CAMPI FLEGREI: 9 THOUSAND BUILDINGS CENSORED FOR SEISMIC VULNERABILITY MAP

There are already 9 thousand buildings located in the Campi Flegrei area already analyzed by the Plinivs Study Center, which has been given the task of creating a map of seismic vulnerability. This was reported by Giulio Zuccaro, scientific director of the Plinivs Study Center and full professor of “Construction Science” at the Federico II University of Naples, on the occasion of the meeting on bradism and volcanic risk, organized today in Bacoli, in province of Naples, the Campania Region, the Civil Protection Department and the Municipality of Bacoli, to actively involve citizens and inform them about the relative seismic risk in the Campi Flegrei area. “We will quickly evaluate the seismic vulnerability on the basis of a total number of buildings of between 10,000 and 12,000 and in the end we will offer the Civil Protection and the Government the data and analyzes necessary to quantify the expenditure to secure the most vulnerable buildings ”, explains Zuccaro. “At the moment, in this first phase of preliminary evaluation foreseen by the Extraordinary Plan for the analysis of the vulnerability of the areas directly affected by the bradyseismic phenomenon, approximately 5000 buildings have been registered. We had already registered another 4,000 or so as Plinivs, before this operation,” he adds. In concert with the various authorities involved and with the coordination of the Department of National Civil Protection, the Plinivs Center is carrying out a mapping activity of the seismic vulnerability of the Campi Flegrei area most affected by the seismic swarms which in the recent past have particularly aroused the alarm in the population. “The activity is divided into two phases – explains Zuccaro – in this first phase the teams of surveyors – which are made up of technicians selected by the professional associations of Engineers, Architects and Surveyors, as well as by the Campania Region and by Specialized Volunteer Associations, appropriately trained – are collecting data through an external inspection on the typological-structural characteristics of the buildings in the area considered: from the vertical structural type (reinforced concrete or masonry), to the type of roofs, to the number of the floors in the presence of chains or curbs in the masonry in the presence of frames in one direction only for the reinforced concrete. or the percentage of openings and so on”. These typological-structural characteristics are related to the earthquake response of buildings. The data is collected via tablet with an open source app called qfield, appropriately customized with the Plinivs analysis card developed by the scientists. The survey technicians are also provided with a short information file (Cartis Compartment Sheet, developed by the Reluis Consortium) containing general information on the characteristics of the buildings and the historical development of the area, which supports them in the filing activities. “Based on this precious information and the data collected in the field we will assign a preliminary vulnerability class to each building (according to the EMS’98 macroseismic scale)”, underlines Zuccaro. “I say preliminary, and it is good to underline this, because by not entering the buildings the estimate of the degree of vulnerability of the individual building is naturally affected by uncertainty. On the other hand, our trend estimates – he continues – will allow us, with a reasonable margin of reliability, to provide a synthetic index of areal vulnerability (Very Low, Low, Medium, High) for each 250 by 250 m cell of an ideal grid with which we will divide the analyzed territory. This operation will allow us to identify where an in-depth analysis is most urgent. Therefore, although precise data is collected, an initial area vulnerability will be returned, precisely for the single cell”. At this point the second phase of the analysis of the Extraordinary Vulnerability Plan will take place and will be conducted by the ReLUIS Consortium, again under the coordination of the Department of Civil Protection. “Once the municipalities have received the maps with our areal assessments – specifies Zuccaro – each owner whose building falls in the most vulnerable classified areas will be able to request an in-depth vulnerability analysis for his individual building, allowing the technicians access to one’s home and an evaluation, still typological, but certainly more in-depth”. In a subsequent phase, the relevant authorities will evaluate the possibility of also acquiring requests from owners of properties outside the areas found to be most vulnerable. At the end of this entire process, it will be possible to provide a clearer picture of the vulnerability of the buildings in the area of ​​interest, the related intervention costs and a first mitigation plan developed by ReLUIS, for the determinations that the government and the competent authorities they will want to adopt. In all of this, discussion with local technicians is essential. “The training of the teams focused not only on the technical knowledge of the analysis tools but also on the knowledge that the local experts have accumulated over decades of experience: this heritage allows us and will allow us to better direct our efforts, making all the most effective and above all more efficient procedure”, concludes Zuccaro.