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the contribution of reLuis to the usabiLity assessment of schooL buiLdings foLLowing the 2016 centraL itaLy earthquake M. Di Ludovico1, A. Digrisolo2, F. Graziotti3, C. Moroni4, G. Baltzopoulos5, S. Biondi6, A. Borri7, S. Caprili8, C. Carocci9, A. Dall’Asta10, L. Dezi11, S. De Santis12, F. Di Fabio13, L. Di Sarno14, B. Ferracuti15,D. Ferretti16, G. Fiorentino12, U. Ianniruberto17, A. Mannella18, C. Mazzotti19, S. Podestà20, P. Riva21, A. Sandoli1, S. Silvestri19, L. Sorrentino22, A. Vignoli23, G. Magenes3, A. Masi2, A. Prota1, M. Dolce4,1, G. Manfredi1

1 Università degli Studi Federico II, Napoli, Italy2 Università della Basilicata, Potenza, Italy3 Università di Pavia, Italy4 Dipartimento della Protezione Civile, Roma, Italy5 CNR ITC, Napoli, Italy6 Università degli Studi “G. d’Annunzio”, Chieti, Italy7 Università di Perugia, Italy8 Università di Pisa, Italy9 Università degli Studi di Catania, Italy10 Università degli Studi di Camerino, Italy11 Università Politecnica delle Marche, Ancona, Italy12 Università degli Studi Roma Tre, Italy13 Università degli Studi dell’Aquila, Italy14 Università degli Studi del Sannio, Benevento, Italy15 Università degli Studi N. Cusano, Roma, Italy16 Università degli Studi di Parma, Italy17 Università Tor Vergata, Roma, Italy18 CNR ITC L’Aquila, Italy19 Università di Bologna, Italy20 Università di Genova, Italy21 Università degli Studi di Bergamo, Italy22 Università degli Studi “La Sapienza”, Roma, Italy23 Università degli Studi di Firenze, Italy

The recent earthquakes have shown the key role of post-earthquake inspections aimed at assessing the seismic safety and/or usability of buildings and the evaluation of the functionality of infrastructural systems. The technical inspections aims at minimizing the impact of the losses on citizens as fast as possible. In the immediate aftermath of the earthquake, the AeDES form (Baggio et al., 2007) is used to evaluate the safety conditions of buildings in order to enable people to return to their social and economic activities. The form can be filled based on the visual in situ inspection of the building, which represents the minimum structural unit with a significant impact on the people safety. The AeDES form is a first level survey form for post-earthquake damage and usability assessment; on May 5, 2011, the AeDES form, together with its field manual, has become the Italian official tool to assess ordinary buildings damaged by an earthquake (D.P.C.M., 2011).

One of the main objectives of the Department of Civil Protection (DPC) in the aftermath of the earthquake is the assessment of damage on public and school buildings and the definition of a sound strategy to quickly repair and strengthen the ones with minor structural damage only. In the post-earthquake emergency of recent central Italy earthquake, which occurred on August 24, 2016 at 03:36 AM local time, the total amount of surveys carried out by technicians of several institutions involved 637 public buildings. In particular, post-earthquake inspections were carried out on 538 school buildings with 374 buildings, corresponding to 70% of the dataset, assessed as usable. The remaining buildings resulted usable only after short-term countermeasures or partially usable (buildings with limited or no structural damage but with severe nonstructural damage, about 24%), or unusable (high structural or nonstructural risk, high external or geotechnical risk, about 6%).

The ReLUIS (i.e. Laboratories University Network of seismic engineering) consortium, which is a Competence Centre of the Department of Civil Protection (DPC), has been strongly involved in the post-earthquake emergency of central Italy earthquake. The Consortium

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support to DPC consisted of technical surveys of public buildings, with emphasis on school buildings, hospitals, strategic infrastructures and sites with historical and monumental heritage. Researchers from several Italian universities have contributed to the surveys in order to reduce social hardship. Usability and damage assessment has been carried out by teams of surveyors made up of two experts of a proper list of ReLUIS researchers to be mobilized in accordance with emergency procedures in case of earthquake.

The activity of ReLUIS consortium started on August 24, 2016 under the supervision of DPC at second floor of DiComaC (Direction of Command and Control), located at Largo Graziosi, Rieti, Italy. The usability assessment of school and public buildings were carried out from August 29 to September 21 in an area near the borders of the Umbria, Lazio, Abruzzo and Marche regions. They involved surveys on 160 schools, for a total of 253 structures, and 47 public buildings, for a total of 54 structures. In particular, 80 school buildings were inspected in Abruzzi region, 51 school buildings all over the Lazio region, 18 and 7 school buildings in the regions of Marche and Umbria, respectively. The school buildings mostly consisted of masonry and reinforced concrete (RC) structures (230 out of 253 structures, 79 masonry structures and 151 RC structures, respectively). From the data collected filling the AeDES forms, it was

(a) (b) (c)Fig. 1 – Construction age (a), number of storeys (b), and average storey surface (c) of RC and masonry school structures.

Fig. 2 – Masonry school building “Dante”: front view (a); damage to the masonry wall (b).(a) (b)

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possible to determine the construction age, number of storeys, and average storey surface of masonry and RC structures, see Fig. 1. The graphs show that masonry structures have been almost built before 1971 while RC ones are related to periods after 1961; most of the structures have 1 or 2 storeys and an average storey surface in the range 170-899 m2.

In terms of usability assessment, about 59% of the masonry structures were assessed with usability rating A (i.e. usable building, no significant damage), about 22% B (i.e. no significant damage on structural members) and about 19% E (i.e. significant damage on both structural and non-structural elements), see Fig. 2. On the RC framed structures the percentage of usable structures was greater than that of masonry ones, about 78% of structures with usability rating A. The most common damage was detected on non-structural members (i.e. partitions and ceiling), see Fig. 3. The usability rating B and E involved 18% and 4% of structures, respectively.

(a) (b)Fig. 3 – RC school Building “Pascal”: drawing of plan (a); damage to infills (b).

ReferencesBaggio C, Bernardini A, Colozza R, Di Pasquale G, Dolce M, Goretti A, Martinelli A, Orsini G, Papa F, Zuccaro

G, Pinto AV, Taucer F (2007) Field manual for post-earthquake damage and safety assessment and short term countermeasures (AeDES).

Decree of the President of the Council of Ministers D.P.C.M. May,5 2011, “Approval of the tool to assess the damages, the emergency countermeasures and usability of ordinary buildings in the post-seismic emergency and relevant manual”. (In Italian), “Approvazione del modello per il rilevamento dei danni, pronto intervento e agibilità per edifici ordinari nell’emergenza post-sismica e del relativo manuale di compilazione”. Pubblicata nella Gazzetta Ufficiale n. 113, Supplemento Ordinario n.123 , 17 Maggio 2011.

nationaL civiL protection organization and technicaL activities in the 2016 amatrice earthquake (centraL itaLy) Italian Department of Civil ProtectionPresidency of the Council of Ministers, Italy

On August 24, 2016, at 03:36 local time, a Ml 6.0 earthquake (Mw 6.0) struck an extensive portion of the Apennines chain in central Italy. This event and the following seismic sequence occurred at the boundaries of four regions, namely Abruzzo, Lazio, Marche and Umbria, roughly between the towns of Norcia and Amatrice. The epicentre was located near Accumoli, a village in the Lazio region.

According to the Italian law 225/1992, the emergency response was coordinated by the Department of Civil Protection (DPC), within the general framework provided by the components and operational structures of the National Civil Protection Service.

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The victims were 298, all caused by the buildings collapsed during the main shock, whereas the injured people hospitalized have been 390. The victims’ figure is comparable to that of the 2009 L’Aquila earthquake (309), although in the current case the affected area is a rural, mountainous zone, while in 2009 the city of L’Aquila, i.e., the Abruzzo Region capital, was strongly damaged being on top of the activated seismogenic fault. The relatively high number of victims caused by the Amatrice earthquake can be ascribed to the low quality of the building stock and to the presence of many tourists, due to the holidays period and the imminence of a local festival.

For the first population assistance, at the beginning tent camps solutions were adopted, with more than 30 camps plus a number of individual tents (to support economic activities in rural areas) and other kinds of structures, for about a thousand tents. Assisted population reached a maximum number of more than 4800 people (4807 on September 5, 2016), whereas the tent availability was for more than 8600 people (8602 on September 5, 2016). The number of people in tents goes on reducing through times; the tent camps need to be dismissed before the incoming cold season, and people is moved to hotels available along the Adriatic sea coast or to usable houses in the neighboring of their villages. Caravans are used to support economic activities in rural areas (livestock, etc.).

Due to the long lapse of time typically required in Italy to complete the repair and reconstruction process, especially in the historical centres, medium/long-term temporary housing arrangement is needed to lodge homeless families for some years. Taking into account the environmental and socio-economic characteristics of the epicentral area, the solution adopted encompasses small independent houses, reusable and made of recyclable materials at the end of their lifetime, with good comfort standards and size. The Government is planning to complete their deployment in 7 months from the main shock. Alternative solution is the monetary contribution for autonomous housing arrangement.

A big effort was also required in order to rapidly provide suitable temporary solutions for unusable school buildings, due to the imminence of the scholar year start after the event. Actually different solutions were adopted, depending on the specific damage state of the school buildings, in relation to the possibility to rapidly repair them, or on the availability of other undamaged schools for temporary arrangements. In the meanwhile, temporary modules or tent schools have been arranged, according to the time needed for the rehabilitation or reconstruction of the damaged schools.

In addition to the search and rescue and to the population assistance activities, many technical activities have been carried out to support the civil protection management of the emergency phase.

The National DPC owns and manages the RAN-DPC strong-motion network (code IT). This accelerometric network is formed by more than 560 permanent digital stations, whose data are teletransmitted to the DPC monitoring centre. The RAN-DPC is able to guarantee a dense cover of all zones of the national territory characterized by high seismic hazard, with an instrumental density proportional to the hazard level. All the data recorded by the network are published on http://ran.protezionecivile.it/. Concerning the main shock, the measured peak ground acceleration (PGA) in the epicentral area, at the Amatrice site (ca. 10 km from the epicentre), reached 452.60 cm/s2 on the horizontal component and 197.62 cm/s2 on the vertical component, while at the Arquata del Tronto site (ca. 14 km from the epicentre), the PGA reached 448.17 cm/s2 on the horizontal component and 396.80 cm/s2 on the vertical component.

Also the Seismic Observatory of the Structures (OSS-DPC) is a national permanent network owned and managed by the National DPC; it monitors the seismic response of more than 150 structures, including schools, hospitals, town halls, bridges, and a dam. The OSS-DPC allows a remote estimation being made in few minutes of the damage suffered by the monitored structures after an earthquake and, by analogy, of the damage possibly suffered by similar structures in the same area. The nearest monitored structure was a hospital at Norcia, 14 km far from the

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epicentre, while a total of 37 monitoring systems were triggered within 200 km distance from the epicentre. All the data recorded by the network are published on http://www.mot1.it/.

The coordination that DPC carries out on the activities performed by academic and research institutions develops in the framework of the so-called “Competence Centres”, which support civil protection technical needs. Competence Centres are institutions which provide services, information, data, elaborations, technical and scientific contributions for specific topics, to share the best practices in risk assessment and management. The main Competence Centres for seismic risk are the following research institutes and academic consortia:

INGV - seismic surveillance, seismological research projects; emergency scientific-technical support;

ReLUIS - earthquake engineering research projects; emergency scientific-technical support;

EUCENTRE - earthquake engineering research projects; emergency scientific-technical support;

CNR (IGAG, IRPI, IREA) - microzonation, landslides surveys, satellite inteferometric analysis; emergency scientific-technical support;

ISPRA - geological mapping, induced geological effects; emergency scientific-technical support;

ENEA - rubble management; emergency scientific-technical support;ASI - satellite data.The activities of the Competence Centres that are present in DICOMAC have been organized

as follows:INGV is responsible for the seismic monitoring and leads the geological field surveys

concerning tectonic features;ISPRA leads the geological field surveys concerning landslides, in particular affecting roads

and buildings;CNR leads the geological field surveys concerning microzonation;ENEA is especially involved in the rubble management;EUCENTRE contributes to the damage assessment and supports the tent camps

management;ReLUIS contributes to the damage assessment of school and strategic buildings and of

cultural heritage, providing the coordination of its expert teams.Researchers from all the institutions and universities, who are willing to contribute to the

different topics, work under the general management of the leading Competence Centre.Moreover, ASI, INGV and CNR-IREA acquired and elaborated satellite images to provide

the National Service of Civil Protection with coseismic deformation maps.Concerning the overall damage, immediately after the main shock occurrence, macroseismic

teams including DPC officers, CNR-IGAG and INGV researchers carried out a number of field surveys to assign a macroseismic intensity MCS to each municipality and locality of the epicentral area. This quick evaluation of the damage in the epicentral area is aimed at a first definition of the zone where the damage is from moderate to high. Results dated September 15, 2016 show values up to intensity X MCS, reaching in few cases the degree X-XI MCS, that means from “completely destructive” to “catastrophic”. More than 291 localities in 76 municipalities have been surveyed and the related intensities assigned.

A huge effort is still ongoing to carry out the surveys for damage and post-earthquake usability assessment of public and private buildings, managed by the DPC. It is actually performed by experts coming from different Regions, by researchers from DPC Competence Centres (ReLUIS and EUCENTRE), and by engineers, architects and surveyors coordinated through the related national professional Councils. At the moment, more than 63,000 requests for inspections on private buildings have been made, and more than 25,000 inspections have already been carried out on private and public buildings (among which 667 school buildings

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and 106 other public buildings). About 50% of the inspected buildings resulted immediately usable, whereas 30% of them resulted unusable due to heavy damage.

Finally, the coordination of the activities related to the damage and usability assessment, as well as to the immediate safety countermeasures of the mobile cultural heritage and the heritage buildings deserves to be mentioned for its complexity and peculiarity. This activity, especially addressed to the safeguard of churches, palaces and monumental buildings, such as municipality towers, is performed in strict collaboration with the Ministry of Cultural Heritage and the Firefighters Corps, and with the technical-scientific support of ReLUIS.