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Safeguarding Cultural Heritage through Technical and Organizational Resources Management (STORM) is a collaborative project which is funded by the Horizon 2020, the European Union (EU) framework programme for research and innovation. The main objective of this project to provide critical decision making tools to all European Cultural Heritage stakeholders charged to face climate change and natural hazards. The project improves existing processes related to three identified areas: Prevention, Intervention and Policies, planning and processes. An important result of STORM will be a cooperation platform for collaboratively collecting and enhancing knowledge, processes and methodologies on sustainable and effective safeguarding and management of account environmental and anthropogenic risks, and of using Complex Events processing. Results will be tested in relevant case studies in five different countries: Italy, Greece, UK, Portugal and Turkey. This study mainly focuses on Ephesus Ancient Theatre which is one of the case sites in STORM project and presents the current status and the ongoing studies to the theatre within the scope of STORM project. In the scope of the project programmes in the first year, three dimensional (3D) laser scanning technology and computational models of Ephesus Ancient Theatre has been developed from high definition laser scanning (HDS) data, namely the Point Cloud (PC) data. Then, a seismic toolset which consists of a 3D seismic sensor (GEOSIG force balance accelerometer), 24 bit A/D converter, a modem, a GPS for synchronizing and a dedicated GSM line for online transfer of the acquired data, has been located at the ground and top level of the theatre and the seismological data has been collected by using the seismic toolset. In the second step, a 3D computational model using the finite element method has been created from the PC data and structural analyses were conducted to investigate the theatre vulnerability by using collected seismic data from the site.

In the context of the STREST project, an engineering multi-level risk-based methodology to stress test critical non-nuclear infrastructures, named ST@STREST, has been developed. This reference report summarizes ST@STREST framework and its exploratory application to six key representative Critical Infrastructures (CIs) in Europe, exposed to variant hazards, namely: a petrochemical plant in Milazzo, Italy, large dams of the Valais region in Switzerland, hydrocarbon pipelines in Turkey, the Gasunie national gas storage and distribution network in Holland, the port infrastructure of Thessaloniki, Greece and an industrial district in the region of Tuscany, Italy. According to the characteristics of each case study, different stress test levels were applied. The application to the selected CIs is presented following the workflow of ST@STREST, comprised of four phases: Pre-Assessment phase; Assessment phase; Decision phase; and Report phase. First the goals, the method, the time frame, and the appropriate stress test level to apply are defined. Then, the stress test is performed at component and system levels and the outcomes are checked and compared to the acceptance criteria. A stress test grade is assigned and the global outcome is determined by employing a grading system. Finally, critical events and risk mitigation strategies are formulated and reported to stakeholders and authorities., JRC.E.4-Safety and Security of Buildings

This report describes the main conclusions of the STREST project (and associated guidelines) to evaluate hazard of Low-Probability High-Consequences (LP-HC) events used to define stress tests for non-nuclear Critical Infrastructures (CIs). Several new approaches have been developed to assess these extreme hazard scenarios and to evaluate the associated uncertainties. This report presents a summary of the developments, results and products issued from Work Package 3 (WP3) of STREST. It is given as a set of “recommendations” for potential users responsible of the estimation of hazard for a particular non-nuclear CI in the European Union and other countries. The methods and guidelines are dedicated to two different target-users: project managers and hazard experts. It poses the main differences with a traditional Probabilistic Hazard Assessment analysis, the benefits and extra challenges, and the particular information requirements for the three selected infrastructure classes covered in STREST. In a simple and understandable manner, it summarizes the principal available tools, the main references and the application examples issued from the project in order to help the users in the realization of theirs studies., JRC.E.4-Safety and Security of Buildings

In the earthquake risk mitigation strategy of buildings, it is aimed to estimate the weaknesses of structures and to take engineering measures against these weaknesses (such as stabilization, strengthening or retrofitting) in order to improve structural performance towards earthquakes. Therefore, it is one of the crucial targets of performance evaluation and risk assessment strategies in structural engineering and it is widely achieved by developing fragility and/or capacity curves using analytical models of structures. However, the earthquake risk mitigation strategy in historical structures are strictly limited by provisions related to the protecting of CH (ICOMOS 2003 and ICCROM 1998). Thus, in the disaster risk management of historical buildings, it is necessary to carry out interdisciplinary studies not only to include engineering aspect, but also architectural conservation, restoration and first aid concerns as well. The H2020 STORM project, which is being implemented in this context, aims to develop an integrated platform for the monitoring and control of environmental and human-induced risks of historical structures at pilot sites in Europe. Ephesus amphitheater was chosen as the pilot site in Turkey. The integrated earthquake risk module of STORM consists of two sources of information, namely: engineering (pre-earthquake) and operational (post-earthquake). Before the arthquake, a numerical simulation is performed by generating the Finite Element Model (FEM) of the structure. A three dimensional (3D) numerical model will help visualize the behavior of the structure under seismic effects. The structure will then be analyzed using the FEM model in order to detect damage mechanisms for the entire structure and its vulnerability to seismic forces. A risk measure (engineering demand parameter: EDP) will be defined to indicate the damage state of the structure. It will be linked to three main objectives, namely, aesthetics, architectonic and structural. Each objective will then be subdivided into three different performance levels. In other words, the structural damage states will be transformed into meaningful information to provide first aid for different disciplines. In the second part, a health monitoring system will be developed for the structure. The structural health monitoring system is a quick and effective method for structural identification and assessment of the current state of the structures after an earthquake. The earthquake module will process the actual data coming from the site after the earthquake and compare it with the threshold values in question and provide preliminary information about whether the damage in the structure is cosmetic, architectural or structural or their combination. In this way, the authority would determine if it is okay to enter and use the structure, damage to fresques or requirements for restoration in the next few minutes after the earthquake and the authorities will be informed via short message. This will help activate emergency scenarios, define triage, and effective use of personnel after a disaster. This approach is related to the “first aid” response for humans, structure and restoration purposes. Because the platform will have a flexible architecture, it is expected to update the system by the addition of new structures to be analyzed

In the earthquake risk mitigation strategy of buildings, it is aimed to estimate the weaknesses of structures and to take engineering measures against these weaknesses (such as stabilization, strengthening or retrofitting) in order to improve structural performance towards earthquakes. Therefore, it is one of the crucial targets of performance evaluation and risk assessment strategies in structural engineering and it is widely achieved by developing fragility and/or capacity curves using analytical models of structures. However, the earthquake risk mitigation strategy in historical structures are strictly limited by provisions related to the protecting of CH (ICOMOS 2003 and ICCROM 1998). Thus, in the disaster risk management of historical buildings, it is necessary to carry out interdisciplinary studies not only to include engineering aspect, but also architectural conservation, restoration and first aid concerns as well. The H2020 STORM project, which is being implemented in this context, aims to develop an integrated platform for the monitoring and control of environmental and human-induced risks of historical structures at pilot sites in Europe. Ephesus amphitheater was chosen as the pilot site in Turkey. The integrated earthquake risk module of STORM consists of two sources of information, namely: engineering (pre-earthquake) and operational (post-earthquake). Before the arthquake, a numerical simulation is performed by generating the Finite Element Model (FEM) of the structure. A three dimensional (3D) numerical model will help visualize the behavior of the structure under seismic effects. The structure will then be analyzed using the FEM model in order to detect damage mechanisms for the entire structure and its vulnerability to seismic forces. A risk measure (engineering demand parameter: EDP) will be defined to indicate the damage state of the structure. It will be linked to three main objectives, namely, aesthetics, architectonic and structural. Each objective will then be subdivided into three different performance levels. In other words, the structural damage states will be transformed into meaningful information to provide first aid for different disciplines. In the second part, a health monitoring system will be developed for the structure. The structural health monitoring system is a quick and effective method for structural identification and assessment of the current state of the structures after an earthquake. The earthquake module will process the actual data coming from the site after the earthquake and compare it with the threshold values in question and provide preliminary information about whether the damage in the structure is cosmetic, architectural or structural or their combination. In this way, the authority would determine if it is okay to enter and use the structure, damage to fresques or requirements for restoration in the next few minutes after the earthquake and the authorities will be informed via short message. This will help activate emergency scenarios, define triage, and effective use of personnel after a disaster. This approach is related to the “first aid” response for humans, structure and restoration purposes. Because the platform will have a flexible architecture, it is expected to update the system by the addition of new structures to be analyzed

Safeguarding Cultural Heritage through Technical and Organizational Resources Management (STORM) is a collaborative project which is funded by the Horizon 2020, the European Union (EU) framework programme for research and innovation. The main objective of this project to provide critical decision making tools to all European Cultural Heritage stakeholders charged to face climate change and natural hazards. The project improves existing processes related to three identified areas: Prevention, Intervention and Policies, planning and processes. An important result of STORM will be a cooperation platform for collaboratively collecting and enhancing knowledge, processes and methodologies on sustainable and effective safeguarding and management of account environmental and anthropogenic risks, and of using Complex Events processing. Results will be tested in relevant case studies in five different countries: Italy, Greece, UK, Portugal and Turkey. This study mainly focuses on Ephesus Ancient Theatre which is one of the case sites in STORM project and presents the current status and the ongoing studies to the theatre within the scope of STORM project. In the scope of the project programmes in the first year, three dimensional (3D) laser scanning technology and computational models of Ephesus Ancient Theatre has been developed from high definition laser scanning (HDS) data, namely the Point Cloud (PC) data. Then, a seismic toolset which consists of a 3D seismic sensor (GEOSIG force balance accelerometer), 24 bit A/D converter, a modem, a GPS for synchronizing and a dedicated GSM line for online transfer of the acquired data, has been located at the ground and top level of the theatre and the seismological data has been collected by using the seismic toolset. In the second step, a 3D computational model using the finite element method has been created from the PC data and structural analyses were conducted to investigate the theatre vulnerability by using collected seismic data from the site.

ÖZETTEZ BAŞLIĞI: Çok Katlı Yapıların Sismik Takviyesinde Kullanılan MetalSönümlendirici TADAS Cihazlarının VerimliliğininAraştırılmasıYAZAR ADI: Serkan ALATAŞYapılarda deprem kaynaklı titreşimlerin azaltılabilmesi için pasif ya da aktifkontrol elemanları kullanılabilmektedir. Metalik üçgensel elemanlardan meydanagelen pasif TADAS (Triangular Added Damping Added Stiffness) bağlantıelemanları, depremler sırasında aktive olabilmeleri için enerji gerektirmemeleri,düşük maliyetli olmaları ve deprem sonrasında kolayca yenilenebilmelerisebebiyle aktif elemanlara göre daha avantajlı olabilmektedirler. Bu elemanlar(cihazlar) kat kolonlarına paralel olarak bağlandıkları için yapıya düşük titreşimgenliklerinde ek rijitlik, yüksek genliklerde ise metalde oluşacak plastikdeformasyondan dolayı sisteme ek sönüm sağlamaktadır. Eleman yüksekliğininkat seviyesinin çok altında olması sebebiyle yanal yönde rijit olduğu varsayılançelik çaprazlarla desteklenmektedir. Bu sebeple yapının deprem performansıkullanılan metal adedi ve akma sınırına bağlı olarak değişebilmektedir.Bu çalışmada TADAS elemanlarla desteklenmiş olan 5 katlı bir yapınındeprem performansı sayısal analizler yapılarak araştırılmıştır. AnalizlerdeSAP2000 sonlu elemanlar yazılımı kullanılmış ve üç farklı yer hareketi altındaönerilen yöntemin konvansiyonel olana üstünlüğü araştırılmıştır. Kat kolonlarınınelastik sınırlarda kalacağı TADAS elemanlarının ise elasto-plastik davranışgöstereceği varsayılmıştır. TADAS'ların akma deplasmanının her katta sabit,sayılarının (rijitliğin) ise katlar arasında homojen göreli deplasmanınsağlanabilmesi için değişken olabileceği varsayılmıştır. Her bir durum içinmaksimum kat arası öteleme değerleri hesaplanmış, sabit ya da değişken sayıdakieleman kullanımında elde edilen değerlerle karşılaştırılmıştır.Sonuçlar, üst katlara doğru azalan rijitlikte TADAS bağlantı elemanıkullanımıyla bütün katlarda eş zamanlı olarak metal akmasına yol açıldığı vebunun da sabit dağılıma göre göreli yer değiştirmelerde azalıma yol açtığınıgöstermiştir. Gerek sabit, gerekse değişken ek kat rijitliğine sahip yapılarınkonvansiyonel olana oranla daha iyi performans gösterdiği görülmüştür. SUMMARYTITLE OF THE THESIS: Efficiency of Metallic TADAS Damping Devices asthe Retrofit Tool for Multi Story BuildingsAUTHOR: Serkan ALATAŞActive or passive control elements can be used for the vibration control ofstructures. The passive TADAS (Triangular Added Damping Added Stiffness)devices which are made of triangular metallic elements can be preferred to thoseof active ones because of; 1) Low cost, 2) Ease in replacement after theeartqhuake and 3) No requirement for extra power to activate themselves duringearthquakes. These elements are connected in parallel to the columns and thusprovide additional stiffness to the existing structure. Additionally they provideadded damping to the system when the plastic limit of the metal is exceeded.These elements are supported by two cross bracings which are assumed to be rigidin lateral direction. Thus the two parameters, the total number of metal elementsand the yield displacement are the main factors which affect the seismicperformance of the retrofitted structure.In this thesis, a number of numerical anaiyses have been performed toinvestigate the seismic performance of a shear beam type multistory building.Analyses have been carried out by utilizing the FE code SAP2000. Three differentinput ground accelerations have been used and the efficiency of the proposedmethod has been investigated. Columns were assumed to behave elastically andthe only nonlinearity in the system was assumed to be due to the elastoplasticbehavior of these connection elements. Yield displacements of these elementswere assumed to be constant whereas lateral stiffnesses vary along the height ofthe building. Maximum relative displacements for each case have been computedand the results were compared to those of the conventional (bare frame) and novarying (constant stiffness) cases.Results revealed that TADAS configuration with variable stiffness weremore effective in controlling maximum story drift values compared to those of theones with constant configuration or conventional (bare frame) cases. 46

ÖZETPASİF HİBRİT CONTROL SİSTEMLERİ TARAFINDAN İZOLEEDİLMİŞ ¼ ÖLÇEKLİ 3 KATLI ÇELİK YAPININSARSMA MASASI DENEYLERİYapılan bu çalışmanın amacı, pasif hibrit yalıtım sisteminin etkinliğinin ¼ ölçekli 3katlı çelik yapı için araştırılmasıdır. Yalıtım sistemi 2 elastomer mesnet ve 4 düz kayıcımesnetten oluşmakta ve sırasıyla elastomer mesnetler uzun doğrultu boyunca orta kolonlarınaltında, kayıcı mesnetler is köşe kolonlar altında yer almaktadır. Yalıtımış ¼ ölçekli çelik yapımodeli sarsma masasında gerçek deprem kayıtları ve sinus dalgaları altında davranışıincelenmiştir. Deney sırasında ölçüm kayıtları üst yapıdan ve taban döşemesinden alınmıştır.İki çeşit yüksek sönümlemeli elastomer mesnetlerden birisi düşük kayma modülüne diğeri iseyüksek kayma modülüne sahip olmak şartıyla farklı hedef yalıtım periyotlarında deneyleryürütülmüştür. Hazırlanan numerik model, yapılmış olan deneylerin sonuçlarına bakılarakayarlanmıştır. Bu tez çalısmasında, hibrit yalıtım sistemlerinin etkinliği, yalıtılmış yapı veyalıtılmamış yapının numerik ve deneysel olarak çıkan değerlerine bakarak doğrulamasıyapılmıştır. ABSTRACTSHAKE TABLE TESTS OF A ¼ SCALED MASS CONCENTRIC THREESTOREY STEEL STRUCTURE ISOLATED BY A HYBRID PASSIVECONTROL SYSTEMObjective of this study is to investigate the effectiveness of a hybrid isolation system fora three-storey mass concentric steel structure. The isolation system consists of 2 elastomericbearings and 4 flat sliding bearings, which are located below the central and corner columns,respectively. A ¼ scaled isolated model of the structure has been tested on a shake tableunder real earthquakes and sinusoidal base motions. Measurements were taken at structuralpoints and at base slab level. Two types of high damping elastomeric bearings, one with lowshear modulus and the other with high shear modulus, were tested to see the effects ofdifferent target isolation periods. A numerical model for the structure was developed andcalibrated by the data from the experimental studies. In this dissertation effectiveness of thehybrid isolation system is verified by comparing the results obtained from isolated and fixedbase models. 161

İV ÖZET Yerel zemin şartları, yer altı can daman sistemlerinin deprem davranışlarını etkileyen en önemli faktörlerdendir. 17 Ağustos 1999 Kocaeli Depreminden iki hafta sonra İller Bankası Genel Müdürlüğü tarafından hasarlı hatların bulunduğu bacalarda nivelman ölçümleri ile hasar tespiti yapılmıştır. Araziden toplanan hasarlı hatlara ait veri, Uçkan ve diğ.,2005 tarafından yapılan çalışmada Coğrafi Bilgi Sistemine (CBS) aktarılarak, bölgelerdeki boru hattı yerleşimi harita üzerinde gösterilmiştir. Bu çalışmada, 17 Ağustos 1999 Kocaeli depremi sırasında, İzmit körfezi güney sahil şeridinin doğu kısmında yer alan, Bahçecik, Yeniköy, Gölcük ilçelerinde bulunan atıksu kollektör hattında incelenen deprem davranışları derlenmiş ve gömülü boru hatlarında hasara sebep olan faktörlerden, etkin yer hızma(PGV) bağlı olan geçici deformasyonlar ile kalıcı yer deplasmanları (PGD) parametreleri üzerinde durulmuştur. Ayrıca çalışma alanının batısında yer alan Ereğli, Karamürsel ve Kaytazdere bölgelerindeki birim deformasyonlar hesaplanarak hasara etki eden faktörler ile arasındaki ilişkilendirmeler yapılmıştır. SUMMARY Local site conditions are one of the most important parameters effecting lifelines. Two weeks after the earthquake Engineering Department of the Bank of Provinces (İller Bankası) has made nivelman measurements in manhole locations and the deformations are determined. Data collected from the deformated pipelines is transferred to Geographical Information System (GIS) and the pipeline locations are shown on the map. The relation between the vertical deformations obtained from this data and damage parameters are explained. In this study, the behaviour of the sewage system in Bahçecik, Yeniköy and Gölcük, which take place in south-east of îzmit Bay, during the 17 August 1999 Kocaeli Earthquake is investigated. Also, Earthquake behaviour of pipelines and the damage parameters which depend on Peak Ground Velocity (PGV) and Permanent ground deformation (PGD) are determined. In addition, the ground strains in Ereğli, Karamürsel and Kaytazdere are calculated and correlated with damage parameters. 60

IV ÖZET Bu çalışma, binaların periyodunu büyülterek deprem etkilerini azaltmak amacıyla kullanılan sismik izolatörleri, avantajlarını ve uygulamalarını incelemektedir. Sismik İzolasyon kavramına genelde uygulamanın yapı ile temel arasında yapılması nedeniyle sismik taban izolasyonuda denilebilir. Sismik taban İzolasyonunun temel ilkesi, bina ile temel arasına yanal rijitliği düşük elemanlar koyarak, binayı depremin yıkıcı etkilerinden uzaklaştırmak ve binaya ankastre temelli durumundaki doğal periyodundan ve özellikle deprem hareketinin hakim periyodundan daha büyük bir doğal periyod kazandırmaktır. Yaklaşık 30 yıllık mazisi olan sismik izolatörler ile ilgili başlangıçtaki kaygılar izolasyon yüzeyindeki aşırı deplasmanlarla ilgili olmuştur; ancak bu etkili enerji sönümleyicilerin geliştirilmesiyle aşılmıştır. Fleksibıl bir mesnet (örneğin elastomer esaslı mesnet) ile birlikte kullanıldığında enerji sönümleyiciler hem deplasmanları hemde deprem kuvvetlerini kontrol altına alabilmektedir. Pek çok izolatör enerji sönümleyicileri bünyesinde barındırmaktadır. (Örnek; kurşun çekirdekli elastomer mesnetlerde sönümleme işini ortadaki kurşun parça sağlar.) Günümüze kadar Yeni Zelanda, ABD, Japonya ve İtalya'da yüzlerce yapı ve köprüde izolasyon sistemleri kullanılmıştır. İzole edilecek yapının deprem analizleri ile izole edilmemiş yapının deprem analizleri arasında çok büyük farklılıkları yoktur. Tipik deprem akselerasyonları 0,1-1 arasmda dominant periyodlara sahiptir. Bu periyod arasındaki yapılar rezonansa girdikleri için şiddetli deprem yüklerine maruz kalırlar. Sismik İzolatörlerin en önemli özelliği yapının doğal periyodunu artırmalarıdır. Yapı periyodu deprem periyodunu aştığı için rezonans önlenmiş olur ve dolayısıyla akselerasyon katsayısı küçülür. Bu durumda tasarım esasıda açıktır. İzole edilmemiş yapı için kullanılan belirli faktörlerin yine belirli kat sayılarla çarpılması ve dolayısıyla yapıya etki edecek deprem yüklerinin küçültülmesi söz konusudur. Bu durumda yapılması gereken, toplam tasarım deplasmanının hesaplanması, akselerasyon katsayısının tespiti, zemin etkileri ve zemin katsayısının dikkate alınması ve response değiştirme katsayısının analizlere dahil edilmesidir. Bu çalışmada dünya üzerindeki sismik izolatör kullanılarak sismik yalıtım yapılan birçok örnek gösterilmiş ve bu örneklerden İstanbuldaki Türk Ekonomi Bankası Yönetim binası projesi detaylı incelenmiştir. SUMMARY This study, examines the advantages and applications of seismic isolators used in order to decrease the effects of earthquakes upon buildings by increasing their periods. Seismic Isolation is generally referred to as Seismic Base Isolation, because' ft is generally applied between the foundation and the building. The basic property of the Seismic Base Isolation is to decouple the building from the earthquakes destructive effects and to increase the undamped period of the building, and the earthquake, by installing low lateral rigidity elements between the foundation and the building. The initial concerns about the seismic isolators had been the large displacements on the isolation surface, however this problem has been solved with the coming of effective energy dissipators. When used with a flexible bearing (e.g. elastomeric based bearings), energy dissipators are able to control both the displacements and the seismic forces. A majority of isolators have dissipators within themselves (e.g. in lead cored elastomeric bearings dissipation is done by the lead core). To this day hundreds of structures have been seismically isolated in New Zealand, U.S.A., Japan and Italy. There aren't much differences between the seismic analyses of the building to be isolated and the unisolated building. Typical Earthquake accelerations' dominant periods are between 0,1-1. Seismic isolators' most dominant characteristic is the lengthening of the natural period of the structure. Because the structural period is larger than the earthquake's period, resonance is prevented and acceleration coefficient is decreased. In this case design principle is obvious. Certain factors multiplication with certain coefficients used for the unisolated building and decreasing the seismic load is in question. In this case, calculation of the total design displacement, establishing the acceleration coefficient, base effects, base coefficient, and response change coefficients needs to be included in the analyses. In this study, many examples have been given on the application of seismic isolators, around the world, and of these examples Türk Ekonomi Bankası Headquarters in Istanbul has been examined in detail. 84

ÖZET Türkiye, şiddetli ve yıkıcı depremlerin oluşum sıklığı bakımından, Dünya' nın sarsım etkinliği en çok olan ülkelerden biridir. 17 Ağustos 1999 Kocaeli Depremi sırasında İzmit Körfezi'nin güney-batısındaki Karamürsel, Kaytazdere ve Ereğli bölgelerinde yer alan gömülü kollektör hattının deprem davranışları, hasar parametreleri, hasar türleri ve hasar ilişkileri incelenmiş; ve yer yer faya paralel ve dik doğrultuda uzanan ve Uçkan ve diğ., 2005, tarafından incelenen Altınova- Hersek, Halıdere ve Değirmendere'deki hatta meydana gelen hasarlar derlenmiştir. Bu çalışma kapsamında, hasar oranı değerleri ile araziden elde edilen hasar verileri karşılaştırılmıştır ve bu karşılaştırma sonucu elde edilen farklılıklar ortaya konulmuştur. SUMMARY Turkey is one of the most important countries which seismic activities occur a lot. In the extent of this study, the behaviour of the buried pipelines during 17 August 1999 Kocaeli Earthquake in Karamürsel, Kaytazdere and Ereğli which are on the south-west coastal site of İzmit Bay is investigated; and the damage parameters, damage types and damage relations are determined. Additionally, the damage rates in Altinova-Hersek, Hahdere and Değirmendere which was investigated by Uçkan ve diğ., 2005, are explained. As a result the repair rate relations and the repair rate data collected from the field are correlated; and the differences are determined. 60

OZET. -*1 ¦'* Köprü ve viyadükler şiddetli depremlere karşı hassas yapılardık. Gijıhümü^de..*^ hatırı sayılır bir ilerleme olmasına rağmen, büyük şiddetli depremler^wetiecSr yıkımlara sahne olmuş birçok örnek karşımıza gelmektedir. Viyadük yapılarında Öncelikli hasar, kolonlarda (pilon) oluşabilen dönmeler sonucu köprü açıklıklarındaki çökmelerdir. Mühendislik uygulamalarında yapıların sismik dizaynı için düktü dizayn kavramı çok geniş kabullere dayanmakla beraber, köprü ve viyadükler için bu kabuller uygun olmayabilir. Ayrıca köprü ve viyadük yapılarının ayaklarında (pilon) sıklıkla görülen kesme dayanımı yetersizliği, bu yapı türünün göründüğü gibi esnek çalışmadığının bir göstergesidir. Bu sebeple bu tür yapıların depremlere karşı korunum çabalarının asıl odağı, taşıyıcı ayakların makul kesme değerlerinde kalabilmesi için taşınan yüklerin minimum seviyelere düşürülmesidir. Sismik izolasyon, mühendislik olarak mümkün olan alternatifler içinde en akla yatkın olan yöntemlerden biridir. Elastomerik kauçuk mesnetler (rubber bearing) ve sürtünme esaslı kayar bilyeli enerji sönümleyici izolatörler (friction pendulum system) temel olarak sismik izolasyon sistemlerinin tipik örnekleridir. Sismik izolatörler, yapının frekansını azaltmaktadırlar. Dolayısıyla, üst yapı rölatif olarak rijit kalabilmektedir. Şekil değiştirmeler daha çok izolatörlerde meydana gelmektedir. Frekansın küçülmesi ile ivme spektrumunun azalan bölgesine ulaşılmaktadır. Böylece yapıya etkiyen ivmeler küçülmekte ve tepkileri de buna bağlı olarak azalmaktadır. Bu çalışmada Bolu Viyadüğü'nün depreme karşı güçlendirilmesinde alternatif bir izolasyon cihazı olan Sürtünmeli Sarkaç Tipi Sismik İzolatörü'nün (Friction Pendulum System) uygulanabilirliği ve performansı, viyadük yapısının doğrusal olmayan dinamik analizi yapılarak incelenecektir. Elde edilen bulgular yorumlanıp, değerlendirmeler göz önüne alınacaktır. SUMMARY I Bridges and viaducts are vulnerable when subjected to severe earthquakes. Although considerable progress has been made in earthquake engineering towards'*'' the end of the century, catasrophic bridge failure examples are found wherever large- scale earthquakes attack. Damage of the bridge structures occour primarily in the piers, which may in turn result in collapse of the bridge spans. Although the ductility design concept has been widely accepted for seismic design of structures in engineering practice, this may not appropriate for bridges since they are short of structural redundancy in nature. Besides, ultimate strength design does not seem to work for bridge structures as often the piers are found to fail in shear rather than flexure. The effort on protection of bridges against earthquakes should therefore be focused on minimizing the forces to be carried by the piers, in particular the shears. Seismic isolation is conceivably one of the most promising alternatives in this regards. Isolation systems are basically typified into rubber bearings and sliding bearings. This type of systems rarely posses re-centering capability, except the Friction Pendulum Bearings (FPB) which, with curved sliding surfaces, can provide the isolated structures with restoring forces by gravity. The seismic isolators reduce frequency value of structures. Consequently, super-structure can remain relatively as a rigid building. Deformations will rather occur in isolators. Reduced zone of the acceleration spectrum is reached by means of frequency reduction. Thus, accelerations acting upon the structure and the related reactions decrease. In this study, the applicability and performance of displacement of the Friction Pendulum System which consists of alternative bearings for retrofit of the Bolu viaduct will be examined by non-linear dynamic analysis of viaduct structure. The results obtained will be commented on the output data. 128