The solution adopted by the structural
Transportation and installation
road. The new bridge was placed
point of view for foundation consists of
One of the crucial aspects in the
above the adjacent road bridge. For
a massive reinforced concrete abut-
construction of a bridge is transport
the launch two cranes for lifting and a
ment, which, with its mass, has the
and assembly.
third for centering have been
purpose of re-center toward the lower
The walkway, of about 40 meters, is
employed (Figure 11). At the end para-
the pressure curve to the taxes that is
made of a single ashlar by G.M.I. s.r.l.
pets were mounted with, the corru-
expressed when the load accidental
and was transported by truck-
gated sheet and the deck.
acts with its maximum intensity. The
mounted platform by Fagioli S.p.A.
The operation of launching lasted a
reaction that arises, however, is equal
(Figure 10).
total of about thirty minutes, during
to about 2400 kN at the ultimate limit
state for each of the two lower arches.
This remarkable thrust exerted on the
abutment has main component almost
horizontal due to the very lowered
geometry of the structure.
To contain this force a group of 17
micro valev poles (12 and 5 to the
bank to the river bed) with a diameter
of 240 mm and armed with Tubfix
88.9×6.3 mm2 and inclined at 30
degrees to the vertical arrangement
have adopted. In this condition, the
resultant thrust is always maintained
within the angle described by the
piling.
The study of the transmission of forces
which the platform
from the steel desk to group of poles,
was lowered on all
via the abutment, has been accom-
four seats.
plished with the use of strut & tie meth-
Testing operations
ods.
were performed by
To ensure optimal comfort in operat-
4 E m m e
S e r v i c e
ing conditions it has been made
S.p.A.. The testing
numerous sensitivity analyzes, inves-
load was simulated
tigating different conditions of crowd
with the use of water
present on the footbridge and verifying
m a t t r e s s e s
a n d
the natural frequencies of vibration of
d e f o r m a t i o n s
i n
the deck, both longitudinally and
c e n t e r l i n e
w e r e
The bridge was carried out 15 km
transversely. Moreover, because of
measured with electronic theodolite.
away from the site and it has trans-
the joint between the lower arches and
The results of the tests carried out
ported from the worksite in less than
the shoulder, it was necessary to
during the testing phase of the work,
two hours.
conduct in-depth studies on the ther-
have fully comforted the results
During transport, the thrust of the arcs
mal expansion of the deck and its
obtained from finite element analysis.
has been eliminated by the use of tie
combination with other actions agents
rods in tensioned strands.
simultaneously, such as the compact
The operation of launching was
crowd and the action of a cross wind.
performed by temporarily blocking the
11
Issue 71 December 2013
2013 71

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