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Öğe 24 January 2020 Sivrice-Elazig, Turkey earthquake: geotechnical evaluation and performance of structures(Springer, 2021) Sayin, Erkut; Yon, Burak; Onat, Onur; Gor, Mesut; Oncu, Mehmet Emin; Tugrul Tunc, Esra; Bakir, DursunThe January 24, 2020 Sivrice-Elazig (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.Öğe Block masonry equation-based model updating of a masonry minaret and seismic performance evaluation(Springer Heidelberg, 2023) Onat, Onur; Toy, Ahmet Tugrul; Ozdemir, EnginThis paper investigates a masonry minaret's current condition and seismic performance, namely Alacakapi Mir-Alay Sah Ali Bey (The short form is Alacakapi Minaret). Two prayer halls surround the Alacakapi minaret. One of these prayer halls was severely damaged by the Sivrice-Elazig earthquake on January 24, 2020. The other prayer hall is moderately damaged and still waiting for restoration and reinforcing solutions. The severely damaged hall was demolished. Due to the demolished hall, boundary conditions and clear height changed. Two surfaces are considered to be fixed supports. One is the bottom side, and the other is the vertical side. To determine the current condition of the minaret, first, dynamic identification is conducted by five accelerometers. Then destructive and non-destructive tests were performed to determine material properties. After that, a solid model was generated, and model calibration was conducted. Eight different formulations were considered for the model calibration proposed in the literature, reflecting a homogenized material approach that includes brick-and-mortar units. Three different mortar strengths were considered to obtain the best material properties that demonstrate the actual situation of the minaret. Local damage is realized when comparing the finite element model and operational modal analysis results. Finally, six different earthquake records were selected to determine the seismic response of Alacakapi Minaret to determine vulnerable locations for retrofit solutions.Öğe Effect of pumice powder and artificial lightweight fine aggregate on self-compacting mortar(Techno-Press, 2021) Etli, Serkan; Cemalgil, Selim; Onat, OnurAn experimental program was conducted to investigate the fresh properties, mechanical properties and durability characteristics of the self-compacting mortars (SCM) produced with pumice powder and Artificial Lightweight Fine Aggregate (aLWFA). aLWFA was produced by using fly ash. A total of 16 different mixtures were designed with a constant water-binder ratio of 0.37, in which natural sands were partially replaced with aLWFA and pumice powder at different volume fractions of 5%, 10% and 15%. The artificial lightweight aggregates used in this study were manufactured through cold bonding pelletisation of 90% of class-F fly ash and 10% of Portland cement in a tilted pan with an ambient temperature and moisture content. Flowability tests were conducted on the fresh mortar mixtures beforehand, to determine the self-compacting characteristics on the basis of EFNARC. To determine the conformity of the fresh mortar characteristics with the standards, mini-slump and mini-V-funnel tests were carried out. Hardened state tests were conducted after 7, 28 and 56 days to determine the flexural strength and axial compressive strength respectively. Durability, sorptivity, permeability and density tests were conducted at the end of 28 days of curing time. The test results showed that the pumice powder replacement improved both the fresh state and the hardened state characteristics of the mortar and the optimum mixture ratio was determined as 15%, considering other studies in the literature. In the aLWFA mixtures used, the mechanical and durability characteristics of the modified compositions were very close to the control mixture. It is concluded in this study that mixtures with pumice powder replacement eliminated the negative effects of the aLWFA in the mortars and made a positive contribution.Öğe Effect of waste textile dye adsorbed almond shell on self compacting mortar(Elsevier Sci Ltd, 2021) Cemalgil, Selim; Onat, Onur; Tanaydin, Mehmet Kayra; Etli, SerkanThe aim of the current experimental study is to investigate the effect of waste textile dye absorbed almond shell on fresh and mechanical characteristics of self-compacting mortar (SCMs). In this context, eight SCMs were designed by substituting Violet Dye Solution adsorbed Almond shell (VDSA) at the rate of 0%, 2.5%, 5.0%, 7.5%, 10.0%, 12.5%, 15.0% and 17.5% as a cement on weight basis including the control mix. To measure the rheological properties of SCMs, mini slump and V-Funnel tests were conducted. A total of 72 beams of 40x40x160 mm(3) dimension specimens were casted and immersed in water curing at the end of the 7, 28 and 56 days to determine the mechanical parameters. 48 cubes of 50x50x50 mm(3) dimensions were casted and kept in the curing tank to determine durability characteristics such as porosity, sorptivity and specific gravity. Quantitative analyses are also performed by using Scanning Electron Microscopes (SEM), X-ray Diffraction Analysis (XRD), Energy-Dispersive X-ray Spectroscopy (EDS) and Fourier Transform Infrared (FTIR). The experimental results indicated that as the content of VDSA enchases, a remarkable enhancement in flexural strength at early days age and 28 days age strength. Whereas, increasing the content of VDSA resulted in a considerable decrease in compressive strength higher than 5%. (C) 2021 Elsevier Ltd. All rights reserved.Öğe An Estimation Proposal for Engineering Properties of Modified Concrete by using Standalone and Hybrid GRELM(Springer Int Publ Ag, 2023) Cemalgil, Selim; Onat, Onur; Aruntas, Hueseyin YilmazThe presented study pertains to an attempt to propose a novel prediction model to predict the flexural and compressive strengths of concrete modulated using steel fiber (SFb) and silica fume (SF). A completed experimental investigation is adopted for the current study, and a research plan is employed. Three different superplasticizers amount (SP), different SF replacement ratios, and a constant amount of SFb were used by the weight of cement to meet the C25 target strength. A sum of 16 distinct mixtures designed by changing SP and SF ratios were developed. Furthermore, SFb was added at a fixed rate of 65 kg/m(3) to all planned concrete mixes. In addition, SFb was used to create a 16-mix design. Finally, a total of 32 distinct mix designs were created. Produced, hardened specimens were exposed to two different curing conditions. This research uses the mechanical characteristics of concrete treated with SF, SP, and SFb to estimate by conducting standalone and hybridized generalized extreme learning machine (GRELM) algorithms based on available experimental data in terms of the metaheuristic aspects of this work. With continuous input data, four separate data sets were constructed. Compressive strength and flexural strength were estimated separately. With the aid of the Grey Wolf Optimization (GWO) and Particle Swarm Optimization (PSO) algorithms, binary and ternary hybrid approaches were developed and tested on the data. Four distinct estimation models were suggested. Two quality metrics were used to evaluate the estimation performance: Root Mean Square Error (RMSE) and correlation of determination (R-2). The estimation results showed that the hybridized GRELM-PSO-GWO estimation model that was built for prediction was relatively successful in all sets.Öğe Field reconnaissance and structural assessment of the October 30, 2020, Samos, Aegean Sea earthquake: an example of severe damage due to the basin effect(Springer, 2022) Onat, Onur; Yon, Burak; Oncu, Mehmet Emin; Varolgunes, Sadik; Karasin, Abdulhalim; Cemalgil, SelimAn 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 Izmir 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) Izmir 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 Bayrakli 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.Öğe INCREMENTAL DYNAMIC ANALYSIS OF MID-RISE RC BUILDINGS TO ASSESS EFFECT OF CONCRETE STRENGTH AND TENSION REINFORCEMENT RATIO IN BEAM(2021) Onat, Onur; Yön, BurakAbstract: IDA is a parametric analysis method that has used commonly in several different forms to assess thestructural performance under seismic loadings. This paper focuses on the effect of tension reinforcement ratioand concrete strength to performance of reinforced concrete (RC) structures. For numerical analysis, two RCframe type structures were selected. One of them is 5 stories other of them is 7 stories. Two different concreteclass, C20 and C25, were considered and three tension reinforcement ratios were considered for analyses.Tension reinforcement ratios were determined half of the compressive reinforcement, equal to compressivereinforcement and double of compressive reinforcement ratio. Incremental dynamic analyses (IDA) wereperformed on these buildings. In this study to execute IDA, eleven seismic acceleration benchmark recordswere multiplied with various scaling factors from 0.2 to 1.2. Maximum base shear and corresponding roofdisplacement responses obtained from IDA curves were generated according to these responses. IDA curveswere compared with each other by using suitable graphs. According to analyses results, increasing tensionreinforcement of beam elements has not any effect on maximum roof displacement. Whereas, increasing oftension reinforcement decreased interstorey drift ratio. This result limited the damage due to decreasedinterstorey drift ratio.Öğe A novel inter-story drift limit proposal for TBEC2018 and fragility prognosis with TSC2007(2021) Onat, Onur; Yön, BurakThe 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).Öğe A novel prediction model for durability properties of concrete modified with steel fiber and Silica Fume by using Hybridized GRELM(Elsevier Sci Ltd, 2022) Cemalgil, Selim; Gul, Enes; Onat, Onur; Aruntas, Hilseyin YilmazThe service life performance of conventional and modified concrete subjected to harsh climatic condition environment is directly related to durability properties of concrete like abrasion, freezing and thawing cycles. These properties are critical issues that should be predicted before performing experimental test. On this basis, the basic purpose of this paper is to predict the abrasion loss, freezing and thawing properties of concrete modified with silica fume (SF) and steel fiber (SFb) by using mix design and additional properties. From this point of view, a conducted experimental study was selected as a case study. In the control concrete (CC) mixtures, Portland cement, crushed stone aggregate, and superplasticizer (SP) were used in the selected experimental study. SP in concrete mixtures was used in the amounts of 1.0%, 1.5%, and 2.0% by weight of cement, and so modified concrete was produced with and without SFb according to the target strength of C25. Furthermore, SF and SFb were used in different amounts to modify the concrete. The SF was replaced with cement in the amounts of 7.5%, 10.0%, and 15.0%. In total, 16 different mix designs were prepared with different SP and SF ratios. In addition, SFb was added to all mixtures of designed concrete at a constant amount of 65 kg/m3. Additionally, a 16-mix design was prepared with SFb. Cumulatively, 32 different mix designs were prepared for the experimental study. Tests on the fresh, hardened, and life-cycle performance properties of the concrete were conducted. As for the metaheuristic part of this study, on the basis of the available experimental data, life-cycle performance parameters of the concrete modified with SF and SFb are predicted by using single and hybrid generalized extreme learning machine methods. Eight different data sets were generated with gradually extended input data. Two different outputs were considered: abrasion resistance (AL) and freezing/thawing (FT). Particle Swarm Optimization (PSO) and Grey Wolf Optimization (GWO) algorithms were used to produce binary and ternary hybrid methods. Four different models were proposed as listed: single use of Generalized Extreme Learning Machine (GRELM), binary use of GRELM-PSO, and GRELM-GWO. Finally, PSO and GWO were hybridized and integrated into GRELM. Two quality indicators, namely Root Mean Square Error (RMSE) and correlation of determination (R2), were considered to see the performance of the prediction. The results showed that the proposed ternary prediction model composed of GRELM-PSO-GWO provided more accurate results in all sets from 74% to 91% by extending input parameters, even if complicated parameters are inserted in as an input to the data set.Öğe Parametric nonlinear static analysis of a RC structure with TLCW exposed to bidirectional earthquake load by using different modelling methodologies(Elsevier, 2021) Onat, Onur; Panto, BartolomeoThe seismic assessment of Reinforced Concrete (RC) buildings with Two Leaf Cavity Wall (TLCW) masonry infills requires reliable and computationally efficient numeric models. The current study has two main goals. First, to understand the contribution of TLCWs to the nonlinear response of RC buildings subjected to dynamic excitations. Second, to investigate the efficiency and accuracy of continuum-based Finite Element Modelling (FEM) approaches and simplified, structural Discrete Macro Element Modelling (DMEM) approaches in predicting the ultimate behavior of RC buildings infilled with TCLWs by performing pushover analyses. A half-scaled two-bay, two-storey RC building prototype infilled with TLCWs, experimentally tested on a shake table and already numerically investigated in the literature by FEM approaches, is considered with these aims. The responses of the FEM and DMEM models are compared to experimental observations in terms of pushover capacity curves and damage patterns. The analyses confirm the ability of the models to effectively predict the lateral deformability and lateral strength of the prototype with a satisfactory level of accuracy. However, some differences are observed in terms of the building's ultimate lateral strength, attributed to the effects of the boundary conditions at the base of the table, not explicitly described by the numerical models. The emphasis is given to the boundary conditions reached during the excitation of the scaled structural system via shaking table. Finally, in the last part of the paper, parametric analyses are performed on the DMEM model to evaluate the main material parameters governing the response of the building effected by the boundary conditions.Öğe Performance evaluation and damage assessment of historical Yusuf Ziya Pasha Mosque after February 6, 2023 Kahramanmaras earthquakes(Elsevier Science Inc, 2023) Onat, Onur; Deniz, Faruk; Ozmen, Alper; Ozdemir, Engin; Sayin, ErkutHistorical masonry heritages are severely affected by the February 6, 2023, Kahramanmaras, earthquakes. The recorded earthquake peak ground accelerations (PGA) are 2.05 g and 0.67 g for Pazarcik and Elbistan earth-quakes at the epicenter, respectively. However, there is not any recorded PGA data related to Kahramanmaras, earthquakes in Malatya. At this point, the current study aims to propose a methodology to estimate the possible resisted load of historical Yusuf Pasha Mosque in Malatya and possible PGA for Malatya by assessing the per-formance located in Malatya city center, which is far from the epicenter of Pazarcik earthquake, which is 162 km, and Elbistan earthquake, which is 100 km, using propagated cracks. After these earthquakes, local damages were registered at the Yusuf Ziya Pasha Mosque. The main prayer hall of the mosque and a tomb were constructed in 1792. Three types of materials were used for the mosque: riyolit tuff, sandy tuff for walls, and timber for the roof. The dimensions of the main hall of the mosque are 17.50 m x 12.53 m. Additionally, there is a small tomb located adjacent to the mosque with dimensions of 7.61 m by 4.46 m. First of all, dynamic identification is conducted, and then a numerical model is generated. Material properties were calculated using non-destructive testing methods. The mosque and the tomb are modeled together. The numerical model is calibrated on the basis of the extracted dynamic parameters. Then, nonlinear time history analyses were performed on the model using eight earthquake records. Three of the used seismic records were international, namely the 1995 Kobe, 1986 Chalfant Valley, and 2010 New Zelland Darfield earthquakes. In addition, five national earthquake records are used for the nonlinear dynamic analyses, namely the 2003 Bingo center dot l, 2011 Van-Ercis,, 2020 Elazig-Sivrice, 2023 Kahramanmaras, Pazarcik, and Elbistan earthquakes. Related graphs were tabulated, and crack propagations of the numerical model were compared to damaged mosques.Öğe Seismic Resistance and Performance Evaluation of Masonry Dwellings After the February 6, 2023, Kahramanmaraş Earthquake Sequence in Türkiye(World Scientific Publ Co Pte Ltd, 2024) Onat, Onur; Yon, Burak; Uslu, Ali; Oncu, Mehmet Emin; Varolgunes, Sadik; Karasin, Ibrahim Baran; Gor, MesutOn 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 Kahramanmara & scedil;-Pazarc & imath;k and Kahramanmara & scedil;-Elbistan, respectively. The Kahramanmara & scedil;-Pazarc & imath;k 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 Pazarc & imath;k station reached 2.05g. In addition, the Pazarc & imath;k earthquake triggered two independent earthquakes, the Nurda & gbreve;& imath; and Islahiye earthquakes, which occurred 10 min later than the Pazarc & imath;k earthquake. However, the last earthquake, with its epicenter in Kahramanmara & scedil;-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, Kahramanmara & scedil; earthquakes, earthquake characteristics, and to evaluate the performance of masonry dwellings during the Kahramanmara & scedil; 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 Kahramanmara & scedil;, Gaziantep, Hatay, and Malatya, according to the current earthquake code in use.Öğe Seismicity of East Anatolian of Turkey and Failures of Infill Walls Induced by Major Earthquakes(World Scientific Publ Co Pte Ltd, 2021) Dogangun, Adem; Yon, Burak; Onat, Onur; Emin Oncu, Mehmet; Sagiroglu, SerkanThere 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 Bingol earthquake (Mw = 6.3) and the last earthquake on the EAF is the Sivrice-Elazig (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 Bingol, 2011 Van earthquakes and January 24, 2020 Sivrice-Elazig 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.
