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TUĞLA DOLGULU SÜNEK OLMAYAN BETONARME ÇERÇEVELERİN ÇELİK ŞERİTLERLE GÜÇLENDİRİLMESİ
No full textÜlkemiz mevcut yapı stokunun büyük bir kısmı tuğla dolgu duvarına sahip sünek olmayan betonarme çerçeve türü yapılardan oluşmaktadır. Yeterli yanal rijitlik, dayanım ve enerji tüketim kapasitesine sahip olmayan bu yapıların depreme karşı güçlendirilmesinde betonarme dolgu duvarları yaygın olarak kullanılmaktadır. Ancak, güncel güçlendirme uygulamaları binanın boşaltılmasını gerektirmekte ve binanın tekrar kullanıma girmesi uzun bir imalat süresi sonrasında mümkün olabilmektedir. Bu çalışmada betonarme çerçeve içerisindeki tuğla dolgu duvarı çelik şeritlerle güçlendirerek yapının sismik performansının iyileştirilmesi amaçlanmıştır. Bir tanesi güçlendirilmemiş referans eleman olmak üzere toplam dokuz adet deney elemanı deprem yüklerini benzeştiren tersinir tekrarlanır yatay yük ve düşey yük altında test edilmiştir. Çalışmada test edilen tek katlı tek açıklıklı betonarme çerçeve deney elemanları ülkemizdeki betonarme yapılarda karşılaşılan önemli yapım kusurlarını içerecek şekilde üretilmiştir. Çelik şeritlerin betonarme çerçeveye bağlantı biçimleri, uygulanan çelik şerit deseni ve uygulama yönünün deney elemanlarının yatay yük kapasitesi, göçme biçimi, rijitliği ve enerji tüketimi üzerindeki etkileri incelenmiştir. Test sonuçları çelik şeritlerle güçlendirilen tuğla dolgu duvarın, betonarme çerçevenin yatay yük taşıma kapasitesini, rijitliğini ve enerji tüketimini önemli oranlarda arttırdığını
göstermiştir. Tez çalışmasının analitik çalışma kısmında ise, önerilen güçlendirme yöntemi kullanılarak yapılacak güçlendirme işleminin tasarımı için pratik önerilerde bulunulmuştur.Major part of Turkey's existing building stock consists of non-ductile brick infilled reinforced concrete frames. This kind of structures does not have sufficient capacity in order to withstand the strong earthquakes. The most popular strengthening method for such buildings in order to satisfy adequate lateral stiffness, strength and energy demands reinforced concrete infill walls are introduced in the bare frames. However, this seismic rehabilitation method requires evacuation of the building. In this study, infill walls are strengthened with steel strips in order to support non-ductile brick infilled reinforced concrete frames. In order to improve the seismic performance of the structure while avoiding long term evacuation and changing architectural partitions. In experiments, single-storey single-span reinforced concrete frames are tested. As one of the unstrengthened test specimen been tested as a reference member total of nine test specimens were tested. Tests are done under reverse cyclic lateral load which simulates the earthquake loads. The frames had common defects similar to the Turkish building stock. Such as poor concrete quality, improper reinforcement layout and inadequate sections. Steel strips to the reinforced concrete frame connection, strengthening layout and symmetry aspects effecting the test frames' experimental lateral load capacity, initial stiffness, and energy absorption are investigated. According to the test results, strengthened brick infilled reinforced concrete frames gained lateral load carrying capacity,
rigidity and significant energy consumption. In the analytical part for the study for the strengthening method proposed, some practical suggestions were made and a reliable way of modeling the strengthened structure was introduced
In-plane behaviour of masonry brick walls strengthened with mortar from two sides
No full text© 2020 Institution of Structural EngineersThe most destructive effects of earthquakes in Turkey are seen in rural areas and slums. Since most of the masonry structures in those areas are not built in accordance with regulations and standards, they are not able to withstand earthquake effects and, eventually collapse. This situation demonstrates the importance of developing effective strenghening techniques for masonry structures. In Turkey, however, scientific studies usually focus on reinforced concrete, steel, and prefabricated structures. Studies on the strengthening of masonry structures, which constitute the majority of the buildings in Turkey, are more limited. Therefore, the shear behaviour of masonry bearing walls must be analyzed to develop appropriate strengthening techniques against potential earthquakes. In this study, walls made of masonry bricks were strengthened by applying lean and steel fibered repair mortar with different thicknesses on both sides. The mortar was applied by plastering the wall surfaces with a trowel. Seven wall specimens were tested diagonally; one was the reference specimen, and six were the reinforced specimens. The results obtained were compared in terms of strength, ductility and energy consumption values
THE EFFECT OF JACKET AREA ON THE BEHAVIOR OF REPAIRED/STRENGTHENED REINFORCED CONCRETE COLUMNS
No full textJacketing is the most popular method for strengthening reinforced concrete columns under axial loading. This repair and strengthening technique is widely used not only in Türkiye but also in other technologically developed countries. In this study, the effectiveness of this method is investigated experimentally, by testing two test parameters which are column section geometry and jacket thickness. The specimens were enlarged on all four sides to understand how the thickness of the jacket layer affects the behavior of the column. Using the experimental data, load versus deformation curves were plotted for each test specimen. The parameters (strength, rigidity, ductility, and energy dissipation capacity) that determine the behaviour of the reinforced column were then analyzed. At the end of this study, the effects of column section geometry and jacket thickness on the jacketing method are discussed, providing valuable preliminary data for future experimental studies
Experimental investigation of RC shear walls with openings under cyclic loading repaired with externally bonded CFRP strips
No full textA total of 9 real scale reinforced concrete shear walls were produced, 3 of them being the reference, representing the basement floor of a reinforced concrete building. These 9 shear walls produced, 3 wall are fully filled, 3 of them have window openings and 3 of them have door openings. The RC shear walls were exposed to displacement-controlled reversed cyclic lateral loading. In the experiments that damaged the experimental specimens, loads up to 0.5% story drift ratio for moderate damage and 1.0% story drift ratio for heavy damage were applied. Within the scope of the experimental study, the damage distributions of the tested nine RC shear walls were examined in detail, and the strengthening technique was developed using CFRP strip and CFRP fan-type anchors. The performance of damaged RC shear walls after using the devised repair method was analysed. The study's findings revealed that the repair method created by employing CFRP strips to restore moderately damaged RC shear walls with and without apertures was well enough successful in restoring the shear walls' performance levels
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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