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 University
    Since 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
    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 Engineering
    The 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: 1
    Modifications 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 Engineering
    Evaluating 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.
  • Conference Object
    Seismic Performance of Damaged Code-Conforming Rc Columns Repaired With Sustainable Structural Mortar
    (Elsevier B.V., 2024) Kolemenoglu, S.; Halıcı, Ömer Faruk; Demir, C.; Aydemir, C.; Aydemir, M.E.; Ilki, A.; 02.04. Department of Civil Engineering; 02. Faculty of Engineering; 01. MEF University
    Examining the seismic performance of damaged reinforced concrete (RC) structures after repair applications is vital for an effective post-earthquake disaster management policy. However, the number of experimental studies investigating the seismic behavior of repaired RC members is insufficient, especially for structural members that have endured slight or moderate level damages. In this study, four identical large-scale code-conforming RC columns were tested under combined effects of axial load and reversed cyclic lateral displacements. The reference column was tested until failure, while the remaining three columns were first imposed to lateral displacements until the formation of damages at different levels, then repaired with structural repair mortar that contains recycled raw materials without removing axial load and tested again until failure. The primary objectives of the experimental program are to enhance the knowledge on the post-earthquake performance of damaged RC columns and to investigate the effects of repair applications after slight and moderate damage levels. This paper provides details on the effectiveness of the aforementioned repair technique on the seismic performance of code-complying RC columns damaged at different damage levels. © 2024 Elsevier B.V.. All rights reserved.
  • Conference Object
    Citation - WoS: 2
    Citation - Scopus: 3
    An 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 University
    Monumental 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: 1
    Investigation 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 University
    The 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).