Download CTRL Contract C240, Tunnels

Civil Engineering
CTRL Contract C240, Tunnels
LONDON, UK
Underground engineering design and
provided to tunnel construction works
management
The Channel Tunnel Rail Link is
being
built
by
London
&
Continental Railways Ltd. It will
be Britain’s first major new
railway for over a century - a
high
speed
109km
line
running
between
for
St.Pancras
Station in Central London and
the Channel Tunnel.
Bachy Soletanche combined in
a Joint Venture partnership in
equal shares with Costain and
Skanska
(UK)
CTRL
240
valued
at
to
construct
contract
£115m.
works,
This
JV
developed into an Alliance with
the other project contractors
and overall project manager,
Rail
Link
Engineering,
to
construct the full length of the
Channel
Tunnel
underground
Rail
tunnels
Link
into
St
valued
at
Tunnelling Machine
CLIENT:
Union Railways (North) Ltd
£534m.
MAIN CONTRACTOR:
Joint Venture of Costain Ltd,
Skanska JV Projects and Bachy Soletanche
In the early stages of tendering
CONSULTING ENGINEER:
Rail Link Engineering
for
DURATION OF WORKS:
174 weeks
Pancras,
the
London
CTRL
works
Bachy
Soletanche provided managerial,
engineering
and
technical
support, following into the final
WORKS QUANTITIES
Tunnels
8.15m diam. tunnels, 2No. 4.7km, Total 9.4km
Shafts
Diaphragm Wall shafts 24m x 10m x 37m depth
& 20m x 16m x 43m depth; Shotcrete shaft 10m dia x 35m depth
contract in February 2001 and
Dewatering
the start of the works on site in
Cross Passages
28 wells, 6km of pipe 600m dia, discharge 1100m3/hr approx = 10
million m3 in total pumped
8 No Cross Passages (3.5m to 4.5m dia with 3.5m dia Nadir sump
shaft) Temp localised drainage systems drilled & installed in tunnel
negotiations and award of the
July 2001.
A403
Dewatering Drawdown Along Tunnel Route Drawdown
Woodgrange
Shaft
Barrington
Shaft
Stratford
Box
Before Pumping
After Pumping
Ground Level
Tunnel Outline
Shafts
Grouting in area of ground settlement
Senior staff were provided for key
teams from the Company’s base in the
detailed design and construction of the
positions on the contract in the tunnel,
UK and France were specifically brought
diaphragm walls to the shafts. The
shaft and de-watering sections, and
on board to start the early works in the
expertise
in
global
de-watering,
Ventilation shaft construction site, Woodgrange Road
previously
used
on
overseas
tunnel
contracts in Denmark and on the Jubilee
Line Extension Project in London, were
paramount in the success of setting up
the deep wells and commissioning the
system in the gravels, sands and chalk
beds
within
the
London
basin,
successfully lowering the water table by
30 metres.
Void
grouting
in
confined
residential
areas, followed by compaction grouting
monitored
by
recording
drilling
parameters, were mobilised in sections of
the
job
where
unexpected
ground
movement developed, and the installation
of pipe arches above tunnelling openings
were developed from Bachy Soletanche’s
expertise in geotechnical works.
Temporary shaft for removal of TBM’s showing shotcreting techniques
Main Ventilation Shaft Construction
The two tunnels, of internal diameter, and 14m x 19.2m by 35m deep. After receive the tunnelling machines. NATM
7.15m
and
length
constructed
machines.
using
The
4.7km,
EPB
were the completion of the diaphragm walls, techniques
were
employed
in
its
tunnelling the shafts were excavated in stages, construction, with monitoring at one
interlinking
cross installing heavy steel walings as the metre stages, as the shaft excavation
passages of internal diameters 3.5m and excavation advanced. After forming the advanced to its full depth.
4.5m will be excavated with robotic bases to the shaft, tunnel eyes were
excavators. The primary trackbed and opened through the heavy reinforced
tunnel walkways will be constructed on walls in preparation for the arrival of the
the completion of the tunnel drives into TBM’s and for the construction of tunnel
the shafts at the terminal end of the adits. A series of reinforced concrete
contract
after
the
removal
of
four slabs,
beams
and
walls
were
then
tunnelling machines and their back-ups at constructed within the shafts as part of
this location. The Fixed Equipment and the
permanent
works.
Architecturally
final tracklaying contractor will complete designed headhouses are to be built
their works under separate contracts. above the shafts.
The commissioning and opening of the
tunnels for public use will be in 2007.
safety on the contract has been heavily
monitored and controlled. Full safety
procedural documents have been put in
place and the works strictly managed
under Railtrack agreed controls, adjacent
to the railways. Self certification has
been adopted to control the works.
Environmental
and
public
designed
by the JV as a temporary
the contract. Two permanent ventilation 10m as a 10.2m diameter cofferdam
and emergency access shafts of internal opening up to an elliptical shape of
dimensions 9.6m x 25.6m by 29m deep maximum 13.55m chord at the base to
relations
departments were established to reach
The third shaft was engineered and agreement with outside parties.
Three shafts have been constructed on shotcreted shaft, constructed in its top
A403
The management of the health and