• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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• pp.29-32
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• 2009

Building foundations for Top-Down construction require a special setting, because the foundations have to be placed way before excavation for the substructure of main building, Usually, the foundation goes into the layer of rock and it is often called rock-pier foundation, Currently, a cage of steel reinforcing bars is inserted to the pre-excavated hole in the rock layer, hanging down from the wide flange steel column above. This paper presents a new method for connecting the prefounded column and the steel cage with a coupler for better connection between the two, The use of a circular Concrete Filled Tube (CFT) as a prefounded column makes it possible to have this type of connection. The details of the connection and application to a Top-Down construction site is also included in this paper.

• 한국지반공학회논문집
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• 제29권10호
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• pp.5-18
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• 2013

부등침하는 연약지반에 시공되는 철탑기초에 있어서 주요한 손상을 야기한다. 송전철탑용 연결형 말뚝기초는 연약지반에서의 송전철탑기초의 부등침하를 방지하기 위한 구조물로서, 주기초체와 주기초체 사이에 위치하여 기초를 연결하는 연결보로 구성된다. 본 연구에서는 송전용 철탑기초에 작용하는 연결보의 영향을 조사하기 위하여, 전라북도에 위치한 건설현장에서 24회의 모형재하시험을 수행하였다. 시험에서는 다양한 하중조건과 연결보 조건이 고려되었으며, 시험결과 수평하중에 의한 연결형 말뚝기초의 발생변위가 철탑에 작용하는 수평하중의 각도에 따라 달라지는 것으로 나타났다. 연결형 기초의 침하는 연결보의 강성이 증가할수록 감소하였으며, 수평지지력은 수평하중이 재하되는 철탑의 높이가 낮을수록 증가하였고, 파괴시점에서의 하중의 크기는 대부분의 경우 하중재하방향에 상관없이 유사한 것으로 나타났다.

• Structural Engineering and Mechanics
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• 제64권1호
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• pp.109-120
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• 2017

The behavior of moment resistant steel structures depends on both the beam-column connections and columns foundations connections. Obviously, if the connections can meet the adequate ductility and resistance against lateral loads, the seismic capacity of these structures will be linked practically to the performance of these connections. The shape memory alloys (SMAs) have been most recently used as a means of energy dissipation in buildings. The main approach adopted by researchers in the use of such alloys is firstly bracing, and secondly connecting the beams to columns. Additionally, the behavior of these alloys is modeled in software applications rarely involving equivalent torsional springs and column-foundation connections. This paper attempts to introduce the shape memory alloys and their applications in steel structural connections, proposing a new steel column-foundation connection, not merely a theoretical model but practically a realistic and applicable model in structures. Moreover, it entails the same functionality as macro modeling software based on real behavior, which can use different materials to establish a connection between the columns and foundations. In this paper, the suggested steel column-foundation connection was introduced. Moreover, exploring the seismic dynamic behavior under cyclic loading protocols and the famous earthquake records with different materials such as steel and interconnection equipment by superelastic shape memory alloys have been investigated. Then, the results were compared to demonstrate that such connections are ideal against the seismic behavior and energy dissipation.

• 한국강구조학회 논문집
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• 제26권6호
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• pp.537-547
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• 2014

골조 유닛 모듈러 구조 형식은 기 제작된 유닛 구조물을 적층하여 건물을 보다 간편히 건설을 할 수 있어 중, 고층 건물에 적용이 확대되고 있다. 이러한 유닛 모듈러 구조 형식은 외력에 의하여 발생하는 축력과 휨모멘트를 지반에 잘 전달시켜야 함으로 각각의 유닛구조물은 기초와 적절히 연결되어야 한다. 본 연구에서는 새로운 형태의 매입형 유닛-기초 접합부를 제안하였으며, 제안된 접합부의 성능을 일련의 실험 연구를 통하여 평가하였다. 총 5개의 실물 크기의 실험체를 제작하여 실험을 수행하였으며, 매입 길이와 엔드 플레이트와 같은 제안된 유닛-기초 접합부의 휨거동에 영향을 미칠 수 있는 인자들의 영향을 살펴보았다. 실험결과, 모든 실험체에서 강성은 최소한 반강접의 강성을 상회하는 것으로 나타났으며, 기둥의 매입길이는 본 연구에서 수행한 실험체에서 약 200mm가 적절한 것으로 파악되었다.

• 한국공간구조학회논문집
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• 제15권4호
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• pp.65-72
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• 2015

To overcome the weakness of spread foundation in large space structure, the research of precast pile for replace spread foundation have been conducted. The new type of joint between PHC pile and steel column is named HAT Joint(Hollow hAlf-sphere cast-sTeel Joint). It connected PHC Pile by bolt that verification of bolt connection should be accomplished. In this paper, pull-out test and flexural performance for HAT Joint to verifying the bolt connection is explained. As a result, the pull-out and flexural capacities of bolt were checked to use in real structure. Furthermore, the equation of pull-out strength was proposed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.184-195
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• 2008

The use of geosynthetics for the reinforced earth wall system has been increasing rapidly for a number of years. The connection strength between wall facing and geosynthetics should be evaluated in the design of geosynthetics. However, the connection strength is not often evaluate, exactly, and it causes problems such as deformation of the wall facing, local failure of the reinforced earth wall system, conservative design and so on. Therefore, the connection strength in the design of geosynthetics should be applied evaluation result by reasonable method. This study is evaluated connection strength using the typical design method, NCMA(1997) and FHWA(1996), in the field case. Then the results compared with the evaluation results of connection strength, which is suggested by Soong & Koener(1997). The analysis results confirmed that the connection strength for the design of geosynthetics should be evaluate using reasonable method with considering various factor, such as safety factor, installation and importance of construction.

• Geomechanics and Engineering
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• 제35권6호
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• pp.617-626
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• 2023

In this study, three-dimensional numerical parametric study was conducted to explore deformation mechanisms of grouped piled-raft-foundation due to lateral load in clays. Effects of load intensity, loading angle, soil stiffness, pile diameter, pile spacing and pile length on foundation deformations were explored. It is found that the smallest and largest movements of pile foundation are induced when the loading angles are 0° and 30°~60°, respectively. By increasing loading angle from 0° to 30°~60°, the resultant horizontal movements and settlements increase by up to 20.0% and 57.1%, respectively. Since connection beams can substantially increase integrity of four piled raft foundation, resultant horizontal movements, settlements and bending moments induced in the piled raft foundation decrease by up to 54.0%, 8.8% and 46.3%, respectively. By increasing soil stiffness five times, resultant horizontal movements and settlements of pile foundation decrease by up to 61.7% and 13.0%, respectively. It is indicated that effects of connection beam and soil stiffness on settlements of pile foundation are relatively small. When pile diameter is less than 1.4 m, deformations of piled raft foundation decrease substantially as a reduction in the pile diameter. Two dimensional groups are proposed to develop calculation charts of horizontal movements and settlements of pile foundation. The proposed calculation charts can directly estimate movements of piled raft foundation under arbitrary loading, ground and pile conditions.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.90-90
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• 2000

The FAS protocol of FOUNDATION Fieldbus playes the roles of interface between Data Link Layer and application layer and establishment of connection between receiver and sender. In this study, the FAS protocol of FOUNDATION Fieldbus was developed. The method of implementation is described in this paper. Software of FAS protocol was implemented by Window-based program and DOS-based program for PC and sensor module, respectively.

• 한국강구조학회 논문집
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• 제28권2호
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• pp.121-128
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• 2016

고장력 볼트를 적용한 원형단면 콘크리트 충전 강재 기둥-기초 연결부의 합리적인 설계범위를 제안하기 위하여 축하중과 수평하중을 동시에 받는 기둥-기초 연결부의 전반적인 구조적 거동과 설계변수에 따른 거동특성을 상용 유한요소해석 프로그램인 ABAQUS를 이용하여 해석적으로 검토하였다. 이를 위해 앵커볼트를 고장력 볼트로 대신하는 선행연구의 실험을 토대로 수치해석을 실시하였으며, 해석방법의 타당성을 검증하였다. 또한 현행 설계기준을 분석하여 기둥-기초 연결부 거동에 영향을 미치는 설계변수(앵커의 묻힘깊이, 앵커의 강종, 리브의 높이, 리브의 두께)를 선정하였으며, 설계변수에 따른 기둥-기초 연결부의 거동특성을 비교 분석하였다. 일반 앵커에 비해 고장력 볼트를 적용하는 것이 기둥-기초 연결부의 거동에 유리한 것으로 나타났으며, 고장력 볼트의 최소 묻힘깊이는 기둥 직경(D)을 기준으로 0.5D이상으로 설계하는 것이 합리적이라고 판단된다. 리브의 높이는 0.5D이상, 리브의 두께는 베이스플레이트 두께($t_b$)를 기준으로 $0.4t_b$이상으로 설계하는 것이 합리적이라고 판단된다.

• 풍력에너지저널
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• 제15권2호
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• pp.23-36
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• 2024

In this study, a health monitoring system was developed for the two most vulnerable parts of a wind tower support structure: the connection between steel towers (L-Flange) and the concrete foundation-steel tower connection. To select assessment parameters for health monitoring, detailed FEM analysis was conducted using the ABAQUS program. Additionally, a testbed was established near the Jeju Woljeongri wind turbine farm to evaluate the applicability of measurement data by installing sensors. Through computational analysis and relevant criteria review, we defined limits for measurement parameters by vulnerable section. We categorized the structural safety evaluation into four stages: normal, caution, warning, and danger, and selected management criteria for each stage. From this, an algorithm to evaluate safety was developed, and a visualized monitoring platform based on the established critical parts monitoring system was developed.