NPTV

SWrucWural Analysis of HisWorical ConsWrucWions – Jerzy Jasieńko (ed) © 2012 DPNH ProcławH PolandH ISSN 0860-2395H ISBN 978-83-7125-216-7

pTorCTroAi fkTbosbkTflk AT Teb ebAanrAoTbop lc BAkK lc mloTrGAi goao Appleton1, sasco Appleton2, Margarida cerreira da oochaP, oui mombo4 ABpToACT qhe aiã çf íhis aríicle is íç describe íhe sírucíural iníerveníiçn cçãéleíed aí íhe head çffice çf íhe mçríuguese Ceníral BankI “Bancç de mçríugal”I lçcaíed in íhe hisíçrical dçwníçwn area çf iisbçn – íhe “Baixa mçãbalina” – a rkbpCl candidaíe. qhe headquaríers includes U buildings and a churchI éurchased çver íiãe and ãçdified by íhe bank during íhe éasí NRM years. qhe çriginal sírucíure çf íhe buildingsI knçwn as “mçãbaline síyle”I aééeared in iisbçn afíer íhe earíhquake çf NTRR. qhis síyle is characíerized by íhe sysíeãaíic iãéleãeníaíiçn çf aníiJseisãic sírucíures wiíh ãasçnry and íiãber eleãenís. jany çf íhe wççden reinfçrced iníeriçr walls were reélaced by irçn cçluãnsI and sçãe flççrs by ãasçnry brick arches suééçríed by síeel beaãs; bçíh çriginal and éçsíeriçr sírucíures were ãainíained during íhe currení reírçfiííing. auring íhe iníerveníiçnsI sçãe NUíh ceníury sírucíures were fçund and éreserved. Aí íhe churchI all íhe dissçnaní cçncreíe eleãenís receníly builí by íhe Bank were reãçved and íhe building was seisãically reinfçrced and cçnveríed iníç a ãuseuã. Aí íhe ceníre çf íhe blçckI archaeçlçgical fieldwçrk uncçvered a éiece çf íhe ciíy wall frçã íhe NPíh ceníury. qhis discçvery fçrced íhe design íeaã íç adaéí íhe érçjecí in çrder íç éreserve íhis sírucíure. qhe sírucíural analysisI develçéed wiíh glçbal Pa and lçcal analyíical ãçdelsI aiãed íç ãainíain all valuable sírucíures – alíhçugh sçãe çf íhe leasí iãéçríaní were deeély ãçdified – íç iãérçve éerfçrãance íç veríical and hçrizçníal acíiçns and íç cçãély wiíh all éresení burçcçde requireãenís. heywords: oetrofitting, peismic behaviour, ptructural intervention NK fkTolarCTflk

qhe head çffice çf íhe mçríuguese Ceníral Bank is lçcaíed in a quaríer çf “Baixa mçãbalina”I beíween oua dç CçãérciçI oua de paç guliãçI oua dç lurç and mraça dç junicíéiç.

cigK N mçríuguese ceníral bank quaríer

N Civil bngineerI AOmI jçaç.aééleíçn@aOé.éí O Civil bngineerI AOmI vascç.aééleíçn@aOé.éí P Civil bngineerI AOmI ãargarida.rçcha@aOé.éí 4 Civil bngineerI AOmI rui.éçãbç@aOé.éí

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qhe ciíy blçck was rebuilí çver íhe ruins çf íhe éreceding ciíy afíer íhe widely desírucíive NTRR iisbçn earíhquakeI using sysíeãaíic aníiJseisãic sírucíures frçã íhe NUíh ceníury knçwn as “daiçla mçãbalina”. qhese sírucíures are characíerized by íhe rigçrçus çrganizaíiçn çf íhe sírucíural íiãber and ãasçnry eleãenís in íhe buildings. qhe headquaríers includes U buildings and a church íhaí were éurchased gradually by íhe mçríuguese Ceníral Bank çver íhe cçurse çf íhe éasí ORM years. lriginally íhe bank çwned çnly çne building çn íhe blçckI buí çver íiãe íhe çíher buildings were acquired and subjecíed íç a cçnversiçn. cçr íhis reasçn ãany çf íhe çriginal “éçãbalinç” sírucíures were reélaced by íhe evçlving cçnsírucíiçn íechniques used çver íhe éasí ORM years. qhe çriginal sírucíures were cçããçnly reélaced wiíhW irçn sírucíuresI síeel beaãs wiíh sãall ãasçnry brick vaulísI and cçncreíe and síeel sírucíures. qhe changes éerfçrãed çver íhe years significaníly endangered íhe seisãic éerfçrãance çf íhese sírucíuresI nçí çnly because çf íhe reãçval çf íhe érinciéal braced wallsI buí alsç due íç íhe increased weighí çf íhe new sçluíiçns. qhe érinciéal aiã çf íhis iníerveníiçn was íç EiF iãérçve íhe seisãic behaviçur çf íhe quaríerI EiiF iãérçve íhe securiíy çf and accessibiliíy íç íhe buildingsI EiiiF adaéí íhe church Eéreviçusly used as a garage and safeíy vaulíF íç iís new funcíiçn as a ãuseuãI and EivF cçãély wiíh íhe necessary burçcçde requireãenís.

cigK O fníeriçr çf íhe church

cigK P fníeriçr hall çf íhe blçck

cigK Q lriginal braced walls reélaced by irçn cçluãns

cigK R píeel beaãs wiíh sãall ãasçnry brick vaulís

OK pTorCTroAi abTAfi abpfGk Aka ClkpTorTflk tloKp

OKNK purveying lne çf íhe ãain cçncerns çf íhe deíail design was íç ideníify and characíerizeI fçr íhe U buildings and íhe churchI íhe exisíing sírucíureI in çrder íç analyse and undersíand iís behaviçur íç veríical and hçrizçníal acíiçns. auring íhis building survey wçrkI ií was recçgnized íhaí ãçsí çf íhe “gaiçla” sírucíures had already been reãçved. eçweverI during cçnsírucíiçn wçrkI íhe íeaã was able íç find and éreserve íwç iníeriçr “frçníal” wallsI wiíh íiãber sírucíures wiíh pí. Andrews crçsses fill wiíh síçne rubble. qhe çriginal sírucíure fçundI cçnsisíed esseníially çf íhe ãasçnry exíeriçr walls and vaulís. qhe exíeriçr walls çn íhe grçund level are ãainly ãade çf regular calcareçus síçnewçrk blçcks wiíh íhickness beíween NJN.Rã. qhe uééer levels have íhinner wallsI wiíh widíhs beíween M.UJNã íhaí are

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usually ãade çf irregular calcareçus blçcks and liãe ãçríar. All íhe çéeningsI windçws and dççrsI çf íhese sírucíures are geçãeírical and regularly séaced in çíher íç have cçníinuçus veríical eleãenís. bach building usually has P íç 4 çéeningsI nçwadays wiíh nç braced sírucíure in beíween Efrçníal wallsFI which increases íheir vulnerabiliíy íç fçrã çuíJçfJélane cçllaése ãechanisãs. qhe cçããçn flççr sçluíiçn fçund was nçí íhe íyéical wççden beaãsI buí raíher íhe sãall ãasçnry brick arches suééçríed by síeel beaãs. OKOK mroject main principles qhe iníerveníiçn criíeria were divided iníç P grçuésW NF íhe church – where íhe érinciéal aiã was íç reãçve all dissçnaní cçncreíe sírucíuresI and íç resíçre all ãasçnry síçne wçrk in çrder íç adaéí íhe new area iníç a ãuseuã; OF íhe ceníral blçck buildings – where íhe síeel éçsíJéçãbalinç sírucíure was cçãéleíely deãçlished in çrder íç creaíe a ceníral cçre síiffness and íç cçnceníraíe all íhe funcíiçnal service requireãenís aí íhe ceníre çf íhe quaríer; and PF cçããçn buildings – where íhe aiã was íç éreserve íhe éçsíJéçãbalinç sírucíures and çnly reírçfií íheã where necessary. denerallyI çn íhe flççrs where a deeé iníerveníiçn was neededI íhe sçluíiçns used were lighíer and siãilar íç íhe çriginal sçluíiçns ãade çf íiãber and síeelI sç as íç érevení íhe increase çf weighí in íhe sírucíure. Cçncreíe reinfçrceãení sçluíiçns were ãainly used íç increase íhe íensile sírengíh çf íhe ãasçnry walls; use çn íhe flççrs was very liãiíed. qhere was alsç a séecific cçncern íç iãérçveI recçver çr creaíe gççd cçnnecíiçns beíween all íhe eleãenís in çrder recreaíe a hçãçgençus glçbal behaviçur. there necessaryI íhe fçundaíiçns where seisãically sírengíhened wiíh ãicrç éiles çf SMíçn caéaciíy and OO ã çf lengíh. qhe sírucíural analysisI develçéed wiíh glçbal Pa and lçcal analyíical ãçdelsI aiãed íç ãainíain all valuable sírucíures – alíhçugh sçãe çf íhe leasí iãéçríaní were deeély ãçdified – íç iãérçve éerfçrãance íç veríical and hçrizçníal acíiçns and íç cçãély wiíh all éresení burçcçde requireãenís OKPK jain construction works 2KPK1K Church Accçrding íç íhe resulís çf íhe sírucíural analysis develçéed in a Pa analyíical érçgraãI íhere was a need íç seisãically reírçfií íhe church’s ãain façade éediãení. qhis was íhe reasçn why a new síeel braced sírucíure was designed inside íhe churchI and íhe éediãení iíself was cçnnecíed íç íhe rççf sírucíure.

cigK S jçdal analysis resulís fçr Church’s façade

qhe ãasçnry walls çn íhe sçuíh and nçríh wings were alsç seisãically sírengíhened wiíh cçncreíe reinfçrced cçaíing çf NM íç OM cã íhickness. qhe çriginal rççf sírucíure was recçnsírucíed wiíh íiãber írusses using íheir çriginal íie beaãI which was íhe çnly çriginal eleãení lefí. rnder íhis sírucíureI a íiãber rib arch was builí íç recreaíe sçãe vaulís fçr íhe ceiling çf íhe ceníral nave.

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cigK T jçdal analysis resulís fçr íhe bell íçwer

cigK U píeel facade sírucíure and vaulíed new ceiling

cigK V Cçnnecíiçn beíween íhe éendaní and rafíer

cigK NM qie beaã and rib arch sírucíure íç suééçrí íhe vaulíed ceiling

cigK NN píeel beaãs being inseríed aí íhe íransiíiçn level çf íhe bell íçwer

aue íç íhe archiíecíural érçgraãI íhe bell íçwer was cuí in half in çrder íç insíall an elevaíçr under ií. qhe bell íçwer was alsç seisãically sírengíhenedI wiíh a cçncreíe reinfçrced cçaíing çn íhe inside çf íhe ãasçnry wallsI and íhe deãçlished area was subsíiíuíed wiíh cçncreíe walls íç suééçrí íhe íçwer

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and íç enable íhe insíallaíiçn çf íhe elevaíçr. qhe íransiíiçn level beíween íhe bell íçwer’s çriginal sírucíure and íhe new cçncreíe sírucíure is ãade çf U ebB4MM beaãs in bçíh çríhçgçnal direcíiçns. qhe cçncreíe and síeel beaã flççrs çf íhe laíeral wings were deãçlished and a new oiga éine wççd and síeel sírucíure was builí. auring íhe cçnsírucíiçn wçrkI éarí çf íhe çriginal alíar was fçund in beíween cçncreíe walls. qhis eleãení was íhen éreservedI resíçredI and sírucíurally reírçfiííed wiíh a cçncreíe wall aí íhe back íç ãiíigaíe íhe risk çf cçllaésing. 2KPK2K Central block buildings qhe síeel sírucíure çf íhe ceníral blçck buildings was íçíally deãçlished in çrder íç cçnceníraíe in íhis area all íhe funcíiçnal eleãenís. As a resulíI ií was éçssible íç reduce íhe level çf inírusiçn çn íhe çíher buildings çf íhe quaríer. qhe ãasçnry walls were reírçfiííed wiíh a cçncreíe reinfçrced cçaíing çf NM cã íhickness. fn íhese buildingsI and due íç securiíy reasçnsI íhe flççr sírucíures çn íhe lçwer levels have 4McãJíhick slabsI while íhe uééer levels are ãade wiíh lighíer íiãber and síeel sçluíiçns. rsuallyI íhere is a hçrizçníal síeel beaã EebBPMMF in beíween every veríical ãasçnry eleãení in çrder íç ãiíigaíe çuíJçfJélane ãçveãení.

cigK NO Cçfferdaã used in íhe excavaíiçn çf íhe

ceníral blçck buildings

cigK NP lverview çf íhe cçncreíe

reinfçrceãení cçaíing çver íhe ãasçnry walls

cigK NQ aeãçliíiçn çf íhe exisíing cçncreíe slab

cigK NR clççr sírucíure cçãéçsed çf íiãber and

síeel eleãenís 2KPKPK Common buildings qhe iníerveníiçn çn íhese buildings was reduced íç çnly íhe esseníial. qhere was a need íç characíerize íheir exisíing sírucíureI which in sçãe cases was çnly éçssible when íhe cçnsírucíiçn wçrk síaríed. All íhese sírucíures were alsç analysed wiíh lçcal analyíical ãçdels íç undersíand íheir veríical behaviçurI and when neededI éuncíual reírçfiííing wiíh síeel çr íiãber beaãs was iãéleãeníed. lnly in çne çr íwç éaríicular insíancesI where íhe iníeriçr walls were reãçved and íhe ceiling heighí was lçwI was a new sírucíural sçluíiçn necessary. qhe ãain iníerveníiçns çn íhese buildings were aí íhe íçé level and rççfI in çrder íç adaéí íhese areas íç ãeeíing rççãs and çffices. qhe ãçsí delicaíe iníerveníiçn in íhis area was íhe creaíiçn çf a garage çn íhe grçund level. qhis invçlved a new sírucíural sçluíiçn fçr íhe firsí flççr íhaí ãade íhe íransiíiçn beíween íhe çéen séaceI

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garageI and íhe abçve irçn cçluãn and síeel beaã sírucíures. qhis sírucíure is ãade çf dçuble beaãs ebBRMMI and íheir iníersecíiçn is cçincidení wiíh íhe irçn cçluãns frçã íhe levels abçve.

cigK NS pírucíure analyzed fçr íhe garage íransiíiçn flççr

cigK NT lne çf íhe cçnsírucíiçn éhases wiíh çne irçn cçluãn suééçríed by íhe éeréendicular síeel

beaãs

cigK NU jçdal analysis resulís fçr a cçããçn building

cigK NV bxisíing síeel cçluãn

cigK OM NPíh ceníury ciíy wall

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cigK ON clççr suséended by dçuble ebBRMM érçfiles

cigK OO oççf grid síeel sírucíure

Accçrding íç íhe Pa sírucíural analysisI íhe buildings wiíh higher seisãic risk are íhe çnes near íhe ceníral blçck buildings due íç íhe difference in síiffness; íhe buildings íhaí have ãçre íhan P çéenings wiíh nç brace sírucíure íend íç develçé çuíJçfJíhe élane cçllaése ãechanisãs. qhese areas were generally seisãically sírengíhened in íhe iníeriçrI wiíh cçncreíe reinfçrced cçaíings. All íhe cçnnecíiçns çf íhe exisíing sírucíures were inséecíed. Alíhçugh in sçãe çf íhe buildings gççd and efficiení cçnnecíiçn beíween flççr and walls was fçundI in çíher sírucíures íhere was a lack çf cçnnecíiçns eséecially beíween íiãber and ãasçnry eleãenís. qhese cçnnecíiçns are nçw adequaíely esíablished in íhe eníire quaríer. qhe effecíiveness çf íhese cçnnecíiçns is crucial fçr a gççd seisãic behaviçur. auring cçnsírucíiçn wçrk çn íhe iníeriçr hallI a NPíh ceníury ciíy wall was fçund. fn çrder íç éreserve and recçver íhis eleãeníI all íhe fçundaíiçn wçrk çf ãicrç éiles had íç be reJanalysed and reJlçcaíed. kçwadaysI íhere is a íechnical gallery frçã íhe ãuseuã EchurchF íç íhe cçããçn buildingsI where éeçéle can see íhis ciíy wall.

PK ClkCirpflk qhis was a highly rewarding engageãení fçr íhe íeaãI as ií érçvided íhe rare çééçríuniíy çf analyzing íhe sírucíural aséecís çf an eníire quaríer. jany lçcal analyíical ãçdels were develçéed íç undersíand íhe séecific sírucíural behaviçurs çf ceríain éarís çf íhe blçck; an iníegraíed and cçãérehensive Pa ãçdel was laíer develçéed in çrder íç evaluaíe íhe éerfçrãance çf íhe eníire quaríer wiíh reséecí íç hçrizçníal lçads and seisãic acíiçn. rndersíanding and ãaniéulaíing hisíçrical cçnsírucíiçns requires cçnsíaní aííeníiçn and dedicaíiçn frçã íhe design íeaãI frçã íhe firsí síage çf surveyingI íç íhe end çf íhe cçnsírucíiçn wçrk. qhe aãçuní çf íiãe séení during íhe érçjecí analysis was very ãuch cçãéarable íç íhe aãçuní çf íiãe séení analysing éçíeníial sçluíiçns and alíernaíives during íhe cçnsírucíiçns wçrk. qhe érinciéal aiã çf íhis érçjecí was achievedI in íerãs çf seisãicJsírengíhening íhe sírucíure and cçãélying wiíh íhe necessary burçcçde requireãenís.

Table N fníeresíing facís

fnteresting facts

Cçncreíe vçluãe O UTT ãP

píeel teighí RPO íçn.

qiãer sçluãe OT4 ãP

Bell íçwer weighí suséended NVU.R íçn

pírucíural design íeaã – eçurs séení during deíailed design érçjecí NN UTN hçurs

pírucíural design íeaã – eçurs séení during cçnsírucíiçn wçrks fçr íechnical advice 4 UMT hçurs

kuãber çf deíailed design drawings UT drawings

kuãber çf deíailed design drawings during cçnsírucíiçn wçrks 4NR drawings

ACKkltibaGjbkTp te wçuld like íç íhank all íhe ãeãbers çf íhe íeaãs invçlved in íhe design and cçnsírucíiçn wçrk relaíed íç íhis érçjecí.