19. yüzyıl tarihi demiryolu binalarında yapısal malzeme ve yapım teknolojilerinin deprem performansına etkisi
The impact of structural materials and construction technologies on the seismic performance of 19th century historic railway buildings
Yazar: SENA MERVE KÜÇÜKAYAN
Danışman: PROF. DR. OĞUZ CEM ÇELİK
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Mimarlık Ana Bilim Dalı / Çevre Kontrolü ve Yapı Teknoloji Bilim Dalı
Derece: Yüksek Lisans, 2024
Konu: Mimarlık = Architecture

Özet:
Bu tez çalışması, Osmanlı Devleti döneminde inşa edilen tarihi demiryolu hatları ve demiryolu yapılarını, yapısal ve mimari özellikleri ile birlikte deprem performanslarını içermektedir. İlk olarak, Osmanlı'da önemli demiryolu ağları olan İzmir-Aydın, Rumeli, Anadolu, Bağdat ve Hicaz demiryolu hatları ve güzergâhları detaylıca araştırılmış ve bu güzergâhların oluşmasında göz önünde bulundurulan durumlar incelenmiştir. Demiryolu duraklarının konumu belirlenirken, stratejik önemleri, doğal kaynaklar ile ilişkisi, ekonomik katkısı, ticaretin gelişebilmesi ve şehir merkezlerine olan yakınlığı gibi durumlar etkili olmuştur.
İncelenen tarihi demiryolu projeleri, devletin modernleşme ve kalkınma sürecinin bir parçası olarak başlasa da zamanla ekomomik durumlardan ötürü yabancı yatırım ve alanında uzman mimar ve mühendislerin katksısı ile gelişmiştir. İnşa edilen demiryolu hatları ile birlikte Osmanlı Devleti'nin iç ve dış ticareti gelişmiş, zamanla hatların genişlemesi ile birlikte farklı bölgeler birbirlerine bağlanmıştır. Yabancı şirketlerin katkısı ve kullanılan yapım teknikleri de demiryolu hatlarının gelişmesi sürecinde önemli bir rol oynamıştır. Demiryolu yapılarında sıkça görülen, ancak günümüzde yaygın olmayan perçin teknolojisi ile birlikte çelik yapılar strüktürel açıdan incelenmiştir. Yığma, ahşap ve çelik yapı malzemeleri ile taşıyıcı ve çatı sistemleri hakında da detaylı bir şekilde inceleme yapılmıştır. 
Son olarak, tarihi demiryolu garlarının ve istasyonlarının zaman içerisinde yaşanan depremler sonrasında performansları analiz edilmiş ve meydana gelen hasar boyutları ele alınmıştır. Bu kapsamda, demiryolu yapılarının ciddi oranda etkilendiği iki deprem olan 10 Temmuz 1894 İstanbul depremi (~M 7.0) ve 6 Şubat 2023 Kahramanmaraş depremleri (Mw 7.9 ve 7.8)  ele alınarak farklı bölgelerde yer alan istasyon yapılarının nasıl etkilendiği detaylandırılmıştır. Yapılan analizler ile birlikte, tarihi demiryolu yapılarının gelecek kuşaklara güvenle aktarılabilmesi için kapsamlı olarak yapısal bakımdan incelenmesi gereği ortaya çıkmıştır. 
Demiryolu yapılarının incelenmesi, bir yandan ait olduğu dönemin teknolojisini ve mühendislik başarısı ile birlikte yapıların nasıl inşa edildiğini, kullanılan malzemeleri, uygulanan tekniklerini ve dönemin koşullarını göstermektedir. Sonuç olarak bu çalışma, demiryolu yapılarınının detaylı bir şekilde incelenerek yapısal sistemlerinin anlaşılmasını ve tarihi demiryolu yapılarının korunması ve güçlendirilmesi için önemli kararların alınmasına yönelik öneriler sunmaya yöneliktir. Tarihi demiryolu yapılarının yapısal özelliklerini ve depremlere dayanıklılığını anlamak, tarihi mirasın gelecek nesillere aktarılabilmesi için önemli bir süreçtir. Çalışmanın, tarihi demiryolu yapılarının yapısal ve mimari değerini anlamak ve korunmasını isteyen uzmanlar, tarihçiler, mimarlar ve mühendisler için yol gösteren bir kaynak olması hedeflenmektedir.

Abstract:
This thesis explores the historical railway lines and structures built during the Ottoman Empire, focusing on their architectural and structural features, as well as their performance during earthquakes over time. The significant railway networks of the Ottoman Empire, such as the Izmir-Aydin, Rumeli, Anatolia, Baghdad, and Hejaz railway lines, are studied in detail, along with the circumstances of their construction. The determination of railway station locations was influenced by factors such as strategic importance, natural resources, economic contributions, trade facilitation, and proximity to urban centers.
In the late Ottoman period, the construction of railways was initially part of the state's modernization and development efforts. Railway projects were designed to facilitate the movement of goods and people and to promote trade and economic integration. The development of railway lines played a significant role in the growth of both domestic and international trade, linking different regions over time. Key railway networks, such as the Izmir-Aydın line, the first railway line in Anatolia, and the Hejaz railway, which aimed to connect Damascus with the holy cities of Mecca and Medina, are examined in detail for their strategic and economic importance.
As the state's economic conditions evolved, foreign investment became increasingly important in the development of these railway projects. Specialized engineers and architects from Europe were often brought in to design and supervise the construction of railway lines. The case studies highlight the contributions of foreign engineers and architects, such as the involvement of Germans. This period saw significant input from foreign companies and construction techniques, greatly influencing the development of railway infrastructure in the Ottoman state.
The structural investigations carried out on railway buildings cover a variety of materials, including masonry, wood, and steel, as well as load-bearing and truss systems. The study examines specific architectural and engineering practices used in the construction of railway buildings, such as stations and other types of railway structures. Notable architectural features include the use of local materials and construction techniques adapted to the geographical and climatic conditions of the regions in which the railways were built.
Particular attention is given to the riveting technology used in railway steel structures, which is a notable feature of these historical buildings. The study includes detailed analyses of load-bearing and truss systems, highlighting the engineering ingenuity that characterized the construction of railway buildings during the Ottoman period. It also explores the influence of European architectural styles and engineering standards on the design and construction of railway buildings.
The study meticulously analyzes the impact of earthquakes on historical railway buildings, providing a comprehensive detailing of the extent of damage. This analysis is critical for understanding the vulnerabilities and structural weaknesses of these historical buildings. It examines how buildings in different regions have been affected by significant seismic activities, focusing on specific case studies to illustrate the wide range of impacts.
One notable earthquake examined is the July 10th Istanbul or Marmara Sea (~M 7.0) earthquake in 1894, which caused considerable damage to many of Istanbul's historical structures, including the existing railway buildings. This study examines the specific effects on the architectural and structural integrity of such buildings, detailing how seismic forces caused various cracks in masonry walls, excessive displacement of structural elements, and, in some cases, partial or complete collapses. The analysis includes archival research, historical documents, and photographs from that period, providing a vivid picture of the destruction and subsequent restoration efforts. Also, this earthquake serves as an important case study for understanding the seismic resilience of historical railway buildings built during the late Ottoman period.
Another significant seismic event discussed is the February 6th Kahramanmaraş earthquakes, which had magnitudes of Mw 7.9 and 7.8, respectively. These recent events provide examples of how current seismic activity continues to threaten the historical buildings. The study documents the extent of damage to buildings in the affected regions in SE Turkey, using data from field surveys, structural assessments, and eyewitness accounts. It highlights the types of structural failures observed, such as different types of collapses, severe cracking in load-bearing elements, and foundation failures. This investigation underscores the continuing risks faced by historical railway buildings in seismically active areas.
By comparing the effects of these two significant earthquakes, the study draws important conclusions about the seismic vulnerability of historical railway buildings. It highlights the differences in damage patterns due to the varying structural materials, architectural styles, and construction techniques used in different periods. For instance, the use of masonry and wood in older buildings versus the incorporation of steel in later structures having larger spans (such as in warehouses, depots) shows different failure modes under seismic loading.
Providing a comprehensive understanding of the structural systems of historic railway structures, this study aims to offer recommendations for their preservation and retrofitting to withstand future earthquakes. Understanding the structural characteristics and seismic performance of historic railway structures is essential for preserving cultural heritage for future generations.
The conservation and retrofitting recommendations are based on detailed analyses of the structural integrity of railway buildings, considering the historical construction methods and materials used. The study emphasizes the need for performance-based analysis and retrofit projects, particularly for buildings designed and constructed prior to current seismic codes. Recommendations include the use of modern engineering techniques to strengthen existing buildings, the application of seismic retrofit methods, and the implementation of regular maintenance programs to ensure the long-term preservation of these historic buildings.
The purpose of this study is to serve as a guide for professionals, historians, architects, and engineers interested in understanding and preserving the structural and architectural significance of historical railway buildings. By highlighting the importance of performance-based analysis and retrofitting projects, particularly for buildings designed and constructed prior to current seismic codes, the study underscores the need for ongoing efforts to protect and preserve these invaluable cultural and historical assets.
The findings of this thesis have wider implications for the preservation of historic buildings in seismically active regions. The study provides a framework for assessing the seismic vulnerability of historic buildings and offers practical recommendations for their preservation and retrofitting. Future research could extend this work by investigating the seismic performance of other types of historic buildings and developing innovative retrofit techniques tailored to the specific needs of different building types.
In conclusion, this thesis underscores the necessity of meticulous preservation and restoration efforts for historic railway structures due to their architectural, structural, and cultural significance. The comprehensive analysis and recommendations provided aim to ensure that these structures can be protected against future seismic events, thereby preserving an important aspect of our architectural and engineering heritage for future generations. It should be noted that inappropriate architectural and/or structural intervention over the cause of time. May alter the existing load path in the structural system and may results in an undesirable behaviour during the future earthquakes. A few buildings in SE Turkey during the February 6th, 2023 earthquakes collapsed from such interventions.
The study of historic railway structures not only provides insights into the construction techniques and materials used during the Ottoman period but also highlights the broader socio-economic and cultural context in which these railway projects were undertaken. By preserving these historic structures, we can ensure that future generations have the opportunity to learn from and appreciate the rich architectural and engineering heritage of the Ottoman Empire.