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

PROBiEMS INVOiVED IN REPAIRING TIMBER CHURCH BUIiDINGS IN NORTHERN RUSSIA pierov bKNI pierov AKOI lrłowicz oKP SUMMARY qhe paper discusses the problems involved in the renovation of historic timber church buildingsK qhe details of the repair of a PMMJyearJold timber lrthodox church on the hizhi fsland in northern oussia are presentedK heywordsW eistoric buildingsI TimberI oenovation fn bastern Christian cultureI especially in the northern zoneI church buildingsI eKgK lrthodox churchesI would be made of timberK qheir loadJbearing structures had the form of framework walls on a stone foundationK qypically underesinated unimpregnated pinewood or spruce logs would be used for this purposeK qhe buildings were usually rectangular or octagonalK pometimesI for architectonic reasonsI the shape of the plan would change along the building’s heightW an octagonal framework would be rested on a rectangular frameworkK puch a loadJbearing structure would be topped with a dome in the form of a single onion or many onionsK qhe onions would be tipped with iron or wooden crossesK qheir sheathing would usually be made from aspen wood slates resistant to the action of atJmospheric precipitationK joreoverI after many years of being in service aspen wood changes it colour to steel blueI which enhances the aesthetic qualities of the buildingK After many years of being in service in the severe climatic conditions of northern oussiaI the buildings undergo degradation and suffer damageI manifesting itself in the following symptomsW

– longitudinal surface cracking of the wooden elements caused by moisture shrinkageI – fungal decay of the woodI – loosening of the nodal carpentry jointsI – excessive horizontal and vertical deformations of the whole structural systemK

Fig. N lnion dome toppled due to loss of stability of supporting structural members N ptate rniversity of Building bngineering and Architecture EoussiaF reser]listKru O Central fnstitute of aesign and oenovation in panktJmetersburg EoussiaF reser]listKru P testJmomeranian rniversity of qechnology EmolandF kboikd]zutKeduKpl

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qhe above kinds of damage are especially critical for the condition of the domeI being most heavily loaded with snow or windK fn the case of uneven settlement of the building’s framework structureI the dome leans out of the perpendicularK fn the extreme caseI when the main structural members supportJing the dome lose their load capacityI the latter may topple EcigK NFK qhe most representative timber building built with this structural design is the lrthodox church erected on the hizhi fsland in northern oussia PMM years ago EcigK OFK qhe church was built from timJber without the use of steel connectorsK qhe building is of great world historical valueI as evidenced by the fact that it is under rkbpCl protectionK

Fig. O lrthodox church on hizhi fsland in northern oussia

qhe characteristic feature of this lrthodox church is its atypical domeI consisting of OO little onion domes tipped with crosses EcigK PFK qhe loadJbearing structure of the little onion domes is made up of solid wood ribs with planking and then aspen slate sheathing fixed to themK Because of their wear the slates are replaced every ORJPM yearsK

Fig. P siew of onionJshaped little domes of lrthodox church

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qhe evidence of the building’s durability is the fact that until the middle of the OMth century this lrJthodox church had not undergone any series repairsK eoweverI due to the lack of proper maintenanceI and because of improper useI in the course of the first half of the OMth century the church suffered series damageI mainly as a result of the excessive and uneven settlement of the loadJbearing frameJwork structureK qhereforeI an attempt was made to brace the whole loadJbearing system with an inner a steel skeletonK fn additionI the most rotten framework logs were replaced with new ones and the reJmaining logs were tapped and impregnatedK As experience showedI the measures turned out to be inefJfectiveK Because of the strict rkbpCl requirementsI in the last decade comprehensive measures have been taken to save this monumentK keverthelessI at the moment there are still no proper repair soluJtions which would guarantee the reliability and durability of the building for a few hundred yearsK qhe various offered repair solutions usually have a declarative characterI but have no scientific basisK qhe problem also consists in thisI that according to the restoration requirements it is necessary to obJserve the principle of authenticity xNzK qhis does not apply only to the shape and the structural soluJtions of the buildingI but also to the materials used Eonly PMB of the materials are allowed to be reJplacedFK lne of the most radical repair proposals which is currently being implemented is korwegian liftingI consisting in introducing a steel skeleton into the buildingK qhe former at certain levels is joined with the framework systemK qhusI along its height the building is divided into six imaginary storeysI deJnoted by different colours in cigK 4K

Fig. 4 pchematic of lrthodox church repair using korwegian lifting method

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fn the first stageI the whole church body is lifted above the imaginary lower storey by means of hyJdraulic jacks resting on the foundationK qhen this storey is completely disassembledK fn a specially built building all the storey’s structural elements Ethe wooden logs and the connectorsF are subjected to comprehensive renovationW mycological xOz and strength testsI decay removalI tappingI impregnation and so onK qhe structural elements or their parts no longer serviceable are replaced with new ones made of wood seasoned for a period of PJR yearsK auring this timeI a major repair of the foundations is being carried outK then it is completed and the wooden elements have been renovatedI they are reasJsembledK fn the next stageI the suspended body of the building is mounted on the repaired lower stoJreyK qhe next stage in the repair consists in lifting the church’s whole body situated above the second imaginary storey by means of the hydraulic jacksK creed of loadI this storey is subjected to disassemJbly and the same renovation procedures as the first imaginary storeyK qhis repair procedure is repeated until the lastI iKeK the topI part of the church is repairedK ft should be noted that this method had been used for a long time by the builders of framework buildJingsI including dwelling housesI located in areas with prevailing humid climatic conditionsK Because of the heavy dampness of the lower bond beams of the framework structure Edue to excessive capillary rise through the foundationsI to rainfall or to the thawing of the snow coverF it was necessary to reJplace the lower bond beams every OMJOR yearsK fn order to facilitate the replacementI there had to be a possibility of prising the higher situated part of the buildingK cor this purposeI as the building was being erected slightly inclined timber columnsI resting at the bottom on the foundation and at the top fitted into sockets cut out in the beams marking the building’s first storey EcigK RFI would be installed along the perimeter of the buildingK ff the bond beams had to be replaced with new onesI wedges would be driven between the columns and the foundation whereby the upper part of the building would be liftedK

Fig. R ptructural framework building solution with columns used to prise building body fn the course of many years’ observation of the lrthodox church on the hizhi fsland it was found that the principal onion dome leaned out of the perpendicular by MKR mK qhe main cause of the displaceJments is the uneven deformation of the framework walls on which the dome restsK qhe walls are subJjected to bending under concentrated load and their flexural rigidity is defined as the sum of the flexJural rigidities of the individual logsK fn order to increase this rigidityI the authors proposed to integrate the logs by means of special screws with a quick sharp threadK cirst pilot holesI with a diameter 4 mm smaller than the screw diameterI are bored in the logsK lnce the screws are screwed inI the logs beJcome integrated whereby the wall under bending behaves as a composite structure EcigK SFK

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Fig. S pchematic of framework wallW N – timber logI O – screw Because of the complexity involved in repairing such building structuresI the repairs should be made under the supervision of research units specializing in timber constructionsK joreoverI any repair propositions should be subject to a discussion among competent internationallyJknown specialists xPI 4zK A situation when buildings of great historical value are experimented on in order to verify variJous unfounded repair propositions should not be allowedK REFERENCES xNz helley pKI ioferski gKoKI palenikovich AKgKI pternK bKdK EedsKF EOMMMF tood structuresW A global

forum on the treatmentI conservationI and repair of cultural heritageK ppecial qechnical mublicaJtion NPRNI ApqjI mhiladelphiaI mennsylvaniaK fpBk MJUMPNJO4VTJuK

xOz histernaya jKI hozlov sK EOMMVF tood science approach for the preservation of historic timber structuresK fnW mrocK fnternational Conference on wooden Cultural heritageW bvaluation of deteri-oration and janagement of changeK eamburgI lctober TJNMI OMMVW httpWLLwwwKwoodcultherKcomL LwpJcontentLuploadsLOMMVLMVLhisternayaJhozlovNKpdfK

xPz gasieńko gK EOMMPF dlued and engineering joints in repairI conservation and reinforcement of historical timber structuresK iower pilesia bducational mublishers EatbFI trocławI Ein molishFK

x4z marisi jKAKI miazza jK EOMMTF oestoration and strengthening of timber structuresW principlesI criJteria and examplesK mractice periodical on structural design and construction NOE4FW NTTJNURK