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Contractors World - International Vol 3 No 8
A Technical and Logistical Construction
Challenge
The project is a huge technical and logistical challenge for all
involved, including MEVA’s formwork engineers. The schedule is
tight due to weather conditions – it snows even in early autumn
and there is virtually no space to move or store building
material and heavy machinery.
The equipment has to be hauled from the base camp at 800
m above sea level to the building sites at 1700 m and 2500 m. To
do so, a special construction cable car and an access tunnel with a
funicular railway equipped with traction sprocket on the ground are
used.
Concrete works are in progress on the inlet and outlet gallery on
Lake Mutt. The walls, 12 m high, are being poured using single and
double-sided applications of the Meva support frame STB 450 and
Mammut 350 wall formwork. Exceptionally high concrete pressure
required back anchoring instead of standard props.
The underground caverns for the power plant equipment are
156
m long, up to 30 m wide and up to 53 m high. Here too, difficult
topography, cramped Alpine conditions, little storage space on the
construction sites especially inside the mountain as well as high
concrete pressure and the need to move the formwork units from
one pour to the next, require considerable effort in planning and
logistics to keep the tight schedule.
Innovative transport solutions
The new facility will have a pumping capacity and turbine output
of 1000 MW respectively. During the construction of the plant,
Scheuerle SPMTs from Viktor Baumann GmbH & Co. KG have been
used. These were transported to the tunnel by means of the
construction cableway. SPMTs “floating” in the Alps.
Construction of this mega expansion project is a logistical
challenge. Only the Tierfehd installation area at the end of
the Glarnerland is accessible by road and rail. From this point
onwards, all the required machinery, construction materials and
site personnel are transported up the mountain by means of the
cableway.
From Tierfehd, the so-called “Access Gallery 1” was built in order
to reach the caverns inside the mountain. The tunnel was realised
with a 160 metre long tunnel boring machine weighing 1,500 t
All equipment had to be taken to the site by cable car,
re-assembled and then carried through the tunnels.
Specialist equipment was needed to transport the large
TBMs and other equipment.