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The beginnings and ends of guardrail designs have the function of providing adequate anchorage for the rest of the system. They should also demonstrate crashworthy performance and should not pose any hazard for errant vehicles. In Europe, the ends of guardrail systems traditionally have incorporated turned down end terminals. Due to its low cost, Turkey also adopted turned down guardrail end terminal, and the majority of these designs are 12 meters long. Accident statistics clearly demonstrate that this particular end terminal poses safety risks for impacting vehicles. However, crash tests performed on the system showed that it worked satisfactorily for cars impacting at 80 kph. In this study, a detailed finite element analysis was performed on a 12 m long turned down guardrail end treatment to fully evaluate its crashworthiness. Data obtained from previously performed TT 2.1.80 and TT 4.2.80 crash tests were used to verify the fidelity of finite element models used in the study. Further simulations performed in accordance with EN1317 part 7 at 100 kph demonstrated unacceptable performance for the end terminal. Results of the study are summarized and recommendations are presented.

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ÖzMaksimum göreli kat ötelemeleri, yapıların yönetmeliklerce güvenlik açısından sınırlandırıldığı temel parametrelerden biridir. Ülkemizde halen yürürlükte bulunan 2007 Deprem Bölgelerinde Yapılacak Binalar Hakkında Yönetmeliğe göre, elde edilen göreli kat ötelemelerinin sınırları ve kriterleri, 2016 Türkiye Bina Deprem Yönetmelik taslağı ile değişmektedir. Bu çalışmada, her iki yönetmeliğin "Etkin Göreli Kat Öteleme" hesabı ve sınır şartları detaylı olarak karşılaştırılmıştır. Taslak yönetmelikte izin verilen göreli kat öteleme sınırlarının, dolgu duvar -çerçeve bağlantısının derzsiz olduğu durum için genel olarak illerin büyük çoğunluğunda arttığı, derzli tasarımda ise derzsize göre iki kat yükseldiği anlaşılmaktadır.Anahtar Kelimeler: Göreli kat ötelemesi, TBDY2016, Elastik tasarım spektral ivmesi Comparison of Reduced Relative Storey Drifts According to Current Earthquake Code (DBYBHY2007) and New Draft Earthquake Code (TBDY2016) AbstractMaximum relative floor displacements are one of the basic parameters that are limited by the regulations in terms of safety for the regulations. According to the Regulation on the Turkish Earthquake Code (TEC) 2007 which are currently in force in our country, the limits and criteria of the relative floor drifts obtained vary according to the TEC 2016 in draft. In this study, the "Effective Relative Floor Shift" account and boundary conditions of both directives are compared in detail. It is understood that the permissible floor folding limits allowed in the draft regulation are increased in the majority of the cases in general, in case of the joint of the filler wall-frame joint, and in the case of the jointed design, two times higher than the joint.

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Infill walls consisting of materials such as hollow concrete, hollow clay and autoclaved aerated concrete bricks are not only preferred in reinforced concrete buildings but also in steel frame structures. It is a well-known fact that infill walls limit the displacement of frames under horizontal loads. However, they may also bring about certain problems due to being placed randomly in horizontal and discontinuously in vertical directions for some architectural reasons. Moreover, cracks in frame-wall joints are observed in steel frame structures in which ductile behaving steel and brittle behaving infill walls are used together. In this study, the effect of infill walls on steel frames has been investigated. In the steel frame structure chosen for the study, four different situations consisting of different combinations of infill walls have been modeled by using ETABS Software. Later, the pushover analyses have been performed for all the models and their results have been compared. As a result of the analyses done by using the equivalent diagonal strut model, it has been found out that infill walls limit the displacement of steel frames and increase the performance of a structure. However, it has been also determined that in the steel frame structure in which the infill walls have been placed discontinuously in vertical and asymmetrically in horizontal, infill walls may lead to torsional and soft story irregularities. As a result, it is possible to observe cracks in the joints of infill walls and steel frame, the deformation properties of which differ, unless necessary precautions are taken.

In the modelling and simulation of reinforced concrete structures, accurate definition of material properties is important in terms of obtaining precise results. Among the parameters defining the behaviour of concrete in structural analyses, stress–strain behaviour has great importance. Since the stress–strain behaviour of concrete is difficult to determine experimentally, many relations have been proposed in which this behaviour is predicted numerically. However, it is seen that the most commonly used of these stress–strain relations are produced with a limited number of samples, and that most of the relations are based on test results obtained from a single laboratory. Accordingly, the stress–strain behaviour relations constituted in different studies for the same concrete are quite distant from each other. Therefore, there is a need for an inclusive and valid relation for low- and normal-strength concrete. In this study, a simple and realistic stress–strain relation for low- and normal-strength ordinary Portland cement concretes in compression was proposed by using stress–strain data obtained from different laboratories by different researchers. The proposed relation, which predicts stress–strain behaviour with relatively low error rates when compared with similar relations, is presented, with comparative graphs, to the benefit of researchers and designers.