32 - Drees & Sommer

INFRASTRUCTURE PROJECT IN THE HEART OF EUROPE
Pushing the envelope:
Infrastructure management
by Drees & Sommer
Can you push a road tunnel
under an existing railway
track? The Drees & Sommer
experts have proved that –
with engineering expertise and
professional management –
nearly anything is possible.
Road tunnel
approx. 120 m
Freeway tunnel
approx. 750 m
A well-developed transport infrastructure
is essential in densely populated and
economically powerful central Europe.
For this reason, the Roads Department
in Luxembourg (Administration des Ponts
et Chaussées) is gradually expanding
its freeway network and – as part of the
extension of the A4 to France – is also
providing access to the disused industrial
site in Belval.
The entire project involves a series of
subprojects such as the rerouting of the
national road, the laying of an oxygen
pipeline, and the construction of a
750-meter long freeway tunnel (Liaison
Micheville) through Belval using a partial
cut-and-cover process. A later project will
link this tunnel to the freeway junction
at Lankëlz. The key purpose of the tunnel
is to direct cross-border traffic between
Luxembourg and France away from the
villages of Esch-sur-Alzette and Sanem.
Push: A heavy load on strong shoulders
A complex infrastructure project of this
nature demands professional management,
above all to ensure that budget
and schedules are adhered to. With a
long track record of experience in this
area, Drees & Sommer convinced the
government principal of its expertise and
supported the entire project professionally
from the beginning. In addition to
specialist expertise, the experts were
Tunnel jacking using the Autofonçage® technique, here with a 120 m road tunnel
able to present a portfolio of successfully
completed local projects.
A special challenge for the project participants
was the routing of the freeway
under a key railway line. The process
by which the necessary tunnel is ‘simply’
pushed under the tracks is known throughout
Europe as Autofonçage® (tunnel
jacking), but never before has it been
undertaken with a weight of 20,000
tonnes, equivalent to 16,000 mediumsize
cars.
The first step in the process is to dig a
rough pit with stable sloping side walls.
As the tunnel section is positioned, the
sides of the pit are further excavated
across the entire width of the structure to
form vertical walls. As the structure slides
into place, it immediately supports the
vertical pit walls. This process is repeated
for the entire insertion length – in this
case 59 meters (see illustration above).
The operation was a complete success:
The tracks only had to be closed for some
72 hours, after which the rail traffic could
resume its schedule.
Huge responsibility – from cost
controlling to waste disposal
Since 2006, Drees & Sommer has been
responsible for project control and cost
Client
Roads Department/Administration des
Ponts et Chaussées, Luxembourg
Project duration Phase 1 and 2
February 2006 – December 2011
Planner
Schroeder & Associés, Luxplan, Luxembourg
Key project data
– 750 m freeway tunnel, 120 m road tunnel,
approx. 2 km services gallery with
high-voltage lines
– Approx. 5 km road construction,
approx. 3.5 km freeway construction,
approx. 80 m freeway bridge
– Cost (Phases 1 + 2): €166.5 million net
Drees & Sommer services
– Project control
– Project documentation
– Cost controlling
– Supplementary claims management
Value-add achieved for client
– Specific Drees & Sommer expertise for
technical and financial issues
– Successful execution of a complex project
as a result of expert control
– Adherence to budget thanks to effective
controlling
– Relieving client burden
controlling of the €166 million project
and has successfully coordinated
cooperation between the two government
agencies – the Roads Department
and the Railway Department (CFL) –
and the companies involved in the
tunnel jacking consortium, Giorgetti/
Tralux and Freyssinet. A particular
difficulty was that the site was partially
contaminated as the result of earlier
use for railway infrastructure systems.
Despite the demanding parameters,
traffic is expected to flow along the
new freeway from 2014.
20 21
Illustration provided by Schroeder & Associés, Luxembourg