Rail conquers the Alps

ceneri base tunnel | switzerland
dismantling of existing and temporary
structures. A contract to build the
1 km viaduct on the Lugano – Bellinzona
line was signed on December
16 2010 and work began on what
will be the centrepiece of the Nodo di
Camorino in early 2011. Construction
of the 400 m long viaduct for the Bellinzona
– Lugano track is due to commence
in 2012.
Southern portal works
To ensure that excavation of the running
tunnel over the PTL road tunnel
close to the southern portal at Vezia
was complete before the road opened, a
start was made on driving a 300 m section
in the opposite direction in spring
2010. Progress was aided by favourable
geology and co-operation from the local
community, so that the point where
the two tunnels cross was reached
ahead of schedule in July 2010.
By the end of 2010 the drive had
progressed beyond the critical area,
and in April 2011 the 300 m top section
for both single-track running
tunnels was fully excavated. Around
200 m of the lower part of the tunnel
has still to be excavated. Now in
progress is a 170 m section of open
cut that will be covered over later.
Several structures are required for
the next section, which runs in the
open as far as the Massagno tunnel.
These include a 650 m long retaining
wall above the SBB main line as well
as sound barriers. Being carried out
in conjunction with SBB, this work is
currently on schedule.
Construction of the Ceneri base
tunnel will absorb around SFr2∙5bn
of the SFr12∙3bn total cost of building
the Gotthard low-level corridor.
About SFr724m had been spent by
the end of 2010 and contracts signed
for the Ceneri Base Tunnel to date are
together worth SFr2∙1bn, keeping the
project within budget. l
The extensive
construction
site at Sigirino
includes the main
spoil disposal
area.
Railway Gazette International | July 2011 51