https://ebookmass.com/product/nonconventional-andvernacular-construction-materials%ef%bc%9a-characterisationproperties-and-applications-kent-a-harries-bhavna-sharma/
Instant digital products (PDF, ePub, MOBI) ready for you
Download now and discover formats that fit your needs...
Optical properties of materials and their applications Second Edition Singh
https://ebookmass.com/product/optical-properties-of-materials-andtheir-applications-second-edition-singh/
ebookmass.com
Nanotechnology in eco-efficient construction: materials, processes and applications Second Edition Torgal
https://ebookmass.com/product/nanotechnology-in-eco-efficientconstruction-materials-processes-and-applications-second-editiontorgal/
ebookmass.com
Olinu2019s Construction: Principles, Materials, and Methods
https://ebookmass.com/product/olins-construction-principles-materialsand-methods/
ebookmass.com
Biology - IB Prepared 1st Edition Debora M. Primrose
https://ebookmass.com/product/biology-ib-prepared-1st-edition-deboram-primrose/
ebookmass.com
Electromyography and Neuromuscular Disorders: ClinicalElectrophysiologic-Ultrasound Correlations 4th Edition
Edition David Preston
https://ebookmass.com/product/electromyography-and-neuromusculardisorders-clinical-electrophysiologic-ultrasound-correlations-4thedition-edition-david-preston/ ebookmass.com
Machine Learning for Risk Calculations: A Practitioner's View (The Wiley Finance Series) 1st Edition Ignacio Ruiz
https://ebookmass.com/product/machine-learning-for-risk-calculationsa-practitioners-view-the-wiley-finance-series-1st-edition-ignacioruiz/ ebookmass.com
Solution-focused brief therapy with clients managing trauma Adam S. Froerer
https://ebookmass.com/product/solution-focused-brief-therapy-withclients-managing-trauma-adam-s-froerer/
ebookmass.com
Arts of Allusion : Object, Ornament, and Architecture in Medieval Islam Margaret S. Graves
https://ebookmass.com/product/arts-of-allusion-object-ornament-andarchitecture-in-medieval-islam-margaret-s-graves/ ebookmass.com
Compulsion in Religion: Saddam Hussein, Islam, and the Roots of Insurgencies in Iraq Samuel Helfont
https://ebookmass.com/product/compulsion-in-religion-saddam-husseinislam-and-the-roots-of-insurgencies-in-iraq-samuel-helfont/ ebookmass.com
https://ebookmass.com/product/treatment-of-skin-disease-comprehensivetherapeutic-strategies-5th-edition/
ebookmass.com
SecondEdition
Editedby
KentA.Harries
WoodheadPublishingisanimprintofElsevier
TheOfficers ’ MessBusinessCentre,RoystonRoad,Duxford,CB224QH,UnitedKingdom 50HampshireStreet,5thFloor,Cambridge,MA02139,UnitedStates
TheBoulevard,LangfordLane,Kidlington,OX51GB,UnitedKingdom
Copyright©2020ElsevierLtd.Allrightsreserved.
Nopartofthispublicationmaybereproducedortransmittedinanyformorbyanymeans, electronicormechanical,includingphotocopying,recording,oranyinformationstorageand retrievalsystem,withoutpermissioninwritingfromthepublisher.Detailsonhowtoseek permission,furtherinformationaboutthePublisher’spermissionspoliciesandour arrangementswithorganizationssuchastheCopyrightClearanceCenterandtheCopyright LicensingAgency,canbefoundatourwebsite: www.elsevier.com/permissions.
Thisbookandtheindividualcontributionscontainedinitareprotectedundercopyrightbythe Publisher(otherthanasmaybenotedherein).
Notices
Knowledgeandbestpracticeinthis fieldareconstantlychanging.Asnewresearchand experiencebroadenourunderstanding,changesinresearchmethods,professionalpractices,or medicaltreatmentmaybecomenecessary.
Practitionersandresearchersmustalwaysrelyontheirownexperienceandknowledgein evaluatingandusinganyinformation,methods,compounds,orexperimentsdescribedherein. Inusingsuchinformationormethodstheyshouldbemindfuloftheirownsafetyandthesafety ofothers,includingpartiesforwhomtheyhaveaprofessionalresponsibility.
Tothefullestextentofthelaw,neitherthePublishernortheauthors,contributors,oreditors, assumeanyliabilityforanyinjuryand/ordamagetopersonsorpropertyasamatterofproducts liability,negligenceorotherwise,orfromanyuseoroperationofanymethods,products, instructions,orideascontainedinthematerialherein.
LibraryofCongressCataloging-in-PublicationData
AcatalogrecordforthisbookisavailablefromtheLibraryofCongress
BritishLibraryCataloguing-in-PublicationData
AcataloguerecordforthisbookisavailablefromtheBritishLibrary
ISBN:978-0-08-102704-2
ForinformationonallWoodheadPublishingpublicationsvisit ourwebsiteat https://www.elsevier.com/books-and-journals
Whilsteveryattempthasbeenmadetoobtaincopyrightpermissionforimagesreproducedinthisbook, thereareaveryfewimagesforwhichpermissioncouldnotbetraced.PleasecontactthePublisherifyou arethecopyrightownerforanysuchimage.
Publisher: MatthewDeans
AcquisitionEditor: GwenJones
EditorialProjectManager: AndraeAkeh
ProductionProjectManager: MariaBernard
CoverDesigner: AlanStudholme
TypesetbyTNQTechnologies
Contributors MartinP.Ansell UniversityofBath,UnitedKingdom
LawrenceC.Bank GeorgiaInstituteofTechnology,Atlanta,GA, UnitedStates
LolaBen-Alon CarnegieMellonUniversity,Pittsburgh,PA,UnitedStates
JulianaCalabria-Holley UniversityofBath,UnitedKingdom
SarahJ.Christian CarnegieMellonUniversity,Pittsburgh,PA,UnitedStates
FranciscoF.Correal UniversidaddelosAndes,Bogota,Colombia
V.C.Correia UniversityofS~ aoPaulo,Brazil
KeithI.Crews UniversityofTechnologySydney,Ultimo,NSW,Australia
L.Dipasquale UniversityofFlorence,Italy
R.Dzombak UniversityofCalifornia,Berkeley,CA,UnitedStates
A.Fabbri EcoleNationaledesTravauxPublicsdel’Etat(ENTPE),Vaulx-en-Velin, France
R.M.Foster UniversityofCambridge,UnitedKingdom
FabioFratini CNRICVBC(NationalCouncilofResearches-InstituteforConservationandPromotionofCulturalHeritage),Florence,Italy
T.D.Gerhardt SonocoProductsCompany,Hartsville,SC,UnitedStates
KhosrowGhavami PontifíciaUniversidadeCatolica,RiodeJaneiro,Brazil
KentA.Harries UniversityofPittsburgh,UnitedStates
AtifHussain UniversityofBath,UnitedKingdom
YunhongJiang UniversityofBath,UnitedKingdom
JohnM.Kinuthia UniversityofSouthWales,Cardiff,UnitedKingdom
Kunal ThaparUniversity,Patiala,Punjab,India
RandolphLangenbach ConservationtechConsulting,Oakland,California,United States
MichaelLawrence UniversityofBath,UnitedKingdom
L.F.Lopez BaseBahayFoundation,Manila,ThePhilippines
D.Maskell UniversityofBath,UnitedKingdom
AnkurMehta ArkadeConsultants,Hisar,Haryana,India
KhanjanMehta LehighUniversity,Bethlehem,PA,UnitedStates
JeanClaudeMorel CoventryUniversity,Coventry,UnitedKingdom
IanNettleship UniversityofPittsburgh,UnitedStates
ChristopherPapadopoulos UniversityofPuertoRico,Mayag€ uez,PR,United States
MichaelH.Ramage UniversityofCambridge,UnitedKingdom
L.Rovero UniversityofFlorence,Italy
S.F.Santos SaoPauloStateUniversity,Brazil
HolmerSavastano,Jr. UniversityofS~ aoPaulo,Brazil
BhavnaSharma UniversityofSouthernCalifornia,LosAngeles,UnitedStates
AndyShea UniversityofBath,UnitedKingdom
RafatSiddique ThaparUniversity,Patiala,Punjab,India
S.Suf fian VillanovaUniversity,Villanova,PA,UnitedStates
A.Thomson UniversityofBath,UnitedKingdom
G.H.D.Tonoli FederalUniversityofLavras,Brazil
DavidJ.Trujillo CoventryUniversity,UnitedKingdom
H.C.Uzoegbo UniversityoftheWitwatersrand,Johannesburg,SouthAfrica
ArjanvanderVegte MOSOInternationalBV,Zwaag,TheNetherlands
PeteWalker UniversityofBath,UnitedKingdom
AndryWidyowijatnoko BandungInstituteofTechnology,Indonesia
YanXiao ZhejiangUniversity UniversityofIllinoisatUrbanaChampaignInstitute,Hangzhou,China
ChuyuanZheng UniversityofPittsburgh,UnitedStates
Preface Safetyinthebuiltenvironmentisafundamentalright1.Whileadequateshelteris perhapsthemostcriticalaspectofacommunityinfrastructure,thelackofstable infrastructureisoftencitedastheprimarybarriertosustainabledevelopment.Indeed, itissuggestedthat ‘sustainabledevelopment’ maybelargelyunattainabletoallbutthe wealthiestandmostadvancedglobalcommunities2.Sustainabledevelopmentismost commonlydefinedasthatwhich “meetstheneedsofthepresentwithoutcompromising theabilityoffuturegenerationstomeettheirownneeds. ”3 Whatisoftenomitted fromthisdefinitionhoweverarethelinesthatimmediatelyfollow: “ .Itcontains withinittwokeyconcepts:1)theconceptofneeds,inparticulartheessentialneeds oftheworld’spoor,towhichoverridingpriorityshouldbegiven;and2)theidea oflimitationsimposedbythestateoftechnologyandsocialorganizationontheenvironment’sabilitytomeetpresentandfutureneeds.” Itisthechallengeofcouplingboth globalandregionalsustainabilitypracticeswithsocialequitythatliesattheheartofthe grandengineeringandsocialchallengesofthetwenty firstcentury.Nonconventional andvernacularconstructionmaterialsareoneaspectofaddressingthesechallenges andbringingsustainabledevelopmentwithinreachoftheentireglobalcommunity. Thereisconsiderableinterest ifjudgedbytheproliferationofjournalarticlesin recentyears inthemodernengineeringapplicationofnonconventionalmaterials (NOCMAT).Oftenthisinterestisdrivenbytheinterestsofsustainableengineering and/orthenewertrendstoward ‘engineeringforhumanity’ and ‘socialentrepreneurship’ (Chapter5).Nonetheless,therearefewrepositoriesofsuchinformation.InEnglish,afewinternationalconferences(theNOCMATseriesbeingoneoftheoldest) andregionallyfocusedjournalsdominatetheliterature.Overthelastfewyears, morehighqualityresearchismakingitswayintoarchivaljournalsbut,withafewexceptions,sucharticlesremainattheperipheryofthejournalfocusandareoften includedbasedontheir ‘sustainability’ credentials.Thisvolumeaimsto fillthissignificantgapintheavailableliteratureandservesasanimportantresourceforengineers, architects,academicsandstudentsinterestedinnonconventionalmaterials.
1 1948UnitedNations UniversalDeclarationofHumanRights reiteratedinthe1994UnitedNations SpecialRapporteur’sReporttotheUnitedNationsCommissiononHumanRights
2 Silberglitt,R.etal.,2006. “TheGlobalTechnologyRevolution2020,In-DepthAnalysesBio/Nano/ Materials/InformationTrends,Drivers,Barriers,andSocialImplications.” ReportTR-303-NIC,Rand Corporation314pp.
3 WorldCommissiononEnvironmentandDevelopment,1987. OurCommonFuture.OxfordUniversity Press[so-calledBrundtlandreport].
Preface
Thefocusofthisvolumeisthematerialsscienceandmodernstructuralengineering (andsomearchitectural)applicationsofancient,vernacularandnonconventional buildingmaterials.Suchmaterialsaredefinedtoincluderelativelyunprocessednaturallyoccurringmaterialsandprocessedorengineeredmaterialsdevelopedfromthe naturalmaterial.Chaptersfocusonindividualconstructionmaterialsandaddress bothmaterialcharacterisationandstructuralapplications.Eachchapterreflectsthe currentstate-of-the-artintermsofthemodernuseandengineeringofthematerial. Forthesecondedition,newChapters4through6havebeenaddedaddressing ‘meta-issues’ impactingallnonconventionalmaterialpractice.Othernewchapters havebeenaddedand firsteditionchaptershavebeenupdated,insomecasessigni ficantly.Foreaseofreferenceanduse,thevolumeisdividedintofourparts.
PartIprovidesanintroductiontononconventionalandvernacularmaterials, exploringtheirroleinbothsocialandengineeringcontexts.Chapter1placesvernacularconstructionmethodsinamodernsocialcontext.Chapter2considersthehistoric contextofthesematerialsanddescribesthedevelopmentoftheirformalstudywhile Chapter3lookstofutureneedsandapplications.Chapters4through6explorethe meta-issuesofCodesandStandardsdevelopment(Chapter4),engineeringeducation (Chapter5),andtheroletheemerging fieldofmaterialinformaticscanplayinthe developmentofnonconventionalmaterials(Chapter6).
PartIIfocusesonnatural fi bres.Chapter7describesnatural fibre-reinforcedcementitiouscompositeswhileChapter8considersnon-cementitious ‘bio-composites’ Chapter9describesstrawbaleconstructionwhichhasbeengainingtractionindiverse communitiesaroundtheglobe.Finally,Chapter10describesapplicationsof bio-compositesandrendersforconstruction.
PartIIIfocusesonnonconventionalconcreteandmasonrymaterials.Chapter11 describesthestate-of-the-artinnaturalashandwastebasedconcrete.Chapters12 through14describevariousmasonrypractices,fromdrystackandpressedbrick (Chapter12),unfiredclay(Chapter13)andadobe(Chapter14).Nonconventional aspectsofstonemasonryconstructionaredescribedinChapter15.
PartIVcoversnonconventionalforest-products.Chapter16considersnonconventionaltimbermaterialsinconstructionandChapter17describestheemergingengineeringofhigh-risetimberconstruction.Chapter18introducesfull-culm(pole) bamboomaterialswhileChapter19describesfull-culmbambooconstruction.Chapter 20focusesexclusivelyonmethodsofconnectingbamboo.EngineeredbamboomaterialsaredescribedinChapter21andtheapplicationoftheseinChina,inChapter22. FinallyChapter23introducesathoroughlymodernnonconventionalmethodofconstruction:papertubes.
Itishopedthatthisvolumewillproveinstructiveandeducationalwhileservingas animportantresourceforengineers,architects,academicsandstudentsinterestedin nonconventionalmaterials.
Theeditorswouldliketothankallcontributingauthorsfortheiroutstandingwork andformaintainingourambitiousscheduleforthisvolume.Thanksaredueallat Elsevier,inparticularProjectManagersforthe firstedition,AlexWhiteandKate Hardcastle,andAndraeAkehwhohelpedguidethesecondedition.
Preface xvii
Theeditorswouldliketoacknowledgetheoutstandingcareerandcontributionsto theNOCMATcommunityofProfessorHectorUzoegbo(Chapter12)whopassed awayinDecember2018.
Finally,wewouldliketodedicatethisbooktothememoryofourfriend,colleague andcollaborator,Ms.GayatriKharelwhoprovidedtheopportunityforusbothtodelve deeperintothis fieldthanwemayhaveimagined.
KentA.Harries,Pittsburgh BhavnaSharma,LosAngeles September2019
Whatwelearnfromvernacular construction 1 RandolphLangenbach
ConservationtechConsulting,Oakland,California,UnitedStates
Chapteroutline
1.1Bam1
1.2Vernacular5
1.2.1 “Vernacular” defined6
1.3Vernaculararchitecture8
1.4The “vernacular” ofindustrialarchitecture8
1.5Srinagar,Kashmir,India11
1.6Thegreat1906SanFranciscoearthquakeand fire18
1.7Skeleton-frameconstruction22
1.8Framesandsolidwalls27
1.9Conclusion:the “ecology” ofthevernacular28 Endnotes34 References34
1.1Bam OnDecember26,2003,whilelocalresidentswerestillsleeping,anearthquakewitha magnitudeof6.6(USGS,2004)strucktheancientcityofBaminIran.Despitetherelativelymodestmagnitude,thesurfaceshakingwasintenseenoughtodevastatethecity, killingapproximately30,000people,one-thirdofthepopulation.Manyofthenews photographsthatcircledtheglobewereofthedevastatedruinsofthecity’smosticonic heritagesite,theancientcitadelrecognizedasthelargestearthenstructureintheworld, the “Arg-e-Bam ” (Fig.1.1).Becauseofthesedramaticviewsofthepulverizedpartsof theArginthenews,manypeopleassumedthatmostofthe30,000peoplewhowere killeddiedintheancientearthenbuildingsoftheArg.Infact,theydidnot.Thedeath tollwasalmostexclusivelycausedbythecollapseofbuildingsinthemoderncity, almostallofwhichhadbeenconstructedduringthepast30years.
The “Arg” wasanancientwalledcitythatbecameanarcheologicalsiteand museumofthehistoryofthecity.Afterbeingcontinuouslyoccupiedfromasearly asthesixthcenturyBCE,ithadfallenintodisuseintheearly19thcentury,when
Fig.1.1 TheArg-e-BamarcheologicalsiteinBam,Iran,beforeandafterthe2003Bam earthquake. BeforeearthquakephotobyJamesConlon,2003.
peoplefeltsafeenoughtoabandontheirhousesprotectedbytheforti ficationsand moveintotheirdatepalmorchardsthatwereplantedaroundtheArg.Bythemiddle ofthe20thcentury,wellaftertheArgbuildingshadfallenintorooflessruins,amajor restorationprojectwasbeguntoturntheArgintoatouristattraction.Overthecourse ofthehalf-centuryprecedingthe2003earthquake,awideswathofbuildingsfromthe maingatetotheGovernor’sHouseonthehillwererestored(Figs.1.2and1.3).These includedthemainmarketstreet,twocaravanserais,themainmosque,theGovernor’s House,andalargepartofthefortifications.Bythetimeoftheearthquake,therestored site,withitsundulatingearthenwalls,hadsuccessfullybecomeaworld-famous attraction.
The2003earthquakerenderedtheArgalmostunrecognizable.Manyofthe formlessrubblepilesactuallystoodhigherthanthewallsthatwereleftstillstanding. ThesitequicklybecameasymbolfortheearthquakeinthesamewayasdidtheNationalPalaceinPort-au-Prince,followingthe2010HaitiEarthquake.WhenIarrived toinspectthesiteasadelegateinaUNESCO-organizedinternationalreconnaissance andconferenceheldfourmonthsaftertheearthquake,theconventionalwisdomwas thatthedamagecouldbeexplainedbythesimplefactthattheArgwasconstructed ofunfiredclay.
ForthoseofuswhoarrivedinBamshortlyaftertheearthquake,theargumentthat theArgcollapsedsimplybecauseitwasunfiredclaydidnotimmediatelyseemtobe unreasonable.Thisimpressionwasreinforcedbywhatcouldbewitnessedinthe surroundingsettlement,wheremanymodernsteel-framebuildingshadalsocollapsed.
Fig.1.2 EarthquakedestructionoftherestoredpartsoftheArg-e-Bamphotographedfour monthsaftertheearthquake.
Fig.1.3 ViewofanarcheologicalsiteinBamwithhighwallsthatcamethroughthe2003 earthquakewithverylittledamage.
Infact,priortomyarrivalinBamIhadbeentoldbyaseismicengineerinTehranthat earthenconstructionshouldbebanned,despiteitscontinueduseandpracticalityinthe desertclimateandashortageoftimberinIranandtherestoftheMiddleEast.
At firstglance,afterenteringtheArg-e-Bamtherewaslittletobeseentoquestion suchanopinion.Thedevastationwasvast.However,ontraversingthesitemorethan onetime,therewereincreasingvisualsignalsthattheunfi redclayconstructioncould notaloneexplainthenatureandextentofthedamage.First,therewasalmostnoevidenceofdiagonaltensioncracksinthecollapsedorstill-standingwalls.Instead, almosteverywherethewallslookedasiftheycollapsedvertically likeaslump testwithtoomuchwaterinaconcretemix(Langenbach,2004).
Lookingfurther,itbecameevidentthatsomewallsandstructureshadappearedto survivealmostentirelyintact,whileotherswereonlyapileofrubble.AsIcontinuedto lookapatternbegantoemerge.ThiswasparticularlyevidentwhenIcameuponan areathathad not beenrestored.Thestandingwallsofunrestoredstructures,abandoned formorethanacenturyandahalf,hadsurvivedwithlittledamage,whilethosethat collapsedwerealmostalwaystheonesthathadbeenrestoredinrecentdecades.In addition,whenexaminingthemilitaryforti fications,counterintuitively,thethicker thewallthe more likelyitwastohavebeencollapsedbytheearthquake.
AsIcontinuedtolookIalsodiscoveredthatinarandomsamplingofthecracked opensectionsofthecollapsedorbrokenwalls,therewasfrass(insectexcrement)in practicallyeverysingleone.TheIranianarcheologiststoldmethiswasfromalocal speciesoftermites. Termites? Inanarcheologicalsitewithwallsdatingback2000 8000years?Thiscommentlaunchedmeonastudythatintheendhadmoretodowith materialssciencethanwithstructuralengineering(Fig.1.4).
The firstquestionwas:Whydidtheunrestoredrooflessbuildingssurvivetheearthquakebetterthantherestoredstructures?Anddidthetermiteshavesomethingtodo withthis?Tosearchforananswertothisquestion,Iturnedtoanewsubjectofinquiry thescienceofthecohesionofunfiredearthenconstruction.Thequestionwashowit mayhavebeencompromisedbythe20th-centuryrestorationwork.Achancemeeting withanengineeringdoctoralstudentfromtheUnitedKingdom,PaulJaquin,provided
Whatwelearnfromvernacularconstruction5
the fi rststepstowardananswer.Hehadbeendoingdetailedresearchonrammedearth construction,includingitsinternalcohesion [1].FromhimandlateralsofromcolleaguesattheFrenchresearchandteachinginstituteCRAterre,Ilearnedthatthe mostsigni ficantcontributortocohesioninunfiredclayisthemeniscusforcesofwater (VanDammeetal.,2010). Water? Inancientstructuresinahotdrydesert?
JaquinandCRAterre’sresearchhadshownthatthecohesiveforcefromwaterisso effectivethattheuseofstabilizerscanonoccasionreduce,ratherthanincrease,thecohesionoftheclay.EveninverydryclimatessuchasthatinBam,thereisaresiduallevelof moisturethatnormallyremainsinintactearthenwalls.Thiscanbeenoughtoholdthe wallstogether,sometimesforcenturies.Soaplausiblehypothesisofwhathadhappened inBamisthattheresidualmoisturehaddisappearedpriortotheearthquake.But why?
WhileinBamIlearnedthatthemodernrestorationworkwasreinforcedwithstraw, whilehistoricallytheclaywaseitherwithout fiberreinforcementorreinforcedwith shreddeddatepalmbark.Thus,themodern-dayrestorershad,ineffect,beenfeeding thetermitesabanquet,whereashistoricallythebuildershadusedamaterial,datepalm bark,whichwasresistanttotermites.Therehadbeen,ineffect,alossoftraditional knowledgebetweenthetimewhentheArgwaslastinhabitedandwhenitwasrestored acenturyandahalflater.
Tounderstandhowthismayhavemadeadifference,Icouldseethatthetermites hadperforatedthewallsbyconsumingthestrawreinforcement.Thisthenlikely contributedtoadesiccationofthewalls,resultinginalossofsuctionprovidedby theresidualwaterthathadgiventhewallsalargepartoftheircohesivestrength.
Thisinvestigationthenledtoevidenceofothercausesofalossofclaycohesionthat mayhavebeenmoresignificantthanthetermiteinfestationsalone.Perhapsthemost importantpathologywasthatovercenturiesofoccupancy,witherosionandrepair,the ancientwallshadevolvedfromhavinghorizontallybeddedmudlayerstowallswith verticalconstructionjoints.Thelaterrestorationwork,whichincludedthereconstructionofthemissingupperpartsofthewallsandroofs,addedoverburdenweighttothe survivinglowerpartsofthewalls.Thehigh-frequencyearthquakevibrationsthus causedthisnewworktosimplycrushtheolderpartsofthewalls.Thisexplained whythewallshadcollapsedinplaceratherthanfallingover,asevidencedbythelocationoftherubblepileswithlittlestillstandingthatremainedrecognizable(Langenbach,2005).
1.2Vernacular So,whatisthesigni ficanceofthisstoryinabookabout “nonconventionalandvernacular” constructionmaterials?Sinceunfi redclaymaystillbethemostcommonlyused buildingmaterialworldwide,howcanitalsobeclassifi edasbeing “nonconventional?”
Ofcourse,onemust firstunderstandthattheuseoftheterms “vernacular” and “nonconventional” inthecontextofarchitectureandconstructiontechnologyare notmeanttoconnote “primitive” orlackinginsophisticationorscientificbasis.For example,Romanconcrete,whichhasdemonstratedaremarkableresilienceand longevity,continuestodefyeffortstoanswerallquestionsaboutitsoriginalprehydrationandcarbonationconstituentsbecauseofthecomplexityofitspolymerizationover
Fig.1.5 ContinuationofavernacularbuildingtraditioninLuongPrabang,Laos.
manyyearsintoasequenceofdifferentminerals.Likethelabelingofahumanlanguage,fromwhichtheterm “vernacular” originallyhasbeenderived,vernacularconstructionisfoundedonthedualityalludedtointheprevioussentence,namelythatit hasevolvedfromhumanobservationandexperienceoverhundreds,ifnotthousands, ofyears(Fig.1.5),whileatthesametimeisscientificallycomplexenoughtojustify manydissertationsandbooks.Thisisoneofthosebooks.
Thestoryoftheearthquake-inducedcollapseoftheArg-e-Bamisastoryofashift fromanempiricallybasedtraditionalknowledgesystemhandeddownovercenturies andevenmillennia,toourownerainwhichthattraditionalknowledgehasbeenlost becauseoftheintroductionofnewmaterialsandconstructionsystems,changesineducation,andincreasinglydisusedconstructionsystemsandtechnologiesthathave beenforgottenasthecraftsmenhaveretiredanddied.Thistime-honoredempirically basedknowledgehasbeenreplacedbyverysophisticatedscientifi cresearchinthe fi eldsofmaterialsscienceandstructuralengineering,butthisscience-basedknowledgeisnotoftencommunicatedtomasons,orevenknownbypeoplewhereitis neededmost:theworkersontheconstructionsite.Whilemodernsciencehasoften confi rmedthetime-honoredempiricalknowledge,ithasnotandcannotentirely replacethekindofknowledgepassedfromgenerationtogenerationthatmadestructuressuchastheArglastaslongastheyhave,basedontrialanderrorexperiencesover centuriesandevenmillennia.
1.2.1 “Vernacular” defined “Vernacular” hasitsoriginintheLatin vernaculus: “domestic,”“native” from verna: “home-bornslave,” awordofEtruscanorigin.Fromthebeginningofthe18thcentury, itcametomeanthe “nativespeechorlanguageofaplace” [2].
“Vernaculararchitecture” accordingtotheOxfordEnglishDictionaryis “Architectureconcernedwithdomesticandfunctionalratherthanmonumentalbuildings.” Itis interestingto findthatitisdescribedinpartas “contrastedagainstpolitearchitecture whichischaracterizedbystylisticelementsofdesignintentionallyincorporatedfor aestheticpurposeswhichgobeyondabuilding’sfunctionalrequirements” [3].This raisesthequestionofaestheticintentionswithinthedomainofvernaculararchitecture. Onecanarguethatvernaculararchitecture particularlythatwhichremainsuniversallylovedbypeoplefrommostwalksoflife showsevidenceofmanydeliberate aestheticintentions,suchasarefoundinanEnglishCotswoldcottage,atraditional TurkishOttomanhouse,afarmsteadinKerala,India,orashophouseinPingyao, China.Thedifferenceswith “polite” architecturearenotthepresenceorabsenceof aestheticintentionsbutratherthepredominantmanifestationoftime-honoredlocally basedcultures(Fig.1.6).
Thesameappliestothequarryingandharvestingofbuildingmaterials.Vernacular architectureismostoftencreatedfrommaterialsobtainedormanufacturedlocally.For example,whilebrickandlimemortararemanufacturedproducts,brickandlimekilns wereoftenerectedinvillagesandtownswheretherawmaterials,clayandlimestone (orinRome,sadly,themarblefromtheabandonedancientRomantemples [4])were available(Fig.1.7).Wherelimestonewasnotavailable,mudmortarwouldserve almostaswell.Wherepozzolanorshalewasmixed(at firstbynature)withthelimestone,naturalhydrauliccementwouldresultsuchasisfoundinthevernacularconstructioninSantorini,Greece,andinItalyclosetoMountVesuviusandthevillage ofPozzouli,fromwhichtheterm “pozzolan” originated.
RomansturnedthisintoabusinessbymarketingpozzolanforthemakingofhydrauliccementmortarsaroundtheMediterranean.Onemaythusaskiftheresulting constructionsare “vernacular?” Iwillleavethatquestionunanswered,usingitonly
Fig.1.6
TraditionalbrickkilnsnearKathmandu,Nepal,2000.
topointoutthatthedefinitionthatisbestmaybetheonethatallowsforexceptions,in thesamewaythatavernacularlanguageisalanguagethatisnotonlylocalinitsorigins,but fluidandever-changing.
1.3Vernaculararchitecture Perhapsthebestdistinctionbetweenvernacularand “polite” architectureandconstructionmaybethefactthatinvernacularbuildings,thebasicstructuralsystemismore oftenexposedor,atthemost,coveredwithacontiguouslayerofmudorlimeplaster. Thisisincontrasttobuildingswithaveneerofnonstructuraldressedstoneorbrickon theexterioranddroppedceilingsandornate fi nishesontheinteriorwalls.
Thereinlaystheessenceoftheaestheticsofvernaculararchitecture.Notonlyare theresimpledesignrulesor “patterns” basedonhuman-scaledproportions,ashave beendocumentedanddescribedbyChristopherAlexanderinhisinfl uentialbook A PatternLanguage,butalsotheaestheticsofthecraftsmanshipoftheprincipalstructuralelements,suchasthemasonry,timberframes,orearthenwalls(Alexanderetal., 1977).Inasense,thedemandsonthequalityofthecraftsmanshipoftheoriginal buildersisevengreaterthanin “polite” architecture,wherethe finishworkhidesthe structuralwallsorframes.Forexample,tiedbamboojointsortheundulatingmud stuccosurfacelaidovertheadobeblocksontheinteriorsandexteriorsformthearchitecturalaestheticofvernacularbuildings(Fig.1.8).Thisdifferenceisapparentwhen onecomparesthesebuildingswithmanymodernconcrete-framebuildings,wherethe rockpockets(gapsintheconcretewheretheunconsolidatedaggregateformsadam) andotherconstructionfaultsmustbecoveredby fi nishes.
1.4The
“vernacular” ofindustrialarchitecture Myresearchonthesubjectoftraditionalbuildingconstructiondidnotbeginintheruralcountrysideofadistantland,butratherintheheartofthe firstindustrialcitiesofthe
Fig.1.7
UnitedStates.Inthemid-1960sIbeganadocumentarystudyoftheearlyarchitecture oftheindustrialrevolution the firstgenerationofmasonryandtimbertextilemills andplannedindustrialcitiesinearly19th-centuryNewEngland [5].Thesebrickand stonebuildingswereconstructedwithtimberplankandbeam floors.Theywereusually fiveorsixstoriesinheight,butinsomerarecasesrosetoashighasninestories, makingthemthelargestandtallestmultistorybuildingsoftheirtime furthercomplicatedinthattheywereheavilyloadedwithcastironmachineryandwares.
Overthecourseofthe19thcentury,thesewater-poweredfactorycomplexesand milltownsevolvedintostrikinglyimpressiveexamplesofarchitectureandurban design(Fig.1.9).However,unfortunately,atthetimeofthisresearchanddocumentationinthemiddleofthe20thcentury,thesehistoricfactoriesinNewEngland werelargelyabandonedandmanywerebeingdemolished,and,justashadhappened totheancientmarblesinRome,theywerequarriedfortheirbrick,stone,andtimberfor newconstruction,whichwasoftenonlyusedforsuburbanhousesforthewealthy.
ItisinterestingtoconsiderwhethertheseearlyAmericanindustrialbuildingsand theircounterpartsinGreatBritain,wheretheIndustrialRevolutiongainedits firstfoothold,meetthedefinitionof “vernacularconstruction.” Whenonestudiestheevolution ofbuildingconstructionfromthepre-industrialeratothepresent,onemustrecognize oneimportantfactwhichseparatesmostbuildingconstructionfromindustrialproducts:forthemostpart,eveninthepresent,buildingsarestillconstructedbyhand. True,moreofthematerialsandlargerelementsaremanufacturedandpreassembled, buttheprocessofbuildingastructureisstillusuallyuniqueandthusdependenton on-sitecraftsmanshipasmuchasonoff-sitemanufacturing.Inthecaseof19th-century factorybuildingsthestone,brick,andtimberwereobtainedaslocallyaspossible. Limestoneandgranitequarrieswereopenedandbrickkilnsconstructedveryclose tothesites.
Fig.1.8 Contemporarydesignofaresort(PlayaViva)constructedwithtraditionalmaterials nearZihuatanejo,Mexico.
Fig.1.9 Nineteenth-centurymillbuildingswithwaterpowercanal,AmoskeagMillyard, Manchester,NewHampshire,USA,in1966.Thebuildingsontherighthavesincebeen destroyedandthecanal filledinforroadsandparkingaspartofaUSgovernmentfunded “urbanrenewal” programinthelate1960sand1970s,beforetheirheritagevaluewas recognized.
InBritain,wherecoalwaslocallyplentifulbutstructuraltimberlargelydepleted, castandwroughtironweremoreoftenusedfortheinteriorpostandbeamframework. Interestingly,intheUnitedStates,castironwasmorecommonlyusedforcolumnsin theearlypartofthe19thcenturythanitwaslaterbecausein1855inLawrence,Massachusettsalargemillcollapsedinthemiddleofaworkdayasaresultof flawsinits castcolumns.Fromthatdayforwardwellintothe20thcentury,textilemillswereconstructedwithwhatonewouldthinkwouldbetheless “industrial” material timber. However,woodhadprovedtobemoreresilientthancastironfortheheavyloadsand strenuousvibrationsofamill filledwithoscillatingpowerlooms.
Today,onecanonlyreflectonthefactthatifthe Rana Plaza,aneight-storyreinforcedconcreteframeindustrialbuildingnearDhaka,Bangladesh,hadinsteadbeen supportedontimbercolumns,the1,129peoplewholosttheirlivesinthe13thof May2013collapseofthestructurewouldstillbealive.Thus,onecanalsosaythat animportantadditionaldefinitionofvernacularconstructionisthatitismoreeasily understoodbylocalownersandbuildersthanisconstructionthatisdependentfor structuralreliabilityoncomplexscienti ficprocessesandtheoreticalanalysiswithdifferentialequations,asisreinforcedconcrete(Figs.1.10and1.11).
PrincetonProfessorRobertMarkin1990touchedonthisissuewhenhemade thefollowingcounterintuitiveyetprescientobservation(Mark,1990):Oneofthe
Fig.1.10 Frontfaçadeofthe Rana Plaza,Bangladeshbeforecollapse.Elevationviewof frontfaçadeof Rana PlazanearDhaka,Bangladesh.Thisrectifiedimagewasconstructedby authorfromacombinationofnewsmediaTVvideoimagestoshowthefaçadepriortocollapse. Thisphotoreconstructionofthebuildingservestobringintofocusafactthat,inadditionto itsstructuralfailings,itwasunremittinglyuglyasaworkofarchitecture.Iwouldsaythat thesetwoaspectsofbuildingdesignareactuallycloselyrelated.ThedeveloperSohelRana’s grotesquefailureeventograspthetruthofhisownengineers’ warningsofimminentcollapseare ofapiecewithhisignoranceandevencontemptforarchitecturalexpressionthatisresponsiveto thelocalandnationalculture [6]
reasonsforthesuccessofthebuildersofmonumentalmasonrystructuresoverthepast twomillennia “istheforgivingnatureoftypicalmasonryconstructionascompared withtherelatively ‘highstrung’ natureofslendermodernstructuralelementsofreinforcedconcreteandsteel” (p.170).
1.5Srinagar,Kashmir,India Whileitcanbearguedthattheconstructiontechnologyfoundin19th-centuryfactories isconsistentwiththedefinitionof “vernacular construction, ” fewwouldarguethatall butthemostremoteruralfactoriesareexamplesof “vernacular architecture.” WhileI havealwaysenjoyedvernaculararchitecture,mymorein-depthengagementwithitas atopicofresearchfollowedavisitin1981toSrinagar,Kashmir,innorthernIndia (Langenbach,1982).Atthattime,morethanathirdofacenturyago,enteringSrinagar waslikegoingbackahalfamillenniumintime.Thehousesappearedtobeancientand
Fig.1.11 Rana Plazaafter2013pancakecollapsethatkilled1,129people. PhotobyRijans,WikimediaCC.
timeless,withmuchevidenceofwearandtear.V.S.Naipaul(1964)madetheobservationin1964:
Itwasamedievaltown,anditmighthavebeenmedievalEurope,Itwasatownof smells:ofbodiesandpicturesquecostumes . atown . ofdisregardedbeauty . a townofnarrowlanesanddarkshopsandchokedcourtyards(p.123).
Srinagarwasin1981adenselypackedcityfullofhouses(Fig.1.12).Unfortunately,overthelast30yearsmuchhasdisappeared,onlytobereplacedbyroads widenedformilitaryvehiclesand “modern” reinforcedconcretebuildings.Intheoldestportionsofthecityin1981,theresidencesweremixedtogetherwithshopsand evensmallmanufacturingindustries,suchascarpetweavingandmetalworking.The viewofthisdensedevelopmentandteemingactivitywaslikeasceneoutofthepages ofDickensoracanvasbythe16th-centuryDutchpainterBruegel.
Thehousesthemselveswere(andmanycontinuetobe)whatformedthebackdrop tothisremarkablescene.Theyappearedricketyandinsubstantial,almostasifthey weredeliberatelybuiltonlyasastagesetforthehumanpageantwhichtookplace aroundthem.Thesebuildingsprovidedanopportunitytostudythelinkagebetween
TraditionalhousesalongtheRaniwariCanal,Srinagar,Kashmir,2005.
traditionalconstructiontechnology,vernaculardesign,andatraditionalwayoflife (Figs.1.13and1.14).
WhenembarkingonhistoricalresearchofSrinagar,Icameacrossremarkablemidandlate19th-centurydescriptionsofthebuildingsbyBritishwriterswhodescribed theirobservationsoftwoseparateearthquakesthatoccurredin1868and1885.These observationswereofparticularinteresttome,asIwasintheprocessofmovingtothe earthquake-proneareaofCaliforniain1984.To findmasonrybuildingsrecognizedin themid-19thcenturyasearthquakeresistantprovidedaninterestingpointofcomparisontotheUnitedStatesatatimewhenhistoricunreinforcedmasonrybuildingswere broadlybeingcondemnedandeithertorndownorretrofittedwiththeirmasonrywalls entombedbehindsteelandconcrete.
WoodintheHimalayanregionwascomparativelyplentifulbeforethemodernera, butithadtobesawnbyhandastherewerenosawmills.Also,nailswerehandforged ratherthanpurchasedbythebox.Thus,theprimarylocallyavailablebuildingmaterial intheValeofKashmirwasclay,whichwas firedintobricksorusedformortar.Timber,however,wasusednotonlytosupportthe fl oorsandroofbutalsotoreinforcethe masonry(Fig.1.15).
MostofthetraditionalbuildingsinSrinagarcanbedividedintotwobasicsystems ofconstruction.The firstsystem,referredtoas taq inKashmiriand bhatar inPashtun, consistsofthickload-bearingmasonrypierswiththinnermasonrywallsinbetween (Fig.1.16).Theseseparatesectionsofmasonrywallsandpiersarethenlacedtogether withtimbersthatformringbeamsaroundtheexteriorwallsandareheldtogetherwith woodentiesthatpassthroughthewallsateach fl oorlevel.Thistimberlacingisconfiguredlikeladderslaidhorizontallyinthewall.Theyarelaidbelowandabovethejoists
Fig.1.12
Fig.1.13 Narrowlanewithtimber-lacedmasonrybearingwallbuildingsincentralSrinagar, Kashmir,2005.
ateach floorlevel,whichthentiethewallstogetherwiththe floorsbecauseofthefrictionprovidedbytheoverburdenweightofthemasonryabove.
Whatisimportanttonoteregardingthissy stemisthattherearenoverticaltimbers oranyotherformofverticaltensionreinforcement.Thisissomethingthatseems counterintuitivetomostengineerstoday,includingtheengineersinIndiawhoproducedtheotherwiseremarkablyforward-thinkingIndianBuildingCodeIS13828for “ non-engineered ” constructionthatisbasedonthissystem [7] .Asaresultoftheir insecuritywithhavingonlyhorizontalreinforcement,thiscoderecommendsthata cementgrout-encasedsteelreinforcingbarbeembeddedinthemasonryineach exteriorcorner.Myconcernisthatthisco lumnofsteel-reinfo rcedconcreteover timeislikelytopreventthenaturalchangesindimensionofthesurroundingloadbearingmasonrylaidinsoftmudmortar,andthesteelrebarswillrustandbeimpossibletomaintainandreplace.Intheevent ofanearthquake,itcoulddisruptthemasonryinsuchawaythatitwillbemuchmore likelytocollapse,ormostcertainlybe moredif fi cultorimpossibletorepair(Langenbach,2009).
Thesecondsystem,knownas “dhajjidewari” construction,consistsofabraced timberframewithmasonryinfill.Itisbrick-noggedtimber-frameconstructionthat inBritainisknownas “half-timber.” Dhajji-dewari comesfromthePersianwords
Fig.1.14 Viewoffour-and five-storybuildingsoftraditional taq (ontheleft)and Dhajjidewari (ontheright)constructioninthecitycenterofSrinagar,Kashmir,2005.
Fig.1.15 Contemporarycontinuationofpreindustrialtechniqueofsawingtimbersintoboards inKashmir. PhotobyAbbidHussainKhan,INTACH,2006.
Fig.1.16 Canalsidebuildingof taq constructionincentralSrinagar,showingthetimber-laced masonryconstruction,photographedin1981.Noticethatthewindowsdonotlineupvertically andthatthemasonryisdividedintopanelsandpiers,whichisonlypossiblestructurallybecause ofthetimberringbeamsinthemasonrywalls.
for “patchquiltwall” (Figs.1.17and1.18).ItissimilartowhatinTurkeyiscalled hımıs ¸ (Langenbach,2009).
AftertheOctober2005Kashmirearthquake,structuralengineeringProfessorsDurgeshRaiandChallaMurtyoftheIndianInstituteofTechnologyKanpurreportedthat (RaiandMurty,2005)
InKashmirtraditionaltimber-brickmasonry(dhajji-dewari)constructionconsistsof burntclaybricks fillinginaframeworkoftimbertocreateapatchworkofmasonry, whichisconfinedinsmallpanelsbythesurroundingtimberelements.Theresulting masonryisquitedifferentfromtypicalbrickmasonryanditsperformanceinthis earthquakehasonceagainbeenshowntobesuperiorwithnoorverylittledamage.
Theycitedthefactthat “thetimberstudsresistprogressivedestructionofthe. wallandpreventpropagationofdiagonalshearcracksandout-of-planefailure. ”
Fig.1.17 Dhajji-dewari buildingshowingthesingle-leafconstructionofthewalls.Thebuilding wasunderdemolitionforaroadwidening,2005.
Fig.1.18 Newconstructionin dhajji-dewari photographedin1989.Morerecently,thisformof constructionhaslargelygoneoutofuse,infavorofreinforcedconcrete.
Theywentontosuggestthat: “thereisanurgentneedtorevivethesetraditional masonrypracticeswhichhaveproventheirabilitytoresistearthquakeloads” Thiscontemporaryobservationisnotwithoutprecedent.Inthe19thcentury,British geologistFredericDrewsaidinabookpublishedin1875(Drew,1895)thattheSrinagar
houseshave “mixedmodesofconstruction[that]aresaidtobebetterasagainstearthquakes(whichinthiscountryoccurwithseverity)thanmoresolidmasonry,which wouldcrack”.Hethusnotesnotonlythatthehousesdemonstratedalevelofearthquake resistance,butalsothatthisattributewasrecognizedbythelocalpopulation.
Later,theBritishphysicianandaward-winningwriterArthurNeve,inabook describinghisexperiencesduring30yearsinKashmirduringthelate19thand early20thcenturies,describedatlength theresiliencedemonstratedbythetraditionalSrinagarhousesofbothsystemsduringtheearthquakeof1885.After describingtheseSrinagarhousesas “ tumbledownanddilap idatedtoadegree” (whichwasnotunlikemy fi rstimpressionacenturylater),hewentontosay thattheirconstructionwas “ suitableforanearthquakecountry.” Hisexplanations ofwhythetraditionalcons tructionworkedsowella reparticularlysigni fi cant. Afterobservingthat “ PartofthePalaceandsomeothermassiveoldbuildings collapsed [but]itwasremarkablehowfewhousesfell,” hegoesontoexplain that “ woodisfreelyusedandwelljointed,” butthenhemadethecounterintuitive claimthat “ clayisemployedinsteadofmorta r,andgivesasomewhatelastic bondingtothebricks. ”
Indescribingthe taq construction,hesaysthatthebricksareconstructed “inthick squarepillars,withthinner fillingin,” bywhichhedescribesthebearingwallmasonry constructionthatisconstructedasaseriesofwallsectionswithunbondedconstruction jointsbetweenthesections,asseenin Fig.1.16.Thisconstruction,hesays “Ifwell builtinthisstylethewholehouse,evenifthreeorfourstorieshigh,swaystogether, whereasmoreheavyrigidbuildingswouldsplitandfall” (Neve,1913).
Bothofthese19th-centurycommentariesseemasremotefrommodernengineeringtheoryandpracticeasthebuildingsthey describearepicture sque.NeitherDrew norNevewasanarchitect,engineer,ormason.Inaddition,thecomparativesizes andcharacteristicsoftheearthquakesare onlyvaguelydocumented.Whatisinteresting,though,isthatthesequotescan beusedtoshedlightonwhathasprovedto berevolutionarychangesthathaveoccurredoverthepastcenturyandahalfinthe designandconstructionofbuildings.Thesechangeseffectivelyhavedivorcedthe buildingtechnicalcommunity,includingarchitects,engineers,andbuilders,from thetactileunderstandingoftraditionalmaterialsandconstructionsystemsthatthese 19th-centuryquotesdemonstrated aproblemthathasonlyrecentlybeguntobe recognizedandaddressed,asshownbythepreviousquotesbyProfessorsRaiand Murty.
1.6Thegreat1906SanFranciscoearthquakeand fire
TurningtotheUnitedStates,considertheengineeringstudydescribingthedamage fromanearthquakehalf-wayaroundtheplanetfromtheoneinKashmir the1906 SanFranciscoearthquakeand fire.SixyearspriortothepublicationofArthurNeve’s bookaboutSrinagar,theAmericanSocietyofCivilEngineers(ASCE)intheir Transactions publishedthe “TheEffectsoftheSanFranciscoEarthquakeofApril 18NonconventionalandVernacularConstructionMaterials
18th,1906onEngineeringConstruction”.(ASCE,1907)Intheircommitteereporton thedamagetobuildingsone fi ndsthefollowingstatement:
Itmaybestated,asoneofthemostobviouslessonsoftheearthquake,thatbrickwalls, orwallsofbrickfacedwithstone,whenwithoutaninteriorframeofsteel,are hopelesslyinadequate.Asamethodofbuildinginearthquakecountries,suchtypes arecompletelydiscredited[p.234].
Laterinthereporttheyrepeatedlyemphasizethispoint,asfollows:
Thewriterssimplyreiteratethestatementthat,speakinggenerally,buildingsofbrick wallsandwoodeninteriorscannotbebuiltwhichwillnotbewreckedinasevere shock,itbeingafaultofdesignandnotofmaterialsorworkmanship[p.250].
Thiswasfollowedbysomeheatedrebuttalsinthe “Discussion” portionofthepublication,inwhich25ASCEmemberengineerscontributedtheirownreports.While sevenofferedstrongrebuttalstotheCommittee’sposition,twoexpressedunequivocal support,addingtheirendorsementtotheevidenceofthetransitionfromempirical observationtotheoreticalanalysisinengineering.(Theotherswereeitherneutralor didnotdiscussmasonrybuildingperformance.)Onesupportingmember,C.Derleth, wrote: “Itisnotrighttoarguethatbrickbuildingsareadequateforearthquakecountriesbecauseahundredbuildingsstoodincertainplaces” [p.313],whileanother, J.D.Galloway,said: “Itisstrangethatengineerswillstillchampionthismaterial which,analyticallyandbyevidence,provesitselftobe ‘hopelesslyinadequate” [p. 326].
Indefenseofmasonry,oneengineer,EdwinDuryea,madethefollowingaptobservation: “Thisconclusionissoseverethat,ifitweretrue,itwouldentirelyexcludethe safeuseofordinarybrickbuildings,foranypurpose,ontheSanFranciscopeninsula” [p.264].Allofthis flowedfromtherepeatedobservationsthatonlysome,butbyno meansallunreinforcedmasonrybuildingsweredamagedbytheearthquake.Another engineer,W.W.Harts,madetheevenmoredirectedrebuttaloftheabsolutistnatureof theCommittee’sposition,basinghispositionasadefenseofempiricalmethodology andevidence:
Itisverydangerous,inanyscientificdiscussion,toformulatesweepinggeneral rules . Theexplanationhasbeenmadethatthetestofengineeringstructuresisnot experience,andthatthemajorities[ofengineeringprofessionals]cannotberelied upon . todiscoverthetruthastotheirstability.Canitbemaintainedthatthescience ofengineeringisnottheresultantofyearsofexperience?Canitbesaidthatsuccesses arenotguidesandthatfailuresarenotwarnings?[p.383].
Hiscolleague,BernardBienenfeld,thenmadethemorespecificobservation:
RegardingthecontentionoftheCommitteethattheordinarybrickconstructionis inelastic,observationoftheactionofthebrickwallsofwreckedbuildingsthatwerebeing torndownsubsequenttotheearthquakeand firewouldindicatethatthereisindeeda considerableandsurprisinginternalelasticityinthisformofconstruction[p.8].
