ROME (ITALPRESS) – “The definitive project of the bridge over the Strait is complete and very in-depth, it does not lack any “seismic green light” or “certification” as reported in today’s article in La Repubblica. INGV researchers collaborated with the General Contractor Eurolink both in the drafting phase of the 2011 definitive project and in the recent update for the further definition in detail of the geoseismotectonic framework, not only through bibliographic analyses, but also through on-site surveys, geoseismic prospecting , geognostic surveys. The Earth Sciences Department of the Sapienza University of Rome, commissioned by Eurolink for in-depth analysis, recently stipulated a scientific agreement with INGV for the updating of the geoseismotectonic framework. Furthermore, the Strait of Messina has recently entered into a technical-scientific collaboration agreement with INGV for the management of the geotechnical monitoring network and for the exchange of scientific data and information. As part of these collaborations, Stretto di Messina confirms its willingness to illustrate in detail what is foreseen in the project for the seismic theme”. This is what we read in a note from the Strait of Messina Society.
“It is useful to remember – continues the note – that the preparation and approval of the definitive project are the result of a complex procedure which, starting from the project drawn up and updated by Eurolink (the main partners are Webuild, IHI, Sacyr, Cowi Massimo specialist in the construction of suspension bridges in the world), involved for the in-depth checks, in addition to the Technical Management of the Strait of Messina, the Parsons Transportation Group as Project Management Consultant, Edison Next as environmental monitor and an Expert Panel as a support body for the technical-specialist High Surveillance activities, composed of four top representatives in the disciplines of aerodynamics-aeroelastic, seismic, geotechnical and environmental. The Company has also acquired a favorable opinion from the Scientific Committee, an autonomous and independent body. The complex articulation of this procedure is not reflected at an Italian or foreign level”.
“For the Cannitello fault – continues the Stretto Society – it is reiterated that it is not seismogenic, i.e. capable of producing seismic shaking of the ground. This certainty derives from extensive studies conducted with field investigations in the area. Much more in-depth studies and investigations than those present in the admittedly bibliographic ISPRA-ITHACA cataloging of active faults on the national territory which suffers from significant deficiencies and is not uniformly accepted by experts. The identification of the faults is not supported in most cases by investigations that reconstruct their geometry in depth, as is the case for the faults described in the INGV database, which does not contain the faults indicated by the Hon. Bonelli”.
Furthermore, “the Cannitello fault lacks a surface expression univocally recognized by researchers who are experts in the subject. Furthermore, from the detailed cores carried out for the preparation of the definitive project, no indication of dislocation which occurred in recent times along the same Cannitello fault was found, such as to involve surface sediments which could be investigated by means of ‘paleoseismological trenches’.
“The definition of the seismic action for the Bridge project has been the subject of great attention since the initial stages of the design studies, considering the particularity of the Strait of Messina in terms of geoseismotectonic problems. As is known, the energy released by an earthquake in a site (magnitude) is closely linked to the dimensions of the tectonic structures (faults) present there and the studies carried out for the Strait of Messina have concluded that the seismogenic structures present can give rise to seismic events of magnitude not exceeding magnitude 7.1 Richter. The Bridge over the Strait was therefore designed to resist, with a safe margin, the strongest reliable earthquake in the Strait area, i.e. an event similar to the Messina earthquake of 1908, classified by studies published in the most authoritative magazines in the sector, as a extremely rare event whose probability of occurrence will remain very low for several centuries (the return period has in fact been determined to be 1500-2000 years)”, underlines the Strait of Messina Society.
“If the Bridge were hit by such a rare earthquake it would not suffer any damage, as its structures were designed to remain in the elastic range, maintaining further margins of resistance even beyond the expected threshold – continues the note -. The project of the Bridge over the Strait is drawn up according to seismic resistance criteria and parameters which are specific and more severe than those envisaged by the current Construction Regulations of 2018 (Ministerial Decree of 17 January 2018, in short NTC18)”.
“In other words – concludes the note -, the Bridge over the Strait has intrinsic characteristics and is designed with seismic actions and criteria that make it one of the most seismically safe structures in Italy and in the world, based on the most modern state of the technical art international science”.
photo agency Fotogramma.
(ITALPRESS).
