FoCus

THE PIANURA PADANA EMILIANA EARTHQUAKE

The paper reports the most common mechanisms of damage in churches, oratories and steeples as a result of the damage survey carried out by ENEA researchers in the areas of Emilia-Romagna region affected by the earthquake of May 2012, with particular reference to the historical centres. The surveys, mainly carried out immediately after the event, concerned the mere observation of the damage from the outside. Considering the great extent of the area affected, from the province of to those of Bolo- gna and , and the large number of churches in any Italian town, it is easy to imagine the amount of damage caused by this earthquake to religious, architectural and artistic heritage. The earthquake showed the high vulnerability of the religious heritage of Emilia-Romagna and, more generally, of the Ital- ian heritage, mostly located in areas of high seismicity, too often subject only to unsystematic interven- tions of repair, consolidation, renovation Damage to religious buildings due to the Pianura Padana Emiliana earthquake

■ Elena Candigliota, Bruno Carpani, Francesco Immordino, Alessandro Poggianti

n ENEA scientific team, composed by architects, number of structures which had been standing up Aconservators, engineers and geologists visit- after the first events eventually collapsed. Although ed several towns damaged by the Emilia-Romagna this work shows many buildings suffering serious earthquake during the period between the quakes damage to the exterior, many others churches and of May 20th and 29th,and in the post-May 29th event. bell towers without evident outside damage were The mission, which is currently ongoing, has been fo- declared unsafe.The present paper reports on a pre- cused on AEDES surveys of housing and commercial liminary qualitative survey exclusively made on the building at first, then several surveys were made to outside damage of the buildings affected. realize the level of damage to historic centres. Of the 2000 events occurred in the first month after the first main event, 7 had magnitudes greater or equal to 5.0 Territorial context and 27 magnitude values ranging between 4.0 and 5.0 [1]. Over time, these continuous shocks worsened Damage to the historical heritage covers a wide area (Fig. the historic monuments’ condition, so that a certain 1) from the to the east to the to the west, affecting some towns in terri- tory too. In , each city has several religious buildings, country churches, parish churches and cathedrals, towers ■ Elena Candigliota, Bruno Carpani, Francesco Immordino, Alessandro Poggianti and historical buildings, hence thinking about the exten- ENEA, Technical Unit for Seismic Engineering sion of the area affected it is easy to imagine the extent of damage to historical heritage. Furthermore, many of these

EAI Energia, Ambiente e Innovazione 4-5/2012 - Parte II 58 FIGURE1 FIGURE3 Source:G.Idone FIGURE2 Historiccentres ofSanFelicesulPanaro (photo1)andMirandola(photos2&3) Historic centreofMay20 ofFinaleEmiliaonthemorning Localization oftheepicentres ofthemainevents,cityvisitedandimagestheirmonumentsbecomesymbolthis earthquake (onimagebyGoogleEarth) th

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ancient buildings served as symbol places for people. quake of May 20th. The first photo of Figure 3 shows a Some of these are now completely destroyed, while oth- view of the square in front of the cathedral of San Fe- ers, albeit without evident damage, were declared unsafe lice sul Panaro, with the church damaged by repeated due to inside structural damage. shocks; photos 2 and 3 of the same figure show two Many historical buildings are located in high-risk areas; views of the historic centre of , the first there are whole towns of particular architectural value close to the cathedral whereas the second offers a with churches and palaces worth preserving. Unfortu- view of what remains of the church of San Francesco. nately, the Emilia-Romagna earthquake revealed, once again, the vulnerability of the historical Italian heritage. In Figure 1, the earthquakes epicentres are marked in The churches: centuries of history destroyed red, and the towns and places (in yellow and green, re- spectively) most affected are shown, each with the im- The earthquake damaged a very large number of age of the building become symbol of this earthquake. churches, maybe some hundreds, several of which The historic centres have lost their symbols, the plac- with major collapse, others with severe structural es that characterized the city – often meeting places damage and many still unusable; some of them were of the community – are now inaccessible and towns in poor condition, also many of those which had sur- show ghostly landscapes with piles of rubble and vived over the centuries through specific maintenance impassable fences (Figs. 2 & 3). Figure 2 shows the interventions, often in roofing. Examples considered historic centre of a few hours after the relevant to the type of damage are shown below.

FIGURE 4 Church of Natività, Rivara, (drawing by [2])

FIGURE 5 Church of Annunziata in Finale Emilia (photos 1&2); Church of S. Possidonio, San Possidonio (photos 3&4 )

EAI Energia, Ambiente e Innovazione 4-5/2012 - Parte II 60 num anddisaggregation oftheunderlying of part There have beencases of overturning ofthetympa- Emilia (photo3inFig. 6). shown inthechurch ofS. Francesco d’Assisiin Finale tos 1&2inFig. 6). Anothercaseof V shapedcrack is badly damaged church ofS. LucainCamurana (pho- crack andthecrumbling ofthemasonry, asinthe In othercases, thecollapseoccurred witha V shaped roelement (Figs. 4&5). crackhorizontal andthecollapseofentire mac- the tympanum. Insomecasesthedamage displays a of severe damage was theout-of-planecollapseof One ofthemostcommonfailure mechanismsincases Mechanisms ofthetopfaçade FIGURE7 FIGURE6 Church ofS.Luca,Camurana,(photos1&2),Church ofSanFrancescod’Assisi,FinaleEmilia(photo3)(drawingby[2]) Church ofSSFilippoeGiacomo,Cathedral,FinaleEmilia (photos 1&2),Church ofSantiSenesioeTeopompo Martiri,Medolla (photos 3&4) the tympanum (photos3&4inFig. 7). crackshorizontal inapositionlower thanthebaseof mechanism clear(photos1&2inFig. 7), or cases of insuchawaymasonry asnotto make thecollapse the interventions ofthefa turning churches isthedetachmentwithconsequentover- Another mechanismobserved inmany damaged mechanisms intheplan Overturning ofthefaçadeand to 3inFig. 12). Mainarda (Fig. 8). beginning The

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61 Focus FIGURE 8 Church of Natività della Beata Vergine Maria, (drawing by [2])

FIGURE 9 Church in Finale Emilia (photo 1); Church of Madonnina, Mirandola (photo 2); Church of SS. Rocco e Sebastiano (photo 3), Pieve di ; Church of S. Giovanni, (photo 4)

FIGURE 10 Church of the Madonnina, Mirandola (drawing by [2])

EAI Energia, Ambiente e Innovazione 4-5/2012 - Parte II 62 sional tierods (Fig. 12). isnowlapsed anditsdrum boundedwithprovi- Maggiore inPieve diCentohascompletely col- 11), whereas thedomeofchurch ofS. Maria ly visible cracks inthefront thesquare facing (Fig. The cause ofthecovering. it isnotpossible toseeany damage tothedomebe- Mirandola was seriouslydamaged, from theoutside of damage. oftheChurch drum The ofMadonninain figuresThe below show somecasesofthistypology Damage ofdomes,drumsandtiburium severitythe various levels ofthistypedamage. the churches –hasbeenobserved too. Figure 9shows trave oftheentrance through portal therose windows of with vertical cracks from thetympanum tothearchi- In plane, –often thedamage mechanismofthefaçade FIGURE12 FIGURE11 tiburium CathedralofS.MariaAssunta,Carpi(MO) Church ofS.MariaMaggiore, PievediCento(BO) ofthecathedral shows ofCarpi clear- the partial collapseofthe the partial lapsed aftertheevent ofMay 29 the earthquake ofMay 20 church ofS. Francesco, already severely damaged by of roof andvault. photoofFig. first The 15shows the was particularly damaged withthecollapse of structural parts. churchThe ofS. EgidioAbatein figuresThe below show collapses someimportant Structural collapses are oftenobserved (Fig. 13). and shearcracks inthewalls ofchapelsandsideaisles outer walls ofthechapelsfrom thewalls ofthechurch chapels ofseveral churches. detachmentofthe The shearcracksSignificant are present inthelateral Damage inthelateralchapels Already damaged by theearthquake ofMay 20 cathedral ofMirandola, withtheevent ofMay 29 EAI

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FIGURE 13 Church of S. Silvestro, Crevalcore (BO); Church of San Michele Arcangelo, (FE); Church of San Possidonio, San Possidonio (MO); (drawing by [2])

FIGURE 14 Church of Sant’Egidio Abate, Cavezzo (MO)

FIGURE 15 Church of S. Francesco (photo 1) and Cathedral (photo 2) in Mirandola; Church of Santa Caterina d’Alessandria, Rovereto di Novi (photo 3, by courtesy of P. Clemente)

EAI Energia, Ambiente e Innovazione 4-5/2012 - Parte II 64 ished, destroyed withbelfries orremoved by fire- declared unsafe, insomecases collapsedordemol- by theearthquake there are steeples damaged and In additiontothechurches, inmany citiesaffected Bell towersdamaged,collapsedordemolished inSanCarlo,of theOratorio Ghisilieri inSant’Agostino town. to recover –ofthechurch ofS. inBuonacompra, Martino and walls andpilesofrubble theperimeter Little isleft–except for causingthedeathofpriest. for has becomeinfamous inRoveretod’Alessandria diNovi, inNovi diModenatown, collapse inthebadly damaged church ofSantaCaterina FIGURE17 FIGURE16 Church ofS.Martino,Buonacompra,Cento(FE) OratorioGhisilieri,SanCarlo,Sant’Agostino(FE) ing damage, example duetoproblems for inthefounda- In somecasesthevulnerability by isinfluenced pre-exist- cells, etc.), orothervulnerable [4]. ones(belfries) ofslenderarchitecturaltop part elements (spiers, bell constraint, thepresence oftierods, thepresence inthe adjacent lowest structures able toprovide ahorizontal the degree ofthewalls, ofgripping thepresence of many factors, ofthestructure, suchastheslenderness heritage inItaly. Itsseismicbehaviour isdependenton earthquake, setofcultural constitutesanimportant typeofconstruction,This by particularly affected this interventions andmeasuresples inneedofsafety [3]. June, there were already reports of147church stee- ofcollapse. duetothehighrisk fighters Attheendof EAI

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4-5/2012 -ParteII 65 Focus tion (frequent cases in the area where inclined steeples removed from firefighters, others made safe. When are found) and to masonry in bad state of conservation. the steeple is placed in contact with other structures of The bell cells, with large openings, show serious shear lower height, this can cause local damage; an example cracks in the little columns, with sliding in the most se- is the bell tower of church in Cavezzo (Fig. 19). vere cases (Fig. 18). Some of them are disaggregated In the pictures in Fig. 20, two cases of severe damage under the action of the earthquake, others have been are reported; the first two photos show the bell tower

FIGURE 18 Steeples of: Cathedral, Mirandola (photos 1 & 2); Church of Sant’Egidio Abate, Cavezzo (photo 3); Church of Santa Caterina d’Alessandria, Rovereto di Novi, (photo 4, by courtesy of P. Clemente), (drawings by [2])

FIGURE 19 Steeple of Sant’Egidio Abate Church, Cavezzo (drawing by [2], photo 1 by Google maps)

FIGURE 20 Steeples of: Church of S. Martino, Buonacompra, Cento (FE), Church of S. Michele Arcangelo, Poggio Renatico (FE)

EAI Energia, Ambiente e Innovazione 4-5/2012 - Parte II 66 due to its serious structural problems.due toitsserious of itsbelltower, blown upasathreat topublic safety the church ofS. MicheleinPoggio Renaticodeprived molish thetower. lasttwoThe pictures inFig. 20show due totorsionalstress, thatledtothedecisionde- Photo 2shows thesevere sheartwo-level damage, of theChurch inBuonacompra thedemolition. during FIGURE22 FIGURE21

Church MatildicaandChurch oftheSanteGrazieinBondeno;Church ofSanBartolomeo,FinaleEmilia Church ofSantaCroce, Crevalcore (BO),(drawingby[2]) fall fromfall thechurch roofs, oftenwithmetalanchors gard totheturnover. Spiers, crucifixes, statuesthat which provides inre- alimitedstabilizingeffect ability duetotheirlow vertical loadandweight, elements, suchasstatuesandspears, withvulner- church andbelltowers façades toremove slender Firefighters intervened many timesonthetopof Hazard causedbynon-structuralelements EAI

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4-5/2012 -ParteII 67 Focus weak or too short, represent a danger often under- religious heritage of Emilia-Romagna and, more gen- estimated. erally, of the Italian cultural heritage, mostly located Many interventions have been made to put the bell in high-risk areas, too often subject to unsystematic cells in safety and, in some cases, disassemble them. interventions of repair, consolidation, renovation, or In other cases, overhang host bells have reported to local interventions carried out without analyzing shear cracks with displacements due to sliding along the global seismic behaviour of the structures. ● the shear cracks, as in the church of Santa Croce in Crevalcore (Fig. 22). Acknowledgements

Conclusions The authors thank the government of the visited municipalities for permission to access the confi ned areas, and the fi refi ghters of The Emilia-Romagna earthquake has destroyed a sig- Bondeno, Salerno, Rimini, Bologna, Parma for their presence dur- nificant part of the cultural heritage and the identity ing the visits, making sure that everything was done safely. A nice of the people living in this region. thank to Giuseppina Idone from Finale Emilia for the photos taken Many churches and bell towers were seriously dam- immediately after the event of May 20th. aged or collapsed, and too many of them are still unus- able. In the churches damage was frequently caused by the out-of-plane failure of the church façade and by the collapse of vaults and roof. Some of them are in bad [1] INGV, Report Terremoto in Pianura Padana Emiliana: alcuni dati state of general conservation, with poor masonry or dei due mesi di attività sismica 23 luglio wood roofs deteriorated, but there are also damaged http://ingvterremoti.wordpress.com churches that have received regular interventions of re- [2] Ministero per i Beni e le Attività Culturali, Dipartimento della Prote-

pair or consolidation. Some churches were apparently references zione Civile, Scheda per il rilievo del danno ai beni culturali: chiese. well preserved, as the cathedrals, which, in spite of the [3] Direzione Regionale per i Beni Culturali e Paesaggistici dell’Emilia various maintenance interventions, have been dam- Romagna, Comunicato stampa, “Emergenza terremoto e beni aged too. As regards the steeples, the most widespread culturali” - Aggiornamento 28 giugno 2012 damage occurred to bell cells that show serious shear [4] Ministero per i Beni e le Attività Culturali, Linee Guida per la va- cracks in the little columns. A type of damage, often lutazione e riduzione del rischio sismico del patrimonio culturale underestimated, concerned the fall of decorative ele- allineate alle nuove Norme tecniche per le costruzioni (DM 14 ments from the roof of churches and steeples. gennaio 2008), Circolare n. 26/2010. The earthquake showed the high vulnerability of the

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