• Journal of the Computational Structural Engineering Institute of Korea
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• v.21 no.1
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• pp.103-111
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• 2008

The purpose of this study is to find the way to determine the thickness of RC shear wall outriggers of tall buildings. For this, the analysis models of tall buildings with 60 stories are generated and analyzed. Then the changes of load transfer and deformation caused by the outriggers are investigated and the equation for the determination of the thickness of RC shear wall outriggers is proposed. Finally, the proposed equation is verified for the variously modified analysis models.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.3
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• pp.255-266
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• 2010

In high-rise buildings, an outrigger system is frequently used as a resisting system for lateral loads. Since the outriggers tie exterior columns and an interior core, exterior columns can participate in the lateral load resisting system and the structural resistance capacity can be increased. However, the outriggers contribute for controlling gravity loads as well as lateral loads. The flows of gravity loads can be changed by the members of outriggers, for the purposes of transferring loads to mega-columns, distributing gravity loads equally among vertical members of columns, walls, or piles, minimizing differential settlements in a foundation system, and so on. In this study, by computational structural analyses of high-rise buildings over 100 floors, the effects of outriggers on controlling gravity loads are analyzed. Analyses for 3-dimensional models with or without outrigger members are performed, and then the gravity load distributions in columns and piles and foundation settlements are analyzed. Also, the effects of outriggers on gravity load controls during construction stages as well as after construction are included.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.5
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• pp.37-47
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• 2019

The study purposed to investigate the optimal location of core and offset outrigger system considering floor diaphragm. To accomplish this aim, a structure design of 70 stories building was performed by using MIDAS-Gen. And the leading factors of the analysis research were the slab stiffness, the stiffness of shear wall and the outrigger position in plan. Based on the analysis results, we analyzed and studied the influences of the shear wall stiffness and the slab stiffness on optimal location of core and offset outrigger considering floor diaphragm. The results of the analysis study indicated whether the slab stiffness, the stiffness of shear wall and the outrigger position in plan had an any impact on optimal location in outrigger system of tall building. Also the paper results can give help in getting the structural engineering materials for looking for the optimal position of outrigger system in the high-rise building.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.149-150
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• 2010

In this study, optimal location of outrigger for reduction of differential column shortening has been proposed. Optimal location of outrigger for reduction of differential column shortening is the position that the largest differential column shortening develops when the outrigger is not installed.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.484-487
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• 2009

초고층구조물의 경우 중저층 구조물과 다르게 설계시 중력하중과 풍하중의 크기가 매우 크므로 이를 제어하는 구조물의 코어에 강성이 큰 전단벽을 설치하고 최상층에 아웃리거나 벨트트러스를 설치하는 방법을 많이 적용한다. 그리고 홍콩의 IFC와 같이 초대형기둥과 아웃리거를 설치하여 횡하중에 저항하는 구조시스템도 제시되고 있다. 이러한 초고층구조물에서 연쇄붕괴가 발생할 경우 세계무역센터의 붕괴에서 나타나듯이 상상을 초월하는 피해를 초래할 수 있다. 따라서 본 연구에서는 이러한 초고층 구조시스템의 연쇄붕괴저항능력을 Pushdown해석을 이용하여 평가하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.139-145
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• 2018

An outrigger system is used widely to increase the lateral stiffness of high-rise buildings, resulting in reduced dynamic responses to seismic or wind loads. Because the dynamic characteristics of earthquake or wind loads are quite different, a smart vibration control system associated with an outrigger system can be used effectively for both seismic and wind excitation. In this study, an adaptive smart structural control system based on an outrigger damper system was investigated for the response reduction of multi-hazards, including seismic and wind loads. A MR damper was employed to develop the smart outrigger damper system. Three cities in the U.S., L.A., Charleston, and Anchorage, were used to generate multi-hazard earthquake and wind loads. Parametric studies on the MR damper capacity were performed to investigate the optimal design of the smart outrigger damper system. A smart control algorithm was developed using a fuzzy controller optimized by a genetic algorithm. The analytical results showed that an adaptive smart structural control system based on an outrigger damper system can provide good control performance for multi-hazards of earthquake and wind loads.

• 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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05b
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• pp.69-73
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• 2010

• Journal of the Computational Structural Engineering Institute of Korea
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• v.16 no.3
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• pp.291-299
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• 2003

Based on the continuum approach, an investigation is made to get the forces and displacements of laterally loaded outrigger braced structures with a pair of coupled cores, and to show the effect of stiffening outriggers on the behavior of the structure. From the condition that the rotation of the core at the outrigger level is matched with the rotation of the corresponding outrigger, the outrigger restraining moment is derived analytically. From this, the core moment diagram, the column axial forces, and the horizontal displacements of the structure may be determined. Comparisons with the results by the program MIDAS-GEN for the structural models, have shown that this analysis can give reasonably accurate results for outrigger-braced structures with a pair of coupled cores. And a lateral displacement at the top of the structure is influenced by the outrigger location than the core location. Although the formulae are accurate only for idealized outrigger braced structures, they have a useful practical purpose in providing a guide to the behavior, and for making approximate estimates of the forces and displacements, in practical outrigger braced structures with a pair of coupled cores.

• Journal of Korean Association for Spatial Structures
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• v.5 no.3 s.17
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• pp.123-130
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• 2005

This study presents an effective stiffness-based optimal technique to control quantitatively lateral drift and evaluate the structural behavior characteristics and efficiency for tall outrigger system subject to lateral loads. To this end, displacement sensitivity depending on behavior characteristics of outrigger system is established and approximation concept that preserves the generality of the mathematical programming and can efficiently solve large scale problems is introduced. Specifically, under the 'constant-shape' assumption, resizing technique of member is developed. Four types of 50 story frameworks are presented to illustrate the features of the quantitative lateral drift control technique proposed in this study.