L’Aquila, 31 March 2009: ten years ago (by Massimiliano Stucchi)

Translated by google translate, reviewed

On March 31, 2009, an earthquake expert meeting convened by the Head of Civil Protection, G. Bertolaso, took place in L’Aquila; the consequences of it were the subject of countless discussions, articles, volumes, and a famous trial.
It is not my intention to take up those arguments, which still see a flourishing of interventions, as always not completely updated.
I just want to remember how it came to that meeting.

A sequence of earthquakes had been going on for months in the L’Aquila area, causing fear and insecurity in the population. On the morning of March 29 there was an M3.8 event in the Sulmona area (60 km far away from L’Aquila). Shortly after – as reported by “Il Tempo” on March 30th:

Schermata 2019-03-31 alle 15.08.42

the technician of INAF (National Institute of Astrophysics) G. Giuliani called the Mayor of Sulmona, F. Federico, who was in Rome, announcing “the loading of a seismic swarm that would have resulted in an earthquake of higher intensity than the first”: in Sulmona, evidently, 60 km far away from L’Aquila.


Later, he also called the Civil Protection of Sulmona, the Police Station and the Municipal Police. The Mayor also recalled that affair in an intervention at the tv show “Porta a Porta” after the earthquake (8 April 2009), recently posted by the group of the “M6.5 Project” of Sulmona


While the Mayor racked his brains in the dilemma about what to do, the news ended up circulating anyway causing panic, aided also by a van announcing the impending earthquake with a megaphone.
It should be remembered that, in the previous weeks, people wearing megaphones were driving around the city of L’Aquila inviting them to leave their homes in anticipation of an imminent destructive earthquake. According to the quotation marks of Libero (7 April 2009) G. Giuliani himself claimed those initiatives

Schermata 2019-03-31 alle 15.12.06

On March 30th the Press Agency ANSA issued the following statement of the Regional Civil Protection:

Object: Civil Protection: no other shocks are foreseen in the Aquila area.
(ANSA) – Pescara, MARCH 30 – In the area of L’Aquila “no other earthquakes of any intensity are foreseen”. This was announced by the permanent [regional] civil protection operations room, highlighting that “all the information disseminated of other content is to be considered false and without any foundation” …

Perhaps the communiqué was intended to state that any prediction was to be considered unfounded, but the text itself could suggest a different reading.
In the press I found no trace of the release itself or any reactions. Only a couple of years later, by means of an interception of a telephone call between G. Bertolaso and the regional Responsible for Civil Protection D. Stati, which was made known only during the trial, we learned that it was precisely that statement to determine, in addition to the obvious resentment of Bertolaso, his decision to organize an expert meeting in L’Aquila, open for local officials.

In the afternoon of the same March 30, an M4.0 earthquake occurred in the L’Aquila area. The Mayor M. Cialente ordered the closure of the schools to carry out checks. Meanwhile, Carabinieri and Police from Sulmona denounced G. Giuliani for procured alarm.

On March 31,  late afternoon, the expert meeting took place. It should be emphasized that the media presented the meeting for what it really was, namely a “meeting of experts from the Great Risks Commission (F. Barberi, E. Boschi, GM Calvi, C. Eva)”, which was expected to be attended also by the deputy head of the Civil Protection (B. De Bernardinis), the Civil Protection Regional Responsible D. States and  the L’Aquila Mayor M. Cialente. Also other local and national officials, the director of the INGV National Earthquake Center G. Selvaggi, invited by E. Boschi, and some “self-invited” persons attended the meeting.

In current use the denomination of the meeting was simplified in “meeting of the Great Risks Commission (CGR)“; however, if such, its convocation should have followed different and well-defined procedures.
Later, the Public Prosecutor and the Judge of the first instance trial, in the respective trial documents, climbed on the mirrors to show that the meeting itself had to be considered in all respects as a meeting of the Commission, to apply its responsibilities accordingly. This interpretation was forcefully and clearly denied by the Judgment of Appeal, confirmed by the Supreme Court.

The results of the meeting are known and include:

  • the (un)famous [glass of wine] tv interview with B. De Bernardinis, released before the meeting itself but later broadcast, and which was therefore considered by many listeners as a summary of the meeting itself. Incidentally, most of the victims’ relatives referred to this interview as a reassuring message, and for this reason B. De Bernardinis was finally sentenced;
  • the press conference by F. Barberi, B. De Bernardinis, M. Cialente and D. Stati after the meeting, of which only the video is kept, without audio.

In addition, youtube preserves a video of a declaration of D. Stati released on March 31, before the meeting, which proposes completely correct arguments (except for the reference to the denomination “meeting of the CGR”)


The minutes of the meeting, long discussed with respect to many scientific, ethical, operational, aspects, had no impact on the behavior of the population as it was released after the earthquake of 6 April.

After the 31 March meeting the Mayor M. Cialente asked the National Government for the declaration of “state of emergency”.
There are no particularly significant traces in the local press regarding the results of the expert meeting and the request of the Mayor in the following days. A detailed analysis of the press can be found in

“Media e traduzione delle conoscenze scientifiche prima del terremoto del 2009” by A. Amato and F. Galadini, in ” Terremoti, comunicazione, diritto “, edited by A. Amato, A. Cerase and F. Galadini, 2015, F. Angeli.

An interesting analysis of how the population lived the period before the earthquake of 6 April 2009, and in particular the last week, can be found in “Sul significato della rassicurazione. L’Aquila una settimana prima del terremoto” (On the meaning of reassurance. L’Aquila one week before the earthquake)”, by V. Valentini


unfortunately incomplete online. The reference to the management of schools is interesting, among other things:

“The mayor ordered the closure of all the school buildings, so as to allow the municipality’s technicians to carry out the tests and verify the viability of the structures. Except for a couple, all the other schools, even those where the shocks of the last few weeks had opened small cracks in the walls, detached the skirting boards or pieces of plaster from the walls, were reopened two days later. Our biology professor, too, had given her a positive response: Palazzo Quinzi, the seat of our high school “Domenico Cotugno”, was a structure of proven stability, having in fact brilliantly survived the catastrophic earthquake of 1703.”

Under the same title there are also interesting comments:


A few days later, on 6 April, the destructive earthquake occurred.
It is still surprising today to see, in the press and in the videos, the enormous space occupied by the question of the alleged, unheeded predictions of G. Giuliani, against the almost total disinterest in the problem of the vulnerability of collapsed buildings. Moreover, the whole first degree trial was tackled around the problem of missed forecasting, hidden under the guise of the lack or inadequate assessment of seismic risk by the experts. The vulnerability of the buildings was considered an inevitable fact, and the reference to the need for its reduction – made by some of the participants to the meeting – was branded by the judge as “as obvious as it was useless“.

This post, and actually the entire blog, is dedicated to colleagues who, in addition to continuing to do their jobs, from 2010 to 2015 went through three levels of judgment.
For six of them the Court of Appeal ruled that “the fact [of which they were accused] does not exist“, a decision confirmed by the Supreme Court.
Among them Enzo Boschi, who recently passed away.


Material for understanding the events related to the so called “L’Aquila” trial, among several others, can be found in:



Stucchi, R. Pinho, M. Cocco, 2016. After the L’Aquila Trial. Seismological Research Letters (2016) 87 (3): 591-596. https://doi.org/10.1785/0220150261


Zamberletti e la gestione del post-terremoto del Friuli (1976-1977)

Di recente è scomparso Giuseppe Zamberletti, considerato con buona ragione il padre della Protezione Civile in Italia. Vogliamo ricordarlo qui pubblicando un estratto da un suo articolo, pubblicato in inglese su un numero speciale del Bollettino di Geofisica Teorica e Applicata (Pdf).

È interessante leggere questo bilancio dell’intervento dello Stato relativo ai terremoti del 1976 in Friuli, scritto dal principale protagonista. In particolare, colpisce la descrizione della situazione alla data finale dell’intervento diretto dello Stato, meno di un anno dopo il primo terremoto: il confronto con gli eventi recenti è impietoso.



Earthquake risk education: a partial statement for Italy (interview with Romano Camassi)

Translated by Google Translate, revised

Romano Camassi is a researcher at INGV (Department of Bologna). ‘Seismologist’ of eccentric training (a degree in Pedagogy, a thesis in modern history), engaged for more than three decades in historical research on earthquakes. Co-author of the main catalogues of Italian earthquakes. For over 15 years he has dedicated a part of his work to seismic risk education projects.

After every destructive earthquake, in Italy as elsewhere, the need to improve the earthquake education the seismic risk education, or even to introduce it at various levels, is recalled. It is true that, albeit not generally, there have been and there are several initiatives in this area. Can you give us an idea, and maybe refer to some publication that summarizes them?
It is true: after every major earthquake, everyone invokes more information, preparation, risk education in schools, information campaigns, exercises. More: it is frequent that at every change of minister (or undersecretary), or just before its decadence, announcements are made, protocols are signed, even, which then have no real following: of this there are very recent examples. The initiatives that in the last decades have set themselves, in various ways, the objective of education to seismic risk have been innumerable, impossible to make an inventory (nor is there a publication that has done so). I refer to initiatives of scientific dissemination on the earthquake, training for schools, awareness of the population. Many local administrations – individual municipalities, provinces, regions – sometimes in a totally impromptu manner, other times in a more organized and continuous way, have promoted initiatives of this kind. The same have been done by individual civil protection associations, or national orders: I remember a beautiful pamphlet of the National Council of Architects, distributed in September 2001 by “Famiglia Cristiana”, or even recent initiatives by geologists and engineers. Could not mention them all.
The problem is that, in many cases (not all), they were short-term initiatives, which often responded to temporary needs, in which the visibility of the promoter was to prevail. Everything is useful, many accomplished things have certainly been of good quality: but the problem is that of sensitization, of risk education, is an essential, fundamental part of that fundamental task of the National Service of Civil Protection summarized by the term, which seems to me almost worn out, of prevention. How can there be prevention, that is to say precise choices, actions that reduce the risk, without people being aware, informed, ‘activated’ to make those choices, every day? And I do not speak so much about the correct behaviours in an emergency, on which we often stop to stop the attention, but of the choices that reduce immediately or in time the vulnerability (not structural and structural) of the environment in which we live. Continua a leggere

Come ridurre una volta per tutte il rischio sismico in Italia (di Patrizia Feletig e Enzo Boschi)

In un articolo sul Corriere della Sera lunedì 19 marzo, Milena Gabanelli scrive di copertura assicurativa contro i terremoti ipotizzando un intervento dello Stato come avviene in alcuni paesi esteri, quale alternativa finanziariamente più sostenibile rispetto al risarcimento finanziato con varie “tasse sulla disgrazia”.
Giusto, anche perché i costi per la ricostruzione inseguono una parabola incontrollabile considerato l’aumento della concentrazione di ricchezza per metro quadro. Ma soprattutto con la diffusione di un sistema di copertura assicurativa, gli edifici verrebbero per forza sottoposti a collaudi strutturali. Come dovrebbe essere per attuare la famosa “carta d’identità del fabbricato” rimasta lettera morta. Mentre negli altri paesi europei un fabbricato senza una validazione strutturale non ottiene l’allacciamento di luce, acqua, ecc. in Italia, ci si limita alla verifica formale della sola certificazione energetica del fabbricato in occasione di vendita o locazione!

Una polizza potrebbe allora diventare un incentivo alla prevenzione con la responsabilizzazione delle istituzioni come testimonia la copertura da rischio contro catastrofi naturali francese a partecipazione mista stato-mercato in vigore dal 1982 e incresciosamente non citato nell’articolo! Per non discriminare tra aree ad alto rischio e quelle poco esposte, il premio è fisso, varia invece la franchigia a secondo se il comune dove risiede il fabbricato ha adottato provvedimenti come dei lavori di contenimento di corsi d’acqua o adeguamenti alle norme antisismiche, per contenere la propria esposizione ad alluvioni, terremoti, eruzioni vulcaniche.
Considerando gli otto terremoti più forti che hanno colpito la Penisola negli ultimi 42 anni, non si può non convenire che una polizza contro il sisma sia una misura più che necessaria. Deplorevole che se ne discuta da un quarto di secolo (il primo disegno di legge risale al 1993) e sebbene a volte la proposta sia anche riuscita a spuntare in qualche Finanziaria, è stata velocemente stralciata come fosse l’ennesima gabella impossibile da fare ingoiare al popolo dei proprietari di case.

Ma proprio la politica è doppiamente colpevole.
Primo per il suo irresponsabile fatalismo a ritenere di poter continuare ribaltare sull’iniziativa del singolo la messa in sicurezza delle abitazioni recentemente “incentivata” con la detraibilità fiscale. Il sisma bonus è un lodevole strumento fortemente voluto da Ermete Realacci ma la cui efficacia si scontra con il cronico vizio dei lavori edili in nero.
Secondo, se il 70% del patrimonio immobiliare di un territorio sismico come l’Italia, risulta inadeguato a scosse di medie magnitudo, è anche grazie alla sconsideratezza con la quale gli amministratori locali spesso, non hanno vietato l’edificabilità in aree a rischio. Casamicciola è solo l’ultimo dei tanti casi. Lo stesso vale quando nelle nuove costruzioni o negli interventi di riqualificazione, non hanno fatto rispettare le leggi sulla prevenzione sismica.
Il sindaco di Amatrice è indagato proprio per il crollo di una palazzina che nel 2009 venne evacuata a seguito delle scosse dell’Aquila e, in seguito degli interventi di ripristino, dichiarata dal comune agibile salvo franare la notte del 24 agosto 2016 causando la morte dei suoi abitanti.

Decisamente scellerata poi è la piaga dei condoni, la cui madre di tutte le regolarizzazioni dell’abusivismo è la legge 47 del 1985 del governo Berlusconi. Una sanatoria per la quale grande fu la protesta affinché almeno i territori dichiarati sismici fossero esclusi da questa delittuosa fittizia idoneità assegnata per default all’edificazione precaria, fuori norma, illecita. Sì delittuoso, perché la natura è matrigna ma le vittime dei terremoti sono attribuibili all’abusivismo, alle irregolarità, alla sciatteria, che hanno molti corresponsabili. In un tragico intreccio dove i colpevoli magari finiscono anche per essere loro stessi vittime delle loro azioni o omissioni. Ma questa non è giustizia.

Masonry buildings to the test of Italian earthquakes (interview with Guido Magenes)

…..This comparison with medicine fits very well, there are really many similarities between the work of the technician who has to understand what to do with an existing building and that of the doctor who tries to make a diagnosis and to find a correct therapy for a patient…..

versione italiana qui: Gli edifici in muratura alla prova dei terremoti italiani (colloquio con Guido Magenes)

Guido Magenes is Professor of Structural Engineering at the University of Pavia and IUSS Pavia. He is also the coordinator of the Masonry Structures division of the EUCENTRE Foundation. His area of ​​greatest competence is the seismic behavior of masonry buildings and for this reason he has also participated and still participates in numerous Italian and European technical-regulatory committees.
We discussed with him the behavior of masonry buildings in Italy, with particular reference to what happened during the last earthquakes.

1. The earthquakes of 2016 have determined a sequence of shaking that has put a strain on the buildings of the affected area, especially those in masonry. The effects seen in the field are very different: next to the buildings already heavily damaged by the earthquake of August 24th, there are others that have seen their condition worsen after the shock in October, and others that seem not to have suffered serious damage in all the sequence. Do you have an explanation for this?

 The masonry buildings stock in our country has very variable characteristics and qualities, depending on the era of construction, the materials and construction criteria that were used, the type and architectural form (ordinary buildings or churches, palaces, towers, etc … ), any maintenance and reinforcement or tampering and weakening processes that may have occurred over time. Certainly there are recurrent types of problems, but the diversity of the behavior of masonry buildings, apart from the severity of the shaking (or the different ground motion in the various sites), is  essentially due to this great variability.
Therefore, in the specific case of the seismic sequence of central Italy, which involved a very large area and a considerable variety of buildings, we observed what you say: from the recently built building, of a few storeys, in great part or fully compliant with the modern design and construction criteria, which did not show significant damage, to historic buildings with large spans and heights, such as churches, which tend to be more vulnerable and have therefore suffered great damage and collapse because of their dimensions, geometric ratios and their structural organization. In many if not most cases, also the poor quality of the materials has further worsened the situation.

2. In all the municipalities affected, seismic regulations were in force, with various years of enforcement (the extremes are represented by Amatrice and Accumoli, 1927, and Arquata del Tronto, 1984). The distribution of the damage does not seem to be influenced by these differences; is there a reason?Schermata 2018-02-05 alle 20.44.50Not all regulations are equally effective: a 1927 standard is obviously very different, under many points of view, from a rule of the 1980s or the years 2000s and, as I mentioned above, the buildings built in compliance with the latest rules behaved generally well (constructed with artificial blocks and mortars of good strength, or even stone buildings demolished and rebuilt with good quality mortars). Therefore, I would not say that the distribution of damage is not at all influenced by the regulatory context. It depends on what was written in the norm and how many buildings were built or repaired or reinforced after the introduction of the norm (in the affected centers a significant percentage of the buildings had been built before the seismic regulations that you mentioned).

The rules and design criteria are not necessarily born perfect and they have to adjust, to evolve based on the experience of earthquakes. For example, it is only fifteen or twenty years that we began to recognize that certain types of interventions proposed and widely applied after the earthquakes of Friuli and Basilicata can be harmful or plainly ineffective (think of the infamous reinforced concrete ring beams “in breccia” inserted at intermediate floors in an existing building in stone masonry: in Umbria-Marche ’97 we have begun to see its shortcomings).
In the areas in which the presence of a regulation or a seismic classification seems to have had no effect, it must also be taken into account that the on-site control of the quality of construction and execution, in particular for masonry buildings, were inexistent or ineffective at least until the more recent regulations. The use of a very bad mortar is a recurrent element in many of the old masonry buildings collapsed or damaged in the last seismic sequence. In centers like Accumoli and Amatrice it seems that even where interventions had been carried out on buildings, replacing old floors, for example, or inserting some ties, the problem of poor quality of the masonry had been greatly overlooked, ultimately making the interventions ineffective. We can add that a large part of those areas suffered a considerable depopulation since the early 1900s, with inevitable consequences on the maintenance of buildings, which has led to an increase in widespread vulnerability.

Then there are some particular cases in which historical norms and more recent norms seem to have had a positive effect. Take Norcia’s example: without going into the details of the measurements of the characteristics of the ground motion, it is a fact that Norcia in the last sequence suffered strong shaking, comparable to those of Amatrice and Accumoli but with a much lower damage to buildings. In the history of Norcia there were two very significant events that may have affected  the response of the buildings in the 2016 sequence, one before and one following the 1962 regulations. In 1859 a strong earthquake caused numerous collapses and victims in some areas of the historical center, and following this the Papal State issued a quite effective regulation that gave a series of provisions for repairs and reconstructions: on geometry, in particular on the maximum height of the buildings (two floors), on the construction details, on the quality of materials. Then, in 1979 there was another earthquake in Valnerina, after which other parts of the historic center were damaged, followed by a series of systematic reinforcement measures on many buildings. In many of these buildings the reinforcement of the vertical walls (even with the controversial technique of the reinforced plaster) has remedied one of the main elements of vulnerability, i.e. the weakness/poor quality of the masonry walls. If for a moment we leave aside the elements that can go against the use of reinforced plaster (such as the durability of the intervention), and we see it simply as a technique that has remedied a factor of great vulnerability, we can say that for Norcia there has been a positive combined effect of pre-modern and more recent regional regulations, stemming from the direct experience of seismic events.

3. Let’s  talk about seismic regulations and in particular of their engineering aspects. We hear that they have changed a lot over time, and that perhaps the non-recent ones were not entirely effective. Is it true, and if so why?

As for the engineering component of the regulation, what we now know about the structural and seismic behavior of buildings, in masonry and other structural systems, is the result of a continuous evolution through the experience of earthquakes in Italy and in other parts of the world. In Italy the engineering study of masonry buildings has resumed life, after decades of almost total abandonment, after the 1976 earthquake in Friuli. The first norms/codes that give indications on how to “calculate” a masonry building in Italy date back to the early 80s (to “calculate” I mean “quantitatively assess the level of safety”). Although “calculation” is not the only component of the design, this fact gives the idea of ​​how only the very recent rules have a technical-scientific basis aligned with current knowledge. I would like to say that the absence of calculation in a project does not necessarily imply that the building is unsafe: in the past we followed geometric and constructive rules of an empirical type, based on the experience and intuition of the mechanical behavior, although not explicated in detailed calculations. Even today, for the design of a simple and regular masonry building, it is possible to follow codified geometrical and constructive rules that avoid detailed or complex calculations, but still achieve an adequate level of safety.
The experience of the earthquakes of Irpinia, Umbria-Marche, until the most recent in central Italy, have been a continuous test and a source of knowledge. For example, as mentioned in my answer to the previous question, the Umbria-Marche 1997 earthquake, besides highlighting the great vulnerability of churches and of certain historical structures, has been an important test for strengthening criteria and techniques on masonry buildings that were proposed and developed following the Italian earthquakes of the late ’70s, showing how some techniques are not very effective or can even be harmful if applied indiscriminately and without awareness

To conclude my answer with my opinion on current technical standards, I think that as regards the design of new buildings we are really at a very advanced state of progress, which effectively attains the levels of safety that today are considered adequate. I think there are more uncertainties on the assessment and strengthening of existing buildings, even if it is not so much a regulatory problem but rather of scientific knowledge and of the correct identification of strategies and techniques for the intervention. It is certainly easier to design and build a seismic-resistant building from scratch, than to assess and intervene on an existing building.

4. How much – and how – does the construction and detailing of a building affect its seismic safety, beyond the design?

The question gives me the opportunity to dwell a little more on what is meant by “design”, which is something different from the mere “calculation”. The design includes all aspects of overall conception, choice and organization of the structure, choice of materials and construction techniques (with the awareness of how they can and should be executed in situ), performance verification calculations in terms of safety against collapse and of satisfactory behavior in normal operation, prescriptions on construction details. In modern seismic design it is also necessary to take into account, when relevant, the seismic response of the non-structural parts of the construction. There must also be a check that what is prescribed in the design is actually implemented during construction.

The calculation is therefore only a component of the design. It is interesting to note that most of the existing masonry buildings were not calculated, at least as we understand structural calculations now. The first Italian national technical standard on masonry constructions with a sufficiently detailed description of the calculations for the structural verification dates back to 1987. Technical standards with indications for the seismic calculation, were issued after the earthquake of Friuli 1976 and in subsequent times. Before those norms, a technical literature and manuals existed, with reference to the principles of mechanics, as well as a building tradition. I would like to clarify that here I am talking about regulations/norms that tell how to calculate the resistance of a masonry building, subject to seismic or non-seismic actions. Just to give an example, the Royal Decree of 1909 (post earthquake of Messina), a historical milestone as regards seismic regulations, gives criteria to define the seismic action, gives constructive and geometric rules but does not tell how to calculate the resistance (the capacity, according to the modern technical language) of a masonry building.

The constructive tradition based on the respect of the “rule of art” always had in mind the importance of construction details, of the quality of the materials, of how the building is built, and this has allowed and allows well-constructed buildings (but not “calculated”, i.e. non-engineered) to withstand even very violent seismic shocks. In modern buildings, the compliance during construction site of the execution rules, the control of the quality of the materials, is equally important, although this holds for masonry as for the other types of construction. The sensitivity of the structure to constructional defects is a function of the level of robustness of the structural system. A masonry box-like construction, strongly hyperstatic (i.e. where the number of resistant elements is higher than the minimum necessary to ensure equilibrium under the applied loads) could in principle be less sensitive to construction defects than an isostatic prefabricated structure (i.e. where the number of resistant elements is just equal to the minimum necessary to ensure equilibrium under the applied loads, so that the failure of a single element is sufficient to generate a collapse). Obviously we are talking about local defects and not generalized over the whole construction. If all materials are poor quality throughout the construction, then it is a great problem, but not necessarily a masonry building is more sensitive to such problem than, say, a reinforced concrete frame, in which also defects in the reinforcement detailing are possible (for instance in beam-column joints or in lap splices or in anchorage of rebars and so forth).

5. Many surveyors in post-earthquake reconnaissance activities have found traces of interventions that have allegedly weakened the structures. Do you agree?

In post-earthquake surveys, carried out quickly in emergency conditions, it is not always possible to clearly understand the history of the building and what changes have been made, in what time and modalities, but sometimes it is clear that some modifications to the construction have been detrimental to safety. Often these are interventions that were made with total unawareness of the effects on structural safety and purely for the purpose of use and redistribution of space. In other cases, more rare, there are also interventions made with “structural” purposes, perhaps even with the idea of ​​achieving an increase in safety, but which in reality were harmful or ineffective. A classic example, often discussed in the literature also on the basis of the Italian post-earthquake recognitions from Umbria-Marche 1997 onwards, is the insertion of new, rigid and heavy structural elements (such as the replacement of a wooden floor with a reinforced concrete floor) in a building with very weak masonry (for example masonry made of irregular stones with poor mortar), without the masonry being properly consolidated. There was a period, following the earthquakes of Friuli and Irpinia, where much emphasis was given to the fact that rigid diaphragms (i.e. the floors and roofs) increase the hyperstaticity, hence the robustness of the construction and the so-called “box behaviour”, by which engineers tried to replicate in existing structures something that is relatively simple to implement, and whose effects are well controllable, in new constructions, but which in an existing construction has great problems of practical implementation (particularly in the connection between new elements and existing elements) and of potentially negative structural effects (increase of stresses in an already weak masonry). It is important to note that the effectiveness of the interventions is tested by earthquakes that take place in later times, and in some areas of central Italy it has been possible to draw indications of this kind. In the earthquake of Umbria-Marche in 1997 it was possible to observe various problematic situations in buildings where the existing floors had been replaced by heavier and more rigid slabs.

Allow me, however, to add a further comment. From the scientific point of view, the fact that an intervention is “harmful” or weakens the structure compared to the non-intervention is verifiable experimentally only if there is a confirmation of what would happen to the building without intervening and what would happen following the intervention . This type of comparison in the vast majority of practical cases  is not possible, except for very fortunate cases of almost identical buildings built on the same ground where one was reinforced and the other not, or that were reinforced with different methods. Or through laboratory experiments, comparing specimens tested on a “shaking table” (earthquake simulator). So, in general I am always rather skeptical of interpretations given on the basis of purely visual rapid surveys, without the necessary in-depth study of the details and without a quantitative analysis carried out in a competent and thorough manner.
I can say (and I know that many colleagues have a similar opinion) that in many cases seen in central Italy the collapse of the construction would have taken place regardless of the type of floor, light or heavy, rigid or flexible, by virtue of the bad quality of the masonry, which appeared to be the main problem.

6. How did the repetition of the strong shocks play in the aggravation of the damage (where it occurred)? Is it something that is implicitly foreseen, and taken care of, by the seismic norms? On the other hand, how do you explain the numerous cases of almost total absence of damage?

The repeated shaking aggravates the damage, the more the damage caused by the previous shock is serious. It seems a rather obvious statement, but essentially it is what happens. For example, if a first shock on a masonry building generates only a few cracks, not very wide and of a certain type (for example horizontal cracks, which close after the shock due to selfweight), the building has not lost much of its resistance; so if it is subjected to repeated shaking, less intense than the first shock, it is possible that the damage does not get too much worse, and if it is subjected to a shaking stronger than the first shock it will have a resistance equal to or slightly less than it would have if the first shock had not been there. On the other hand, if a shock leads to the development of diagonal cracks (so-called “shear cracks”) or vertical cracks with spalling, the damaged part has lost a significant portion of its ability to resist and subsequent repeated shaking can lead to progressive degradation and collapse, even if the subsequent shocks suffered by the building, individually, are perhaps less strong than the first one. This is something visible and reproducible also in the laboratory.

That said, there are types of constructions and structural elements that are more or less sensitive to the repetition of the seismic action. When seismic engineers speak of “ductility” of the structure or of a mechanism, they also refer to the ability of a structure to resist repeated loading cycles well beyond the threshold of the first crack or the first visible damage, without reaching collapse. A well-designed modern reinforced concrete construction is a structure of this type, for example. Unreinforced masonry, on the other hand, is more susceptible to damage induced by the repetition of loading cycles beyond cracking. As a consequence, existing masonry buildings, once damaged by a first shock, are more vulnerable to subsequent shocks. On the other hand, if the first shock does not cause significant damage, the safety of the building remains, in most cases, more or less unchanged and this accounts for the fact that numerous masonry constructions have also resisted repeated shocks. Unfortunately, sometimes the damage may not be clearly visible. Damage in masonry originates in the form of micro-cracks (not visible to the naked eye) which then develop into macro-cracks. If in a laboratory test a sample of masonry is pushed to a condition very close to the onset of the macro-cracks but the load is removed just before they develop, it may happen that in a subsequent loading phase the macro-cracks develop at a load level lower than that achieved in the first phase. It may therefore happen that a building that has resisted a violent shock without apparent damage is visibly damaged by a subsequent shock less violent than the first.

You ask me if the behavior of the structure under repeated shocks is implicitly considered in the seismic norms: the answer is yes, at least for certain aspects. For example, the respect of certain construction details in reinforced concrete and the application of certain rules in the sizing of the sections and of the reinforcement have this purpose: to make the structure less susceptible to damage under repeated actions. Moreover, less ductile structures, such as those in unreinforced masonry, are designed with higher seismic “loads” than the more ductile structures, also to compensate their greater susceptibility to degradation due to repeated action. However, there are some aspects of the problem of resistance and accumulation of damage under repeated shaking that remain to be explored and are still cutting-edge research topics. In particular, if it is true that theoretical models are becoming available to assess how the risk (i.e. the probability of collapse or damage) evolves in a building or a group of buildings as time passes and seismic shocks occur, these models must still be refined to give results that are quantitatively reliable.

7. It seems to me that the variety of masonry buildings, at least in Italy, is really large: so large that knowing them requires an approach similar to that of medicine, where each case has its own peculiarities. Therefore, there is perhaps no universal therapy, every case requires a specific care: is it correct? And if so, given that the building and construction techniques and quality of different areas of the Apennines (and others) are similar to those of the areas affected in 2016, should a similar destruction be expected to repeat again?

This comparison with medicine fits very well, there are really many similarities between the work of the technician who has to understand what to do with an existing building and that of the doctor who tries to make a diagnosis and to find a correct therapy for a patient. From the technical point of view there is no universal therapy and no (good) doctor would be able to apply a therapeutic protocol without the anamnesis, the objective examination, any necessary instrumental or laboratory tests and the formulation of a diagnosis (which tells us what is the patient’s disease / health status, and then defines what he needs, the therapy). The good technician follows a similar path to arrive at the evaluation of safety and possible hypotheses of intervention (or not intervention). Of course it is possible and necessary, as is the case for medicine and public health, to define strategies and policies for prioritization and allocation of resources to ensure that the overall seismic risk in our country decreases. Certainly, where the old buildings have not been subject to maintenance, or just to aesthetic and functional maintenance without structural reinforcement, we can expect destructions similar to those seen in 2016 on the occasion of future earthquakes of comparable magnitude. This applies to both public and private buildings.

Where instead we have intervened or will intervene in a conscious way, paying attention to the problem of seismic safety, the level of damage to be expected is  lower, as the experience of the past earthquakes teaches us.
Allow me to conclude this interview with some non-purely technical engineering comments. The possibility of reducing the seismic risk in Italy depends on many factors, ranging from how politics govern the problem of natural hazards, to how technicians, individually and collectively, interact and communicate with politics, to how the presence of risk is communicated to the population, to how, as a consequence,  the citizen makes his choices when he buys or takes decisions to maintain a property. In my opinion it is necessary to progressively evolve into a system in which the citizen recognizes that it is in his own interest to pursue a higher seismic safety, initially spending a little more, because he will have a return in the future not only in terms of safety but also of economic benefit, for example in the market value of his property. The “Sismabonus” initiative is certainly a first step in this direction, but other steps will have to be taken. The goal, certainly not easy to achieve, should be that the safety level of a building has a clear and recognized economic market value, and I think this would work for both the small owner and for real estate investors. I know that some are scared by this perspective, but personally I think that, at least for what concerns privately owned real estate and facilities, there are no other ways to achieve, within a few decades, a substantial and widespread reduction of seismic risk in Italy.


Sopra i nostri piedi – Above our feet (di M. Stucchi)

(english version below)

Questo titolo prende manifestamente spunto da quello del bellissimo volume di Alessandro Amato: “Sotto i nostri piedi”, arrivato alla seconda ristampa (con integrazione sulla sequenza sismica del 2016 in Centro Italia) e in distribuzione nelle edicole con “Le Scienze”, dopo che l’autore è stato finalista del Premio Letterario Galileo 2017.

Il volume di Amato tratta di sismologia, previsione dei terremoti, aspetti scientifici, culturali e politici. I sismologi si occupano di descrivere, nel miglior modo possibile, come si generano i terremoti e come le onde sismiche si propagano nella Terra; il tutto, appunto, sotto i nostri piedi. Alcuni sismologi si occupano, in una specie di terra di confine dove operano anche alcuni ingegneri, di descrivere come le onde sismiche interagiscono con la superficie del terreno e con gli edifici: quindi, di fornire la descrizione del moto del suolo nelle modalità più adatte all’ingegneria sismica. Questa terra di confine si chiama in inglese “engineering seismology”, le cui possibili traduzioni italiane suonano tutte male. Una Sezione dell’INGV, quella di Milano, si occupa in prevalenza di questi aspetti ed era denominata “Sismologia Applicata”; tempo fa aveva ricercato una collaborazione stretta, istituzionale, con la Fondazione Eucentre di Pavia, alla cui costituzione INGV aveva peraltro contribuito come socio fondatore, sia pure con poco merito e ancor meno investimento. Continua a leggere

Ischia, Torre Annunziata, perception of risk and magnitude (M. Stucchi)

This is a quick translation from the Italian version, with the help of Google. Sorry for the imperfect English. Thanks to Ina Cecic for her prompt review.

Italy was beginning to remember the anniversary of Amatrice’s earthquake (August 24, 2016) in different ways, of course, when the Ischia earthquake dramatically reopened the problem of so-called prevention, of which so much has been said and spoken about.
On the morning of the 21st, the day of the earthquake, Minister Del Rio had spoken at the Rimini (Comunione and Liberazione) meeting. Del Rio is a Minister of a couple of governments I do not like, but among the many is a person I trust. After (unfortunately) reproposing a “pearl” that must have remained in his pocket since the earthquakes of 2012 (“the area was not known as seismic“, ignoring the work done by the Emilia and Romagna Region to delay as much as possible the affiliation to a seismic zone of much of its territory), he recalled, illustrated and defended the so-called “sismabonus” and the initiatives of “Casa Italia”, also reminding that the solution of the problems is not for tomorrow. Stimulated by some interlocutors, he also pushed further on, talking about the necessity of the “building dossier” and of demolitions, where necessary. Ohibò! Continua a leggere

Earthquakes and Great Risks: a blog 2014-2015 (M. Stucchi)


“Earthquakes and Great Risks” è stato, a partire dall’ottobre 2014, il cugino di lingua inglese di questo blog. E’ nato soprattutto per fornire al lettore internazionale la versione “corretta” dei fatti legati al processo “Grandi Rischi”, a fronte di una diffusione impressionante di informazioni e interpretazioni che possiamo definire inesatte – nel migliore dei casi.
Il blog ha contenuto una ventina di post, parte dei quali – a cura di G. Cavallo e di M. Stucchi – dedicati a fare chiarezza su quanto sopra, e parte a fornire una cronaca, quasi in diretta, del processo d’Appello.
E’ stato letto da qualche migliaia di lettori provenienti da 98 nazioni (vedi  mappa).

Schermata 2017-08-02 alle 15.44.13

Rileggendolo oggi, a parte le imprecisioni e gli inevitabili errori di lingua, si ha l’impressione che abbia fornito una analisi attenta e circostanziata – forse più che in questo stesso blog – dei principali “pitfalls” riguardanti il processo sulla base dei quali sono stati costruiti numerosi articoli internazionali, anche su riviste “peer reviewed”, scritti anche da illustri colleghi. Questo sforzo è stato riconosciuto da diversi lettori.

Per non perdere questi contenuti il blog, che verrà chiuso a breve, è stato  salvato nella sezione “English material”.

La vicenda processuale alla prova del romanzo. Luci e ombre del volume “La causalità psichica nei reati colposi” di Marco Billi (di Cecilia Valbonesi)

Cecilia Valbonesi è Dottore di ricerca in Diritto penale presso l’Università degli Studi di Firenze e Avvocato del Foro di Firenze. Per motivi scientifici ha seguito e commentato il cosiddetto  processo Grandi Rischi. In ultimo si veda “Terremoti colposi e terremoto della colpa: riflessioni a margine  della sentenza “Grandi Rischi”, in Rivista Italiana di Diritto e Procedura Penale, 2016, n. 3, p. 1498.
Le abbiamo chiesto un commento al volume – uscito lo scorso marzo – del Giudice di primo grado del processo stesso, Marco Billi.

Di recente, il copioso panorama letterario sulla vicenda giudiziaria relativa alle responsabilità della c.d. Commissione Grandi Rischi si è arricchito di un nuovo volume dal titolo “La causalità psichica nei reati colposi”.
L’ambizioso progetto reca la firma del Giudice estensore della prima sentenza di merito (Tribunale di L’Aquila, 22/10/2012, n. 380) che, accogliendo pienamente le prospettazioni accusatorie, ha condannato per omicidio colposo plurimo e lesioni colpose i sette scienziati i quali, a suo giudizio, “componevano la Commissione Grandi Rischi” della Protezione civile nella riunione del 31 marzo 2009. The L’Aquila Seven  furono ritenuti responsabili di quella scorretta valutazione e informazione sul rischio sismico che avrebbe cagionato la morte ed il ferimento di 29 cittadini (13 secondo la Corte d’Appello e la Corte di Cassazione)  rimasti schiacciati sotto le macerie delle proprie case. Continua a leggere