• Steel and Composite Structures
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• 제20권5호
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• pp.1067-1085
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• 2016

Recent research on steel moment-resisting connection between steel beams and concrete filled steel tubes has shown that there are considerable advantages to be obtained by anchoring the connection to the concrete infill within the tube using anchors in blind bolts. In the research reported here, extensive experimental tests and numerical analyses have been performed to study the anchorage behaviour of cogged deformed reinforcing bars within concrete filled circular steel tubes. This data in essential knowledge for the design of the steel connections that use anchored blind bolts, both for strength and stiffness. A series of pull-out tests were conducted using steel tubes with different diameter to thickness ratios under monotonic and cyclic loading. Both hoop strains and longitudinal strains in the tubes were measured together with applied load and slip. Various lead-in lengths before the bend and length of tailed extension after the bend were examined. These dimensions were limited by the dimensions of the steel tube and did not meet the requirements for "standard" cogs as specified in concrete standards such as AS 3600 and ACI 318. Nevertheless, all of the tested specimens failed by bar fracture outside the steel tubes. A comprehensive 3D Finite Element model was developed to simulate the pull-out tests. The FE model took into account material nonlinearities, deformations in reinforcing bars and interactions between different surfaces. The FE results were found to be in good agreement with experimental results. This model was then used to conduct parametric studies to investigate the influence of the confinement provided by the steel tube on the infilled concrete.

• 대한공간정보학회지
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• 제20권3호
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• pp.3-10
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• 2012

화성의 계곡망 추출 및 체적 분석은 과거 화성에 존재했을 지표수의 흐름을 규명할 수 있는 중요한 정보를 제공하고 있다. 이를 위해 본 연구에서는 기존의 이미지 프로세싱 분석을 대체할 수 있는 포인트 클라우드 기반의 지형 필터링 알고리즘을 사용한 새로운 방법론을 제시하였다. 우선 추출하고자 하는 계곡을 지면으로부터 분류하기 위해 대상지역에서 취득한 포인트 클라우드 자료의 고도값을 역전한 뒤, Adaptive TIN 필터링을 적용하였다. 분류한 지면과 대상물의 포인트 클라우드로부터 각각 ground DEM과 object DEM을 생성하고, 격자 단위로 두 DEM 간의 고도차와 object DEM으로부터 취득한 계곡 면적을 곱함으로써 최종적으로 계곡의 체적을 추정하였다. 화성 Tuscaloosa 분화구에 인접한 두 계곡을 대상으로 추정된 체적의 총 합은 약 $1.41{\times}10^{11}m^3$으로 Tuscaloosa 분화구 내 퇴적물의 체적 및 기존의 이미지 프로세싱 기법인 BTH 결과와 각각 12% 및 16%의 차이를 나타내었다.

• Structural Engineering and Mechanics
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• 제37권2호
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• pp.233-251
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• 2011

The seismic provisions of the current edition (2005) of the National Building Code of Canada (NBCC) differ significantly from the earlier edition. The current seismic provisions are based on the uniform hazard spectra corresponding to 2% probability of exceedance in 50 years, as opposed to the seismic hazard level with 10% probablity of exeedance in 50 years used in the earlier edition. Moreover, the current code is presented in an objective-based format where the design is performed based on an acceptable solution. In the light of these changes, an assessment of the expected performance of the buildings designed according to the requirements of the current edition of NBCC would be very useful. In this paper, the seismic performance of a set of six, twelve, and eighteen story buildings of regular geometry and with concrete moment resisting frames, designed for Vancouver western Canada, has been evaluated. Although the effects of non-structural elements are not considered in the design, the non-structural elements connected to the lateral load resisting systems affect the seismic performance of a building. To simulate the non-structural elements, infill panels are included in some frame models. Spectrum compatible artificial ground motion records and scaled actual accelerograms have been used for evaluating the dynamic response. The performance has been evaluated for each building under various levels of seismic hazard with different probabilities of exceedance. From the study it has been observed that, although all the buildings achieved the life-safety performance as assumed in the design provisions of the building code, their performance characteristics are found to be non-uniform.

• 한국실내디자인학회논문집
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• 제16권3호
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• pp.66-75
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• 2007

In this study, by comparing the development and the space types of local and foreign flexible apartments, basic data will be derived for the development of various flexible types of apartments in Korea. A total of 60 unit plans, including 30 domestic cases and 30 overseas cases of flexible apartments, are analyzed for this study. In terms of the unit plan types, Korean apartments usually had a wide front bay with shallow depth, placing more rooms on the front bay; whereas foreign apartments tend to have various unit plan types: (1) a narrow front bay with deep depth, (2) a wide front bay with shallow depth, and (3) variegated open-plan types. Many apartments in foreign countries had a double-layered structure with the. upstairs and downstairs areas. In terms of the flexible types, many Korean apartments achieved interior flexibility using non-bearing wall or sliding doors; whereas foreign apartments had a flexible space by separating the support elements and the infill elements. There was found to be a close relationship between the location of support elements and the variability of unit plans. Support elements can be placed largely into three locations: (1) Between the front side bay and the rear side bay, (2) in the center bay of a unit plan, and (3) others. Depending on the location of support elements, various types of flexible unit plans can be created. Through a comparative analysis of domestic and foreign apartments, basic data that can be used for developing various flexible unit plans was derived.

• 대한토목학회논문집
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• 제32권3A호
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• pp.139-148
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• 2012

원형 콘크리트 충전 강관 (CFT)은 강관과 콘크리트 내부채움재로 이루어진 합성구조로 급속 시공이 가능하고 치수 대비 강도의 효율성이 좋아 교량의 교각이나 건축물의 기둥으로 사용되고 있다. CFT에 대한 실험적 연구는 지난 수년간 꾸준히 연구되어 왔지만 이러한 실험 연구만으로 CFT의 거동을 파악하기는 충분하지 않다. 따라서, CFT의 실험 연구를 보완하고 보다 다양한 제원 및 하중 조건을 고려하여 CFT의 구조 거동을 파악하기 위해서는 수치해석 모델이 필요하다. 본 연구는 CFT의 비선형 유한 요소 해석 기법을 개발하는데 목표가 있다. 개발된 CFT의 유한 요소 해석 모델 기법은 다양한 하중이 작용하는 실험 결과들과 비교하여 그 타당성을 입증하였으며, 제안된 유한 요소 해석 모델은 CFT의 구속 효과 및 CFT의 구조 거동을 잘 모사할 수 있었다.

• 한국주거학회논문집
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• 제18권5호
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• pp.11-22
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• 2007

The purpose of this study is to propose prototypical plans for a dwelling unit applying the concepts of 'open housing' and 'aging in place' for senior citizens living in cities focusing on specific life patterns with chronic disease. Especially, a unit was designed for diabetes patients because diabetes, a representative disease of elderly people, often accompanies complications such as arthritis and Alzheimer disease. A unit design suitable for the convenient life of the elderly people with diabetes will provide a guideline for the similar unit designs of the senior citizens with other diseases. In this study, three types of unit plan are proposed. A-type plan is for type-1 diabetes patients, B-type alt.1 for the independent seniors of type-2 diabetes patients, and B-type alt.2 for the dependant seniors of type-2 diabetes patients. And a support design for a unit plan with the exclusive area of $60\;m^2$ is proposed. The same support design is used for all three unit types. Although the locations of bathroom and storage room are fixed and the location of the kitchen is changeable only in wet-zone. In conclusion, senior residents with diabetes can choose one of three unit types before occupation and the chosen unit type can be renovated by replacing infill systems as the health condition or life style changes.

• Earthquakes and Structures
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• 제8권3호
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• pp.761-778
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• 2015

The objective of this paper is to report the result of an experimental program conducted on the strengthening of nonductile RC frames by using external mesh reinforcement and plaster application. The main objective was to test an alternative strengthening technique for reinforced concrete buildings, which could be applied with minimum disturbance to the occupants. Generic specimen is two floors and one bay RC frame in 1/2 scales. The basic aim of tested strengthening techniques is to upgrade strength, ductility and stiffness of the member and/or the structural system. Six specimens, two of which were reference specimens and the remaining four of which had deficient steel detailing and poor concrete quality were strengthened and tested in an experimental program under cyclic loading. The parameters of the experimental study are mesh reinforcement ratio and plaster thickness of the infilled wall. The effects of the mesh reinforced plaster application for strengthening on behavior, strength, stiffness, failure mode and ductility of the specimens were investigated. Premature and unexpected failure mode has been observed at first and second specimens failed due to inadequate plaster thickness. Also third strengthened specimen failed due to inadequate lap splice of the external mesh reinforcement. The last modified specimen behaved satisfactorily with higher ultimate load carrying capacity. Externally reinforced infill wall composites improve seismic behavior by increasing lateral strength, lateral stiffness, and energy dissipation capacity of reinforced concrete buildings, and limit both structural and nonstructural damages caused by earthquakes.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.844-847
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• 2007

전 세계적으로 환경에 대한 관심이 고조되는 가운데 각 산업에서의 환경보호를 위한 노력이 꾸준히 진행되고 있다. 건설분야에서도 환경보존 을 노력이 지속되고 있는 실정이다. 이에 본 논문에서는 친환경성, 고내구성, 가변성, 갱신성능 그리고 쾌적성 등의 종합적인 성능을 갖춤으로써 미래형 건축물의 기본요소가 될 수 있는 친환경 지능형 건축 Component system 제안을 위한 요소기술 분석에 초점을 맞추었다. 친환경 지능형 건축 Component system 개발을 위해 요구되는 성능을 파악한 후 그 성능을 구현시키기 위한 요소기술을 분석한 결과, SI주택과 Home Automation 기술이 주요 요소기술로 도출되었다. 그리고 이론 및 문헌 고찰을 통해 도출된 요소기술의 개념 및 개발동향에 대하여 대해 살펴본 후 최종적으로 이러한 기술요소의 융합을 통한 친환경 지능형 건축 Component system 을 제안하였다.

• 한국지반환경공학회 논문집
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• 제9권4호
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• pp.5-13
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• 2008

충전물이 암 절리면의 전단강도를 감소시키는 것과 유사하게 콘크리트와 주변 암반근입부 사이의 연약한 물질은 암반에 근입된 현장타설말뚝의 주면저항력을 감소시킨다. 이러한 현상은 콘크리트 타설 후에 암반 근입부 측벽에서 천공잔류물이나 스미어 또는 재성형 암반을 생성시키는 시공과정에서도 형성되게 된다. 콘크리트 말뚝과 주변 암반 사이의 접촉면의 특성은 시공법에 따라서 크게 영향을 받는다. 콘크리트 타설과정 또는 그 이후 형성되는 연약한 물질이 존재하거나 거칠기와 같은 콘크리트-암 접촉면의 특성은 말뚝의 주면부 거동에 큰 영향을 미친다. 본 연구에서는 유한차분법 코드를 기반으로 하는 FLAC 2D를 이용하여 스미어현상이 발생한 암반에 근입된 현장타설말뚝의 거동특성을 조사하기 위하여 변수분석을 실시하였다. 본 연구의 결과로서, 정적연직하중을 받는 암반에 근입된 현장타설말뚝의 극한주면저항력에 영향을 미치는 요소와 말뚝두부의 침하에 영향을 미치는 요소들을 확인할 수 있었다.

• Steel and Composite Structures
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• 제23권4호
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• pp.473-481
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• 2017

Steel plate shear wall (SPSW) system has been increasingly used for lateral loads resisting system since 1980s when the utilization of post-buckling strength of SPSW was realized. The structural response of SPSWs largely depends on the behavior of the surrounded beams. The beams are normally required to behave in the elastic region when the SPSW fully buckled and formed the tension field action. However, most modern design codes do not specify how this requirement can be achieved. This paper presents theoretical investigation and design procedures of manually calculating the plastic flexural capacity of the beams of SPSWs and can be considered as an extension to the previous work by Qu and Bruneau (2011). The reduction in the plastic flexural capacity of beam was considered to account for the presence of shear stress that was altered towards flanges at the boundary region, which can be explained by Saint-Venant's principle. The reduction in beam web was introduced and modified based on the research by Qu and Bruneau (2011), while the shear stress in the web in this research is excluded due to the boundary effect. The plastic flexural capacity of the beams is given by the superposition of the contributions from the flanges and the web. The developed equations are capable of predicting the plastic moment of the beams subjected to combined shear force, axial force, bending moment, and tension fields induced by yielded infill panels. Good agreement was found between the theoretical results and the data from previous research for flexural capacity of beams.