Italy, a country with high seismic risk, is at the forefront of designing anti-earthquake systems. Yes, because despite the fact that there are no obligations for owners of private structures to adapt adequate anti-seismic measures as well as the fact that anti-seismic planning in not considered in projects and designs, with the consequences that we have seen in recent years, our country has produced and exported anti-seismic measures on innovative technologies for a long period of time.
Causes of failures to adapt anti-seismic measures
The reasons for the lack of adaptation for Italian buildings, even with the presence of adequate anti-seismic plans, are mainly due to the lack of political will to use public funds for preventive interventions. In fact, there are projects that have existed for decades now but have not been implemented.
A particular mention must go to resort and hotel communities who obstruct any initiatives of radical construction interventions that could, as they claim, alter the landscapes.
If this behavior, on the one hand, is understandable, on the other, it poses a serious threat to the safety of both residents and tourists.
Incentives for structures that adapt measures
A study that was brought out in 2015 states that approximately 44% of the national surface areas, corresponding to 36% of municipalities for a total of 2893 square km of nearly 132,000 total, are in areas classified as 1 and 2, namely, at seismic risk.
As previously mentioned, private buildings today are not subject to any type of requirement of adapting anti-seismic measures, but tax incentives totaling 65% are currently in place for homeowners in municipalities that are included in the list of the most vulnerable zones.
How to secure old buildings
The requirements for adapting seismic measures exist for buildings considered “strategic”, such as schools, hospitals, public buildings, libraries, and all structures used for public use for the community.
But how can we prevent earthquake damage in the many old buildings built without regulations?
Given that an old building built in traditional masonry that followed old construction criteria can never obtain a level of safety similar to that of modern buildings, built with different criteria and materials, such as steel, it is possible however to significantly improve their anti-seismic performance by carrying out a series of “seismic retrofit” strategies.
These strategies consist of modifying existing structures in order to make them more resistant and more deformable compared to the seismic activities.
The techniques consist of the application of simple slabs or the addition of steel supports and constraints between pillars and beams or in laying steel tendons to reinforce arches and support walls and all the most fragile and sensitive points of the buildings.
For buildings in reinforced concrete, and especially for those hosting many people like universities, nursing homes, and sports centers, there is the available addition of very resistant columns which, thanks to a coat of various composite materials including concrete, represents an effective isolation that is able to absorb seismic waves. For buildings in steel, instead, seismic dampers or dissipators are used, while for those over 10 floors there are more complex and expensive techniques such as the “slosh tank”, a technique that is conceptually identical to dampers.
Examples of anti-seismic reconstruction
New anti-seismic constructions in steel are slowly replacing constructions carried out in just masonry. This phenomenon is expanding not only in earthquake areas but in a much larger basin that also includes areas adjacent to high-risk areas, even in neutral areas. It is an important measure for the entire country that has discovered the simplicity and contained costs in these constructions. The areas where we can find some buildings made of structures in steel are Reggio Emilia, Udine, Molinella (Bo), Fabbrico (Re), Nola (Na), Bondeno (Fe); Reggiolo, Ravarino, Padova, Lucignano (Ar) Bellusco, Foligno, and Grosseto.