Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2026Scopus SJRQ1Impact of soft-storey irregularity on the seismic safety of reinforced concrete buildings
Tektaş, Şeyhmus; Tam, Gürkan; Yön, Burak
This study evaluates the effect of soft-storey irregularity on the seismic fragility of reinforced concrete buildings by comparing fragility curves based on inter-storey drift and element damage. This comparison highlights the novelty of the study. For numerical analyses, a typical four-storey reinforced concrete building with a ground storey of 4.5 m and typical storeys of 3 m, having a current storey plan, was modeled as both a regular and soft-storey building. To model nonlinear behavior, the assumption of lumped plastic hinges at the ends of the structural elements was made. Static pushover analyses of the building models created in SeismoStruct 2022 were performed until the roof displacement reached 3% of the building height, while nonlinear incremental dynamic analyses were carried out using 11 real ground motion records obtained from AFAD. The records were scaled between 0.1 g and 1.0 g and applied in the x- and y-directions for both buildings, yielding a total of 440 dynamic analyses. Static pushover analyses generated capacity curves for both regular and soft-storey buildings. Incremental dynamic analyses revealed maximum responses, inter-storey drifts, damage distributions, and fragility curves for both regular and soft-storey buildings. Fragility curves were obtained using both HAZUS inter-storey drift limit values and TBEC 2018 section-based strain limits. The results showed that fragility curves generated based on inter-storey drifts yielded more sensitive results than those generated based on damage at the critical storey. Furthermore, it was determined that for an earthquake acceleration of 0.5 g, the probability of a soft-storey building collapsing was 30% higher than that of a regular building.
- MakaleAçık Erişim2026Scopus SJRQ1Failure of a Code-Compliant Reinforced Concrete Building: Damage Patterns and Nonlinear Seismic Response
Onat, Onur; Karaşin, İbrahim Baran; Yön, Burak; Varolgüneş, Sadık; Öncü, Mehmet Emin; Uslu, Ali
This study investigates the seismic performance limitations of a newly constructed reinforced concrete building that collapsed during the 6 February 2023 Kahramanmaraş–Elbistan earthquake despite formal compliance with current seismic design requirements. Beyond the specific earthquake event, the study addresses a broader scientific problem: the limited understanding of the relationship between observed damage mechanisms and nonlinear dynamic response in mid-rise reinforced concrete buildings. The first part classifies recurring structural and non-structural damage patterns identified in newly constructed RC residences. The second part presents a nonlinear fiber-based static and dynamic analysis of a collapsed mid-rise building. Nonlinear dynamic analyses were conducted using ground motion records scaled to match the site-specific elastic design spectrum defined by TBDY 2018, corresponding to predefined seismic performance levels rather than an incremental dynamic analysis framework. The results indicate that an extremely low shear wall–to–floor area ratio (0.0357%) combined with asymmetric vertical element distribution significantly amplified torsional response and local shear demands. Nonlinear dynamic analyses showed that critical shear walls exceeded Collapse Prevention limits under DD2-level excitation, while system-level shear contribution limits remained within code-defined thresholds. Dynamic base shear demand corresponded to approximately 30% of the maximum nonlinear capacity obtained from pushover analysis, indicating that localized member failure rather than global strength deficiency governed the collapse mechanism. The analytically identified critical members were consistent with the observed collapse configuration, particularly at the soft ground story. The findings demonstrate that prescriptive code compliance alone may not ensure satisfactory seismic performance when structural irregularities, torsional amplification, and detailing deficiencies coexist. The results are consistent with damage patterns reported in other recent destructive earthquakes and contribute to improving the understanding of collapse mechanisms in code-compliant RC buildings.
AtıfScopus4OpenAlex7
İncele - MakaleAçık Erişim2025Improving earthquake resistance in rc buildings via steel bracing members
Yön, Burak; Tam, Gürkan
In this study, the effect of retrofitting with steel bracing members on the seismic behavior of reinforced concrete buildings was examined. A reinforced concrete building with low concrete strength was modeled for the numerical study. This modeled building was strengthened with steel X-braced members to create a total of two buildings. To evaluate the seismic behavior of the modeled buildings, incremental dynamic analyses were performed using static pushover analysis and 11 different earthquake records. Due to the symmetrical structure of the modeled buildings, a total of 220 analyses were carried out simultaneously in the x and y directions. As a result of the analysis, the capacity curves of the existing building and the strengthened building with steel bracing members, maximum responses, inter-storey drifts, and fragility curves according to the damage status were obtained. As a result of the analysis, it was determined that the maximum response of the building strengthened using X steel cross members increased significantly compared to its current state, while the damage to the structural elements was significantly reduced.
AtıfOpenAlex1
İncele - MakaleYalnız künye2025Scopus SJRQ2Assessment of seismic fragility of reinforced concrete buildings retrofitted with steel bracing elements: A numerical study
Tam, Gürkan; Yön, Burak
In this study, the effectiveness of reinforcement with steel diagonal elements in a reinforced concrete building was investigated. A typical reinforced concrete building with ground floor+4 floors was designed for the numerical study. All column dimensions were 400×400 mm, all beam dimensions were 250×500 mm, transverse reinforcement spacing in column and beam elements was 100 mm and floor heights were 3 meters. The existing building was strengthened with X steel diagonal elements and two models were obtained. Nonlinear static pushover and incremental dynamic analyses of the buildings were performed. 11 earthquake records were used for incremental dynamic analyses. The acceleration amplitudes of these records were increased from 0.1 g to 1.0 g by 0.1 g and the analyses were performed. In order to model the nonlinear behaviour, lumped plastic hinges were assumed at the ends of the structural elements. As a result of nonlinear static pushover and incremental dynamic analyses of the buildings, capacity curves, maximum responses, inter-storey drifts, hysteretic curves at the ends of selected columns and damage patterns were obtained. Fragility curves were created by considering the damage levels in the buildings. According to the results, the average inter-storey drifts of the building strengthened using X steel diagonal elements decreased by approximately 90% compared to its current condition for 1.0 g PGA, while the damage probability and vibration period were also significantly reduced. In addition, the base shear force encountered by the strengthened building increased more than 4 times compared to its current condition.
AtıfScopus11WoS8İncele - MakaleAçık Erişim2025Scopus SJRQ1Evaluation of the seismic response of reinforced concrete buildings in the light of lessons learned from the February 6, 2023, Kahramanmaraş, Türkiye earthquake sequences
Yön, Burak; Dedeoğlu, İbrahim Özgür; Yetkin, Musa; Erkek, Hakan; Calayır, Yusuf
On 6 February 2023, two significant seismic events occurred in the southeastern region of Türkiye. The seismic activity, which was perceptible in numerous countries beyond Türkiye, resulted in a considerable number of fatalities. A considerable number of individuals lost their lives and were rendered homeless as a result of the disaster. Two of the most significant factors contributing to the occurrence of these tragedies are the magnitude of the earthquake and structural deficiencies. The present study is concerned with a detailed analysis of these two factors. This study initially considers the seismicity of the region where the earthquakes that occurred on 6 February 2023 took place, as well as the seismic characteristics of these earthquakes. Subsequently, the findings of the field studies conducted in Hatay, Adıyaman, Kahramanmaraş and Malatya, the cities where the earthquakes caused the most destruction, are presented. The objective of the field study is to ascertain the collapse patterns, structural damages and the factors influencing these damages in reinforced concrete structures in the region. The primary causes of damage to structures can be attributed to several factors, including the presence of a strong beam-weak column mechanism, the soft story-weak story mechanism, the pounding effect, the short column damage, the long cantilever and overhangs, the short beam damage, the buckling damage, the torsion effect, the quality of the materials, the insufficient transverse reinforcement, the compressive failure due to over-reinforcement, the corrosion effect, the damage to reinforced concrete shear walls, the infill wall damage, and the damage caused by the soil and foundation system. These causes have been evaluated and recommendations have been formulated to prevent structural damage.
AtıfScopus55WoS50OpenAlex61İncele - MakaleAçık Erişim2024Birleşik Deprem Etkilerinin ve Ek Dışmerkezliğin Betonarme Binaların Davranışına Etkisi
Yön, Burak; Tam, Gürkan
Bu çalışmada birleşik deprem etkilerinin ve ek dışmerkezliğin betonarme binaların davranışına etkisi incelenmiştir. Çalışma kapsamında modellenen betonarme yapının beş zemin sınıfına (ZA, ZB, ZC, ZD ve ZE) göre X ve Y yönlerinde olmak üzere toplam 30 adet doğrusal olmayan statik itme analizleri yapılmıştır. Kolon ve kirişlerin doğrusal olmayan davranışları toplanmış plastik mafsal kabulüne göre, perde duvarların doğrusal olmayan davranışları ise yayılı plastik mafsal kabulüne göre yapılmıştır. Analizler sonucunda birleşik deprem etkileri ve ek dışmerkezlik dikkate alınarak her zemin sınıfı için kapasite eğrileri, her zemin sınıfı için X ve Y yönlerinde en düşük yük faktöründe oluşan plastik mafsal dağılımları, X ve Y yönlerinde ilk mafsalın oluştuğu yük faktörü ve maksimum yük faktörü değerleri elde edilmiştir. Analizler sonucunda zemin sınıfı ZA’dan ZE’ye doğru gidildikçe hem kapasite değerlerinde hem de yük faktörü değerlerinde azalmanın olduğu belirlenmiştir. Bununla birlikte, ek dışmerkezlik ve birleşik deprem etkileri dikkate alındığı zemin sınıfındaki değişime bağlı olarak plastik mafsal dağılımlarının yoğunlaştığı tespit edilmiştir. Sonuç olarak betonarme yapıların tasarımlarında ve performans değerlendirmelerinde zemin sınıflarına ilave olarak birleşik deprem etkilerinin ve ek dışmerkezliğin dikkate alınması gereken önemli parametreler olduğu tespit edilmiştir.
AtıfTR Dizin1İncele - MakaleAçık Erişim2024Scopus SJRQ2Seismic Resistance and Performance Evaluation of Masonry Dwellings After the February 6, 2023, Kahramanmaraş Earthquake Sequence in Türkiye
Onat, Onur; Yön, Burak; Uslu, Ali; Öncü, Mehmet Emin; Varolgüneş, Sadlk; Karaşin, I.B.; Gör, Mesut
On February 6, 2023, two catastrophic earthquakes occurred on the East Anatolian Fault. The earthquakes had magnitudes of Mw = 7.7 and 7.6 and struck Kahramanmaraş-Pazarclk and Kahramanmaraş-Elbistan, respectively. The Kahramanmaraş-Pazarclk earthquake was triggered at 04:17 local time on the Dead Sea Fault (a branch of the East Anatolian Fault). The last earthquake on the addressed fault occurred about 500 years ago. The recorded peak ground acceleration (PGA) at the Pazarclk station reached 2.05g. In addition, the Pazarclk earthquake triggered two independent earthquakes, the Nurdaǧl and Islahiye earthquakes, which occurred 10 min later than the Pazarclk earthquake. However, the last earthquake, with its epicenter in Kahramanmaraş-Elbistan, struck at 13:24 local time. The recorded PGA for the Elbistan earthquake is 0.68g. This study aims to present the fault rupture mechanism of the February 6, 2023, Kahramanmaraş earthquakes, earthquake characteristics, and to evaluate the performance of masonry dwellings during the Kahramanmaraş earthquake doublet, which affected 10 provinces and numerous towns and villages. This paper also aims to illustrate the damage and failure mechanisms of the masonry dwellings, despite unexpectedly high accelerations that exceeded the design spectrum in the field, specifically in Kahramanmaraş, Gaziantep, Hatay, and Malatya, according to the current earthquake code in use.
AtıfScopus16OpenAlex22İncele - MakaleYalnız künye2024Scopus SJRQ1Sustainable use of boron waste and volcanic scoria in slag-based self-compacting alkali-activated mortars: fresh, mechanical and durability properties
Yön, Merve Şahin; Yön, Burak; Karataş, Mehmet; Benli, Ahmet
Sustainable self-compacting alkali-activated concrete (SCAAC) manufacturing is an environmentally friendly concrete that has a reduced carbon footprint than ordinary concrete. Alkali-activated binders have been demonstrated in experiments to reduce concrete's energy consumption and carbon emissions by over 50%. This paper focuses on manufacturing boron waste (BW), volcanic scoria (VS) and ground blast furnace slag (GBFS) incorporated binary and ternary blends of self-compacting alkali-activated mortars (SCAAM). The main objective of this study is to investigate the fresh, mechanical, durability and microstructural properties of SCAAM based on binary and ternary mixtures of BW, VS, and GBFS. SCAAM samples were synthesized at 60 °C and 100 °C for 72 h then exposed to ambient cured at 3, 28 and 90 days. The compressive strength, flexural strength, physical, and sorptivity properties of the SCAAM mixtures, as well as flowability, were investigated. The performance of the produced blends at freeze-thaw exposure were also examined. SEM, and EDS was also used to examine the microstructures of the mixtures. The findings showed that 50% GBFS and 50%VS based SCAAM mixture heat cured at 100oC activated with NS/NH ratio of 3.0 produced a compressive strength of 40 MPa at 90 days. The findings indicated that inclusion of BW to the SCAAM mixtures decreased the compressive strength notably regardless of NS/NH ratio and curing temperature. Inclusion of BW also affected the durability performance negatively.
AtıfScopus38WoS36OpenAlex35İncele - MakaleAçık Erişim2022Scopus SJRQ1Field reconnaissance and structural assessment of the October 30, 2020, Samos, Aegean Sea earthquake: an example of severe damage due to the basin effect
Onat, Onur; Yön, Burak; Öncü, Mehmet Emin; Varolgüneş, Sadık; Karaşin, Abdulhalim; Cemalgil, Selim
An earthquake with a magnitude ranging from Mw = 6.9 (KOERI) to Mw = 7.0 (USGS) struck Samos Island in the Aegean Sea on October 30, 2020, with an epicentre 70 kms from the İzmir city centre in Turkey. The earthquake took place at 14:51 local time (11:51 UTC). The peak ground acceleration (PGA) of this earthquake was recorded to be 0.179 g at the epicentre of the earthquake. This earthquake occurred at a depth of 17.26 km (AFAD (2020) İzmir Earthquake Report, (In Turkish)) and lasted 16 s. The main shock from the earthquake triggered a tsunami that hit the building stocks built near the coast. During the gradual deregulation of COVID-19 pandemic regulations, various events caused considerable damage to the building stock, particularly in the Izmir Seferihisar and Bayraklı regions and resulted in a massive disruption of daily habits. The main shock caused 117 deaths in both Turkey and Greece, and 1632 people were also injured in Turkey. Moreover, several injuries occurred in Greece. A total of 103 buildings collapsed, 700 were severely damaged, 814 buildings were moderately damaged, and 7889 were slightly damaged. The basic aim of this paper is to briefly present the past and present seismotectonic characteristics of the region, present building stock, and former structural conditions before the earthquake, assess structural performance and classify distinguished earthquake-induced failures and damage due to the basin effect.
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İncele - MakaleAçık Erişim2021Beton Dayanımının ve Kirişlerdeki Çekme Donatısı Oranının Orta Yükseklikli Betonarme Binaların Sismik Davranışı Üzerine Etkisinin Belirlenmesi için Artımsal Dinamik Analiz
Onat, Onur; Yön, Burak
Artımsal Dinamik Analiz (ADA), sismik yükler altında yapısal performansı değerlendirmek için birkaç farklı biçimde yaygın olarak kullanılan parametrik bir sonuç analizi yöntemidir. Bu yöntem, seçilmiş olan bir grup sismik kayıtın ölçeklenerek yapısal sisteme etki ettirilerek, bu etki altında, elastik tepkiden genel dinamik yapısal stabiliteye ulaşmayı öneren bir analiz türüdür. Bu çalışmada çekme donatısı oranı ve beton dayanımının orta yükseklikli betonarme yapıların sismik davranışı üzerine etkisi incelenmiştir. Sayısal çalışma olarak 5 açıklıklı, 5 ve 7 katlı iki farklı sayısal model oluşturulmuştur. Her bir model için üç farklı çekme donatısı oranı ve iki farklı beton sınıfı seçilmiştir. Çekme donatısı oranları, basınç bölgesindeki donatının yarısı, bir katı ve iki katı olarak belirlenmiştir. Sayısal modeller artımsal dinamik yük altında analiz edilmiştir. Bu analiz için on bir farklı sismik kayıt kullanılmıştır. Bu kayıtlar 0.2g’den 1.2g’ye kadar 0.2g artımlar ile ölçeklenmiştir. Yapılan artımsal dinamik analizler sonucunda yapısal sistemlerin taban kesme kuvvetleri ve karşılık gelen çatı katı deplasmanları karşılaştırılmıştır. Elde edilen analiz sonuçlarına göre kirişlerde çekme donatısı oranını arttırmak çatı katı deplasmanını düşürmese de katlar arası göreli ötelenmeyi azaltmıştır, böylelikle hasar seviyesini azaltacağı için hasar oranını düşürmektedir.
AtıfOpenAlex2TR Dizin1İncele - MakaleAçık Erişim2021A novel inter-story drift limit proposal for TBEC2018 and fragility prognosis with TSC2007
Onat, Onur; Yön, Burak
The basic purpose of this paper is to investigate and propose a novel inter-story drift limits for the currentTurkish Seismic Code to get easy structural assessment by using software. For this aim, numerical analysiswas performed by modeling two types of RC frame structures. One of them is 5 stories, the other of them is7 stories. Two different concrete classes, C20 and C25, were considered and three tension reinforcementratios were considered for analysis. Tension reinforcement ratios were determined by half of the compressivereinforcement, equal to compressive reinforcement and double the compressive reinforcement ratio.Incremental dynamic analyses (IDA) were performed on these buildings. In this study to execute IDA, elevenseismic acceleration benchmark records were multiplied with various scaling factors from 0.2 to 1.0.Maximum base shear and corresponding roof displacement responses obtained from IDA curves weregenerated according to these responses. IDA curves were compared with each other by deriving fragilitygraphs. According to results, proposed limits for the current Turkish seismic code (TBEC-2018) provide,0.6%, 2.4% and 3.3% respectively for MN, GV and GC, rather safe limits compared to drift limits presentedin the foredate seismic code (TSC-2007).
AtıfOpenAlex2TR Dizin2İncele - MakaleAçık Erişim2021Scopus SJRQ124 January 2020 Sivrice-Elazığ, Turkey earthquake: geotechnical evaluation and performance of structures
Sayın, Erkut; Yön, Burak; Onat, Onur; Gör, Mesut; Öncü, Mehmet Emin; Tuğrul Tunç, Esra; Bakır, Dursun; Karaton, Muhammet; Calayır, Yusuf
The January 24, 2020 Sivrice-Elazığ (Mw = 6.8) earthquake occurred on the East Anatolian Fault zone. Main shock of this earthquake was occurred 20:55 at local time. The Peak Ground Acceleration was equal to 0.3 g at the epicenter (Sivrice district) of the earthquake. Even though the main shock was moderate, its effects on the structures were rather serious. The main shock caused significant damage and resulted in 41 casualties. 1540 buildings were damaged moderately, while 8519 buildings were damaged heavily and collapsed. This main shock effected four cities surrounded the epicenter due to its shallow earthquakes. The purpose of this paper is to summarize past and present seismic characteristics of the earthquake region. In addition, the aim of this paper is to summarize the seismotectonic of the region, the general characteristics of the earthquake and more specifically to report on the structural damage, and structural damage caused by the earthquake, observed during the site investigation. The damages were classified for reinforced concrete structures, masonry dwellings and non-residential structures. All distinguished earthquake induced failures and damages were discussed. Moreover, lessons learned were presented in this study.
AtıfScopus74WoS68OpenAlex93İncele - MakaleYalnız künye2021Scopus SJRQ3Seismicity of East Anatolian of Turkey and Failures of Infill Walls Induced by Major Earthquakes
Doǧangün, Adem; Yön, Burak; Onat, Onur; Emin Öncü, Mehmet; Saǧlroǧlu, Serkan
There are three major fault zones in Turkey scattered around the country known as East Anatolian Fault (EAF), North Anatolian Fault (NAF) and Anatolian-Aegean Subduction Zone (AASZ). Last two decades, EAF has been rather quiescent compared with NAF. However, this quiescence was broken in the beginning of the millennium. The strong shaking was started in 2003 with Bingöl earthquake (Mw = 6.3) and the last earthquake on the EAF is the Sivrice-Elazlǧ (Mw = 6.8) on January 24, 2020. Strong seismicity of these faults damaged the structures severely and caused death of the habitants. This study aims to present, seismotectonic of the region, general characteristics of the earthquakes and more specifically to report structural damage of infill walls of the structure's damages caused by these earthquakes. Damage evaluation and identification of the observed infill wall damages due to 2003 Bingöl, 2011 Van earthquakes and January 24, 2020 Sivrice-Elazlǧ earthquake occurred Turkey's Eastern region, were presented, and possible solutions were suggested. Moreover, the effects of the infill walls on the behavior of structures under static and dynamic load cases are discussed that experienced in these earthquakes. Damages are classified according to formations such as in-plane or out-of-plane, evaluations and the results obtained from the discussions are presented for each category.
AtıfScopus35WoS32İncele - MakaleYalnız künye2021Scopus SJRQ1Identification of failure mechanisms in existing unreinforced masonry buildings in rural areas after April 4, 2019 earthquake in Turkey
Yön, Burak
Many unreinforced masonry buildings are completely destroyed after destructive earthquakes but, their failure mechanisms cannot be precisely determined. More specifically damage to such buildings is evinced during low or moderate magnitude earthquakes. The aim of this study is to identify the failure mechanisms of existing unreinforced masonry buildings and present a reconstruction strategy or offer strengthening procedures, in order to inhibit damage to masonry structures after destructive earthquakes. For this purpose, a moderate magnitude earthquake which occurred on April 4, 2019 near the township of Sivrice in Elazığ city, in the east of Turkey, was investigated. The magnitude of the studied seismic motion was expressed as Mw=5.2 by the Ministry of Interior Disaster and Emergency Management Presidency. Although this seismic effect was a moderate magnitude earthquake, significant failures occurred. Many masonry buildings and adobe dwellings in the villages of Sivrice were severely damaged by the earthquake. For field observations, ten villages located around the epicentre were visited 65 dwellings were observed and the damage patterns were assessed in detail. The observations showed that the main reasons for the damage to the dwellings were weak structural detailing of wall-to-wall and wall-to-roof connections, inhesion of earthen roofs, and a lack of bond beams in the structural walls. According to field observations, it is deduced that the performance of the undamaged masonry dwellings after earthquakes does not prove that they have adequate seismic safety. Therefore, reinforcing methods (shotcrete implementation, decreasing of space, corner reinforcing etc.) and innovative strengthening procedures (fibre reinforced polymer) are recommended for the undamaged existing unreinforced buildings at the end of the paper.
AtıfScopus53WoS48OpenAlex56İncele - MakaleYalnız künye2020Scopus SJRQ1Failures of masonry dwelling triggered by East Anatolian Fault earthquakes in Turkey
Yön, Burak; Onat, Onur; Emin Öncü, Mehmet; Karaşi̇n, Abdulhalim
Turkey is located on active fault zones such as the East Anatolian Fault (EAF), the North Anatolian Fault (NAF) and the Anatolian-Aegean Subduction Zone (AASZ). Ground seismicity activities of the NAF zone are relatively active compared with other faults. Eleven high-intensity earthquakes have been produced on this fault zone since 1939. Whereas the EAF zone was relatively quiescent in the last century, on the basis of historical records, destructive seismic activities occurred on the EAF zone in the last two decades. In this study, the rupture reason of faults, updated active fault data, and seismic maps are presented briefly. Moreover, failure reasons and failure mechanism of conventional masonry structures damaged from seismic ground motions on the EAF zone are evaluated in detail. Possible solutions are suggested on the basis of seismic codes. For this purpose, EAF-sourced earthquakes, i.e. 2003 Bingöl, 2010 Kovancılar (Elazığ), 2011 Maden (Elazığ), 2011 Tabanlı (Van) and Edremit (Van) hit in last two decades on this fault are investigated. Failures of conventional masonry buildings triggered from these earthquakes are assessed. Statistical evaluation, damage of earthquakes and failure pattern are deeply investigated and revealed. Eventually, one of the most significant reasons of severe damage or collapse to masonry structures due to this seismicity is the inability to construct the structures according to the requirements of seismic codes.
AtıfScopus41WoS39OpenAlex46İncele - MakaleYalnız künye2020Scopus SJRQ2Seismic vulnerability assessment of RC buildings according to the 2007 and 2018 Turkish seismic codes
Yön, Burak
Fragility curves are useful tools to estimate the damage probability of buildings owing to seismic actions. The purpose of this study is to investigate seismic vulnerability of reinforced concrete (RC) buildings, according to the 2007 and 2018 Turkish Seismic Codes, using fragility curves. For the numerical analyses, typical five-and seven-storey RC buildings were selected and incremental dynamic analyses (IDA) were performed. To complete the IDAs, eleven earthquake acceleration records multiplied by various scaling factors from 0.2g to 0.8g were used. To predict nonlinearity, a distributed hinge model that involves material and geometric nonlinearity of the structural members was used. Damages to confined concrete and reinforcement bar of structural members were obtained by considering the unit deformation demands of the 2007 Turkish Seismic Code (TSC-2007) and the 2018 Turkey Building Earthquake Code (TBEC-2018). Vulnerability evaluation of these buildings was performed using fragility curves based on the results of incremental dynamic analyses. Fragility curves were generated in terms of damage levels occurring in confined concrete and reinforcement bar of structural members with a lognormal distribution assumption. The fragility curves show that the probability of damage occurring is more according to TBEC-2018 than according to TSC-2007 for selected buildings.
AtıfScopus16WoS12OpenAlex7İncele - MakaleYalnız künye2019Scopus SJRQ1Earthquake Damage to Nonstructural Elements of Reinforced Concrete Buildings during 2011 Van Seismic Sequence
Yön, Burak; Onat, Onur; Öncü, Mehmet Emin
Infill and partition walls as nonstructural elements are generally constructed with hollow brick masonry and briquette as single or multilayered vertical walls. The seismic responses of infill walls and reinforced concrete (RC) framed buildings have been investigated with field observations after earthquakes all over the world. This study focuses on the reasons infill and partition walls failed as a result of the October 23, 2011 (Mw=7.2), and November 9, 2011 (Mw=5.7), Van earthquakes in Turkey. In this paper, in-plane, out-of-plane, and combined failure mechanisms of single and multilayered infill walls enclosed within reinforced concrete structures were investigated, and construction rules were suggested. To limit the failure of nonstructural elements enclosed within an RC frame, design and construction requirements should be included in the seismic code by adopting suitable solutions for both in-plane and out-of-plane behavior. This paper will be a reference for future studies that investigate infill wall damage. (c) 2019 American Society of Civil Engineers.
AtıfWoS51OpenAlex62İncele - MakaleYalnız künye2019Scopus SJRQ1Elimination of a measurement problem: A robust prediction model for missing eigenvector value to assess earthquake induced out-of-plane failure of infill wall
Onat, Onur; Yön, Burak
One of the effective methods to assess local or global behavior of structural system is to perform shake table experiment. The biggest challenge of all experiments, either shake table or others, are missing data during the experiments due to removed instruments. This problem is arose especially during the out-of-plane tests. This problem is named as “Measurement” problem. This paper is focused on detection the measurement problem and solving this problem by using Adaptive-Network Based Neuro Inference System (ANFIS). Definition of the problem is briefly missing out-of-plane eigenvector value during the implementation of a shake table experiments on a full scale one bay one storey reinforced concrete structural system. For this aim, two shake table experiments were performed with reinforced concrete frame (RCF)and infill wall at the National Civil Engineering Laboratory (LNEC)Portugal. The out-of-plane failure of infill wall was assessed under combined bidirectional seismic load. Shake table experiments were conducted on two types of specimens. One of them is Unreinforced Brick Infill Wall (URBIF)composed of single layer 22 cm thick brick. The other is single layer 22 cm thick Infill Wall with Bed Joint Reinforcement solution (IwBJR). Both specimens were made of a single-layer brick infill wall enclosure with the RCF. Bed joint reinforcement term refers horizontal bed joint reinforcement as a strengthening technique. Shake table experiments were performed on each specimen at four stages. After third level of earthquake load, the accelerometers were removed on the wall to prevent damage to them. The removal of these instruments results in missing data. The missing eigenvector values were predicted with a robust Adaptive-Network Based Neuro Inference System (ANFIS)model to present failure mode of infill wall. The estimation quality was tested with R2, Mean Absolute Percentage Error (MAPE), Mean Square Error (MSE)and Root Mean Square Error (RMSE)among with available data. The results of the quality indicator of R2 are 0.999 for URBIF model and 0.997 for IwBJR model, respectively. Moreover, rest of the indicator results are less than %1. The proposed approach is reliable on the base of quality indicator. Moreover, this study can be used for seismic engineering to predict eigenvector values to see local behavior of infill wall and mode shape evolution to determine which mod prone for partial and total collapse of infill wall.
AtıfScopus12WoS11OpenAlex10İncele - Derleme MakaleYalnız künye20183 Aralık 2015 Bingöl-Kiğı depreminin Tunceli ilindeki yığma yapılara etkisinin değerlendirilmesi
Onat, Onur; Yön, Burak
Türkiye’de yapı stokunun büyük bir kısmı yığma yapılardan oluşmaktadır. Özellikle kırsal bölgelerde inşaedilen bu yapılar orta büyüklükteki depremlerde bile büyük hasar görebilmektedir. 3 Aralık 2015 tarihindeDoğu Anadolu Fay hattı üzerinde, Bingöl ilinin Kığı ilçesine bağlı Açıkgüney mevkii merkez üssü olmak üzere(Enlem: 39.2610 K Boylam: 40.2170 D) yerel saat ile 01:27’de aletsel büyüklüğü M W =5.3, odak derinliği10.66 km olan sığ odaklı bir deprem meydana gelmiştir. Bu çalışmada, söz konusu depremin karakteristiközellikleri verilerek, farklı sönüm oranlarına göre ivme spektrumları elde edilmiştir. Orta büyüklükteki budepremin Tunceli ilinde kırsal bölgelerde yer alan yığma yapılarda oluşturduğu hasarlar incelenmiş ve buhasarların nedenleri irdelenmiştir. Oluşan hasarların genel olarak düzlem-içi ve düzlem-dışı hasar, uygunolmayan ve yetersiz hatıl kullanımından kaynaklı hasarlar, eğimli arazide uygun olmayan yapı inşasındankaynaklı hasarlar ve çimento harcı yerine çamur harcı kullanılması sebebiyle oluşan hasarlar olduğugörülmüştür. Çalışmanın sonucunda hasar sebeplerine göre çözüm önerilerine yer verilmiştir.
AtıfTR Dizin4İncele - MakaleAçık Erişim2018Scopus SJRQ3Seismic assessment of existing RC buildings before and after shear-wall retrofitting
Onat, Onur; Yön, Burak; Calayir, Yusuf
The existing reinforced concrete (RC) buildings are analysed in the paper before and after shear-wall retrofitting. For numerical application, an existing RC building was selected and retrofitted with shear walls. Incremental dynamic analyses and static pushover analysis of these buildings were performed using the distributed plastic hinge approach. The results show that seismic retrofitting with shear walls increases rigidity and capacity of the building, while decreasing lateral displacements and damage.
AtıfScopus4WoS3OpenAlex3İncele