Conservation of Earthen Architectural Heritage inSeismic Areas

Julio Vargas NeumannJulio Vargas Neumann

Marcial BlondetMarcial Blondet

Carlos IwakiCarlos Iwaki

Pontificia Universidad Católica del PerúPontificia Universidad Católica del Perú

HUARAZ EARTHQUAKEHUARAZ EARTHQUAKE19701970

Due to the availability of these naturDue to the availability of these naturalalmaterials, monumental architecture materials, monumental architecture built using earth and stones joined built using earth and stones joined with mud is the world’s oldest and with mud is the world’s oldest and most common type of constructionmost common type of construction

Huaca de la Luna and Chan Chan, TrujilloHuaca de la Luna and Chan Chan, Trujillo

Chan Chan, Trujillo, PerúChan Chan, Trujillo, Perú

VULNERABILITY FACTORSVULNERABILITY FACTORS

1.1. Earth makes up for an extremely Earth makes up for an extremely weak and brittle construction weak and brittle construction material. It represents a unique case material. It represents a unique case in the field of architectural heritage in the field of architectural heritage in the field of architectural heritage in the field of architectural heritage conservation.conservation.

2. There is a tragic correlation

between the location of earthen architecture and the world’s seismic areas

(De Sensi 2003)

Earthen Architecture

Seismic Hazard

3. 3. TThe International Conservation he International Conservation Charters Charters

approved by ICOMOS do not providapproved by ICOMOS do not providee any any specific technical guidelines regardspecific technical guidelines regarding the ing the conservationconservation of architectural heritage built of architectural heritage built using earth as a construction material in using earth as a construction material in seismic areas nor do they alert about the seismic areas nor do they alert about the

risk of their disappearance.risk of their disappearance.risk of their disappearance.risk of their disappearance.

CARALCARALStone Stone and and

mud mortar mud mortar

masonrymasonry

Seismic forces are too strongSeismic forces are too strong and and earth is an extremely weak earth is an extremely weak constructionconstruction materialmaterial

Adobe MasonryAdobe MasonryHuacaHuacade lade lade lade laLunaLuna

Trujillo, PerúTrujillo, Perú

Stone Masonry joinedStone Masonry joined witwithhmud mortarmud mortar

Chavín deChavín de Huántar 1500 Huántar 1500 years after CARALyears after CARAL

Advanced DesignAdvanced Design

VulnerabilityVulnerabilityThe strength of these structurs depend on the material The strength of these structurs depend on the material used: earth, which is the weakest construction materialused: earth, which is the weakest construction material

Vulnerability of mudVulnerability of mudmortar masonrymortar masonry

Chavín de HuántarChavín de HuántarOrganizedOrganized earth earth

and stones infilland stones infill

Retaining wallRetaining wall

Seismic Damage and Seismic Damage and CollapseCollapse

�� Seismic damage is accumulativSeismic damage is accumulativ

�� Recurrent earthquakes will damage earth Recurrent earthquakes will damage earth constructions that have been restored following constructions that have been restored following a traditional intervention criterion. It is therefore a traditional intervention criterion. It is therefore imperative to end the damage cycleimperative to end the damage cycle

�� The International Conservation Charters should The International Conservation Charters should �� The International Conservation Charters should The International Conservation Charters should expand to include modern and innovative expand to include modern and innovative solutions. They should contemplate the use of solutions. They should contemplate the use of modern restoration techniques and the rational modern restoration techniques and the rational use of reinforcement methods that follow a use of reinforcement methods that follow a criterion of reversibility and minimum impact.criterion of reversibility and minimum impact.

Damage Cycle Example: Damage Cycle Example: Acllawasi Temple, PachacamAcllawasi Temple, Pachacamac,ac,Lima.Lima.

The original Inca construction was built using The original Inca construction was built using stones around the stones around the XXIII century and was III century and was subsequently destroyed by earthquake activity. subsequently destroyed by earthquake activity. subsequently destroyed by earthquake activity. subsequently destroyed by earthquake activity. It was rebuilt over the remains of the original It was rebuilt over the remains of the original structure using earth, which was the local structure using earth, which was the local

construction material, in the construction material, in the XXIV century.IV century.

Julio C. Tello rebuilt the temple between 1941 Julio C. Tello rebuilt the temple between 1941 and 1945. and 1945.

Acllawasi after the 1940 Acllawasi after the 1940 earthquakeearthquake

Only some Only some

ruinsruinsruinsruins

remainremain

Reconstruction by Julio C. TeReconstruction by Julio C. Tello llo between 1941 and 1945 usinbetween 1941 and 1945 usinggtraditional materialstraditional materials and and techniquestechniques

Damage, traditional reconstructDamage, traditional reconstructionion andandseismic damage once again. Coseismic damage once again. Could thisuld this

be a vicious damage cycle?be a vicious damage cycle?After 500 years, After 500 years, up until 1940up until 1940

After 44 yearsAfter 44 years of earthquakes.1966, 1970, 1974 y 20071966, 1970, 1974 y 2007

The accumulative damage caused by earthquakes The accumulative damage caused by earthquakes affects first the restored parts of the buildings, affects first the restored parts of the buildings,

which are usually weakerwhich are usually weaker

The damage caused to the structurThe damage caused to the structure is tooe is tooserious to attempt to reconstruct itserious to attempt to reconstruct it using using

the originalthe original materials andmaterials and technolotechnologygy

Similar example: ReconstructSimilar example: Reconstruction ofion ofthe Argthe Arg--e Bam Citadel, Iran,e Bam Citadel, Iran,19701970--20032003

The 2003 earthquake reThe 2003 earthquake re--destroyed destroyed everything that had been restored during everything that had been restored during the previous centurythe previous century..

Reconstruction andReconstruction andrere--destruction. destruction. Damage Cycle?Damage Cycle?

Traditional intervention without Traditional intervention without reinforcementreinforcement

International Conservation International Conservation Charters approved byCharters approved byICOMOSICOMOSVenice Charter 1964Venice Charter 1964--1965: “Where 1965: “Where traditional techniques prove traditional techniques prove inadequate, the consolidation of a inadequate, the consolidation of a inadequate, the consolidation of a inadequate, the consolidation of a monument can be achieved by the monument can be achieved by the use of any modem technique for use of any modem technique for conservation and construction, the conservation and construction, the efficacy of which has been shown by efficacy of which has been shown by scientific data and proved by scientific data and proved by experience.”experience.”

Victoria Falls Charter,Victoria Falls Charter,Zimbabwe 2003Zimbabwe 2003

“… No action should be undertaken “… No action should be undertaken without having ascertained the without having ascertained the achievable benefit and harm to the achievable benefit and harm to the achievable benefit and harm to the achievable benefit and harm to the architectural heritage, except in architectural heritage, except in cases where urgent safeguard cases where urgent safeguard measures are necessary to avoid the measures are necessary to avoid the imminent collapse of the structures imminent collapse of the structures (e.g. after seismic damages)”.(e.g. after seismic damages)”.

Structural Criteria of Vulnerable Structural Criteria of Vulnerable Patrimonial Intervention ResearPatrimonial Intervention Researchch

��In the last 40 years it was In the last 40 years it was development some research on the development some research on the two structural criterion:two structural criterion:two structural criterion:two structural criterion:

��StrengthStrength--based Design Criterionbased Design Criterion

��PerformancePerformance--based Design Criterion.based Design Criterion.

StrengthStrength--based Design Criterion:based Design Criterion:Crack repair on historic earthCrack repair on historic earthenenwalls inwalls in seismic areasseismic areas

�� Ongoing research conducted by the Catholic Ongoing research conducted by the Catholic University of Peru, from 2005 up to date, with University of Peru, from 2005 up to date, with the support of the Getty Conservation Institute. the support of the Getty Conservation Institute. the support of the Getty Conservation Institute. the support of the Getty Conservation Institute.

�� The cracks on the adobe walls were repaired The cracks on the adobe walls were repaired with the injection of clayey soils with high with the injection of clayey soils with high water contents and sifted with fine screens.water contents and sifted with fine screens.

�� Tests have shown that it is possible to restore Tests have shown that it is possible to restore the masonry strength by 100%. the masonry strength by 100%.

Friendly solutions: RestoredFriendly solutions: Restored areaareaof Acllawasi, Pachacamac.of Acllawasi, Pachacamac.

Restoring before reconstructing.Restoring before reconstructing.

Injection Methods for Injection Methods for Cracks RepairCracks Repair

Pedro Espinosa, Archeologist Pedro Espinosa, Archeologist ––Mirna Soto, Mirna Soto, Conservator Conservator ––Julio Vargas N., Structural AdvisorJulio Vargas N., Structural Advisor

National Institute of CultureNational Institute of Culture

Mateo Salado, Ychsma/Inca CultureXII-XIII

AntesAntes DespuésDespués

Beginning of the InterventionBeginning of the Intervention: One: Oneof the Truncated Pyramid Strof the Truncated Pyramid Structureucture

Crack repair and wall Crack repair and wall interventionintervention

Structural performanceStructural performance--based based design criteria.design criteria.Reinforcement use.Reinforcement use.

�� 35 years of earthen construction studies 35 years of earthen construction studies conducted by the Catholic University of Peru conducted by the Catholic University of Peru evidence the importance of incorporating evidence the importance of incorporating reinforcements as a safe solution in modern reinforcements as a safe solution in modern reinforcements as a safe solution in modern reinforcements as a safe solution in modern design methods.design methods.

�� The reinforcement should have strong tensile The reinforcement should have strong tensile resistance and should also be compatible with resistance and should also be compatible with the earth walls, in order to prevent the the earth walls, in order to prevent the structures’ irreparable displacement caused by structures’ irreparable displacement caused by seismic activity. seismic activity.

Reinforcement useReinforcement use

��Reinforced walls can still retain Reinforced walls can still retain their strength after the initial their strength after the initial cracking. cracking. cracking. cracking.

��Reinforced earth is currently Reinforced earth is currently available, as well as earthquake available, as well as earthquake resistant construction methods. resistant construction methods.

International OutlookInternational Outlook�� The Getty Seismic Adobe ProjectThe Getty Seismic Adobe Project (GSAP(GSAP) studied) studiedthe behavior of earthenthe behavior of earthen architecturalarchitectural heritage in heritage in California for 6 years.California for 6 years.

�� The international conservation community The international conservation community objects to the use of irreversible objects to the use of irreversible reinforcement methods, which can affect reinforcement methods, which can affect reinforcement methods, which can affect reinforcement methods, which can affect the value of architectural heritage the value of architectural heritage

�� This situation calls for a restricted and This situation calls for a restricted and rationalized use of reversible and rationalized use of reversible and permanent reinforcements. permanent reinforcements.

GSAP ReinforcementGSAP Reinforcement SolutionSolutionss“Las Flores Adobe Seismic “Las Flores Adobe Seismic Retrofit”Retrofit”Jake Barrow, Doug Porter, Steve Jake Barrow, Doug Porter, Steve Farneth, Leroy TollesFarneth, Leroy Tolles

Upper steel cable Reversible Solution

Incompatible and irreversible Incompatible and irreversible solutions (Chile)solutions (Chile)Recoleta DominiRecoleta Dominica Cloisterca Cloister

National Center for Conservation and RestorationNational Center for Conservation and Restoration (CNCR)(CNCR)

Steel frames inlaidSteel frames inlaidwithin the wallswithin the walls

Tarapaca CathedralTarapaca Cathedral�� The reinforced concrete beam thatThe reinforced concrete beam that wawas s supposed to offer support to thesupposed to offer support to the CathCathedral edral destroyed its main adobe wall during the destroyed its main adobe wall during the 2005 Iquique earthquake2005 Iquique earthquake

Foto Arq. Julio Foto Arq. Julio ChestaChesta

Aggressive and irreversible soluAggressive and irreversible solutiontionSecond reconstruction of theSecond reconstruction of thesouthwestern wall’ssouthwestern wall’s tower. Bam Citadeltower. Bam Citadel..

“Tecnicas de Recuperación y Refuerzo “Tecnicas de Recuperación y Refuerzo Estructural” Valter Santoro, ItaliaEstructural” Valter Santoro, Italia

““““

Building’s conditions after theBuilding’s conditions after the 22003 003 earthquakeearthquake

Destruction of the tower’s insDestruction of the tower’s insideide

Cross section with the Cross section with the reinforcementsreinforcements

View of the scaffolding used View of the scaffolding used forforperforations and for the perforations and for the reinforcement plareinforcement placementcement

Drilling equipmentDrilling equipment

Video endoscopy conducted Video endoscopy conducted during the placement of the during the placement of the glass fiber rodsglass fiber rods

Detail view of the external Detail view of the external anchorageanchorage

Final state, Final state, rendered anchorage rendered anchorage

Enlucido de barroEnlucido de barro

It is imperative to establish It is imperative to establish “Conservation Principles for “Conservation Principles for Earthen Structures or masonry Earthen Structures or masonry builtbuilt withwithmudmud mortars”mortars”

Earthen constructionsEarthen constructions

are an exceptionare an exception

because of theirbecause of their

vulnerabilityvulnerability

THANK YOUTHANK YOU