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Genoa. It would have prevented the collapse of the Morandi viaduct the completion of the refurbishment, the call for which was tendered by Aspi three months before the tragedy of August 14, 2018. The investigating judge Angela Nutini’s experts write it in black and white, responding to a specific question.
“The execution of research aimed at acquiring a cognitive picture more sensitive to the reality of the facts would have allowed us to highlight the anomaly at the top of stack 9; the execution of the intervention, as reported in the project documents, would have prevented the collapse with high probability ”. Giampaolo Rosati and Stefano Tubaro from the Milan Polytechnic, Massimo Losa and Renzo Valentini from the University of Pisa reconstruct the entire history of the Morandi Bridge in almost 500 pages of experience where construction defects arise and where over the years, above all, correct inspections and heavy maintenance interventions have been lacking, at least on the pile 9.
Morandi himself had repeatedly drawn attention to the risk of corrosion. particularly in a 1981 report in which the designer of the proposed bridge highlighted “the urgent need for restoration, so as not to compromise the static consistency of the work,” and proposed “a general restoration plan that referred, in particular, to the reintegration of reinforcement in the ribs of the damping covers, the restoration of weathered concrete surfaces. ”With regard in particular to the tie rods, the engineer Morandi stressed the need for a thorough and precise inspection,” in manual contact “from the control of steel through X-ray inspections” and then intervened
Mother For the experts, it is precisely the subsequent controls that have been lost, as well as the interventions. The Morandi collapsed due to the corrosion of the cables of a forestay on the south side of pile 9, which caused the rapid collapse of the entire structure (“The breakage of a tie causes the breaking of the symmetry that triggers the collapse” Explain the experts Corrosion was the consequence of poor maintenance which in turn stems from inadequate controls and inspections, this is the chain of causes according to the experts.
“The frequency of diagnostic inspections with direct inspection of the condition of the batteries and rooms was really modest. If we exclude the painstaking work done on Pila 11, which was already clearly deteriorated at the beginning of the 90s and in any case subjected to a heavy restoration, The scarcity of these inspections on piles 9 and 10 and relative stays in the approximately 25 years after the important works of 1993 is surprising.”.
Among other things, the experts emphasize, “These investigations, although carried out with logics that are not always congruent with each other and despite the scarcity of truly significant tests, have already revealed for many years the presence of injection defects in the pile room systems with a high probability of loss of design functionality envisaged by Prof. Morandi, precisely in relation to the protective function exercised by the injection against the possible corrosive risks of the Bridge cables ”.
Among the report papers a detail emerges, particularly disturbing. After a long interval of 18 years since the works in 1993, in 2009 we found in the documents available a new inspection of the sea entitled “Diagnostic investigations of the forestay at sea.
A first handwritten page of this document draws attention to, among other things, what will obviously result from the examination of the cement with a comment on Lot 9 declared “+ ugly than 10”, clarifies the reference to the results of the test itself “.
“Similar tests to those carried out in the period 90-92 were not carried out, or at least no trace is found, in particular direct investigations on the state of prestressing cables.”
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