Page 37 - Industrial Plant 2020

Pictures 20a, 20b

Pictures 21, 22 - Balance system on Berger beam No. 8

take place in conditions of maximum safety and The external vertical load, equal to about 300 tons,
stability. was applied by means of two Fagioli Strand Jacks
positioned onto the cantilever beam of the pile,
contrasted at the base by a counterweight of adequate
Analysis of the structure, tests mass, in order to satisfy the balance verification. The
and engineering solutions load of each strand jack was distributed in an isostatic
way on no. 2 beams by means of a metal carpentry
In order to identify the conditions of post-incidental structure (pictures 21 and 22)
stress and the residual resistant capacities, the entire Another example of re-balancing load is the one
work was modeled on the finished elements and applied to the cantilever bridge sections of the large
calculated in all its temporal phases from construction Eastern piles no. 10 and no. 11. No. 3 pairs of Fagioli
to collapse up to the representation of all the lifting towers equipped with strand jacks were erected,
intermediate steps of the planned dismantling two for pile 10 and one for pile 11, each 50 m high,
operations. Detailed studies were executed, with a positioned onto concrete foundations. The lifting
comparison with the available data of the original towers, had the function of temporarily supporting the
project. three cantilever beams of the piles from below, in the
Fagioli proceeded with repeated load tests, carried out event of structural collapse of the stays (See picture
by detecting the deformations of the structure at the 23).
passage of remote controlled heavy vehicles (SPMT), The lifting towers, had the function of temporarily
simulating the future loads to which the structures supporting the three cantilever beams of the piles from
would have been stressed during the dismantling below, in the event of structural collapse of the stays.
phases. (Pictures 20a, 20b) The support beams also applied a vertical load
One of the most crucial aspect was the dismantling of upwards of about 600 tons to ensure a re-balancing of
the berger beam no. 8 (the first one), due to its the loads. The lattice lifting towers and beams were
unbalanced condition created by the loss of the therefore designed for two load combinations: the first
adjacent beam and pile. called “service”, with loads imposed by the hydraulic
The re-balancing operation was executed by applying system on the concrete structure equal to 600 tons per
external forces at the support of the collapsed pad. pair of towers and the second called “extra-heavy” with

IndustrIal Plants - May 2020
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