Metalo ir medžio panaudojimo Vilniaus XVII-XIX a. pastatų sienų ir skliautų tvirtinimo konstrukcijose pavyzdžiai

LTMedis sienų tvirtinimui Lietuvoje naudotas iki XVII a. pradžios. XVII a. I pusėje tvirtinant sienų mūrą, neutralizuojant skliautų skėtimo jėgas imta naudoti metalą. Nuo tada metalas tokiai paskirčiai naudotas kone tris šimtmečius. Straipsniu siekiama dar kartą priminti medžio ir, ypač, metalo vaidmenį senosiose mūro konstrukcijose, atkreipti dėmesį į galimas metalinių konstrukcijų erodavimo, pertempimo pasekmes, metalinių elementų mūrinėse konstrukcijose tyrimų svarbą. Nagrinėjama tema turėtų atskleisti metalo bei medžio panaudojimo mūro konstrukcijose subtilybes, parodyti kai kurias iki šiol mažai žinotas senųjų mūrų konstrukcijų savybes. [Iš leidinio]Reikšminiai žodžiai: Senųjų mūrų konstrukcija; Templės; Metalo juostos mūre; Old stone construction; Temples; Metal tape for masonry.

ENSince the oldest times walls made of clay or clay bricks and even stones, were reinforced with wooden structures, embedded into walls. In Lithuania the most usual structure is the one made of two logs, embedded along the wall and connected with cross logs. The oldest examples of the buildings of the masonry of stones or bricks, reinforced with log structures, were found in the masonry of the castles of the 14-16th c. in Vilnius, Trakai peninsular, Kaunas, Liškiava. The log-jointed structures under walls built in watery places joined the masonry together into a solid structure, did not allow them to settle because of weaker soils of uneven resistance. Such or similarly jointed structures, embedded into the walls, strengthened them, allowed bricking a higher wall without waiting lime mortar to harden, which usually took a long time. Since the 17th c., the wall masonry was consolidated by using one or two metal stripes embedded along the walls. The comers and the sections of stripes were inter-connected with plugs. One of the tasks of metal in this case is to neutralise thrust forces of wide arch or window lintels. In many buildings anchors can be seen on the surface of facades. There were some examples found when in the 17th c. builders used wooden beams with metal anchors at the ends for wall binding in order to save metal. One more task intended for metal is to help the wall masonry neutralising thmst forces of vaults. Usage of metal allows to build thinner, not so massive walls and buttresses are not necessary. In this case metal stringers are recommended to be mounted in the weakest place of the vault (the stringer projects in the area of the room) or on the top of the vault. Sometimes in weak parts of the vault temporary metal stringers are mounted intended only for the period till mortar hardens. After mortar hardens they are cut out.One of the examples of such decision is the belfry of Vilnius church of Sts. Johns. Here the temporary stringers have remained uncut till now. The reinforcement means of old masonry prolong the existence of buildings in case of unfavourable conditions for the building, but they are not everlasting - wooden elements of wall reinforcement got rotten long time ago, they are slowly cracking, splitting and “blowing” masonry by the corrosive metal embedded into the walls. Unfortunately, today not so much attention is given to the means of masonry reinforcement and their state as recommended. The prevailing attitude is that even after finding out the old systems of metal connections, it is too difficult to evaluate their reinforcing effect for stone structures, it is difficult to calculate the durable effect of lime mortar on metal, the resistance of metal hammered several centuries ago, etc. Metal in old buildings, whether we know about it or not, still works or is waiting for the moment caused by unfavourable circumstances for the building, when its integration would protect the building from an accident. But only in case it is not too abraded and still able to accomplish the work assigned to it. [From the publication]