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Öğe Air pollution due to coal mining: Literature review about particulate matter and methane emissions(Union of Chambers of Engineers and Architects of Turkey, 2017) Demirarslan, Kazim Onur; Kaya, AliIn spite of development of renewable energy technologies, our dependence on fossil fuels still has been continuing. Coal is the most suitable fuel in terms of price and efficiency in fossil fuels. With the industrial revolution, coal using steam engines increased and as a result of this, coal demand increased. The need for coal makes coal production increased and so, environmental problems increase because of coal mining. One of these problems is air pollution. Especially Particulate Matter (PM) and Methane (CH4) emissions which occurred in open and underground mining represent major place. In this research, PM and methane emissions situation and precautions in coal mines around the world are explained by making literature review. Also, this research is intended to be resource to other planned studies.Öğe Dynamic characteristics changes of masonry arches exposed to elevated temperature(Elsevier Ltd, 2024) Altunışık, Ahmet Can; Öztürk, Muhammed Mustafa; Genç, Ali Fuat; Günaydın, Murat; Kaya, Ali; Akbulut, Yunus Emrahan; Sunca, FezayilIn this study, the changes in the dynamic characteristics of masonry arches exposed to elevated temperatures were investigated experimentally and numerically. Firstly, the material properties were analyzed at different temperatures, ranging from 200°C to 800°C, through experimental tests. The constructed arch specimens were then subjected to heat to investigate the effects of elevated temperatures on their dynamic characteristics. Ambient vibration tests were performed before and after heating to identify natural frequencies and mode shapes. Furthermore, numerical models of the arches were developed, and a model updating procedure was implemented to minimize the differences between the numerical and experimental data. The findings indicated that elevated temperatures led to notable decreases in the compressive strengths of both the stone and the mortar. This decrease significantly degraded the stiffness of the masonry arch samples, consequently having a profound effect on their dynamic properties.Öğe Estimating fundamental frequency of masonry arches under elevated temperature: Numerical analysis and validation using ambient vibration tests(Springer Nature, 2024) Altunışık, Ahmet Can; Öztürk, Muhammed Mustafa; Genç, Ali Fuat; Kaya, Ali; Akbulut, Yunus Emrahan; Sunca, Fezayil; Gunaydin, MuratIn this study, the changing of dynamic characteristics of masonry arches at varying geometric parameters and temperature histories was investigated through a combination of experimental and numerical methods. First, the dynamic characteristics of laboratory-built arch models were determined both pre- and post-high-temperature test using ambient vibration testing. Then, the finite element (FE) models of the arches were developed for both, allowing for dynamic characteristics to be assessed numerically. To refine the accuracy of numerical models, FE analyses were adjusted based on experimental data. These updated FE models were used to investigate the dynamic characteristics of arches with different spans, heights, widths, and thicknesses under different temperature history scenarios. Finally, utilizing the data repository obtained, formulation and graphs/charts, providing valuable insights into the dynamic response of masonry arches under fire conditions, were developed and presented for practical application. The experimental study revealed that the natural frequencies of arches decreased by 55% with increasing temperature exposure.Öğe Evaluating the high-temperature endurance of FRP-strengthened concrete using an innovative insulation system: Experimental investigation(Elsevier Ltd, 2023) Altunışık, Ahmet Can; Akbulut, Yunus Emrahan; Adanur, Süleyman; Kaya, Ali; Günaydın, Murat; Mostofi, Sara; Mosallam, AymanExtensive research on fiber-reinforced polymer (FRP) composites has led to the presumption that this material is an effective solution for repairing and strengthening the reinforced concrete (RC) elements. The use of FRP significantly enhances the carrying capacity of elements under structural loads. However, the poor fire performance of this material poses a major concern, particularly in buildings. High temperature exposure can damage the adhesive bonding of polymer matrices and degrade their strength. Therefore, the use of thermal insulation is essential to ensure the safety of FRP-strengthened buildings. This study experimentally investigated the effectiveness of a recently developed thermal insulation system, “DYMAT® FIREWRAP”, in protecting the carbon and glass FRP wrapped concrete specimens. The tested insulation system comprised two different materials namely DYMAT® RS and Dymatherm. During the experiments, 50 concrete specimens with different strengthening and insulation configurations were prepared and exposed to high temperatures of 200 °C and 400 °C. The results highlight the importance of using thermal insulation on FRP repaired concrete elements. After high temperature exposure of 200 °C, the compressive strength losses of CFRP wrapped specimens were 12% lower than those of the non-insulated specimens. For GFRP strengthened specimens, the strength loss was 17% less than that for the non-insulated specimens. After high temperature exposure of 400 °C, the CFRP wrapped specimens experienced 27% less reduction in their compressive strength, and the strength loss for GFRP wrapped specimens was reduced by 32%. Among the considered configurations, the presence of the RS material as an inner layer played a major role in protecting the epoxy from deterioration. Dymatherm provided adequate protection; however, the number of layers did not significantly affect the high temperature endurance of the specimens.Öğe Experimental investigation on story-to-column pounding between RC buildings via shake table tests(Springer Science and Business Media Deutschland GmbH, 2025) Sunca, Fezayil; Altunışık, Ahmet Can; Kaya, Ali; Genç, Ali Fuat; Şahin, Muhammed Cihat; Karahasan, Algıhan Kaşif; Şen, DoğaThis study experimentally investigated the effects of story-to-column poundings between adjacent RC buildings through shake table tests. Two scenarios were considered: (i) without pounding and (ii) with story-to-column pounding. The tests were conducted on two 1/2 scaled 2-story RC frames, employing natural ground motion records. The accelerations, displacements, IDRs, and modal parameters of the test specimens were comparatively investigated. The experimental results revealed that pounding significantly influenced structural responses, causing severe shear damage in the columns of the test specimen due to story-to-column collisions. Pounding represented a critical loading condition, inducing abrupt spikes in acceleration responses and resulting in damage. Moreover, pounding caused decreases in displacement responses but led to abrupt increases in base shear forces. This resulted in irregular and asymmetrical hysteresis loops, indicating varying energy distribution in the pounding direction due to repeated impacts. The modal parameters also changed significantly due to the impact, and the changes were observed earlier and more pronounced in the test specimen subjected to pounding.Öğe Nonlinear seismic damage analysis of low-rise masonry buildings using different materials(PERGAMON-ELSEVIER SCIENCE LTD, 2025) Roudane, Boudjamaa; Kaya, Ali; Adanur, SüleymanMasonry buildings represent inherently complex construction systems, with their seismic response behavior still not fully understood. Ensuring life safety in masonry structures subjected to seismic excitations is of paramount importance, which underscores the need for advanced numerical modeling and comprehensive analysis. This requirement is particularly critical due to the inadequate seismic resistance observed in certain key aspects, including mechanical properties and the number of stories. Consequently, numerical studies have become indispensable for understanding the seismic behavior of low-rise buildings. This paper addresses this gap through a numerical investigation into the seismic performance of unreinforced masonry (URM) buildings with varying floor counts. The analysis integrates four material properties derived from experimental data available in the literature. For each building, a detailed three-dimensional (3D) continuum Finite Element Model (FEM) is developed, employing nonlinear Time History analysis as the primary analytical method. The Concrete Damage Plasticity (CDP) model is applied to simulate the masonry walls and concrete components. This study encompasses modal analysis, static response analysis, and seismic response analysis of the buildings. The findings, based on both undamaged and damaged models, are carefully evaluated and compared, covering modal behaviors, natural frequency values, mode shapes, displacement and stress distributions, and damage patterns. Furthermore, the research seeks to offer insights into how these structural dynamic parameters affect the structural response and failure modes under various seismic loads. Finally, conclusions and recommendations are provided for addressing damage in masonry building walls.Öğe Post-earthquake damage assessments of unreinforced masonry (URM) buildings by shake table test and numerical visualization(Elsevier, 2023) Kaya, Ali; Adanur, Süleyman; Bello, Ridwan Adebayo; Genç, Ali Fuat; Okur, Fatih Yesevi; Sunca, Fezayil; Sevim, BarışMasonry structures are one of the structures most affected by earthquakes. In addition, since masonry structures constitute a large part of the building inventory, it is important to determine the dynamic characteristics of these structures. The present study is aimed to evaluate the seismic performance of a half-scale hollow brick unreinforced masonry (URM) building considering different damage states. Shake table test was conducted with seven loading conditions. In order to obtain different damage states, seismic excitations were applied incrementally to structure. After each loading, the damage conditions and the corresponding damage patterns were examined comparatively, and the structure collapsed in the last loading condition. To experimentally observe the damage, the modal parameters for un-damaged and damaged situations of the building were identified by ambient vibration tests performed before and after the seismic loadings. The experimental results obtained were then compared with the analyses made in numerical softwares, and similar results were obtained.Öğe Shake table tests on story-to-story pounding between adjacent RC buildings(Elsevier Ltd, 2024) Sunca, Fezayil; Altunışık, Ahmet Can; Kaya, Ali; Genç, Ali Fuat; Şahi̇n, Muhammed Cihat; Karahasan, Algıhan KaşifPounding between adjacent buildings and their devastating effects have been frequently reported during numerous major earthquakes. Although poundings exhibit more destructive effects on RC buildings compared to steel buildings, the majority of previous experimental studies have mainly concentrated on steel specimens. Furthermore, there has been a notable scarcity of extensive large-scale experimental studies on this subject. Therefore, the primary objective of this study is to experimentally determine the effects of different types of pounding on the seismic responses of RC buildings. To this aim, three half-scaled two-story RC specimens were constructed and were tested. In the tests, three cases were considered: (i) without pounding, (ii) pounding between taller and shorter buildings (slab-to-slab interaction at one floor), and (iii) pounding between buildings with equal heights (slab-to-slab interaction at the two floors). The experimental results showed that pounding and its types played a critical role in structural responses such as floor accelerations, displacements, hysteretic responses, and dynamic characteristics. Additionally, each pounding type led to different damage mechanisms in the specimens.Öğe Structural response of half-scale pumice concrete masonry building: Shake table/ambient vibration tests and FE analysis(Springer Science and Business Media B.V., 2024) Kaya, Ali; Roudane, Boudjamaa; Adanur, Süleyman; Sunca, Fezayil; Genç, Ali Fuat; Gunaydin, Murat; Altunışık, Ahmet CanSeismic performance evaluation of masonry structures is of paramount importance for ensuring the safety and resilience of buildings in earthquake-prone regions. There are limited number of studies on pumice elements in the literature. In addition, there are almost no studies investigating the earthquake behavior of pumice masonry building as a whole structure. In this context, a comprehensive understanding of their seismic response and dynamic characteristics has been lacking. To address this knowledge gap, a shake-table experimental campaign was undertaken, wherein half-scale pumice masonry building was exposed to simulated seismic forces. To enhance the experimental findings, numerical simulations were performed to confirm and expand our comprehension of how the pumice masonry structure responds to dynamic forces. Integrating both experimental and numerical outcomes provides a holistic understanding of how pumice masonry buildings behave during seismic events. At the end of the experimental study, the frequency values of the pumice model were observed to decrease up to 23.5% in the modes compared to the undamaged state. In the numerical model, this value decreases up to 19.85%. For the undamaged and damaged model, the first three experimental mode shapes were similar to the numerical mode shapes. Both experimental and numerical results show that the expected damages occur in the same regions. These results show that nonlinear FE models can be helpful in determining potential damage model locations. The findings have implications for the seismic design and retrofitting of similar traditional masonry buildings, facilitating the development of resilient and sustainable engineering solutions in seismic-prone regions.Öğe Tarihi yığma kiliselerde hasarların fotogrametrik ölçme tekniğiyle incelenmesi: Artvin Tbeti Kilisesi örneği(Murat Yakar, 2020) Zeybek, Mustafa; Kaya, AliGeçmişte yaşamış farklı medeniyetler inşa ettikleri anıtsal yapılarla günümüze önemli kültürel miraslar bırakmışlardır. Bu yapıların en ihtişamlıları ve döneminin özelliklerini yansıtan; kilise, cami gibi önemli dini yapılar genellikle yerleşim yerlerinin merkezinde inşa edilmiştir. Sonrasında gelen toplum bu yapıları kendi inançları doğrultusunda kullanarak şekillendirmişlerdir. Estetik görünüşlerinin yanında birçok medeniyetin kültürel hafızasını günümüze taşıyan tarihi yapıların korunması ve gelecek nesillere aktarılması insanlığın görevlerindendir. Doğu Karadeniz Bölgesi’nde yer alan Artvin ili ve çevresi zengin tarihe sahip olmakla birlikte farklı uygarlıklara da ev sahipliği yaptığı bilinmektedir. Bu çalışmada Tbeti (Cevizli) kilisesinin yapısal durumunun belirlenmesi, onarım ve güçlendirme için deplasman ölçümleri ele alınmıştır. Deplasman ölçümleri tek periyot olarak tasarlanmıştır. Duvarların üst kısımlarında oluşan hasarlar zemine yakın duvarlar baz alınarak incelenmiştir. Fotogrametrik olarak elde edilen veriler robust regresyon ve polinomal eğri uydurma yöntemleriyle değerlendirilmiştir. Değerlendirme sonucunda yapının kuzey kesiminde bulunan duvarlarda 5 cm’ye varan deplasmanlar tespit edilmiştir. Örnek bir çalışma olarak yığma yapım sistemiyle inşa edilen Tbeti kilisesinde meydana gelen deplasmanlar sunulmuştur. Çalışma sonucunda tek periyotluk ölçüler ile kilise ve diğer yapılarda duvarlar boyunca meydana gelen sapmaların düşeysel olarak tespit edilebileceği kanısına varılmıştır.Öğe The effect of earthquake damages created by shaking table tests on dynamic characteristics of masonry structures(Springer Science and Business Media B.V., 2023) Kaya, Ali; Roudane, Boudjamaa; Altunışık, Ahmet Can; Adanur, SüleymanMasonry constructions are edifices created through the amalgamation of fragile substances like stones, bricks, and pumice utilizing mortar. The masonry structures, which do not show the desired ductile behavior against dynamic effects, show a brittle behavior. In scenarios like earthquakes, when masonry structures surpass their load-bearing capabilities, this circumstance leads to heavy damage. Knowing the dynamic behavior of masonry constructions will help to take precaution to minimize the loss of life and property, since a significant part of people live in masonry buildings. Both analytical and experimental methods are employed to determine the damping ratios, natural frequencies and mode shapes of the buildings. which depend on the dynamic properties of the structures subjected to dynamic loads. This study explored variations in the dynamic attributes of a half-scale, single-span, and single-story masonry model constructed with hollow bricks under various damage scenarios. To acquire varying levels of damage cases, the model is tested on a shaking table with gradually different earthquake data. To observe the earthquake damages experimentally, the modal parameters of the masonry model were ascertained through ambient vibration tests conducted under both intact and impaired conditions. Also, A nonlinear analytical one-story masonry model is developed using finite element ABAQUS software with macro modelling methodology for examining the characteristics of masonry models subjected to different earthquakes. Six different test cases using same model are investigated analytically.
