=

NV4M=

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

mob pqobppba sboqfCAi fkgbCqba AkCelop lk efpqlofCAi MAplkovW A CApb pqravI qeb Bbii qltbo lc BlqqA af plqql fi Mlkqb mAmA dflsAkkf uufff cK SilveriNIdK mrofetaOI mK oivaPI CK Algeri4I bK BologniniRI bK moverelloSI mK manzeriT ABpqoACq qhe=Bell=qçwer= çf= the=`hurch=“pacrç=`uçre=desù= e= pK=bgidiç=Abate”= in=pçttç= il=jçnte= EBergamçI=ftalyFI= represents= a= case= study= çf= the= research= prçgramme= “Akfjrp”I= funded= by= the= burçpean=mrçgramme=cbpoJOMMTJOMNPK=qhe =necessity =çf =building =a =steel =belfry =çn =tçp =çf =the =bell =tçwer =required =a =detailed =study =çf =its =cçnnectiçn=with=the=suppçrting=masçnry=structureK=qhis=cçnnectiçn=has=been=realized=by=means=çf=deep=vertical=anchçrsI=çbtained=by=grçuting=steel=bars=by=injecting=the=grçut=in=special=sçcksI=such=that=any=dispersiçn=çf=the=mçrtar= in=the=masçnry=is=avçidedK=By=this=techniqueI=a=“bulb”=creating=an=effective=interlçck=with=the=masçnry=structure=is=createdK=qhe=behaviçur=çf=the=system=has=been=studied=by=means=çf=a=finite=element=mçdelI=allçwing=tç=assess=the=perfçrmance=çf=the=cçnnectiçn=under=wind=and=seismic=lçads=bçth=at=service=and=ultimate=limit=statesK=qhe=results=have=highlighted=the=çppçrtunity=tç=design=vertical=anchçrs=with=a=dçuble=bulb=çf=mçrtarK=qhis=wayI=by=grçuting=the=deeper=bulb=sççn=after=installatiçnI=the=anchçr=cçuld=be=preJstressed=tç=avçid=any=decçmpressiçn=çf=the=cçnnectiçn=between=the=superstructure=and=the=masçnry=tçwer=under=service=lçadsK= qhe= upper= bulbI= grçuted= at= a= later= timeI= has= the= rçle= çf= transferring= the= lçads= exceeding=serviceability=limit=state=tç=the=masçnry=structureK=After= the= installatiçn=çf=vertical=anchçrsI=an=experimental=campaign=was=carried=çut= çn=the=anchçrsI=thus= allçwing= tç= evaluate= the= effectiveness= çf= the= interventiçn= and= tç= cçmpare= experimental= and=numerical=resultsK==heywords: eistorical masonryI fnjected anchorsI Seismic behaviourI mre-stressed tie NK fkqolarCqflk =qhe=architectural=prçject=calls=fçr=a=rehabilitatiçn=prçgram=çf=the=whçle=churchI=fçcusing=in=particular=çn=a=new=steel=superstructure=EUIM=m=highF=tç=be= installed=çn=tçp=çf= the=existing=masçnry=bell=tçwer=EO4IP= m= highFK= qhe= analysis= aims= at= verifying= the= stress= state= induced= by= external= actiçns= such= as=earthquake=and=wind=çn=the=injected=anchçrs=used=tç=cçnnect=the=steel=superstructure=tç=the=tçp=çf=the=masçnry=bell=tçwer=çf=the=̀ hurch=çf=Bçtta=di=pçttç=il=jçnte=EBergamç=–=ftalyFK=Actiçns= at= service=and=ultimate=limit= states= were=therefçre=calculated=cçnsidering=the=expçsure=çf= the=church= tç=seismic= and= wind= lçadsK=qhe=actiçns= çn= the= steel=superstructure=and=çn= the= anchçrs= were=calculated=accçrding=tç=the=fçllçwing=assumptiçnsW==

================================================N=mha=ptudentI=rniversity=çf=BergamçI=francescaKsilveri]unibgKit=O=mha=ptudentKI=rniversity=çf=BergamçI=giacçmçKprçfeta]unibgKit=P=mrçfessçrI=rniversity=çf=BergamçI=paçlçKriva]unibgKit=4=bngineerI=`Jpmfk=BergamçI=cristiançKalgeri]cJspinKeu=R=bngineerI=`Jpmfk=BergamçI=mail]cJspinKeu=S=bngineerI=Bçssçng=ppA=drassçbbiç=EBdFI=cçnsçlidamentç]bçssçngKcçm=T=bngineerI=mCm=lmcsrl=periate=EBdFI=panzeri]pepcçnsultingengineersKit=

=

NV4N=

– masçnry=and=upper=cçncrete=curb=respçnd=çnly=tç=cçmpressiçn=due=tç=vertical=lçads;=– the=injected=anchçr=respçnds=çnly=tç=tensile=lçadsK=– tind=and=earthquake=actiçns=have=been=calculated=at=serviceability=limit=state=assuming=thatW=– at =ripI =a =tensile =fçrce =cçmpatible =with =the =resistance =çf =the =tie =dçwn =anchçrs =as =well =as =

a=cçmpressiçn=cçmpatible=with=the=masçnry=are=admitted;=– a=prelçad==can=be=applied=tç=the=anchçrs=EpreJstressF=in=çrder=tç=balance=the=tensile=actiçns=at=pipK=

qhis=actiçn=is=cçmpatible=with=the=level=çf=acceptable=stress=fçr=the=masçnry=Eless=than=MKR=jmaF;=– due=tç==the=applied=prestressI=anchçrs=are=nçt=subjected=tç=significant=tensile=fçrce=increase=at=pipK=

=

==== =

cigK N siew=çf=the=bell=tçwer=and=the=upper=steel=structure==

OK cfkfqb bibMbkq Mlabi Aka obpriqp lBqAfkba

OKNK dlobal cb analysis A=simplified= numerical=analysis= was= cçnducted= in=çrder= tç=understand= the=dynamic=behaviçur= çf= the=masçnry=bell=tçwer=mçdelled=as=a=cantilever=beam=using=cbK===

=

cigK O aF=view=çf=the=entire=mçdel=and=bF=anchçrs=scheme=at=the=base=çf=the=steel=superstructure=

qhis=first=mçdel=is=validated=çn=the=frequency=results=çf=the=in=situ=test=carried=çut=by=using=a=shakerK==qhe=frequency=values=are=listed=in=qable=NK==

qable N=`çmparisçn=between=experimental=and=numerical=mçdel==

Mode crequency by shaker

xezz

crequency by cb model

xezz

qolerance xBz airection referred to the church

f== OKNS= OKNU= MIV= qransversal==ff= OKTO= OKTT= NIU= içngitudinal=fff= PKSU= PKVR= TIP= içngitudinal=

=ptarting=frçm=this=calibrated=mçdelI=a=respçnse=spectrum=analysis=at=ripI=cçnsidering=a=return=periçd=çf= V4V= yearsIand= pipIwith= a= return= periçd= çf= NMN= yearsIwas= cçnductedI= cçnsidering= elastic= spectra=

=

NV4O=

Estructure= cçefficient= q= Z= NIMFKqhe= maximum= bending= mçment= and= shear= fçrce= at= the= base= çf= each=cçlumn=çf=the=steel=superstructure=at=pip=resulted=equal=tç=UR=kkm=and=NS=kkI=respectivelyK=pimilarlyI=at= the=rip= Ein=accçrdance=tç= the= ftalian=cçde=kq`OMMUFI= the=maximum=bending=mçment=and=shear=fçrce=resulted=equal=tç=OON=kkm=and=4O=kkI=respectivelyK== OKOK aetailed cb analysisW interface problem qhe=maximum=bending=and=shear=fçrces=have=been=intrçduced=in=a=secçnd=cb=mçdelI=shçwn=in=cigK=PI=tç= investigate= in=detail= the=respçnse=çf= the=anchçrsI= cçnsidering= their= nçnlinear= behaviçur= Etie=dçwn=anchçrs= have= tensile= strength= but= nç= cçmpressiçn= strengthF= and= perfçrming= an= equivalent= static=analysisK= fn= çrder= tç= apply= the= cçrrect= fçrces= tç= the= anchçrsI= the= applicatiçn= pçint= çf= the= hçrizçntal=fçrcesI =which =invest =simultaneçusly =the =4 =steel =piersI =was =placed =at =OLP =çf =the =height =çf =the =superstructureI=being=the=respçnse=mainly=gçverned=by=the=first=vibratiçn=mçdeK=qhe=applied=hçrizçntal=fçrce=was=equal=tç=S4=kk=at=the=pip=and=NST=kk=at=the=rip=EiKeK=NS=kk=and=4O=kk=çn=each=pierFK==cçr=a=cçmprehensive=evaluatiçn=çf=the=anchçring=systemI=a=reference=mçdel=that=simulates=nçt=çnly=the=fçur=cçlumns=çf=the=metal=structureI=but=alsç=the=reinfçrced=cçncrete=curb=at=the=tçp=çf=the=masçnry=çf=the=bell=tçwer=was=develçpedK=Bçth=the=anchçrs=in=cçrrespçndence=tç=the=base=plate=çf=the=single=pier=and=the=intermediate=anchçrs=have=been=mçdelled=accçrding=tç=the=scheme=shçwn=in=cigK=ObK=All=fçrces=have=been=applied= tç=a=rigid= link= lçcated=at= a=height=equal= tç=RK4M= m=frçm=the=base=çf= the=rKcK=curbK=A=further= link= has= been= intrçduced= tç= capture= the= full= behaviçur= çf= the= structureK= fn= additiçn= tç= the=cçnstraints=prçvided=by= the=anchçrs= Etensiçn=çnlyFI= the=curb=has=been=cçnstrained=with=cçmpressiçn=çnly= springs= in= çrder= tç= simulate= the= cçntinuçus= cçntact= çn= the=masçnry= surfaceK= qhe= link= has= been=mçdelled= thrçugh=a= series= çf= springs= such=as= tç= evaluate=alsç= the= tçrsiçnal=behaviçur= çf= the=curbI= as=shçwn=in=cigK=PbK=qhe=equivalent=axial=spring=stiffness=was=taken=equal=tç=R=kLmmPK===

== == =

cigK P aF==siew=çf=the=detailed=mçdel=with=edge=curb=and=bF=`urb=nçnlinear=spring=scheme==and=cF=bxample=çf=the=effect=çf=çne=çf=the=lçad=cçmbinatiçns=çn=the=curb=

=OKPK aetailed cb analysisW double bulb stress analysis qhe=presence=çf=a=dçuble=bulb=EcigsK=Va=and=VbF=has=made=it=pçssible=tç=impçseI=by=means=çf=a=prelçad=çn=the=anchçrI=the=absence=çf=tensile=fçrces=at=pip=çn=the=anchçrsI=thus=avçiding=a=decçmpressiçn=çf=the=wall=sectiçnK=Based=çn=the=characteristics=çf=the=masçnryI=this=preJstress=is=çbtained=with=an=anchçr=bulb=NKR=m=lçngK=qhis=is=necessary=tç=avçid=tçç=high=tensiçnal=regimes=within=the=mçrtar=surrçunding=the=stainless=steel=bar=and=tç=allçw=a=higher=preJstress=tç=cçmpensate=fçr=any=deferred=lçssK=qhe=secçnd=bulb=must=cçllect=the=actiçns=at=rip=exceeding=thçse=at=pipI==iKeK=thçse=induced=by=rare=lçads=EwindF=çr=with=high=return=periçds=EearthquakeFK=qhis=bulb=has=a=minimum=length=çf=OKM=m=and=a=maximum=length=çf=OKR=m=depending=çn=the=vertical=çffset= çf= the=bulbs= in=çrder= tç=avçid=preferential=masçnry=crack= surfacesK= qhe= dimensiçn= çf= the= anchçr= bulb= led= tç= emplçy= O4= mm= diameter= bars= in= çrder= tç=resista =maximum =tensiçn =equal =tç =OMM =kk =at =rip =EearthquakeFK =qhe =“nçminal” =shear =strength =as =defined=in=xNzI=in=cçrrespçndence=tç=bçth=deep=and=upper=bulbs=have=values=lçwer=than=thçse=çbserved=experimentally= by= in= situ= test= accçrding= tç= xNzI= assuming= a= safety= factçr= equal= tç= PK= qhe= nçminal=maximum=shear=stressi=n=the=NKRm=lçng=deeper=bulbs=appear=tç=be=abçut=MKOO=jma=while=in=the=upper=bulbs= it= is=between=MKOMJMKOR=jmaK=Bçth= these=values= are=lçwer= than=MK4T=jmaI=which= is= the=failure=value =çbtained =frçm =experimental =tests =Eeven =reduced =by =a =safety =factçr =equal =tç =PFK =pimilarlyI =the =cçmpressive=stress=çn=the=masçnry=fçr=each=limit=state=has=values=lçwer=than=MKR=jmaK=qhis=value=is=fully=cçmpatible= with= the=cçmpressive=strength= çf= the= masçnryI= as= it= resulted= frçm=flat= jack= experiJmental=tests=previçusly=cçnducted=in=situK==

=

NV4P=

PK mobifMfkAov iABloAqlovqbpqp =Befçre=starting=with=the=in=situ=tests=çn=the=anchçrsI=a=preliminary=labçratçry=test=has=been=carried=çut=with=the=aim=çf=testing=the=instrumentatiçn=designed=fçr=the=anchçrs=and=çf=measuring=the=pçssible=lçss=çf=lçad=çver=time=in=the=preJstressed=injected=anchçrs=and=the=distributiçn=çf=the=tangential=stress=alçng=the=anchçr= lengthK=Astress=relaxatiçn=test=under= cçnstant=strain=çf= the=anchçr=steel=bar=has=alsç=been=separately=carried=çutK=qhe=preliminary=tests=results=allçwed=tç=verify=the=cçrrect=layçut=çf=the=adçpted=instrumentatiçn=and=tç=define=sçme=imprçvement=fçr=the=fçreseen=in=situ=testsK==PKNK oelaxation test on steel bar qç=assess=the=lçss=çf=tensiçn=with=cçnstant=strainI=due=tç=the=relaxatiçn=çf=the=steel=bar=in=the=anchçrI=a=specific=test=has=been=carried=çutI=based=çn=the=indicatiçn=çf=burçcçde=Eb`=O=bk=NVVOJNJN=–=marK=PKP=="mrestressed=pteel”F=and=British=ptandard=EBp=RSOUJOWOMMMFKqhe=resultsI=shçwn=in=cigK=4I=demçnstrate=that=after=NMMMh=at=cçnstant=strain=the=tensiçn=drçp=due=tç=relaxatiçn=in=the=bar=is=arçund=RB=ENM=kkFK==

=

cigK 4 arçp=çf=lçad=at=cçnstant=strain=after=NMMM=hçurs=in=the=steel=bar==

PKOK qest bench and equipment for preJstressed anchor tests A= brick= masçnry= test= bench= has= been= built= with= dimensiçns= MIO=×=MINT=×=MIMTR=m= and= with= lçw=mechanical= strength= fçr= bçth= mçrtar= and= bricks= tç= replicate= the= structural= typçlçgy= çf= histçrical=buildingsK=qhe=masçnry=wallet= has=been=preJlçaded=by=means= çf= a= metallic= frame= in=çrder= tç= apply=a=vertical= lçad=such=as=tç=simulate=the=bçundary=cçnditiçns=çf=a=real=building;= the=frame=structure=is=cçmpçsed=çf=three=ebBN4M=beamsI=OIN=m=lçngI=welded=with=transverse=steel=plates=Esee=cigK=RFK=A=dBlp=O4JTM=m=anchçr=has=been=usedI=grçuted=by=injecting=the=grçut=in=special=sçcksI=cçmpçsed=byW=

– O4mm=threaded=BarI=dBlp=O4LPM4=mçdelI=çf=stainless=steel=Afpf=PM4=EqabK=NF;=– pçck=in=special=textile=material=tç=cçntrçl=the=mçrtar=injectiçn=with=the=injectiçn=tube;=– `ement=mçrtar=EqabK=OFI=specific=fçr=injectiçn=with=sçcks=in=hçle=çf=diameter=çf=TM=mmK=

qhe=anchçr=and=the=grçut=have=been=instrumented=by=means=çf=strainJgauges=and=placed=in=the=wallet=Eas=shçwn=in=cigK=RFK=cigK=R=shçws=alsç=the=pçsitiçn=çf= the=pçtentiçmetric=transducers=used=tç=mçnitçr=displacements=in=the=wallet=and=the=lçad=cell=used=fçr=measuring=the=fçrce=applied=tç=the=anchçrK==

qable O=deçmetrical=and=mechanical=characteristics=çf=the=bar==

Material Bar aiameter Area

cailure tensile stress

vield point stress

Minimum tensile

failure load

Minimum yield point

load ptainless=

steel=abar=xmmz=

p==xmmOz=

ft=nçm=xjmaz=

fy=nçm==xjmaz=

ktIs==xkkz=

kyIs=xkkz=

Afpf=PM4= O4= PTU= TRM= SRM= OUP= O4S=

qable P jechanical=characteristics=çf=the=grçutingmçrtar==

Average Compressive strength xMma]

Average tensile strength in bending xMma]

voung’s Modulus xMma]

at=P=days= at=T=days= at=OU=days= at=P=days= at=T=days= at=OU=days= at=OU=days=ONIO= PTIO= RNIR= OIR= PIR= 4IR= OUKMMM=

=

NV44=

=

cigK R mreliminary=test=bench=with=pçsitiçn=çf=strainJgauges=and=pçtentiçmetric=displacement=transducers==

PKPK qestsexecutionand results After=the=necessary=aging=periçd=fçr=the=mçrtarI=a=TR=kk=preJlçad=has=been=applied=tç=the=test=anchçr=by=a=hydraulic=jackK=auring44=days=çf=çbservatiçnI=the=lçad=cell=has=read=the=lçss=çf=lçad=in=the=anchçr=çver=timeK=cinallyI=the=pull=çut=test=çf=the=anchçr=has=been=carried=çut=up=tç=a=lçad=equal=tç=OSM=kkK=qhe=yielding=çf=the=bar=was=çbtainedI=while=the=anchçr=cçuld=nçt=be=pulledJçutK=cigsK=Sa=and=Sb=shçw=the=lçad=EkkF=vs=strain=EµεF=diagrams=registered=by=the=strain=guages=up=tç=the=maximum=lçad=appliedK=

cigK Sa mullJçut=testKaiagram=içad=EkkF=–=ptrain=EµɛF=

in=the=mçrtar==cigK Sb mullJçut=testK=aiagram=içad=EkkF=–=ptrain=

EµɛF=çn=the=steel=bar==qhe=maximum=strain= in= the=mçrtar=was= measuredI= fçr= all= lçading= levels=by= the=middle=strainJgauge=EbOjI=in=magenta=in=cigK=SaFI=while=very=small=strain=values=Enear=zerçF=where=registered=by=the=çne=pçsitiçned=tçwards=the=end=the=bulb=EbNjFKAs=expectedI=the=maximum=strain=alçng=the=steel=bar=was=measured=by=the=strainJgauge=pçsitiçned=clçser=tç=the=lçaded=end=EbPAI=in=yellçw=in=cigK=SbFI=while=the=çthers=measured=lçwer=strain=EbOA=pçsitiçned=in=the=middle=and=bNA=pçsitiçned=tçwards=the=end=çf=the=bulb=çn=the=steel=barI=see=cigK=RFK==4K fk pfqrJqbpqp =qhe=çbject=çf=the=in=situ=tests=wasW=

NF= measuring==the=pçssible=preJstress=lçss=çver=time=çf=the=anchçrs;=OF= executiçn=çf=cyclic=tests=çn=vertical=anchçrsK=

After=installatiçn=and=injectiçn=çf=the=instrumented=anchçrs=in=the=`hurch=bell=tçwer=wall=accçrding=tç=the=rehabilitatiçn=designI=measurements=were=taken=with=the=fçllçwing=purpçsesW=

– measure=the=pçssible=preJstress=lçss=çver=time=çf=the=injected=and=preJstressed=anchçrs;=– measure=the=distributiçn=çf=shear=stress=alçng=the=anchçr;=– mçnitçr=the=evçlutiçn=çf=the=behaviçr=çf=the=anchçr=çver=timeK=

`yclic= tests= with= the=aim=çf= studying= the=behaviçr= çf= the=anchçr= subjected= tç=dynamic= stress= actiçns=were=alsç=perfçrmed=çn=twç=“testJanchçrs”I=instrumented=as=indicated=in=cigK=VaK=

=

NV4R=

4KNK Anchors description and position qhe=installatiçn=çf=vertical=anchçrs=falls=within=the=prçject=fçr=the=realizatiçn=çf=a=metal=superstructure=tç=prçtect=the=bell=chamber=installed=çn=tçp=çf=the=tçwer=in=questiçn;=this=superstructure=is=fçrmed=by=fçur= steel= cçlumns= at= the= fçur= cçrners= çf= the= wallI= cçnsisting= çf= a= truss= structure= cçvered= by= steel=sheetingI=and=a=cçvering=cçnstituted=by=the=intertwining=çf=mçre=steel=beamsK=qhe=arrangement=çf=the=anchçrs= is= shçwn=in=cigK=TW=insertiçn=çf=fçur=cçrner=anchçrages=in=cçrrespçndence=çf= each=cçlumn=çf=the=steel=superstructure=and=twç=lateral=anchçrages=in=the=central=area=çf=each=side=çf=the=bell=tçwerK=qhe=angular= anchçrsI= pçsitiçned=at= the= fçur= cçrners= çf= the= tçwerI= have= different= lengthsW= 4KM= m=fçr=iJtype= anchçrs= ElçngF= and= PKR= m= fçr= `Jtype= anchçrs= EshçrtF= because= çf= a= vertical= çffset= alçng= the=lçngitudinal=axis=çf=the=tçwerI=at= least=RM=cm=due=tç=the=need=tç=avçid=weak=surfacesK=qhe=remaining=perimeter=side=ElateralF=anchçrs=alsç=have=a=length=çf=PKR=m=E`JqypeFK=qç=allçw=the=applicatiçn=çf=a=preJstressI=all=anchçrs=were=designed=with=a=dçuble=bulb;=the=length=çf=the=deeper=bulbI=absçrbing=the=preJstressI=was=equal=tç=NKR=mK=qhe=upper=bulbI=designed=tç=absçrb=the=fçrces=exceeding=the=preJstress=valueI=hada= length=çf=either=OKM=m=E`Jtype=anchçrsF=çr=OKR=m=EiJtype=anchçrsFK=qhe=arrangement=and=the=lengths=çf=the=anchçrs=are=summarized=in=cigK=UK==

= =cigK T Anchçrs=pçsitiçn=with=indicatiçn=çf=the=test=

anchçrs=cigK U Arrangement=and=length=çf=anchçrs=with=

indicatiçn=çf=the=twç=bulbs==qhe= dimensiçning= çf= the=anchçr= has= led= tç= the=use= çf= O4= mm=diameter= bars= in= çrder= tç= cçllect= the=maximum=stress=çf=tractiçns=at=the=pa=EearthquakeF=equal=tç=VM=kk=withçut=reaching=tçç=high=tensiçnal=regimesK=qhe=anchçr=injected=with=Bçssçngsçck=mçdel=dBlp=m=O4JTMI=used=fçr=the=wçrks=describedI=is=çf=the=same=type=indicated=in=sectiçn=4KO=Efçr=technical=and=mechanical=characteristics=çf=the=anchçrI==steel=bar=and=mçrtar=fçr=injectiçnI=see=qable=O=and=qable=PFK==4KOK ptain gauges position in the test anchors cigsK=Va=and=Vb=shçw=the=lçcatiçn=çf=the=anchçr=strain=gaugesK=qhe=cçrner=anchçrs=NKN=and=PK4=Efçr=preJstress=lçss=evaluatiçnF=were=instrumented=withN=strain=gauge=çnly=çn=the=steel=bar=EbSAFI=while=the=twç=anchçrs=bKN=and=tKO=Efçr=cyclic=testsFI=were=instrumented=with=R=strain=gauges=çn=the=steel=bar=EbNA=KKK=bRAF=and=R=strain=gauges=in=the=mçrtar=EbNj=KKK=bRjFK==

==

cigK Va ptrain=gauges=pçsitiçn=in=anchçr=bKN=and=tKO cigK Vb ptrain=gauges=pçsitiçn=in=anchçr=NKN=and=PK4=

=

NV4S=

4KPK qension of the anchors qensiçn=was= applied= simultaneçusly= tç= the=4=pier= anchçrs= Ecçrner= anchçrsFby= means= çf= 4= hydraulic=jacksK=qç=measure=the=applied=fçrce=a=pressure=cell=was=usedK=qhe=tensiçn=çf=the=central=anchçrs=has=been=applied=by=a=hydraulic=jackK=A=UR=kk=preJlçad=was=applied=tç=the=anchçrsK==4K4K Cyclic tests on anchorages bKN and tKO qhe=cyclic=tests=were=perfçrmed=çn=anchçrs=bKN=and=tKO=Esee=cigK=TFI=`Jtype==anchçrs=with=length=çf=PKR=mI=dçuble=bulb=Eupper=bulb=with=a=length=çf=OIM=mI=deep=bulb=with=a=length=çf=NKR=mFKqhe=cyclic=tests=cçnsisted=çf=twç=phasesI=as=shçwn=in=table=4W=

– mhase=NW=after=the=injectiçn=çf=the=deeper=bulbI=and=subsequent=aging=çf=the=mçrtar;=– mhase=OW=after=the=injectiçn=çf=the=upper=bulbI=and=NU=days=çf=agingK=

qable 4 `ycles=in=mhase=N=and=mhase=O=

=

mhase N mhase O kçK=P=cycles=çf=lçading=M=–=OM=–=M=kk= kçK=P=cycles=çf=lçading=M=–=VM=–=M=kk=kçK=P=cycles=çf=lçading=M=–=4M=–=M=kk= kçK=P=cycles=çf=lçading=M=–=NMM=–=M=kk=kçK=P=cycles=çf=lçading=M=–=SM–=M=kk= kçK=P=cycles=çf=lçading=M=–=NNM=–=M=kk=kçK=P=cycles=çf=lçading=M=–=UM=–=M=kk= kçK=P=cycles=çf=lçading=M=–=NOM=–=M=kk=kçK=P=cycles=çf=lçading=TM=–=VM=–=TMkk= kçK=P=cycles=çf=lçading=M=–=NPM=–=TMkk=unlçad=tç=M=kk= =increase=up=tç=VM=kk= =tightening=çf=the=anchçr=lçcking=nut= =unlçad=the=hydraulic=jack== =

=cigK=NM=illustrates=that=during=phase=N=the=upper=steel=bar=strain=gaugesEb4A=and=bRAF=measure=larger=defçrmatiçns= than= thçse= pçsitiçned= in= the= deeper= bulbK= cçllçwing= the= injectiçn= çf= the= secçnd= bulb=EphaseOF=it=was=çbserved=that=a=strain=variatiçn=was=recçrded=by=the=tçp=bulb=strain=gaugesI=while=thçse=in= the= deep= bulb= EbNAI= bOA=and= bPAF= did=nçt= measure= any= defçrmatiçn= increaseI= prçving= that= the=upper=bulb=effectively=prevents=the=deeper=bulb=tç=absçrb=any=lçad=beyçnd=the=initial=preJstressK=

=oeadings=iM= meApb=NW=initial=reading=iNKKiPP= meApb= NW= reading= during=

cycling=test=iP4= meApb= NW= oeturn= tç= zerç=

cçrce=iPR= oeading= çf= the= day= after=

return=tç=zerç=iPS= meApb=OW=initial=reading=iPTKKiSR= meApb= OW= reading= during=

cycling=test=iSS= meApb= OW= oeturn= tç= zerç=

cçrce==iST= oeading=after=N=mçnth=

cigK NM pteel=bar=strain=gauges=results=in=anchçr=tO =

=oeadings=iM= meApb=NW=initial=reading=iNKKiPP= meApb= NW= reading=

during=cycling=test=iP4= meApb=NW=oeturn=tç=zerç=

cçrce=iPR= oeading =çf =the =day =after =

return=tç=zerç=iPS= meApb= OW= initial= =

reading=iPTKKiSR= meApb= OW= reading=

during=cycling=test=iSS= meApb=OW=oeturn=tç=zerç=

cçrce=iST= oeading=after=N=mçnth=

cigK NN jçrtar=strain=gauges=results=in=anchçr=tO=

=

NV4T=

`çnsistently=with= the=steel= strainJgauges= readingsI= cigK=NN= shçws= that= during=phaseN= çnly= the= strain=gauges=in=the=bçttçm=bulb=mçrtar=EbNjI=bOj=and=bPjF=read=defçrmatiçnsI=while=thçse=in=the=upper=bulb= Eb4j=and=bRjF= read=zerç=strainK=cçllçwing= the= injectiçn=çf= the= secçnd=bulb= Ephase=OF= it= was=çbserved= that= çnly= thçse=placed= in=the=secçnd=bulb=Eb4j=and=bRjF=read=defçrmatiçnsI= while= thçse=pçsitiçned=in=the=bçttçm=bulb=remained=stableK=

=4KRK Monitoring over time

=

=====

oeadings=iM= werç=reading=iN= içad=at=first=level=EPM=kkF=iO= içad=at=secçnd==level=ESM=kkF=iP= içad=at=third=level=EUR=kkF=i4= qightening= the= anchçr= lçcking=

nut=iR= rnlçad=the=hydraulic=jack=iS= oelçad=iT= curther= tightening=çf=the=lçcking=

nut==iU= oeturn= tç= zerç= in= the= pump=

pressure=iV= oeading=after=N=hçur=iNM= oeading=after=NR=days=iNN= oeading=after=N=mçnth=iNO= oeading=after=O=mçnth=

==

=

cigK NO jçnitçring=çf=anchçrs=NKN=EaF=and=PK4=EbF=çver=time =Anchçrs= NKN= and= PK4I= placed= and= instrumented= as= shçwn= in= cigsK= T= and= VbI= respectivelyI= were=mçnitçred=çver=time=in=çrder=tç=assess=their=lçngJterm=behaviçrK=qhe=results=are=shçwn=in=cigK=NOK=As =shçwn =in =cigK =NOaI =the =first =readings =after =preJstress =applicatiçn =in =anchçr =NKN =EiUI =when =the =pressure=in=the=pump=return=tç=zerç=after=the=tightening=çf=the=lçcking=nutF=indicate=a=lçss=Ein=terms=çf=defçrmatiçnI=in=micrç=strainF=equal=tç=OMBI=while=nç=further=significant=lçsses=were=recçrded=up=tç=the=last=reading=EiNOI=after=O=mçnths=when=the=lçss=is=OOBFK=cigK=NOb=shçws=that=in=anchçr=PK4=immediately=after=the=tightening=çf=the=lçcking=nut=the=lçss=is=equal=tç=PB=and==after=N=mçnths=EiNNF=the=lçss=was=equal=tç=NTBI=remaining=steady=at=this=value=alsç=after=O=mçnths=EiNOFK=qhe=results=indicate=that=a=OMB=çf=preJstress=lçss=can=be=expected=in=this=sçrt=çf=anchçrK=AnywayI=preJstress=mçnitçring=will=cçntinue=in=the=future=tç=validate=this=resultK==RK ClkCirafkd obMAohp =

qhe=cyclic= test= results= allçwed=tç=demçnstrate=that= the=use=çf= a=dçuble=bulb= in=cçmbinatiçn=with=an=initial=preJstress=after=grçuting=the=deeper=bulb=ensures=that=any=lçad=in=excess=çf=the=initial=preJstress=is=absçrbed=çnly=by=the=secçnd=bulbK=fn=factW=

– the=deep=bulbI=injected=first=and=preJstressedI=underwent=defçrmatiçns=until=the=secçnd=bulb=was=injected=and=then=did=nçt=shçw=any=further=defçrmatiçn;=

– the=tçp=bulb=takes=charge=çf=the=increase=çf=actiçns=with=respect=tç=the=pretensiçnI=after=all=lçssesI=apprçximately=equal=tç=OMBI=take=placeK=

=

NV4U=

qhe=sçlutiçn=prçpçsed=allçwed=tç=design=the=anchçrage=çf=the=new=steel=bellfry=in=such=a=way=that=nç=decçmpressiçn=çf=the=anchçrs=wçuld=ever=çccur=fçr= the=pip=cçnditiçnsI=whereas=sçme=tensiçn=in=the=anchçrs=may=çccur=çnly=at=ripI=fçr=the=part=çf=lçad=exceeding=pip=actiçnsK=qhis=sçlutiçn=permits=alsç=tç=avçid=çverJstressing=the=bell=tçwer=masçnry=under=rip=cçnditiçnsI=such=as=earthquake=and=extreme=wind=cçnditiçnsK==AhkltibadbMbkqp =qhis=research=is=part=çf=the=research=prçject=“AnfjupW=Ancçraggi=iniettati=in=muratura=stçrica”=funded=by=“mloJcbpo=OMMTJOMNP=–=oegiçne=içmbardia=–=Asse=N=–=iinea=di=interventç=NKNKNKNK=–=Aziçne=B”K===obcbobkCbp xNz Algeri= `KI= mçverellç= bKIdiuriani= bKI= mlizzari= dKEOMNMFK= “bxperimental= ptudy= ln= qhe= fnjected=

Anchçrs=Behaviçur=ln=eistçrical=jasçnry”K=fn=“Structural Analysis of eistorical Constructions”=a=cura=di=jçdenaI=içurenççI=oçcaI=phanghai=SJU=lttçbre=OMNMK=

xOz san=oickstalI=cI=qçumbakariI=bI=fgnçulI=pI=and=san=demertI=a=EOMMPFK=“aevelçpment=çf=mineral=grçuts= fçr= cçnsçlidatiçn= injectiçn”I= sf= fnternatiçnal= `çnference= jaterials= pcience= and=oestçratiçnI=harlsruhe=NSJNUKMVKOMMPI=SNJTSK=

xPz burçcçde=Eb`=O=bk=NVVOJNJN=J=marK=PKP==“mrestressed=pteel”FK=x4z British=ptandard=EBp=RSOUJOWOMMMFK=xRz BassiniI=`=ENVVUFK=“drouted anchorages in masonry walls”=jaster=qhesisI=caculty=çf=bngineeringI=

rniversity=çf=Brescia=Ein=ftalianFK=xSz diglaI= B= EOMM4FK= “Bçnd= strength= çf= injectiçn= anchçrs= as= supplementary= reinfçrcement= inside=

histçric= masçnry”I= 1Pth fnternational Brick and Block jasonry conferenceI= AmsterdamI= =4JTKMTKOMM4K=

xTz magançni= pKI= a’Ayala= aK= EOMNMF= “bxperimental= and= `çmputatiçnal= salidatiçn= çf= aissipative=mrçtçtype=fçr=the=peismic=mrçtectiçn=çf=eeritage=Buildings”K=fn=“ptructural=Analysis=çf=eistçrical=`çnstructiçns”=a=cura=di=jçdenaI=içurenççI=oçcaI=phanghai=SJU=lttçbre=OMNMK=

xUz diglaI=B=ENVVVFK=“cield=pullJçut=tests=çf=supplementary=injectiçn=anchçrs=in=histçric=masçnry”I=in=mrçceedings=çf=ptructural=studiesI=repairs=and=maintenance=çf=histçric=buildings=sfK=`KAK=Brebbia=and=tK=gagerI=edsK=pçuthamptçnI=rhW=tfq=mressI=VRJNMSK=