• Journal of Korean Society of Steel Construction
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• v.16 no.2 s.69
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• pp.235-245
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• 2004

The advantages of composite construction are now well understood in terms of structural economy, good performance in service, and ease of construction. However, these conventional composite construction systems have some problems in application to steel framed buildings due to their large depth. So, in this study we executed an experimental test with the "Slim Floor"system which could reduce the overall depth of composite beam. Slim Floor system is a method of steel frame multi-story building construction in which the structural depth of each floor is minimized by incorporating the steel floor beams within the depth of the concrete floor slab. Presented herein is an experimental study that focuses on the flexural behaviour of the partially connected slim floor system with asymmetric steel beams encased in composite concrete slabs. Eight full-scale specimens were constructed and tested in this study with different steel beam height, slab width, with or without shear connection and concrete topping thickness. Observations from experiments indicated that the degree of shear connection without additional shear connection was $0.53{\sim}0.95$ times that of the full shear connection due to inherent mechnical and chemical bond stress.

• Structural Engineering and Mechanics
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• v.64 no.6
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• pp.765-781
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• 2017

The out-of-plane response of infill walls has recently gained a growing attention and has been recognised fundamental in the damage assessment of reinforced concrete and steel framed buildings subjected to seismic loads. The observation of damage after earthquakes highlighted that out-of-plane collapse of masonry infills may occur even during seismic events of low or moderate intensity, causing both casualty risks and unfavourable situations affecting the overall structural response. Even though studies concerning the out-of-plane behaviour of infills are not as many as those focused on the in-plane response, in the last decades, a substantial number of researches have been carried out on the out-of-plane behaviour of infills. In this study, the out-of-plane response is investigated considering different aspects. First, damages observed after past earthquakes are examined, with the aim of identifying the main parameters involved and the most critical configurations. Secondly, the response recorded in about 150 experimental tests is deeply examined, focusing on the influence of geometrical characteristics, boundary conditions, prior in-plane damage, presence of reinforcing elements and openings. Finally, different theoretical capacity models and code provisions are discussed and compared, giving specific attention to those based on the arching theory. The reliability of some of these models is herein tested with reference to experimental results. The comparison between analytically predicted and experimental values allows to appreciate the extent of approximation of such methods.

• Journal of Korean Society of Steel Construction
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• v.13 no.1
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• pp.29-40
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• 2001

Steel frames are increasingly used in commercial buildings. and most steel frames are designed to achieve composite action with the concrete floor slab. The advantages of 'composite construction' are now well understood in terms of structural economy. good performance in service. and ease of construction. But. these conventional composite construction system are difficult to apply steel framed apartment due to their large depth. So. in this study we developed Semi Slim Floor system which could reduce the overall depth of composite beam. Semi Slim Floor system is a method of steel frame multi-story building construction in which the structural depth of each floor is minimised by incorporating the steel floor beams within the depth of the concrete floor slab. Twelve composite slab specimens with different deck-type. slab width. with or without stud bault and concrete topping thickness were tested to evaluate the flexural capacity.

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.107-115
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• 2007

In this paper, the damping ratios of two methods, namely the half-power bandwidth method and random decrement method from the vibration measurement were examined. Ambient vibration tests were conducted on two steel-framed and one composite tall building ranging from 27 to 36 stories. The performance of the half-power bandwidth method was investigated using four sample sizes, such as 1024, 2048, 4096 and 8192. Damping by the half-power bandwidth method is slightly more overestimated than the random decrement method due to insufficient record length. Damping evaluation by the half-power bandwidth method was found to be enhanced when using the narrower bandwidth with long recorded data.

• Steel and Composite Structures
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• v.30 no.5
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• pp.443-456
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• 2019

Although numerous researchers demonstrated the significant difference in performance between the various beam-to-column connection types, most of the previous studies in the area of infilled steel frames focused on the behaviour of frames with welded connections. Therefore, there is a need for conducting studies on infilled steel frames with other common connection types (extended endplate with and without rib stiffeners, flush endplate and shear connections). In this paper, firstly, a two-dimensional finite-element model simulating the cyclic response of infilled steel frames was presented. The infill-frame interaction, as well as the interactions between connections' components, were properly modelled. Using the previously-validated model, a parametric study on infilled steel frames with five different beam-to-column connection types, under cyclic loading, was carried out. Several parameters, including infill material, fracture energy of masonry and infill thickness, were investigated. The results showed that the infilled frames with welded connections had the highest initial stiffness and load-carrying capacity. However, the infilled frames with extended endplate connections (without rib stiffeners) showed the greatest energy dissipation capacity and about 96% of the load-carrying capacity of frames with welded connections which indicates that this type of connection could have the best performance among the studied connection types. Finally, a simplified analytical model for estimating the stiffness and strength of infilled steel frames (with different beam-to-column connection types) subjected to lateral cyclic loading, was suggested.

• Earthquakes and Structures
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• v.23 no.2
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• pp.139-150
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• 2022

In most self-center braces, decreasing residual deformation is possible only by increasing pretension force, which results in lower energy dissipation capacity. On the other hand, increasing energy dissipation capacity means higher values of residual deformation. The goal of this research was to find the best design for a self-centering buckling restrained brace (SC-BRB) system by balancing self-centering capability and energy dissipation. Three, six, and nine-story structures were investigated using OpenSees software and the TCL programming language to achieve this goal. For each height, 62 different SC-BRBs were considered using different values for the pretension force of cables, the area of the buckling restrained brace (BRB) core plate, and the yield stress of the core plate. The residual deformation and dissipated energy of all the models were calculated using nonlinear analyses after cyclic loading was applied. The optimum design for each height was determined among all the models and was compared to the structure equipped with the usual BRB. The residual deformation of the framed buildings was significantly reduced, according to the findings. Also the reduction of the energy dissipation was acceptable. The optimum design of SC-BRB in 6-story building has the most reduction percent in residual deformation, it can reduce residual deformation of building 83% while causing only a 57% of reduction in dissipated energy. The greatest reduction in residual deformation versus dissipated energy reduction was for the optimum SC-BRB design of 9-story building, results indicated that it can reduce residual deformation of building 69% while causing only a 42% of reduction in dissipated energy.

• Journal of architectural history
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• v.32 no.5
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• pp.95-105
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• 2023

Focusing on Hwaseokjeong in Paju, the work seeks to clarify the social production of Nujeong (樓亭: Korean traditional pavilions) space, which took place over the 1960s and 70s, and its cultural-political implications. To make the effort as such meaningful, a theoretical framework based not merely on the thesis of 'social production of space' advocated by Henri Lefebvre but especially on some discussions related to 'state production of space' is prepared, according to which Hwaseokjeong is analyzed and explained. As a consequence, two principal arguments are put forward: one is that Hwaseokjeong was a social space which had been built and constructed in accordance with the unique mode of production dominating Korean society at that time called 'the state mode of production (le mode de production étatique)'; the other is that what lies beneath the denotation of a 'social space of tradition restoration' that Hwaseokjeong appears to carry is in fact the connotation of 'infiltration of anti-communist ideology'. All of these claims are once again supported both by examining Roland Barthes's semiology and mythologies and by considering Hwaseokjeong's P yeonaek (扁額: a plaque or framed text) as 'the practice of naming power through Jesa (題詞: inscribing dedications)'. While providing a succinct summary, the paper finally evaluates what 'social production of space' implies to social practices of architecture and related criticisms by taking into account the relationship between visibility and readability of space including buildings.