İnşaat Mühendisliği Bölümü Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1943
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Article Seismic Behavior and Design of Reinforced Autoclaved Aerated Concrete Load-Bearing Panel Walls(Taylor & Francis Ltd, 2026) Halıcı, Ömer Faruk; Halici, Omer Faruk; Demir, Cem; Comert, Mustafa; Ilki, Alper; 02.04. Department of Civil Engineering; 02. Faculty of Engineering; 01. MEF UniversitySince the 1970s, numerous low-rise buildings in T & uuml;rkiye constructed with AAC load-bearing panels have withstood devastating earthquakes without significant damage, demonstrating a lightweight yet robust solution for seismic regions. This study investigates the seismic performance of AAC load-bearing panel wall systems through material tests, member-level cyclic in-plane testing, and finite element micro-modeling. The experimental results showed that individual panel behavior initiated at low lateral drift ratios of 0.25-0.50%, accompanied by measurable uplift and rocking at panel bases, with flexure governing failure in two-panel walls and combined flexure and diagonal tension - shear governing failure in four- and six-panel walls. Numerical models exhibited adequate reliability in terms of strength, stiffness, and cumulative energy, when validated against experimental data. The load-bearing capacity in the numerical simulations increased with both the number of panels and higher axial loads, consistent with observed experimental trends. These combined findings were used to determine seismic design factors leading to recommended values of D = 2 for overstrength and R = 4 for structural behavior. Experimental results were compared with corresponding design documents, including ACI 523.4 R and the Turkish Building Earthquake Code (TBEC). The findings indicated that flexure predominantly governed the failure of two-panel walls, while combined flexure and diagonal tension - shear mechanisms governed the failure of four- and six-panel walls. Accordingly, a revised diagonal tension capacity expression is proposed for the seismic design of AAC systems in future versions of TBEC.Book Part Comparison of the Observed and Numerical Performance of a Seismic Isolated Hospital(International Association for Earthquake Engineering, 2024) Şadan, Bahadır; Sahin, B.; Tüzün, C.; Demircioglu-Tumsa, M.B.; Erdik, M.; Demircioglu Tumsa, M.B.; 01. MEF University; 02.04. Department of Civil Engineering; 02. Faculty of EngineeringThe southeastern region of Turkiye was struck by powerful earthquakes on February 6, 2023, with magnitudes measuring M7.7 and M7.6. These earthquakes resulted in significant damage, destruction, and loss of life, affecting both Türkiye and extending into northern Syria. Among the approximately 100 isolated buildings in Turkiye, 11 isolated hospitals were located in the impacted region. This paper presents a comprehensive assessment of the seismic performance of the seismically isolated Osmaniye State Hospital during the Kahramanmaras earthquakes. The evaluation comprises site observations and numerical analysis utilizing ground motion records obtained from the nearest accelerometers. Site observations involved monitoring the movements of the isolators located at the moats around the perimeter of the hospital. Using a borescope allowed for detailed internal inspection of the isolation bearings, facilitating close-up examination of the isolators and enabling the identification of movement scuff marks on the sliding surfaces. These observations were used to estimate the maximum isolation bearing movement and determine the residual displacement offset of the bearings. The observed displacements of the isolation system were compared with the design values to assess the performance of the seismically isolated structure. Discrepancies between the observed and designed displacements provide valuable insights into the actual behavior of the isolation system. A nonlinear time history analysis was conducted using ground motion records obtained from the nearest accelerometers to further analyze the seismic response. This numerical analysis allowed for the simulation of earthquake excitations and the evaluation of the dynamic behavior of the seismically isolated Osmaniye State Hospital. The combination of site observations and numerical analysis yielded important findings regarding the seismic performance of the seismically isolated Osmaniye State Hospital during the Kahramanmaras earthquakes. The comparison between observed and design displacements provided insights into the efficacy of the isolation system, while the numerical analysis further validated the structural response. These findings contribute to improving the design and implementation of seismically isolated structures. © 2024, International Association for Earthquake Engineering. All rights reserved.Book Part Numerical Analysis of Buildings in Golbasi During the 2023 Turkey-Syria Earthquake(International Association for Earthquake Engineering, 2024) Tönük, Gökçe; Kunisawa, M.; Sendir Torisu, S.; Kiyota, T.; Tönük, G.; Çinicioğlu, O.; Shiga, M.; Torisu, S.; 02.04. Department of Civil Engineering; 02. Faculty of Engineering; 01. MEF UniversityOn February 6, 2023, earthquakes of Mw 7.8 and Mw 7.5 occurred in south-eastern Turkey. In Golbasi, located on the East Anatolian Fault, severe damages such as building subsidence and tilting due to liquefaction were observed. In this study, settlement and tilting behavior due to liquefaction of relatively large structures in Golbasi, when adjacent to each other, were reproduced using effective stress analysis. The research results demonstrates that the differential subsidence behavior of adjacent buildings can be replicated. Furthermore, the interference of stresses within the soil beneath adjacent structures resulted in behaviors such as inward collapsing or conversely an outward leaning differential subsidence. This study also discusses the subsidence trends associated with varying distances between structures and varying in the embedment depth of shallow foundations. © 2024, International Association for Earthquake Engineering. All rights reserved.Book Part Japanese and Turkish Joint Detailed Survey of RC Buildings Damaged by the 2023 Turkey Earthquake(International Association for Earthquake Engineering, 2024) Halıcı, Ömer Faruk; Yazgan, U.; Maeda, M.; Liu, H.; Shegay, A.; Monical, J.; Andirir, G.; 01. MEF University; 02.04. Department of Civil Engineering; 02. Faculty of EngineeringThe Architectural Institute of Japan formed an investigation team to survey the damage to buildings damaged by the February 2023 Turkey earthquakes. The investigation team was dispatched to the affected area from March 28 to April 4, 2023 and conducted field surveys jointly with a Turkish expert group. As part of this investigation, the authors conducted detailed surveys of damaged reinforced concrete buildings. The survey area covers five provinces where extensive building damage was confirmed: Gaziantep, Hatay, Kahramanmaras, Adiyaman, and Malatya. The buildings surveyed were those that are useful for comparative analysis, and ones that allowed for relative ease of an on-site inspection. As a result, a total of 25 buildings were investigated, many of which were constructed after 2000, and the damage level ranged from slightly to severely damaged. In each building, the arrangement, dimensions, and damage grades of columns and walls on the floors that suffered the most damage were recorded, and their damage level was evaluated based on the Japanese and the Turkish post-earthquake damage assessment guidelines. In this paper, an overview of the results of this survey is reported. Based on the survey results, we report the results of an analysis of the structural features and seismic performance of the surveyed Turkish buildings compared to typical Japanese buildings. In addition, the causes of commonly observed damage characteristics in the surveyed buildings and the damage level determined by the Japanese and Turkish guidelines are discussed. © 2024, International Association for Earthquake Engineering. All rights reserved.Book Part Citation - Scopus: 1Modifications on Seismic Damage Assessment System of TCIP Based on Reparability(International Association for Earthquake Engineering, 2021) Halıcı, Ömer Faruk; Halici, O.F.; Kupcu, E.; Cömert, M.; Demir, C.; 01. MEF University; 02.04. Department of Civil Engineering; 02. Faculty of EngineeringEvaluating the damage state of buildings has always been one of the major challenges that both engineers and authorities face after catastrophic earthquakes in seismic regions. After such events, considering the number of buildings in need of inspection and the insufficient number of qualified inspectors, the availability of a thorough but rapidly applicable damage assessment method is vitally important. An assessment system serving this purpose was developed for the Turkish Catastrophe Insurance Pool (TCIP, known as DASK in Turkey) at the beginning of the new millennia to evaluate the damages in reinforced concrete (RC) and masonry structures. The assessment system assigns a damage state (related with a damage modifier for the capacity loss) to each vertical structural member (columns and shear walls) based on the observed residual damages, such as crack width, concrete crushing, cover spalling and buckling of reinforcement. Beam damages are also taken into account in a similar way. After that, the weighted damage percentage (WDP) is calculated by taking into account the damage state and the cross-sectional area of each vertical member and the number of heavily damaged horizontal members. Since its development, this assessment method has been used by TCIP to decide the indemnities (and somehow future) of damaged structures to be either ‘repaired’ (partial indemnity) or ‘demolished’ (full indemnity) after earthquakes that took place in Turkey. In recent years, the number of scientific studies in regard to the concept of reparability of damaged structures, which is a determining parameter in buildings’ future decisions after seismic events, is increased. Consequently, TCIP initiated a research project to adjust the damage assessment method with the conclusions of up-to-date state-of-the-art scientific research. This paper presents the followed methodology and brief results of different phases of the project. In order to propose modifications for the current method, firstly, an experimental database was established focusing on the performance of damaged structural members. The database was used to validate/revise the member damage modifier parameters. Secondly, in order to define a reparability limit in terms of the building WDP value, a literature survey investigating the fundamental mechanical characteristics (such as stiffness, strength and ductility) that can be used to define the seismic behavior of damaged, and damaged-and-repaired structural members was performed. These mechanical characteristics were then used in a series of nonlinear structural analyses on typical buildings representing the common typologies of buildings in Turkey. The analyses covered the undamaged, damaged and damaged-and-repaired cases in order to determine the damage state/level where the cost of the repair applications become unfeasible or the seismic performance of the repaired structure deviates considerably from that of its undamaged state. Finally, by comparing the seismic performances of undamaged, and damaged-and-repaired cases together with the repair costs, new threshold values were proposed for WDP for different damage levels (and indemnity decisions). © The 17th World Conference on Earthquake Engineering.Editorial The Flipped Approach To Higher Education Designing Universities for Today's Knowledge Economies and Societies Preface(Emerald Group Publishing Ltd, 2016) Sahin, Muhammed; Kurban, Caroline Fell; Fell Kurban, Caroline; Şahin, Muhammed; 04.02. Department of Psychology; 02.04. Department of Civil Engineering; 02. Faculty of Engineering; 04. Faculty of Economics, Administrative and Social Sciences; 01. MEF UniversityArticle Citation - WoS: 3Citation - Scopus: 4Reconnaissance and Discussion on Ground Motion Induced by the 2023 Türkiye-Syria Earthquake(Taylor and Francis Ltd., 2025) Towhata, I.; Tönük, Gökçe; Tönük, G.; Erginağ, U.C.; Sendir Torisu, S.; Torisu, Seda Sendir; 02.04. Department of Civil Engineering; 02. Faculty of Engineering; 01. MEF UniversityThis paper discusses the output from the damage reconnaissance conducted after the 2023 Türkiye-Syria earthquake. First, a large landslide occurred in a limestone gentle slope without much ground water. Second, the ground subsidence in the coastal area does not comply the the local soil conditions and other observed post-seismic situations. Third, the acceleration records exhibit stronger motion with longer period and shorter duration towards the western end of the causative fault and suggest supershear rupture. To understand these features of the ground motion, this paper proposes a hypothetical model that can reproduce these observations to a good extent. © 2025 Taylor & Francis Group, LLC.Conference Object Citation - WoS: 2Citation - Scopus: 3An Overview on the Structural Monitoring, Assessment and Retrofitting of Historical Structures With a Focus on 13th Century Monuments(Springer international Publishing Ag, 2024) Ilki, Alper; Halıcı, Ömer Faruk; Halici, Omer F.; Demir, Cem; Comert, Mustafa; Kuran, Fikret; 02.04. Department of Civil Engineering; 02. Faculty of Engineering; 01. MEF UniversityMonumental historical structures affirm natural and cultural identity and hence they should be transmitted to future generations. The protection and preservation of these structures against aging and natural hazards, particularly seismic actions, requires a comprehensive approach including diagnosis of the present condition of the structure and enhancement of structural capacity for disaster mitigation, if necessary. It is obvious that due to their historical values, any attempt towards the preservation of the monumental historical structures must be carried out with respect to the principles of integrity and authenticity. In this study, the structural performance assessment procedures, implementation of structural health monitoring systems and seismic strengthening strategies are discussed and described with reference to 13th-century monumental historical structures in Turkiye. The structural engineering aspects of recent activities for the restoration and preservation of the Great Mosque and Hospital of Divrigi (a world heritage listed structure) and Sivas Ulu Cami (Mosque) Minaret are briefly presented. In light of the structural analysis and monitoring results, recommendations for interventions to these monumental structures are outlined.Conference Object Citation - Scopus: 1Investigation Procedure for the Diagnosis of Historical Minarets: Inclined Minaret of Sivas Ulu Cami (mosque)(Springer, 2024) İnci, Pınar; Halıcı, Ömer Faruk; Aldırmaz B.; Çoban S.; Halıcı, Ömer Faruk; Cömert M.; Kiraz F.; Comert, M.; Aldirmaz, B.; Ilki, A.; Coban, S.; 02.04. Department of Civil Engineering; 02. Faculty of Engineering; 01. MEF UniversityThe inclined minaret of Sivas Ulu Cami (Mosque) from the 13th century Danishmend Period is one of the most invaluable architectural heritages in Turkey. The extent of inclination of the minaret towards the North-West direction, the seismicity of the region, and structural damages that occurred in time have emphasized the need for comprehensive structural and geotechnical investigations. Accordingly, a rehabilitation project is currently going on under the coordination of the General Directorate of Foundations of Turkey. Within the scope of the project, first, a series of field surveys have been conducted to obtain the current features of the minaret including the characteristics of the structural system, damages, deviation from the vertical axis, ground conditions and foundation details. In addition to that, a monitoring system including inclinometers, linear potentiometers and accelerometers has been mounted for tracking the evolution of deformations and damages in time under environmental influences and extracting the dynamic properties of the minaret. Findings from the field survey and monitoring system were used for constructing an analytical model of the structural system of the minaret. Then nonlinear time history analyses were conducted under various strong ground motion records to estimate the seismic performance of the minaret when subjected to earthquakes of different characteristics. The results showed that the tensile stresses that occurred due to seismic actions exceeded the tensile strength of the brick masonry at the region of the transition segment and the cylindrical body (top level of the boot).Conference Object Citation - WoS: 7Citation - Scopus: 5State of the Art in Application of Seismic Isolation and Energy Dissipation in Turkey(Springer International Publishing Ag, 2023) Şadan, Bahadır; Şadan, Bahadır; 02.04. Department of Civil Engineering; 02. Faculty of Engineering; 01. MEF UniversityThis paper summarizes the passive structural control system applications and other related developments in Turkey, emphasizing the period between 2019 and 2022. The country hosts state-of-the-art seismic isolation applications, relatively greater in size, and use more isolators in each project (415 isolators per building on average) compared to the other seismic isolation projects worldwide. Construction of the world's largest seismic isolated building, Istanbul Basaksehir Pine and Sakura City Hospital, covering more than 1 million square meters of area and employing more than 2000 seismic isolators, was completed and has been in service since May 2020. 1915 Canakkale Bridge, constructed in memory of the great war of Canakkale during World War I, is now the world's longest suspension bridge with a 2023m main span length. Eight massive hydraulic dampers were used at the main deck and 48 at the approach viaducts in combination with 72 seismic isolators. Construction of a residential building complex in Istanbul consisting of 16 isolated blocks covering more than 170,000 m(2) area and having 454 seismic isolators is coming to an end very soon. Historical Nusretiye Clock Tower in Istanbul was relocated a few meters over seismic isolators. Historical Goztepe Railway Station in Istanbul was retrofitted to accommodate an additional railway line using seismic isolation technology. Seismic codes for buildings and bridges now include rules for the seismically isolated design of structures. Additionally, all seismic isolation designs must be peer-reviewed by law. A new seismic isolator testing facility was established in Eskisehir to respond to the demand for the large number of isolators that need to be tested.