Tahribatsız yöntemlerle tarihsel yapılarda ayrışmanın belirlenmesi: Türkmenistan'ın Merv şehrine ait uygulama

Arkeolojik alanlar, tarihsel yapılar ve sit alanları yasa ve yönetmeliklerle korumaya alınmış ve izinsiz herhangi bir değişiklik veya restorasyon yapılması da yasal sınırlarla engellenmiştir. Tarihsel bir miras olarak günümüze kadar özelliklerini koruyan mimarı yapılar ve yerleşim alanlarında zamanla doğal veya yapay etkenlerle meydana gelen hasar, fiziksel ve iklim koşulları nedeniyle meydana gelen mukavemet kaybının tespiti önemlidir. Ancak bu tür çalışmalar yapılırken yapılarda kalıcı deformasyona neden olacak karot numunesi alma, sıyırma vb. uygulamalardan kaçınılması istenir. Bu nedenle hasarsız yöntemlerin kullanılması öncelikli ve zorunludur. Bu çalışma kapsamında Türkmenistan’ın antik şehri olan Merv’de sahabelerden Hakem El Gıfari ve Bureyde el-Eslemi’nin bulunduğu 2 kule ve 2 türbe üzerinde ultrasonik hız, çatlak derinliği ve basınç mukavemetlerinin hesaplanmasıyla yenileme yapılacak alanlar hakkında bilgiler elde edilmiştir. Hızların Uluslarası Atom Enerjisi Ajansı tarafından önerilen sınıflandırmaya göre çok kötü ve kötü kaliteye sahip olduğu, çatlak derinliği sınıflamasına göre II ve III derece çatlak sınıfına girdiği ve basınç mukavemetlerinin kulelerde 2-8 MPa arasında değiştiği, türbelerde ise 20 MPa değerlerine sahip olduğu görülmüştür. Beton kalitesinin dayanımındaki bu farklılıklar, kuzeybatıdan esen rüzgarlar ve alanın tarihin farklı dönemlerde restore edilmesinde işçilik farklılıklarından kaynaklı olabileceği düşünülmüştür. Elde edilen sonuçlar kullanılarak yapıda güçlendirme yapıldığında, hem daha iyi korunacak hem de bütçe azaltılacaktır.

Non-destructive methods for determining weathering in historical monuments: a case study from Merv city, Turkmenistan

Any changes or restorations to archaeological sites or historical buildings that are protected by law are prohibited without permission. In order to preserve the architectural heritage of a structure or a residential area that has retained its original character as a historical legacy, it is important to identify the weathering of used structural material or deterioration of strength, which can occur due to environmental conditions, or damage caused by natural or artificial factors over time. It is desirable, however, to avoid applications that will cause permanent damage in the structures, such as core sampling or stripping, when such studies are made. Non-destructive methods can eliminate this problem, but must be investigated to show theirapplicability. In this study, ultrasonic velocity and crack depth compressive strengthdeterminations are applied to assess the integrity of brick structures in Merv, an ancient city of Turkmenistan. Two towers and two mausoleums are investigated, where Hakem El Gifari and Bureyde el-Eslemi are lying. The structural integrity of the towers and mausoleums are classified as weak and poor, respectively, according to classifications of the International Atomic Energy Agency. Crack depth classification infers classes II and III for the structures, and the compressive strengths show a variation between 2-8 MPa in towers and 20 MPa in mausoleums. This variation in brick performance can be attributed to winds that blow from NWdirection and differences in the workmanship in the restoration over the buildings’ history. When restoration shall be conducted according to the results obtained, both historical heritage can be better preserved and any budget for structural reinforcement could be reduced.

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