October 31 November 1, 2011 Antalya, Turkey

Transcription

1 WCCE-ECCE-TCCE Joint Conference 2 SEISMIC PROTECTION OF CULTURAL HERITAGE October 31 November 1, 2011 Antalya, Turkey S Turkish Chamber of Civil Engineers European Council of Civil Engineers World Council of Civil Engineers

2 Turkish Chamber of Civil Engineers Necatibey Cad. No:57 Kızılay, Ankara / Turkey Tel: Fax: imo@imo.org.tr - ISBN: IMO Publication Nr.: E/11/12 Printing: Mattek Matbaacılık Basın, Yayın Tanıtım Tic. San. Ltd. Şti. Adakale Sok. No: 32/27 Kızılay / Ankara Tel: Faks:

3 Preface Throughout history territories of Turkey have been a cradle for many civilization; thus it is very rich in cultural and historical heritage. Protecting ages old historical structures against natural disasters should be priority issue for Turkey. Nations aware of this importance are striving through various scientific, social and cultural means, to make the new generations aware of the importance of historical structures and their safe transfer to the future generations. Conservation of historical and cultural structures which have survived countless natural disasters for millennia can be achieved successfully by appropriate restoration, repair and strengthening applications. And this process can only be accomplished by collaboration of civil engineering and other disciplines concerned. Civil engineering plays a major role in the restoration and rehabilitation of historical structures in the activities concerning soil-structure interaction, restoration design and material and construction techniques etc. Being aware of its responsibility and its central role and also its conviction in the necessity of protection of historical structures, our chamber organised the symposium on Strengthening of historical structures and their safe transfer to the future in 2007, executed by TCCE Ankara branch. The second symposium with the same title was organised by TCCE Diyarbakır branch in 2009 with international participation. Following the successful completion of the ECCE-WCCE-TCCE Joint Conference on Earthquake and Tsunami in 2009, the Presidents of the three organisations have agreed to organise the Second Joint Conference on As a result of the interviews with WCCE and ECCE after the conference on Seismic Protection of Cultural Heritage. Our chamber considers this conference a step forward in its concern for cultural heritage bringing an international dimension to its activities in this area, during the 42nd term of office. The major objective of this conference organised by our Chamber jointly with WCCE and ECCE is to contribute to the betterment of the seismic retrofitting and restoration practice on cultural heritage through disseminating the recent research results and communicating successful applications in our country and throughout the world. Papers reflecting artistic and historical evaluation, conservation, seismic vulnerability assessment, seismic repair and strengthening, seismic monitoring etc. will be presented at the conference. We believe that the conference will be beneficial to our colleagues and also to those interested in this area and contribute to the protection of cultural heritage. We would like to thank TCCE Antalya Branch for hosting the conference. We are grateful to Prof. Dr. Tuğrul Tankut, the chair of the Organising Committee for iii

4 his endless efforts. We also thank the Organising Committee and the Scientific Committee for their contributions. We appreciate the valuable contributions of the keynote speakers and the authors of the papers. Lastly, we would like to express our appreciation and satisfaction for the contributions of our organising partners, WCCE and ECCE Executive Committees. TCCE Executive Committee iv

5 Foreword The present booklet consists of the abstracts of the fifty four papers to be presented either orally or as posters at the Seismic Protection of Cultural Heritage conference jointly organised by the World Council of Civil Engineers (WCCE), the European Council of Civil Engineers (ECCE) and the Turkish Chamber of Civil Engineers (TCCE) to be held on October 31 and November 1, 2011 in Antalya, Turkey. Both natural disasters and conservation of cultural heritage have always been areas of prime concern for all of the three organising institutions. After the successfully realised first joint conference on Earthquakes and Tsunamis, the three Presidents agreed to organise the second joint conference on the subject of Seismic Protection of Cultural Heritage. The objective of the conference is to contribute to the betterment of seismic retrofitting and restoration practice on cultural heritage, through disseminating the recent research results and communicating the recent successful applications. The scope of the conference has been kept rather broad to embrace all aspects of the problem concerning the architectural, structural, material etc. dimensions. Consequently, the abstracts included in the present booklet deal with various aspects of heritage conservation vis-à-vis earthquakes. The abstracts take place in the present booklet in the order of presentation as indicated in the conference programme. A. Tuğrul Tankut Ankara, September 29, 2011 v

6 International Advisory Board Emilio Colon, WCCE President Vassilis Economopoulos, ECCE Immediate Past President Serdar Harp, TCCE President Tugrul Tankut, Organising Committee Chair Organising Committee Ahunbay, Zeynep, Istanbul Technical University Akcan, Serhat, Ministry of Culture & Tourism Cengiz, Safak, General Directorate of Foundations Cili, Feridun, Istanbul Technical University Dari, Levent, Turkish Chamber of Civil Engineers Ersoy, Ugur, Bogazici University Gul, Melike, Antalya Regional Council for Conservation of Cultural and Natural Assets Karaesmen, Erhan, Middle East Technical University Madran, Emre, Middle East Technical University Oguz, Cem, Turkish Chamber of Civil Engineers Antalya Sayın, Sancar, Metropolitan Municipality of Antalya Soydemir, Faruk, Turkish Chamber of Architects Soygur, Unsal, Gazi University Tankut, Tugrul, Middle East Technical University Unay, Ali Ihsan, Gazi University Scientific Committee Arun, Gorun, Yildiz Technical University, Turkey D Ayala, Dina, University of Bath, UK Bayraktar, Alemdar, Karadeniz Technical University, Turkey Bilgin-Altinoz, Guliz, Middle East Technical University, Turkey Boke, Hasan, Izmir Higher Institute of Technology, Turkey Cevik, Nevzat, Akdeniz University, Turkey El Harrouni, Khaild, Ecole Nationale d Architecture, Morocco Kubin, Danyal, Prota Engineering, Turkey Mazlum, Deniz, Istanbul Technical University, Turkey Modena, Claudio, University of Padova, Italy Mungan, Ihsan, Halic University, Turkey Müller, Urs, Federal Institute for Materials Research and Testing, Germany Seckin, Nadide, Yildiz Technical University, Turkey Sert, Halide, State Highway Department, Turkey Vintzileou, Elizabeth, National Technical University of Athens, Greece vi

7 Table of Contents Chapter 1 - Principles & Methods of Conservation Miccoli et. al. Comparison of Mechanical Behavior of Different Earth Masonry Typologies In Cultural Heritage...1 Vintzileou Structural Survey: A Prerequisite for Reliable Seismic Protection of Historic Structures...2 D Ayala and Erkal The Role of Environmental Monitoring in Conservation of Cultural Heritage...4 Chadzidakis The Problems Faced by the Structural Engineer during the Reconstruction of Monuments...5 Chapter 2 - Codes, Regulations and Procedures Tankut and Erdemgil A Critical Look at the Conservation Practice in Turkey...8 Erdemgil and Halifeoğlu A Common Fallacy in Restoration of Historical Buildings - Lack of Engineer Contribution...9 Örmecioğlu et. al. The Protection of Built Heritage from Earthquakes: General Remarks on Technical Workshop Series...11 Chapter 3 - Structural and Seismic Evaluation Tankut and Ersoy Remarks on the Structural Aspect of Heritage Conservation...12 Novelli and D Ayala Seismic Damage Identification Of Cultural Heritage Assets...13 vii

8 Gülkan et. al. The Fatih Project: A Pilot Seismic Assessment of the Architectural Heritage in the Historic Peninsula of Istanbul...14 Vatan and Arun Pre-Hazard Evaluation Criteria for Risk Assessment of Masonry Monumental Historic Structures...16 Chapter 4 - Conservation Studies - Structural Tortorella et. al. Seismic Response Control of Rigid Block Systems by Using Tendon System: The Case of Greek Columns...17 Bayraktar et. al. Structural System Identification of Cultural Heritage Structures by Ambient Vibration Testing...18 Duppel On the Structural Characteristics and Present Stability of the Hagia Sophia in Istanbul...19 Türer et. al. Structural Health Monitoring of Sivas Divrigi Great Mosque...21 Köseoğlu and Canbay Investigation of a Damaged Historical Mosque with Finite Element Analysis.. 23 Chapter 5 - Conservation Studies - Geotechnical Arun Sub-Structure Design of Ancient Building Masters...24 Erdemgil and Bilhan Restoration and Foundation Stabilization of Karacabey Mosque in Ankara...25 Kuruşçu and Arun Effects of Timber Footing Used in Ancient Masonry Foundations...26 Çakır and Mohammadi Seismic Retrofitting Using Micropiles for Historical Bridges...27 Sağın et. al. Investigation of Construction Techniques and Material Properties Used in the Domes of Historical Baths...28 viii

9 Chapter 6 - Case Studies Özmen et. al. Seismic Performance of Ruined or Partially Collapsed Historical S tructures with Temporary Scaffolding...29 Čaušević et. al. Fortification Towers In Korčula...30 Erdil and Okuyucu Seismic Performance Evaluation of Adilcevaz Zal Pasha (Tuğrul Bey) Mosque...32 Mohd and Fahjan Seismic Assessment of Historical Masonry Structure in Famagusta...33 Erkan and Demir Seismic Behavior of Masonry Structures; a Case Study: Afyon Mihrioğlu House...34 Tekdal-Emniyeti et. al. City GML Model of Seddülbahir Fortress for Protection and Documentation Doğangün et. al. Seismic Performance of the Main Entrance of Basilica (Kızılavlu) at Bergama (İzmir)...36 Kuzucuoğlu et. al. Determination of Optimum Exhibition Conditions of Cultural Heritage Against Seismic Risks: The Case Study of Istanbul Beylerbeyi Palace...37 Clark Seismic Resistant Performance of Unreinforced Masonry Buildings: Recent Experience in New Zealand and Initial Lessons to be Learnt...38 Küçükdoğan et. al. Assessment of Seismic Resistance of Kara Ahmet Pasa Mosque in Istanbul...40 Özden et. al. Flexural Strengthening Of Timber Floor Girders...41 Doğan and Sert Earthquakes and Arched Stone Bridges...42 Çelik Construction Techniques of Traditional Ormana Houses...43 Topbaş et. al. Restoration of Ayışığı Monastery Chapel, Ayvalik, Turkey...45 ix

10 Farjadmand et. al. Seismic Evaluation and Retrofit of Ghaflankouh Historical Railway Masonry Arch Bridge...46 Shendova and Gavrilovich Seismic Upgading of Mustafa Pasha Mosque in Skopje...47 Mohd et. al. Investigation Concerning the Cause of Damage of St. George of the Latins in Famagusta...48 Kazaz et. al. Collapse Simulation of a Four-Legged Masonry Minaret...49 Erdem et. al. Analytical Modeling of Sivas Divrigi Great Mosque and Hospital...50 Aköz et. al. Structural and Earthquake Response Analysis of Murat Pasha Mosque...51 Nohutçu et. al. Investigation of Earthquake Behavior of Historical Muradiye Mosque in Manisa...52 Chapter 7 - Poster Presentations Bayraktar et. al. Damage Assesment of Historical Arch Bridge for Blast-Induced Ground Excitations Using Operational Modal Analysis...53 Akın and Özen Cultural, Artistic and Historic Evaluation - Cultural Heritage and Earthquakes - Tokat City Example...55 Ateşsal et. al. Adiyaman Kap Mosque Restoration and Strengthening Works...56 Özek Inventorization and Multi-Hazard and Earthquake Performance Evaluation of the Cultural Heritage Buildings in Istanbul...57 Paşapur Seismic Rehabilitation of Historic Buildings a Sample of Traditional Turkish Houses: Cemil Toksöz Mansion...60 Begimgil Repair and Strengthening Techniques of Masonry Arch Bridges...61 x

11 Mehrabzadeh and Türer Nonlinear Modeling and Earthquake Simulation of Stone Masonry Minarets...62 Bakır et. al. Proposals for the Preservation of an Ancient Rock Tomb in Muğla-Akyaka...63 Işıkoğlu et. al. Structural Assessment, Nonlinear Modeling and Seismic Strengthening of Hellenistic Perge Twin Towers...64 Güldoğan and Arıöz Disappearing Cultural Values of Eskişehir: Historic Turkish Baths...66 İlter et. al. Reinforcement Methods Applied to Haseki Hürrem Sultan Bath and Hagia Sophia...67 xi

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13 COMPARISON OF MECHANICAL BEHAVIOR OF DIFFERENT EARTH MASONRY TYPOLOGIES IN CULTURAL HERITAGE Lorenzo Miccoli 1, Chiara Perrone 2, Urs Müller 1, André Gardei 1, Christof Ziegert 2 The paper has been developed in the framework of a larger EC-research program called NIKER, in which BAM and other seventeen research partners from the Mediterrean area are jointly involved. It aims to develop and validate innovative materials and technologies for the systemic improvement of the seismic behavior of Cultural Heritage assets. The death tolls brought about by recent catastrophes in developing countries where many inhabitants lived in earthen dwellings (Gujarat, India 2001, Bam, Iran 2003 and Concepción, Chile 2010 Earthquakes, Tamil Nadu 2004 Tsunami) have brought about research studies aimed at improving earth construction in terms of strength, seismic resistance and speed of construction. In comparison to the recent advances in research on stone and brick masonry, knowledge on the material properties and failure mechanisms of earthen building construction is limited and scattered. The research presented here by aims making a comparison of mechanical behaviour between different earth masonry material typologies, consisting of earth block masonry, rammed earth and cob. Keywords: Earth masonry, Material test, Cultural Heritage, Seismic resistance 1 BAM Federal Institute of Material Research and Testing, Division 7.1-Building Materials, Berlin, Germany 2 Ziegert Roswag Seiler Architekten Ingenieure, Berlin, Germany 1

14 STRUCTURAL SURVEY: A PREREQUISITE FOR RELIABLE SEISMIC PROTECTION OF HISTORIC STRUCTURES Elizabeth N. Vintzileou * In the last decades, powerful analytical tools are used by Structural Engineers both for the assessment of historic structures and for the design of structural interventions. Computer codes based on finite element methods are used to reproduce the pathological image of historic structures and, hence, to assess the available margins of safety and to select adequate remedial measures. This is a step of paramount importance for preservation of the built cultural heritage, especially in the case of structures that are subject to seismic risk. Although the level of sophistication adopted for the analytical work is quite often very high (in the sense that a fine mesh is adopted, nonlinear parameter analyses are carried out for numerous real or artificial accelerograms, etc.), the obtained results may be of limited reliability, in cases where important structural parameters (such as in-thickness geometry of masonry, interconnection of structural elements, etc.) are not adequately surveyed and modeled. Some examples are presented and commented upon in the paper: (a) The behaviour of three-leaf stone masonry (a construction type common to numerous monuments and historic structures) is strongly dependent on the in-thickness geometry of walls (namely, on the thickness of external leaves and of the intermediate filling material, on the mechanical properties of the infill, on the bond between subsequent leaves, etc.). It does also depend on whether structural elements resting on walls made of three-leaf masonry transfer actions over the entire thickness of masonry or only on part of it. It has to be noted that the in-time behaviour of this type of masonry is significantly affected by its geometry. (b) The mechanical properties of masonry repaired/strengthened by means of deep * National Technical University of Athens, Department of Structural Engineering 2

15 re-jointing are usually estimated taking into account the mechanical properties of both the in-situ mortar and the mortar used for the intervention. Nevertheless, experimental results show that the mechanical properties of masonry-and, hence, the estimated available safety of the structure-depend both on structural parameters (namely, relative strength of masonry units and repair mortar), as well as on construction parameters (namely, in-depth dimension of repair mortar, degree of filling of joints by the repair mortar, etc.). (c) Timber reinforcement affects the behaviour of masonry (it ensures-at intervalsthe connection among subsequent leaves of masonry), as well as the overall behaviour of the structure (acting as reinforcement, as connection between intersecting walls, etc.). By means of the above examples, the author of this paper attempts to prove that structural identification of historic structures should be carried out with special care, as it allows for better understanding of the local and overall behaviour of the structural system. It may also guide the Structural Engineer in modeling the more significant structural parameters and, hence, in enhancing the reliability of the obtained results. 3

16 THE ROLE OF ENVIRONMENTAL MONITORING IN CONSERVATION OF CULTURAL HERITAGE Dina D Ayala 1, Aykut Erkal 2 For forethoughtful societies, conservation of historic buildings is one of the pivotal issues from economic and cultural points of view. Environmental effects can lead to damage due to their simultaneous, cumulative, repetitive, and synergetic action. They contribute to the deterioration and destabilisation of already at risk historic masonry structures with structural deficiencies or previously subjected to earthquake, foundation settlement and/or moisture problems and vice versa. Environmental monitoring plays a vital part in the understanding of deterioration process since it reliably illustrates the role of critical and damaging environmental parameters, on a continuous basis. This paper discusses the significance of environmental monitoring for historic buildings and presents an innovative multi-sensor monitoring system design able to characterise humidity and temperature profile across building walls and to record continuously wind, precipitation and atmospheric pressure conditions, and surface levels of adjacent water bodies. Keywords: Cultural Heritage, Historic Building, Conservation, Environmental Monitoring, System Design. 1 Dr., Reader, Department of Architecture and Civil Engineering, University of Bath, UK, absdfda@bath.ac.uk 2 Dr., Research Officer, Department of Architecture and Civil Engineering, University of Bath, UK, ae301@bath.ac.uk 4

17 THE PROBLEMS FACED BY THE STRUCTURAL ENGINEER DURING THE RECONSTRUCTION OF MONUMENTS The Experience of Three Minaret Restoration Projects Aristodimos Chadzidakis * The aim of this presentation is to point out certain particularities of the structural treatment of monuments, by showing the way we faced three real restoration cases. These particularities result mainly from the restrictions imposed by the need to respect the architectural form and the structural identity of the monument, which normally contradict the interventions, which would be necessary to make the construction conform to the current levels of safety, according to the Regulations and to the current scientific knowledge on the behavior of structures and their expected response. I will try to show how we faced the structural problems of three minarets and how our ideas and engineering approach evolved in time. The real cases on witch our presentation will focus are the project and the reconstruction of the minaret of Splantzia in Chania, the study and the reconstruction of the minaret of the Suleiman mosque in Rhodes, as well as the study of restoration of the Neratze minaret in Rethymnon. The main points we would like to discuss are the following: The Regulatory context. The existing regulatory framework concerns mainly the new structures. However, during the last years, our knowledge has been significantly enriched and we have adopted many Recommendations on the methodology and the techniques of interventions on existing structures both on monuments and other buildings. The complexity of the subject and the necessity of estimating the specific parameters for each monument renders the scientific community circumspect concerning the effort to create a Regulation dealing with the existing structures and especially with the monuments. * Civil engineer 5

18 The design prototype. A general and essential difference between monuments and the other structures is that monuments constitute constructions, which have been conceived and designed according to the, so-called, rules of art, which certainly are very well adapted, through the enormous constructional experience, to the stone material, which is mainly used in the monuments construction. The respect of the empirical geometrical regulations and rules of art automatically ensured the static safety and resistance of the structure. A similarly geometric view of the static sufficiency was dominant until very recently for simple structures made of concrete and it continues to persist for stonework simple buildings, according to Eurocode 6. The material and analytical models. We believe that we should seriously consider whether or not the best structural approach of these structures is the current analytical methods, which usually presuppose a relative uniformity of material with known constitutive laws, which usually refer to industrial materials. However we know that in the stonemasonry of one monument itself, we often find stones with differences in strength rising to 1/10, as well as mortars with various compositions and corresponding differences in strength. Besides, the strength of the whole masonry depends directly on the degree of artistic layout and entanglement of the stones, which expresses the personality of the craftsman and differs from place to place. One limited constructional defect usually causes a completely different type of failure than the one that we expected, based on our analysis. The Minaret of Splantzia in Chania (1997) Constructed during the beginning of the Ottoman rule in Crete, in 1645, the minaret was dangerously unstable during these last years. The top presented a 40 cm deviation from the perpendicular line and in some areas there was a great disarrangement of the stonework. The monument had been built as an imperial cylindrical minaret with two balconies, with big stones of good quality. Its 13-meter base is contiguous to the neighboring church. From that point above, begins the stone-made cylindrical part of the minaret, whose height is 21 m. The diameter of the cylinder s base was 2.50 meters; the width of the stones was 40 cm; the average arched length was 105 cm and the height of the layers was 30 cm. These large horizontal layers of stone were connected with horizontally lead-casted iron bifurcate hooks (tzinetia) which worked like rings, as well as with vertical wedges, which were also lead-casted layer by layer. The helical stairway, whose construction was complex in each step that occupied roughly the area of a quadrant, is also very interesting from a structural and a statics point of view. The seismic analysis of the minaret as a monolithic cylindrical cantilever cannot prove its safety or even its stability, according to the current earthquake design codes. However, the minaret is in fact a non-monolithic structure, with numerous constitutive elements, which are not strongly attached to each other and whose total rigidity is difficult to measure however, it is certain that it s low. Flexibility is essential for the monument s response, since it implies a long natural period of the 6

19 minaret and, hence, very low rates at the accelerations spectrum. In other words, each effort to reinforce the minaret will lead to a proportional increase of the seismic forces that it will have to endure. The minaret of the Suleiman mosque in Rhodes (2003) The part of the minaret which was preserved until today was saved thanks to its reconstruction in After the earthquake of 1923, the Italians made extensive restoration works on the minaret. During the last years, it was in an extremely tottery condition. Therefore, in 1988, it was partly removed and now only 9.60 m. of its trunk remain above the roof of the minaret. In the form that it was preserved until nowadays, the minaret had two balconies and a total height of m. above the roof of the mosque in which it is found, without its aciculate ending. Above its polygonal base and its cylindrical-conical adaptation part, starts the main polygonal-cylindrical part of the monument, at a height of 3.0 m. above the roof of the mosque. At this height, which statically is the critical crosssection of the minaret, the external diameter is 2.01 m., the internal diameter is 1.29 m. and the thickness of the ring is 0.36 m. The height of the construction above this part is roughly m. without the aciculate ending. The dynamic analysis of the structural system rendered obvious the its instability and its direct dependence on the values of damping that we adopt, as well as on whether we accept the progressive degradation of its rigidity, in each cycle of charge. In general, we confirmed our qualitative estimate on the importance of the friction mechanisms which can increase the damping of the system by consuming energy and the importance of the relative laxity that allows it to present reduction of its initial rigidity, in the framework of its geometrical integrity. However, due to the lack of relative experimental data, a further parametrical investigation of the problem is required. The Neratze minaret in Rethymnon The Neratze minaret is a two balcony 36,0 m high stone built minaret. It was built 1890 and has presented some serious degradation damage the last few years. So it has been decided to be protected by a strong scaffolding and to demolish its upper part so that no danger from falling stones could occur to the visitors of the center of the old town. The restoration study of this minaret is now going on. 7

20 A CRITICAL LOOK AT THE CONSERVATION PRACTICE IN TURKEY Tuğrul Tankut 1, Mete Erdemgil 2 The paper summarises the personal views of the authors on the basis of their observations during their involvement in a number of restoration projects of various types and various objectives. The authors are of the opinion that the cultural heritage in Turkey has not received the careful and affectionate treatment it deserves. Observations and interpretations of the authors concerning various aspects of heritage conservation practice are explained and their recommendations on various issues are given in the paper. The observations elaborated in the paper are (i) shortcomings in design, (ii) problems in application, (iii) difficulties in supervision, (iv) insufficiency of technical expertise, (v) problems of approval authorities and (vi) difficulties of Regional Conservation Councils. Furthermore, recommendations of the authors concerning each and every one of the issues cited above are given and briefly explained. Keywords: Conservation, Cultural heritage, Historical structures, Problem identification, Restoration, Restoration design 1 Professor, Middle East Technical University, Ankara, Turkey. ttankut@metu.edu.tr 2 Professor, SMP Engineering Co., Ankara, Turkey. smpmuhendislik@gmail.com 8

21 A COMMON FALLACY IN RESTORATION OF HISTORICAL BUILDINGS - LACK OF ENGINEER CONTRIBUTION Mete Erdemgil 1, Zülfikar Halifeoğlu 2 Administration of most of the historical heritage in Turkey is governed either by the General Directorate of Foundations, in some cases together with descendents of the founder (trustees), or by the Ministry of Culture and Tourism. However, this administrative power is limited to the selection of the building to be restored, preparation of the designs and allocation of financial resources for the foreseen expenditures. All major or minor decisions concerning the intervention on the work need to be approved by a commission with supreme power, the Commission of Protection of Cultural and Natural Heritage. Any intervention on the historical heritage without the consent of the concerned commission or any act deviating from their decision is legally a violation of the current law and may lead to imprisonment for some years as a criminal act. It is now worth to focus the attention on these super powered commissions. How are they formed and how are the members selected, what are the disciplines, backgrounds and experiences of the commission members and what tools do these commissions have. A quick review of the commission structure yields that there are more than thirty commissions countrywide acting regionally. They occasionally meet for a period 1-2 days in a town of their jurisdiction area, where most of the members are not residing. Commission members come from educational backgrounds like archaeology, architecture, city planning, art history, law and peculiarly not engineering. The time allocated for the discussions, decisions and necessary paper work for each item in the agenda is limited to several minutes. If a longer discussion is inevitable, then the time shares of the following items become even less. 1 Professor, SMP Engineering Co., Ankara, Turkey, smpmuhendislik@gmail.com 2 Zülfikar Halifeoğlu Eng. Cons. CO., Diyarbakır,Turkey, z.halifeoğlu@hotmail.com 9

22 The missing engineering services like structural safety and stability of the structure, heating, cooling, ventilation, illumination etc are usually left to the discretion of the contractor in charge. The contractor either employs engineers or subcontracts the engineering problems at the least cost. The outcome of the intervention is often an unsafe structure in this land of earthquakes, and inappropriate, mechanical, electrical and chemical engineering solutions. The object of this paper is to shed some light on the problem, and propose a solution for the missing engineering services which are essential for the reliable and sustainable restoration of the invaluable and irreplaceable items of heritage this country owns. 10

23 THE PROTECTION OF BUILT HERITAGE FROM EARTHQUAKES: GENERAL REMARKS ON TECHNICAL WORKSHOP SERIES Hilal Tugba Ormecioglu 1, Bilge Kucukdogan 2, Aslı Er Akan 3 Between October 2010 and May 2011, the Turkish Chamber of Civil Engineers pioneered three technical workshops to provide open discussions on the problems regarding the protection of built heritage from earthquakes in Turkey under three main headings: Principles, Concepts, Terminology and Legislation, Project Design and Application Examples and Structural System, Foundation, Earthquake Safety and Material in delicately chosen three different historical contexts of Turkey Eskişehir, Kastamonu and Van. The workshops included various professionals related with the topic such as engineers, architects, restorers, art historians, public officers and authorities, and academicians, and aimed to create a mutual understanding among different professions that concentrate on built heritage with different perspectives. In this article, main problems of conservation and restoration in Turkey and general conclusions outlined by the participants will be provided as well as the proposals for the amelioration of the current conditions of conservation applications and legislative regulations. Keywords: earthquake safety, built heritage, technical workshops 1 Akdeniz University, Department of Interior Architecture and Environmental Design, Antalya, Turkey. htugba@gmail.com 2 NIKER Project Office Gazi University, Ankara, Turkey. bkucukdogan@gmail.com 3 Süleyman Demirel University, Department of Architecture,Isparta, Turkey. asli.akaner@gmail.com 11

24 REMARKS ON THE STRUCTURAL ASPECT OF HERITAGE CONSERVATION Tugrul Tankut 1, Ugur Ersoy 2 Over the past few decades, the authors have been involved in the structural repair and/or strengthening of a number of historical structures. Some years ago, they have carried out an investigation on the structural damage observed in a mosque considered to be an extremely valuable piece of heritage. During their study, they were surprised to find out that the repair intervention, that had earlier been introduced to remedy minor problems then observed, was the major cause of the severe and irreversible structural damage that took place following the repair work. This interesting case is reported in the present paper. The damaging effect of the repair intervention is explained in terms of a simple numerical analysis of a simplified structural model. On the basis of the above mentioned case, a few important remarks are made to reflect the observations of the authors during their involvement in heritage conservation. These remarks also include some proposals towards improving the present seismic/ structural retrofitting and restoration practice on cultural heritage. Keywords: Conservation, Cultural heritage, Historical structures, Restoration, Structural repair, Structural strengthening 1 Professor, Middle East Technical University, Ankara, Turkey, ttankut@metu.edu.tr 2 Professor, Boğaziçi University, Istanbul, Turkey, ugur.ersoy@boun.edu.tr 12

25 SEISMIC DAMAGE IDENTIFICATION OF CULTURAL HERITAGE ASSETS Viviana Iris Novelli *, Dina D Ayala * PERPETUATE is a FP7 funded project with the aim of providing European Guidelines for the evaluation and mitigation of seismic risk to cultural heritage assets, with innovative techniques for the seismic strengthening of historical buildings and the preservation of unmovable artworks. In the framework of PERPETUATE a methodology, called LOG-IDEAH: LOGic trees for Identification of Damage due to Earthquakes for Architectural Heritage, is proposed, entailed at developing logic trees to assess the state of damage and the global seismic behaviour of cultural heritage assets. The methodology has been set by introducing three levels, at which damage should be assessed: structural elements, macroelements, and architectural asset. According to this, algorithms have been developed: a) to collect local damage type and local damage level of structural elements which belong to structural macroelements from onsite survey or photographic records; b) to create a database with the collected basic geometry data, damage data and images; c) to process the data to identify the damage mechanism of architectural assets. The capability of LOG-IDEAH is validated by applications to buildings damaged by the L Aquila earthquake in April 2009 and comparison with the collapse mechanisms derived by FaMIVE method. Keywords: cultural heritage assets; assessment; damage scenarios; database * Department of Architecture and Civil Engineering, University of Bath, Bath BA2 7AY, UK 13

26 THE FATIH PROJECT: A PILOT SEISMIC ASSESSMENT OF THE ARCHITECTURAL HERITAGE IN THE HISTORIC PENINSULA OF ISTANBUL P. Gülkan 1, M.A. Sozen 2, A. Yakut 1, Z. Celep 3, K. Güler 3, J. Kubin 4, D. Kubin 4, E. Eroğlu 4, A. Irfanoğlu 2 and Z. Ahunbay 3 Istanbul is under threat of a devastating earthquake that experts consider as imminent, similar to those on record that have visited it in recorded history. Reflecting on past experience and current interpretation of tectonics in the vicinity, a very high probability of occurrence has been postulated for an M7 or larger earthquake sometime during the next quarter century. The Metropolitan Municipality of Istanbul has committed itself to an ambitious program that targets urban rehabilitation and strengthening. Part of this is seismic loss mitigation for the urban building stock. The city s long history is reflected in the architectural heritage embedded in its urban texture. Most historic buildings are situated in the Historic Peninsula, now within a single administrative district, Fatih, that boasts some 5,000 registered such buildings under protection. The ambitious Fatih Historic Buildings project is funded by the Metropolitan Municipality of Istanbul. A sample group of 285 buildings was surveyed as part of field and office work that lasted approximately two years. Many of these buildings are places of worship or facilities built for charitable purposes. Each building was carefully scanned using laser devices and its architectural, material and structural attributes were collected. Then the likely seismic performance of the building was estimated on the basis of the assessment-basis ground motion that was compatible with the local site geology. The first-tier seismic assessment was done on the basis of the shear capacity of the 1 Middle East Technical University, Ankara, Turkey 2 Purdue University, W. Lafayette, IN, USA 3 Istanbul Technical University, Turkey 4 Prota Engineering, Ltd., Ankara, Turkey 14

27 masonry walls. The detailed dynamic studies for the fewer number of designated structures were run on complete models of the buildings that had been derived from the point clouds of the scans. Our estimates showed that while most buildings would be likely to survive the postulated earthquake without collapse they would be likely to be damaged. The slender minarets of mosques proved to be their most vulnerable components. 15

28 PRE-HAZARD EVALUATION CRITERIA FOR RISK ASSESSMENT OF MASONRY MONUMENTAL HISTORIC STRUCTURES Meltem Vatan *, Görün Arun ** There is a big stock of historic monumental structures in Turkey. Since there are few specialists on this field it is not possible to inspect all historic structures and assess their structural safety before any hazardous event. Detailed inspections and surveys need team of specialists and take more time and money. Due to this fact detailed inspections are applicable to the limited number of buildings. As a first step of vulnerability and safety assessment it is very important to classify the potential risk of historic cultural heritage buildings in order to prioritize conservation and intervention procedures. This paper presents the study on developing a visual inspection method which is based on obtaining data by the building inspection form for pre-hazard safety assessment of historic monumental structures. Determination of the safety assessment is based on scoring system to classify the risk level of inspected buildings. * Istanbul Aydin University, Faculty of Engineering and Architecture ** Yildiz Technical University, Faculty of Architecture 16

29 SEISMIC RESPONSE CONTROL OF RIGID BLOCK SYSTEMS BY USING TENDON SYSTEM: THE CASE OF GREEK COLUMNS E. Tortorella 1, I. Marino 1, M.N. Khanlou 2, U. Dorka 2, L. Petti 1 Improving the seismic strength of historical monuments, representing world cultural heritage, is the issue widely discussed in the scientific community and, in addition, a challenging task. Any intervention of these monuments, indeed, must be reversible thereby to protect their historical value and preserve the originality and the uniqueness of itself. Despite the classical intervention, in the early years, the advanced methods are developing. Among others, the structural control, active, passive or semi-active, is taking hold. In this within, this paper presents and discusses the effectiveness to apply a Tendon System to improve seismic performance of Greek columns like the ones, for example, in Paestum (SA), Italy. In particular the work presents the main theoretical and experimental results obtained by small-scale models tested on a shaking table. Keywords: Tendon System, Rigid Body, Dynamic Response, Greek Temple 1 University of Salerno - IT 2 University of Kassel - DE 17

30 STRUCTURAL SYSTEM IDENTIFICATION OF CULTURAL HERITAGE STRUCTURES BY AMBIENT VIBRATION TESTING Alemdar Bayraktar *, Temel Türker *, Ahmet Can Altunişik *, Barış Sevim * Structural system identification is based on dynamic parameters such as natural frequencies, mode shapes and modal damping ratios. Cultural heritage structures have complex structural systems and it is difficult to determine modal behavior of these structures correctly due to some inherent modeling uncertainties. The paper presents the structural system identification of cultural heritage structures by ambient vibration testing. A masonry tower, a masonry minaret, a masonry arch bridge and a wood bridge are selected as applications. Operational Modal Analysis method is used to determine the dynamic parameters experimentally under ambient vibrations. The dynamic characteristics are extracted from the collected signals using Enhanced Frequency Domain Decomposition (EFDD) and the Stochastic Subspace Identification (SSI) methods. The identified modal parameters provided a sound basis for the structural identification and will provide a proper baseline for future monitoring for damage assessment, restoration, etc. Keywords: Ambient Vibration Test, Cultural heritage structures, Operational modal analysis, Structural system identification. * Karadeniz Technical University, Civil Engineering Department, Trabzon, Turkey 18

31 ON THE STRUCTURAL CHARACTERISTICS AND PRESENT STABILITY OF THE HAGIA SOPHIA IN ISTANBUL Christoph Duppel * The Hagia Sophia in Istanbul, which is one of the most important and remarkable buildings of the past 1,500 years from the point of view of architectural and cultural history as well as from a civilengineering perspective, has been the object of extensive research - first, regarding its structure and then, its structural behavior as the subject of the DFG Project Engineering Studies of the Main Dome and Main Pillars of the Hagia Sophia in Istanbul. A thorough examination of the structural characteristics was performed directing the project s initial attention to the past of the building and its development over the centuries and through several partial collapses, to the present day. The resulting considerable expansion of the body of knowledge about the existing building then allowed a more reliable evaluation of its structural behavior and its present stability under static loads, contributing to a better assessment of the risk presented by future earthquakes. The Past - Researching the structural characteristics Examining this sensitive structure required proceeding with utmost caution; consequently, nondestructive geophysical study methods were used exclusively. They resulted in extensive findings regarding the currently existing structure, as well as the inner state of the pendentive dome made of brick masonry work and the four main pillars made of natural stone. In addition to determining building component geometries precisely, identifying structural and material characteristics, as well as moisture content, this also allowed detecting and differentiating the specific geometric and structural characteristics of the different construction phases. This provided knowledge that did not only allow * Dr., BfB Büro für Baukonstruktionen GmbH, Karlsruhe. christoph.duppel@bfb-ka.de 19

32 a better technical assessment of the historic structural design, but also added new facts regarding the history of the Hagia Sophia and its construction. The Present - Assessing the structural behavior The new findings and data on the structural design as well as on its history represent a completely new starting point for assessing the load flow and the structural behavior of today s building realistically. This allowed - in contrast to simplified assumptions of existing analyses - defining more differentiated boundary conditions and formulating more precise calculation approaches. And it provided a basis for taking into account the irregularities and discontinuities in geometry and materials found on the building, the time differential between the partial collapses and reconstruction measures, as well as the material properties determined. The studies and structural analyses performed succeed in reflecting the actual deformations detectable on the building. This also allowed making reliable statements regarding load flow, stress states, and stability behavior, and it showed that the cause for the partial collapses, even though ultimately caused by earthquakes, is already noticeable when looking at the building under the load of its own weight. Its dead load, however, does not represent a risk for the building. The Future - The earthquake risk for the Hagia Sophia The probability of a strong earthquake affecting the region surrounding the Sea of Marmara in the not-too-distant future has been rated as very high by proven earthquake experts. A study on the extent to which such a quake can actually impact the stability of the Hagia Sophia is being conducted in the context of a follow-up project entitled The earthquake risk for the Hagia Sophia in Istanbul - verification and validation of numerical calculation models for dynamic loads. The related dynamic analyses will be based on all the findings acquired during the present study of the building s structure in terms of geometry and material-technology, as well as on detailed numerical calculation models. This will allow researching the question how high the earthquake risk is with a reliability that is appropriate for the Hagia Sophia s importance from the point of view of cultural and architectural history. 20

33 STRUCTURAL HEALTH MONITORING OF SIVAS DIVRIGI GREAT MOSQUE A. Turer 1, Ozerk Sazak 2, Sadık Açan 3, Caglayan Yaman 4, Aysenur Kandemir 5, Şafak Cengiz 6, Tamer Topal 7 Sivas Divrigi Great Mosque is one of the most important cultural heritage structures with precious stone carvings on the door gates and domes. The construction date goes back to the 13th century, the time of Ahmet Shah who was the ruler of the Beylik of Mengücek. The adjacent medical center (darüşşifa) was built by his wife Melike Turan Melik. The seven centuries old historic structure is an outstanding example of Selçuk mosques in Anatolia but is suffering various structural cracks and tilts on the walls and columns. A recent study initiated by the ministry of culture targets structural monitoring and evaluation of the mosque. The studies involve detailed instrumentation of the structure using sensitive accelerometers, crackmeters, tiltmeters, temperature and humidity sensors, lasermeters, inclinometers, water table and ground settlement and movement sensors. As the current condition and possible progress of structural problems are identified, a better rehabilitation project can be prepared. Removal of the 50 years old reinforced concrete gallery on the east side of the structure raise concerns about the structural stability of the east façade. Such a removal operation may only be made in a controlled manner as the structural response will be monitored a priori for full a year including seasonal shifts. Possible instability that may be caused by the gallery removal would be identified by 1 Assoc. Prof. Dr., Middle East Technical University, Civil Engineering Dept., Ankara, Turkey. aturer@metu.edu.tr 2 Opteng Project and Engineering, Turkey. ozerk.sazak@opteng.com.tr 3 Sangari International Trade, Turkey. sadik@sangari.com.tr 4 Ministry of Culture, General Directorate of Monuments and Museums, Turkey. cagyaman@yahoo.com 5 Ministry of Culture, General Directorate of Monuments and Museums, Turkey. aysenur2000@hotmail.com 6 General Directorate for Foundations, Turkey. safakceren63@gmail.com 7 Middle East Technical University, Geology Engineering Dept., Ankara, Turkey. topal@metu.edu.tr 21

34 the sensors and necessary precautions can be immediately taken. The results of the first 5 months of monitoring are presented and cross correlations between collected data series are discussed. Keywords: Sivas, Divrigi, mosque, monitoring, evaluation. 22

35 INVESTIGATION OF A DAMAGED HISTORICAL MOSQUE WITH FINITE ELEMENT ANALYSIS G. Çağıl Köseoğlu, Erdem Canbay * Historical structures form a very important part of our cultural heritage and should be well protected. Therefore, full comprehension of the structural behavior of historical structures is of prior importance. In this study, a seriously damaged single domed mosque of 16th century classical Ottoman Architecture was investigated. Serious damages have been observed at various structural elements including the dome and the structural masonry walls, recently leading the structure s closure to service. The main objective of the study is to propose a rehabilitation method suitable for the observed damage. The Mosque was constructed on silty-clay soil and due to the drought in recent years, the water table has been changed excessively causing soil displacements which are especially effective on masonry structures. The results of the structural analyses have been compared with the observed damage and final comments on the structure have been made accordingly. Keywords: Historical Structures, Modelling, Damage Analysis, Masonry, Structural Analysis of Historical Structures * Assoc. Prof. Dr., Middle East Technical University, Ankara, Turkey 23

36 SUB-STRUCTURE DESIGN OF ANCIENT BUILDING MASTERS Görün Arun 1 The study of building construction method and structural details, such as foundations and other related sub structure elements, has great importance in the interpretation of the building construction methods and details during investigation. Although foundations of heritage structures are the best surviving part of a building, they are often the least studied portion for it is difficult to excavate and very few information are available. Generally, the old foundation systems that support the historical structures are different from the current practice in terms of materials used and foundation organization. Substructure design was also an important consideration for ancient builders to control the underground water movement and to make their structure withstand the lateral forces. With the accumulation of knowledge from previous cultures, ancient building masters were able to empirically size and design a foundation system through; designing an effective underground drainage system, providing seismic joints and changing the natural frequency of soil. The main objective of this paper is to point out the design of historical foundation and water drainage systems of master builders through reviewing history of architecture and archaeological publications, discussions with archaeologists and experiences met during diagnosis phase of restoration works. The study of ancient design methods can improve the evaluation of the failures so that proper measures can be taken for the rehabilitation of the architectural heritage and contribute to today s design considerations. Keywords: ancient water drainage, ancient foundations * Prof. Dr., Yıldız Technical University, Istanbul 24