Investigating the effect of infill walls on steel frame structures

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

Comparison of Reduced Relative Storey Drifts According to Current Earthquake Code (DBYBHY2007) and New Draft Earthquake Code (TBDY2016)

Maksimum 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 anlaşılmaktadırMaximum 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 join

Investigating the effect of infill walls on steel frame structures

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

Soil based design of highway guardrail post depths using pendulum impact tests

Guardrails are passive road restraint systems (RRS) used at roadsides and medians to improve road safety. In the case of inadequate post embedment depth of soil driven posts may not function as intended and design cannot provide adequate safety nor security for the impacting vehicles. In general, the height of the steel guardrails varies between 1600 and 2400mm. However, the characteristics of the soil where the guardrails are driven are not taken into consideration. In other words, a constant depth of guardrail is used regardless of the type of soil. Post embedment depths (PED) in steel guardrail systems are currently determined based on strong soil properties. The crash performance of these designs may not be appropriate for locations where soil conditions are weaker than tested conditions. In this study, a series of field impact tests were performed on soil embedded posts to determine optimum PED for three different soil conditions, namely hard, medium hard and soft soil. A pendulum device is used to perform dynamic impact tests on C type (C120x60x4), H type (H150x90x6) and S type (S100x50x4.2) posts. Seven different PED values were used for each type of soil. A total of 63 impact tests proved that increased soil stiffness resulted reduction in PED for the posts. Optimum PED values are determined based on energy absorption of posts. With the use of optimum length guardrail posts considerable amount of installation time, labor and material savings are expected

Determination of optimum post embedment depth for C120 steel posts using field and full scale crash test

C120 steel sections are the most widely used post shapes in European guardrail designs. The design length of these posts is determined based on guardrail containment level and engineering judgment. The soil properties where these posts are embedded are usually not considered in design. It is a well-known fact that the crash test performance of soil embedded posts depends mostly on post–soil interaction and post embedment depth (PED). In this study, a series of field impact tests were performed on soil embedded C120 posts to determine optimum PED for three different soil conditions. Seven different PED varied from 650 to 900mm was used for each soil type. Based on these findings a full-scale crash test is performed on a guardrail to verify optimum PED for hard soil conditions. With the use of optimum length guardrail posts considerable amount of installation time, labor and material savings are expected