• Journal of Korean Society of Steel Construction
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• v.25 no.3
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• pp.255-265
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• 2013

The major goal of this study is to develop the industrialized structural system that can build high-rise buildings using the box-shaped steel frames such as a unit module system. In order to achieve such a goal, we need the advanced details for joints that consist in a single unit. Furthermore we also need to commercialize the unit modular building system through the basic experiments, research of theoretical analysis and the achievement of seismic performance. This study derived to develop the derails in the beam-to-column joint and to carry out structural performance test. Test results, a joint with thickness of 6.0T can be possible to maintain the plastic rotational angle for strength and seismic performance. Therefore, joint with thickness of 6.0T is able to apply when considering reinforcement in the local of stress concentration.

• Steel and Composite Structures
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• v.19 no.4
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• pp.917-937
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• 2015

During a seismic event, a considerable amount of energy is input into a structure. The law of energy conservation imposes the restriction that energy must either be absorbed or dissipated by the structure. Recent earthquakes have shown that the use of concentric bracing system with their low ductility and low energy dissipation capacity, causes permanent damage to structures during intense earthquakes. Hence, engineers are looking at bracing system with higher ductility, such as chevron and eccentric braces. However, braced frame would not be easily repaired if serious damage has occured during a strong earthquake. In order to solve this problem, a new bracing system an off-centre bracing system with higher ductility and higher energy dissipation capacity, is considered. In this paper, some numerical studies have been performed using ANSYS software on a frame with off-centre bracing system with optimum eccentricity and circular element created, called OBS_C_O model. In addition, other steel frame with diagonal bracing system and the same circular element is created, called DBS_C model. Furthermore, linear and nonlinear behavior of these steel frames are compared in order to introduce a new way of optimum performance for these dissipating elements. The obtained results revealed that using a ductile element or circular dissipater for increasing the ductility of off-centre bracing system and centric bracing system is useful. Finally, higher ductility and more energy dissipation led to more appropriate behavior in the OBS_C_O model compared to DBS_C model.

• Steel and Composite Structures
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• v.18 no.6
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• pp.1423-1450
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• 2015

The paper presents the details and results of an experimental study on bolted end-plate joints of industrial type steel building frames. The investigated joints are commonly used in Lindab-Astron industrial buildings and are optimized for manufacturing, erection and durability. The aim of the research was to provide an experimental background for the design model development by studying load-bearing capacity of joints, bolt force distribution, and end-plate deformations. Because of the special joint details, (i.e., joints with four bolts in one bolt-row and HammerHead arrangements), the Eurocode 3 standardized component model had to be improved and extended. The experimental programme included six different end-plate and bolt arrangements and covered sixteen specimens. The steel grade of test specimens was S355, the bolt diameter M20, whereas the bolt grade was 8.8 and 10.9 for the two series. The end-plate thickness varied between 12 mm and 24 mm. The specimens were investigated under pure bending conditions using a four-point-bending test arrangement. In all tests the typical displacements and the bolt force distribution were measured. The end-plate plastic deformations were measured after the tests by an automatic measuring device. The measured data were presented and evaluated by the moment-bolt-row force and moment-distance from centre of compression diagrams and by the deformed end-plate surfaces. From the results the typical failure modes and the joint behaviour were specified and presented. Furthermore the influence of the end-plate thickness and the pretension of the bolts on the behaviour of bolted joints were analysed.

• Journal of the Korean Institute of Landscape Architecture
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• v.30 no.2
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• pp.79-87
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• 2002

This landscape design proposal was presented to a design competition for the KangWon Province Police Agency(KPA). The site, about 27,711 $m^2$, is located at 293-4 Udu-dong, Chunchun, KangWon-Do. Design objectives of the KPA were to build a symbolic place which fall community members with pride, to elevate an identity and status of the KPA by creating a landscape correspondent to the concept of the building design, to provide community residents with a space to enjoy cultural and social activities, and to make environment friendly space. The main concept was developed by one of characteristics of the traditional spatial structure of Korea known as an, 'Open and Closed spatial structure.'By re-interpreting the traditional spatial structure and applying it to the site, the design met the various desires of the KPA. The site is primarily segmented into 6 sub spaces; entrance space Podori plaza, symbolic court, police billeting area, sports area, and rear rest area. The entrance space, Podori plaza, and symbolic court on the south-west part of the site represent the publicity of the site as the concept of ″open space.″ On the contrary, considering the specialty of police affairs, the north-east part of the site, which contains the police billeting area and rest area, were designed to maintain security by using the concept of ″closed space.″ To express an identity of the KPA, 'Podori', a police mascot, the plaza was designed and is suppose to function as the hub of the community. In the front section of the plaza, a symmetrical planting pattern, centering the strong axis, was introduced to strengthen its symbolic meaning. Traditional window frames such as the pattern of 'Pisal-jige'and 'Umulsal-jige' were used for the paving system which is applied as the environment friendly design. Site facilities and furnitrue were placed at every important spot in order to connect various spaces organically. As these well-tied spaces properly shared their function, spatial sequence and management would be promoted. The entire space was designed to allow free access of handicapped people. This proposal is meant to create a new image of KangWon province and to enhance the way of inhabitants' think about their community.

• Journal of Korean Society of Steel Construction
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• v.20 no.2
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• pp.303-312
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• 2008

In this paper, the seismic behavior of shear wal-frame systems is analyzed. The governing equations of the wall-frame systems with outrigger truss are formulated through the continuum approach and the whole structure is idealized as a shear-flexural cantileverwith rotational spring. The effect of shear deformation and flexural deformation of the wall-frame and outrigger trusses are considered and incorporated in the formulation of the wall-frame structures with and without outriggers are compared by using finite element analysis incorporated with the Newmark-${\beta}$ method. Numerical results are obtained and compared with the finite element package MIDAS. The proposed method is found to be simple and efficient, and provides reason ably accurate results in the early design stage of tall building structures.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.657-666
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• 2006

The precast concrete beam-column connectors to retrofit an apartment building were investigated experimentally. Five precast concrete beam-column connectors were considered to develop a modified model which was adapted to domestic construction conditions from the DDC(dywidag ductile connection) of Germany. Special H-shape steel hardware was used to decrease the width of column and beams for the construction of external frames in apartments. It was found that the DDC had high joint strength and ductility, however failed in inclined shear crackings in the columns. The modified one showed better behaviors in tests because they did not show critical column crackings at failure. The test result of modified one with grouting was compared to that of the one without grouting within the duct. The one with grouting showed higher strength and ductility in failure than that without grouting.

• Steel and Composite Structures
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• v.21 no.4
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• pp.863-882
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• 2016

This study aims to introduce a new bracing system by which even super-wide frames with large openings can be braced. The proposed system, hereafter called Cable-Pulley Brace (CPB), is a tension-only bracing system with a rectilinear configuration. In CPB, a wire rope passes through a rectilinear path around the opening(s) and connects the lower corner of the frame to its opposite upper one. CPB is a secondary load resisting system with a nonlinear-elastic hysteretic behavior due to its initial pre-tension load. As a result, the required energy dissipation would be provided by the MRF itself, and the main intention of using CPB is to contribute to the initial and post-yield stiffness of the whole system. Using a stiffness calibration technique, optimum placement of the CPBs is discussed to yield a uniform displacement demand along the height of the structure. A displacement-based design procedure is proposed by which the MRF with CPB can be designed to achieve a uniform distribution of inter-story drifts with predefined values. Obtained results indicated that CPB leads to significant reductions in maximum and residual deformations of the MRF at the expense of minor increase in the maximum base shear and developed axial force demands in the columns. In the case of a typical 5-story residential building, compared to SMRF system, CPB system reduces maximum amounts of inter-story and residual drifts by 35% and 70%, respectively. Moreover, openings of the frame are not interrupted by the CPB. This is the most appealing feature of the proposed bracing system from architectural point of view.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.2
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• pp.137-146
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• 2007

Numerical analyses are performed to show the effect of stiffening facade riggers on the behavior of the structure and to investigate the optimum locations of facade riggers. Optimum locations of the facade riggers to minimize the drift at the top of the structure are obtained by maximizing the drift reduction caused by the facade riggers and are significantly influenced by the bending and shear stiffnesses of the braced frame and facade riggers. Three standard load cases of uniformal and triangularly distributed lateral loads as well as a lateral point load at the top of the structure are considered in this paper Optimum locations of facade riggers are plotted as functions of nondimensional relative stiffness parameters ${\omega}$ and ${\beta}$ for structures with one to four riggers. Although the analysis presented herein is based on certain simplifying assumptions, it is believed that the results do provide sufficiently accurate information for determining the optimum locations of facade riggers in highrise structures.

• Journal of the Earthquake Engineering Society of Korea
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• v.5 no.6
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• pp.47-54
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• 2001

Unbond brace hysteretic dampers are generally used to prevent or decrease structural damage in building structures subjected to strong earthquake by its energy dissipating hysteretic behavior. In the study, a straightforward design procedure for unbond brace hysteretic dampers was developed. The required amount of equivalent damping to satisfy given performance acceptance criteria was obtained conveniently based on the capacity spectrum method without carrying out time-consuming nonlinear dynamic time history analysis. Then the size of the unbond braces is determined from the required equivalent damping. Parametric study has been performed for the design variables such as natural period, yield strength, the stiffness after the first yield stress of the unbond brace. The procedure was applied to 5-story and 10-story steel frames for verification of the proposed method. According to the earthquake time history analysis results, the maximum displacement of the model structure with unbond braces supplied in accordance with the proposed method corresponds well with the given target displacement.

• Magazine of the Korea Concrete Institute
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• v.11 no.1
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• pp.255-266
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• 1999

The objective of this experiment is to observe the elastic and inelastic behaviors of high-rise reinforced concrete frames having non-seismic details. To do this, a building frame designed according to Korean seismic code and detailed in the Korean conventional practice was selected. A 1:12 scale plane frame model was manufactured according to similitude law. A reversed lateral load test and a monotonic pushover test were performed under the displacement control. To simulate the earthquake effects, the lateral force distribution was maintained to be an inverse triangle by using a whiffle tree. From the tests, base shears, crack pattern, local rotations in the ends of critical members and the relations between interstory drift versus story shear are obtained. Based on test results, conclusions are drawn on the implications of the elastic and inelastic behaviors of a high-rise reinforced concrete frame having non-seismic details.