeguarded
Baggage basement built
and tunnel safeguarded
across Lima taxiway
3
Baggage link to Terminal 1
4
Vertical circulation core
connection to tunnel
when complete
9
5
Passenger tunnel to T2B
when complete
10 Cooling station for air
6
Preparation for Europier
demolition
Rebuilding Heathrow’s Terminal 2 unearthed significant environmental
and logistical challenges that demanded a great deal of creative thinking
conditioning
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3
9
4
project report
Damon SchÜnmann
2
Project Phase 1 of Heathrow Terminal 2
Start date October 2010
1
10
Diagram for illustrative
purposes only
Completion date 2013, opens 2014
Big projects will never fail to
present challenges, and the
redevelopment and consequent
expansion of Heathrow’s
Terminal 2 demonstrates a pretty
good range of what can be thrown
at contractors.
The scheme involves the
demolition and replacement
of the passenger terminal (T2A),
10 new aircraft piers (T2B) and
a possible future passenger
terminal and car park expansion
(T2C).
BAA Eastern Campus
programme director Joanne
White says: “It’s very challenging
because the T2B [aircraft piers and
stands] work is all airside.
“This means vehicle deliveries
must all be security screened,
with the workforce vetted before
arriving on site.
“T2A alone is one of the biggest
construction projects in the UK.
But the total current £2.2 billion
project is one of the biggest in
Europe, with only the likes of
Crossrail exceeding it. And the
proposed T2C expansion will also
be in the same ball park.”
Passenger capacity
T2C would increase passenger
numbers from 20 to 30 million by
expanding the car park and
terminal capacity.
The overall purpose of the
project, says BAA, is to develop
Terminal 2 for the Star Alliance
airline consortium to ensure it is a
convenient hub for onward flight
connections.
The old T2 demolition was
18 | 28 July 2011
Client BAA
The T2B pier and basement
T2A passenger terminal design and build main contractor HETCo (Laing
O’Rourke and Ferrovial Agroman jv)
T2B (aircraft piers and stands) main contractor Balfour Beatty
Design Ferrovial Agroman
M&E Hoare Lea
Aircraft stands, cooling station, service diversion Scott Wilson
London Underground structural remodelling Arup
T2A architect Foster + Partners, Vidal + Asociados
T2A electrical infrastructure UK Power Networks Services
Car park Laing O’Rourke
completed last year, and BAA says
this included the recycling of 95
per cent of the material, adding
that the new building will
produce 40 per cent less carbon
than the old one.
An excavation that is currently
under way will safeguard space
for an underground baggage
handling system as well as a
light rail line connecting the
main T2A transit building with
the T2B aircraft pier (and later,
the proposed T2C passenger
expansion).
This excavation requires 600
vehicles a day at the peak of the
works, with soil either becoming
backfill or being used to cap a
nearby tip – as a result, 90 per
cent of it is reused.
Ms White says: “The new
north-facing T2A passenger
terminal will afford excellent
solar gain protection and a
canopy roof extension will
provide more shade to prevent
excessive summer heat, as well
8
7
5
£2.2bn
Value of T2A
and T2B
as weather
protection for
passengers
arriving from
the car park.”
New aircraft
The building
Total number of
has been
stands at T2B
site workers
designed with
several key things
in mind that include
biomass unit for supplying hot
environmental considerations,
water as well as heating the whole
site constraints and speed of
eastern campus.
construction.
Mr Pickard explains that being
T2A programme leader Duncan
an operating airport, the site
Pickard says the north-facing
has a variety of site constraints.
windows within the roof still
For example, work must not
allow sunlight without the solar
interfere with the line of sight
gain. “So you reduce your carbon
from the control tower to the
footprint by turning off the
ends of the runway and
lights,” he says. “The brise-soleil
means you have sufficient canopy construction equipment must
not block the overhead horizontal
shading without preventing
radar pulse.
natural light.”
Other sustainability features
include borehole water that feeds
Heavy influence
the cooling station – negating the
Although the busy airport
need for potable water – while
environment necessitates a quick
the energy centre incorporates a
build, the site constraints have
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4,500
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heavily influenced the
construction sequence and
methodology.
“We are aiming to build T2 in
40 months, that is from spring
2010 to autumn 2013,” says Mr
Pickard. “But while T5 had 30-odd
tower cranes, we can’t use any
because of the impact on the sight
lines from the control tower.
“The inner horizontal surface
is 45 m above the runway
threshold, which provided
another construction constraint.
“While T5 had
30-odd tower
cranes, we can’t
use any because
of the impact on
the sight lines from
the control tower”
duncan pickard –
T2a programme leader
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“This is an area that would be
needed should a plane get into
difficulty,” he says. “So we had to
have a design that allowed crawler
cranes to construct from T2A’s
leading edge, which means a
weight limit of 20 tonnes for any
one element.”
Building cores
The passenger terminal building
is based on 12 vertical cores
measuring 9 m x 18 m x 24 m
high. To maximise speed and
quality, the project team opted for
offsite manufacture for the M&E,
using designed-for-manufactureand-assembly (DfMA) products,
while the 27,000-tonne steel frame
is being fabricated and erected.
“There is a an ethos on the
project that if it’s simple do it
onsite, and if it’s complex do it
offsite,” says Mr Pickard.
The four-floor building has a
composite metal deck while the
roof is a traditional Kalzip
aluminium standing seam design.
BAA T2B programme leader Richard
Walker explains the process.
“The basement for a baggage and
light rail transit system in the next
phase of T2C is under the main
aircraft pier here at T2B. It’s 360 m
long, 60 m wide and 15 m deep,
and with the other subsurface
connectivity structures will entail
2 km of diaphragm walling.
“The designers opted for
diaphragm walling over a more
traditional open cut and reinforced
concrete wall system due to
the reduced footprint of the
construction works, an easing of
impacts on logistics, and to create
a more flexible construction
sequence.
“The north and south sections of
the pier will be delivered using
top-down construction, enabling
the early commencement of the
superstructure. However, the centre
section will be built from the bottom
up, providing for the earliest
completion of the critical path
subsurface plant rooms and
communications rooms.
“At the same time as the
diaphragm walling, about 700
large-diameter bored piles and plunge
columns are being installed from
ground level to take advantage of the
predominantly existing concrete
stand and taxiway pavement.
“The main excavation is about
750,000 cu m, with sands and gravels
overlying London clay. All excavated
material is being recycled for use in
the works or for environmental
capping off site. This includes the
existing pavement quality concrete,
which is being crushed on site for
piling mats or stored for the future
stand and taxiway works.”
The structure is glazed on the
east, south and west faces, while
the north face is temporary to
allow the structure to be extended
further to the north.
Mr Pickard says the passenger
experience is intended to give
them the impression of following
a wave as they walk beneath the
undulating ceiling.
Work has included excavation
for a basement for the phase 2
baggage system installation – a
function that is currently being
handled by Terminal 1 for
outbound flights. The basement
has a raft foundation to minimise
movement and spread the load.
Mr Pickard says: “Traditionally
you might have designed a
building and then worked out
how to build it.
“What we have done is have a
concept of what we wanted, and
then taken into consideration all
the constraints before deciding
how to build it first. The design
informs the method of
construction.
“For example, the modular
M&E and the steel roof sections
and frame need to be assembled
with crawler cranes. The steel
sections must be able to be
28 July 2011 | 19
Technical
“We only have
about 400 people
on site, which is
perhaps half
the amount
needed for a
traditional job
of this kind”
duncan pickard –
T2a programme leader
delivered by trucks without
escort. It’s all about minimising
logistics as there is one main road
tunnel entrance to the central
terminal area. An escort would
impact on Heathrow operations,
as it takes out both of the three
lanes coming in.
“It’s all about being the invisible
silent builder that does not impact
on Heathrow’s daily operation.”
20 | 28 July 2011
fitting material deliveries to the airport’s schedule
“We have to protect the airport from
disruption and, at the same time,
ensure the logistics plan is capable of
supporting the construction
programme – and that’s a constant
balancing act,” says BAA Eastern
Campus logistics leader Tim Brent.
The two key themes are
movement of materials and people,
back and forth. “With materials, it’s a
large site – over 1 km long – and the
perimeter is 3 km,” he says. “Over the
whole project we have 400,000
vehicle deliveries. And we have about
4,500 people across T2A, B, the car
park and the baggage handling
element of the scheme.
“However, material deliveries don’t
begin until after 9am to keep them
outside of peak passenger times.
“The Icelandic ash cloud last year
actually had a positive effect on
work at Heathrow: it accelerated the
programme, since the airport was
not operating for a limited period.
But we had to be ready to decelerate
at short notice.”
And other weather conditions
affected the contractors’ role beyond
the ordinary. “During the adverse
winter weather, site workers helped
clear ice and snow from the airport,”
he says.
Project director of the HetCo JV
between Laing O’Rourke and
Ferrovial Agroman Pablo Riesco
says: “In a project like this, in the
middle of the airport, the most
important thing is getting the
logistics right from the very
beginning. We have 25-30 lorries
delivering steel every day. On T2A
we have delivered 95 per cent of
the materials to the landside. But
to the aircraft stands on T2B, they
have to go airside.
“The project reached a milestone
before the beginning of June by
completing the entire basement
and substructure, and we are
talking about a 200,000 sq m
construction area.”
Mr Pickard adds: “To put that
into context, the commencement
of the excavation to having a
watertight box is 20 months.”
He concludes: “The next big
one is the building envelope,
which is scheduled for February
2012. So by then we will have
completed the substructure,
superstructure and roof.
“Yet we only have about 400
people on site, which is perhaps
half the amount needed for a
traditional job of this kind.”
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