İnşaat Mühendisliği Bölümü Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1943
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Article Revitalizing Water Storage Capacity: Remote Sensing and Optimization-Based Design for a New Dam(MDPI, 2026-03-29) Akbıyıklı, Rıfat; Uğur, Latif Onur; Genç, Ömer; Ateş, Volkan; Bozali, BeytullahMost of the dam structures around the world are approaching the end of their economic life of 50 to 70 years, especially due to sediment accumulation in reservoir areas. This situation necessitates the development of proactive infrastructure management strategies. This study presents an original framework for the process of renewal of aging dams that blends remote sensing techniques and meta-intuitive optimization methods. Within the scope of the study, the Hasanlar Dam located in Düzce was selected as a sample, and a new dam axis was determined in the upper part of the basin. A detailed volume-height curve was created using 12.5 m resolution ALOS PALSAR numerical height models (DEM) and GIS-based spatial data curation to calculate the reservoir storage capacity in precise increments of 2 m. To maximize the structural efficiency of the proposed New Hasanlar Dam, the cross-sectional area has been minimized through seven current algorithms such as Genetic Algorithm (GA), Arithmetic Optimization Algorithm (AOA), Gray Wolf Optimizer (GWO), Dragonfly Algorithm (DA), Particle Swarm Optimization (PSO), Crayfish Optimization Algorithm (CAO), and Cheetah Optimizer (CO). The findings obtained prove that the PSO and CAOs achieved a significant reduction in cross-sectional area by 29.36% and successfully approached the global optimum. The replacement of the 55.5 million m3 capacity of the existing Hasanlar Dam with a new structure with a height of 78 m will guarantee sustainability and structural safety in water management. As a result, this study reveals that the integration of high-resolution remote sensing data and advanced heuristic methods is a cost-effective and powerful tool in the strategic renovation of aging hydraulic infrastructures.Article Seismic Behavior and Design of Reinforced Autoclaved Aerated Concrete Load-Bearing Panel Walls(Taylor & Francis Ltd, 2026-02-16) Ugurlu, Koray; Halici, Omer Faruk; Demir, Cem; Comert, Mustafa; Ilki, AlperSince 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.Article Citation - WoS: 3Citation - Scopus: 4Reconnaissance and Discussion on Ground Motion Induced by the 2023 Türkiye-Syria Earthquake(Taylor and Francis Ltd., 2025-02-18) Towhata, I.; Çağlayan, P.Ö.; Tönük, G.; Erginağ, U.C.; Sendir Torisu, S.; Torisu, Seda SendirThis 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; Inci, Pinar; Halici, Omer F.; Demir, Cem; Comert, Mustafa; Kuran, FikretMonumental 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.Article Citation - WoS: 10Citation - Scopus: 10Site Response Analysis in Performance Based Approach(Elsevier Sci Ltd, 2024-03-01) Ansal, Atilla; Tönük, Gökçe; Sadeghzadeh, Shima; Sadegzadeh, ShimaA performance based approach for site response analysis requires a probabilistic approach accounting for the observed variability in soil stratification and engineering properties of the soil layers. The major variability in site-specific response analysis arises from the uncertainties induced by the (a) local seismic hazard assessment, (b) selection and scaling of the hazard compatible input earthquake time histories, (c) soil stratification and engineering properties of encountered soil and rock layers, and (d) method of site response analysis. Even though the uncertainties related to first item, local seismic hazard assessment, has primary importance on the outcome of the site-specific response analyses, the discussion in this article focuses on the possible uncertainties in selection and scaling of the hazard compatible input earthquake time histories, soil stratification, thickness, type and their engineering properties, depth of ground water table and bedrock and properties of the engineering bedrock. One alternative may be to conduct site response analyses for large number of soil profiles generated by Monte Carlo simulations using relatively large number of hazard compatible acceleration time histories to assess probabilistic performance based design acceleration spectra and acceleration time histories calculated on the ground surface with respect to different performance levels. A remaining issue may be considered as the variability induced by 1D, 2D, and 3D site response analysis.Article Citation - WoS: 1Citation - Scopus: 2Probabilistic Seismic Microzonation for Ground Shaking Intensity, a Case Study in Türkiye(Springer, 2023-10-01) Tönük, Gökçe; Ansal, AtillaThe purpose of seismic microzonation is to estimate earthquake characteristics on the ground surface based on a probabilistic approach to mitigate earthquake damage in the foreseeable future for the new buildings, as well as for the existing building stock. The probabilistic analysis and related results are very important from an engineering perspective since the nature of the problem can only be dealt with in a probabilistic manner. The uncertainties associated with these analyses may be large due to the uncertainties in source characteristics, soil profile, soil properties, and building inventory. At this stage, the probability distribution of the related earthquake parameters on the ground surface may be determined based on hazard-compatible input acceleration-time histories, site profiles, and dynamic soil properties. One option, the variability in earthquake source and path effects may be considered using a large number of acceleration records compatible with the site-dependent earthquake hazard. Likewise, large numbers of soil profiles may be used to account for the site-condition variability. The seismic microzonation methodology is proposed based on the probabilistic assessment of these factors involved in site response analysis. The second important issue in seismic microzonation procedure is the selection of microzonation parameters. The purpose being mitigation of structural damage, it is possible to adopt earthquake parameters like cumulative average velocity (CAV) or Housner intensity (HI) that was observed to have better correlation with building damage after earthquakes. A seismic microzonation procedure will be developed with respect to ground shaking intensity considering probabilistic values of the cumulative average velocity (CAV) or Housner intensity (HI).Article Citation - WoS: 10Citation - Scopus: 16Out-Of Seismic Performance of Bed-Joint Reinforced Autoclaved Aerated Concrete (aac) Infill Walls Damaged Under Cyclic In-Plane Displacement Reversals(Elsevier Sci Ltd, 2023-07-01) İlki, Alper; Demir, Uğur; Halıcı, Ömer Faruk; Zabbar, YassinThe infill walls made of Autoclaved Aerated Concrete (AAC), which is a lightweight, fire resistant and energy efficient material, provide effective insulation solutions for building types of structures and becoming more and more popular in earthquake prone regions. Although the number of experimental tests examining the seismic response of clay brick infills is extensive, the amount of prior research on infill walls built of AAC blocks is rather limited. Past research revealed that the use of bed-joint reinforcement is one of the promising solutions to improve the global seismic response of masonry walls by enhancing strength and displacement capacity. In this study, the out-of-plane (OOP) seismic performance of AAC infill walls with flat-truss and innovative cord-type bed-joint reinforcement is experimentally evaluated. Also, consideration is given to the prior in-plane (IP) damage, which was found to degrade the seismic performance of infills in OOP direction. For this purpose, three IP and four OOP, in total, seven experimental tests were performed on four full-scale AAC infill wall specimens. The test parameters were selected in such a way as to make it possible to parametrically compare the OOP performance of AAC infills with flat-truss and cord-type bed-joint reinforcements with unreinforced AAC infill walls, together with the effect of prior IP damage on the OOP response of unreinforced AAC infill walls. It was found that the use of innovative cord-type bed-joint reinforcement improved the OOP strength to a similar extent to what was obtained from the truss-type reinforced specimen. In terms of ultimate displacement and energy dissipation capacity enhancement, the specimen with cord-type reinforcement performed better. In addition, the damages formed due to IP cyclic displacement reversals up to 0.005 drift ratio, which is defined as the drift limit for buildings with brittle infill walls in certain design codes, resulted in a significant reduction in the OOP strength and stiffness properties of AAC infills. The theoretical OOP strength calculations were found to provide unconservative strength values for the IP-damaged specimens.Article Citation - WoS: 12Citation - Scopus: 13Damage Accumulation Modelling of Two Reinforced Concrete Buildings Under Seismic Sequences(Springer, 2023-06-30) Tönük, Gökçe; Oyguç, Reşat; Oyguç, Evrim; Uçak, DorukThe extent of earthquake damage depends solely on the seismicity, site conditions and vulnerability of the building stock in a region. Hence, studies to assess the seismic behavior of building stocks with similar vulnerabilities are important to mitigate seismic risk in earthquake-prone regions. This study aims to simulate the seismic behavior of selected reinforced concrete (RC) school buildings by modelling damage accumulation under multiple earthquakes sequence. The observed data of two RC school buildings heavily damaged after the 2011 Van earthquake sequence in Turkey, namely, the Gedikbulak and Alakoy schools is used. Among these two school buildings, the Gedikbulak school building collapsed immediately after the main excitation, while the Alakoy school building withstood several seismic sequences, suffering heavy damages. In this study, three-dimensional numerical models that can consider the deterioration effects are developed and the capacities of the buildings were evaluated by conducting a force-based adaptive pushover procedure. Additionally, non-linear dynamic analyses were conducted using the concrete plastic damage model. Both degrading and conventional material models were used to examine the structural response under multiple ground motion sequences. The hysteretic behaviors of the studied buildings are presented. Consequently, analytical results are well correlated with the reconnaissance studies and neither of the considered structures are found to satisfy the design performance level.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, BahadırThis 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.Conference Object Citation - WoS: 6Citation - Scopus: 11Near-Fault Earthquake Ground Motion and Seismic Isolation Design(Springer International Publishing Ag, 2023) Harmandar, Ebru; Erdik, Mustafa; Demircioglu-Tumsa, Mine B.; Şadan, Bahadır; Tuzun, Cuneyt; Ulker, OmerSeismic isolation is one of the most reliable passive structural control techniques with adequately established standards for the earthquake protection of structures from earthquakes. However, it has been shown that the seismic isolation systems may not function the best for the near-fault ground motions, since in the proximity of a capable fault, the ground motions are significantly affected by the rupture mechanism and may generate high demands on the isolation system and the structure. In fact, several earthquake resistant design codes state that the seismically isolated structures located at near-fault sites should be designed by considering larger seismic demands than the demand on structures at far-field sites. When the fault ruptures in forward direction to the site most of the seismic energy arrives in coherent long-period ground velocity pulses. The ground-motion prediction equations (GMPEs) typically cannot account for such effects with limited distance metrics and lack adequate data at large magnitudes and near distances. For the reliable earthquake design of the isolated structure in near fault conditions that meets the performance objectives, the 3D design basis ground motion(s) need to be appropriately assessed. Measures in the design of the isolation system, such as modifications in the stiffness and damping characteristics, as well as in the limitation of vertical effects are needed. The behavior of the base-isolated buildings under near-fault (NF) ground motions with fling-step and forward-directivity characteristics are investigated with a rational assessment of design-basis near-fault ground motion, are investigated in a parametric format. The parametric study includes several variables, including the structural system flexibility; number of stories; isolation system characteristic (yield) strength, and the isolation periods related to the post-elastic stiffness. Furthermore, the effect of additional damping by viscous dampers were tested for some selected cases. Important findings observed from the parametric performance results and the overall conclusions of the study are provided.