• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.2
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• pp.94-102
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• 2020

Precast concrete segment arch system has an economic and construct ability that combined with advantage of precast concrete and arch behavior. A precast concrete segment arch system with outrigger is consisted of segmented precast panels, a steel outrigger rib, and V-strip to connect precast panels with a steel outrigger rib and cast-in-place anchors in precast panels to connect V-strip should have sufficient pull-out capacity to form its arch shape by site lifting for assembled precast panels and outriggers. However, it is difficult to secure its embedment depth due to the relatively shallow thickness of precast panel. It can be also occurred that flexure deformation of precast panels caused by its pull-out behaviors. In this study, pull-out capacity of cast-in-place anchor was examined for construction of precast concrete segment arch system with outriggers. Therefore, a total of 24 precast panel specimens were fabricated to examine pull-out capacities of cast-in-place anchor in precast panels, and installation depth of anchors, diameter of anchors and wire mesh effects for the precast panel were examined. From this pull-out tests, its pull-out capacities and failure modes were evaluated and the type of the cast-in-place anchor applicable to the precast concrete segment panel arch system with outriggers was determined from comparison of the design specification values.

• International Journal of High-Rise Buildings
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• v.11 no.1
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• pp.41-50
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• 2022

The Spiral, a supertall tower at the Hudson Yards Zoning District of NYC is an new iconic commercial office tower. The spiraling terraces throughout the height of the building creates unique outdoor spaces at each level for its occupants while introduces structural challenges unlike common office towers. Innovative structural solutions and an integrated connection design and steel detailing delivery process proved to be a key factor in the success of the project.

• 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.

• International Journal of High-Rise Buildings
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• v.1 no.3
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• pp.237-246
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• 2012

Outrigger systems have been widely used in super tall buildings constructed since the 1980's, eclipsing previously favored tubular frame systems. However, outriggers are not listed as a seismic lateral load resisting system in any code. Design guidelines are not available. The CTBUH formed the Outrigger Working Group to develop the first-ever outrigger system design guide with an historical overview, considerations for outrigger application, effects on building behavior and design recommendations including concerns specific to this structural system such as differential column shortening and construction sequence impacts. Project examples are presented for various outrigger system types, including advancements in their technology. The guide provides a basis for future discussions on this important topic.

• International Journal of High-Rise Buildings
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• v.7 no.3
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• pp.215-221
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• 2018

Buckling-Restrained Braces (BRBs) have been widely applied to tall buildings in seismic areas in the world. In this paper the author summarizes representative types of BRB compositions and shows two cases of special applications of BRBs. In the first case, BRB diagonals for tall building were used to provide stable cyclic nonlinear hysteresis and also used to limit forces generated at columns, connections and walls. The top outriggers are pre-loaded by jacks to resolve long-term differential shortenings between the concrete core wall and concrete-filled steel box columns. The second case is the retrofit work for a communication tower by replacing the insufficiently strong members with BRBs in Japan.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.710-716
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• 2005

The objective of the present study is to design a hull form of a 9.77 ton class trimaran for use as a Pleasure boat around the bay of Gyounggy. The boat will be made of fiber reinforced plastics and equipped with a 650 hp diesel engine with a conventional water jet propulsion system and the maximum speed be 25 knots after fully loaded. In the present study, the optimal configuration such as relative location of outriggers of the 9.77 ton class trimaran is selected and the resistance characteristics are carefully studied through a series of model tests. The general arrangement of the boat are also considered in the final decision of the hull form.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.05a
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• pp.438-440
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• 2022

산업 현장에서 인력으로 작업할 수 있는 물리적 한계를 극복하기 위해 특수 목적 차량 작업 시 차량의 넘어짐 방지와 차체 보호를 위해 아웃트리거를 착지시키는데 도로 상태에 따라 사용자가 직접 최적화를 수행하는데 어려움이 존재한다. 본 논문에서는 도로 표면 상태를 신속하게 판단하여 아웃트리거 수직 및 수평 전개 착지 시 시간 소모, 안전사고 발생을 낮추기 위해 시멘틱 분할을 이용한 도로 표면 상태를 분석하는 연구를 수행하였다. 13가지로 구분된 도로 표면 상황에 대하여 DeepLabV3+를 통해 실험한 결과 픽셀 성능0.7819, mIoU 0.7085 결과를 도출하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.293-299
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• 2018

Steel truss outriggers can be replaced by reinforced concrete walls to control the lateral drift of tall buildings. When reinforced concrete outrigger walls are connected to perimeter columns, not only axial forces but also shear forces and moments can be induced on the perimeter columns. In this study, the shear force of the perimeter column due to the rotation of the outer edge of the outrigger wall is derived as analytic equations and the result is compared with the finite element analysis result. In the finite element analysis, the effects of connecting beams at each floor and the effect of modeling shear walls and outriggers with beam element and plane stress element was analyzed. The effect of the connecting beam was almost negligible and the plane stress element was determined to have greater stiffness than the beam element. The inter-story rotation and the shear force of the perimeter column due to the rotation of the outer edge of the outrigger wall was considerably smaller than the allowable value. Therefore, even if the outrigger wall made of reinforced concrete is applied to a tall building, it is considered that there is no need to study the shear force and moment induced in the perimeter columns.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.3
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• pp.76-88
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• 2024

A significant cause of fall or overturning accidents in the construction industry, including landscaping construction and management, is work at heights using portable ladders. Portable ladders are classified as A-type or triangular support ladders depending on the number of supporting leg and support conditions. The tripod mobile ladder, which supports itself with only three supporting legs, is unstable and more prone to overturning compared to the A type ladders. Therefore, using the specifications of the tripod mobile ladder and the stability regulations of EN131-Part 7, overturning and resistance moment calculation formulas were derived for all directions in which overturning could occur. The moments calculated using these equations, and the overturning stability in each direction were evaluated. According to the calculation results, although there are differences depending on the direction, most are unstable for overturning at 8 or more steps. Based on these results, this study proposed measures to increase the moment of resistance by changing the weight, depth, and width, and using outriggers to ensure stability against the overturning of ladder. However, when changing the specifications of these measures, the size increases are excessive and the applicability is insufficient. On the other hand, outriggers are an applicable measure as they can ensure stability against overturning with only a minimum expansion length.

• Steel and Composite Structures
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• v.20 no.5
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• pp.1133-1153
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• 2016

In this article, an additive performance ratio method using structural analysis of both 2D and 3D is introduced to mitigate the complexity of work evaluating structural performances of numerous steel outrigger alternatives in multi-story buildings, especially high-rise buildings. The combined structural analysis process enables to be the design of economic, safe, and as constructional demanding structures by exploiting the advantages of steel, namely: excellent energy dissipation and ductility. First the approach decides the alternative of numerous steel outriggers by a simple 2D analysis module and then the alternative is evaluated by 3D analysis module. Initial structural analyses of outrigger types are carried out through MIDAS Gen 2D modeling, approximately, and then the results appeal structural performance and lead to decide some alternative of outrigger types. ETABS 3D modeling is used with respect to realization and evaluation of exact structural behaviors. The approach reduces computational burden in compared to existing concepts such as full 3D analysis methods. The combined 2D and 3D tools are verified by cycle and displacement tests including comprehensive nonlinear dynamic simulations. The advantages and limitations of the Additive Performance Ratio Approach are highlighted in a case study on a high rise steel-composite building, which targets at designing the optimized alternative to the existing original outrigger for lateral load resisting system.