• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.90-90
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• 2011

최근 전 세계적으로 지진의 발생 빈도가 증가하며 그 규모도 점차 커지는 경향을 보이고 있다. 대형지진의 발생 시 저층 구조물의 붕괴로 인한 인명 및 사회, 경제적 피해가 두드러짐에 따라 기존 저층 구조물의 내진보강기법에 관한 연구가 활발히 진행 중인 추세이다. 우리나라의 경우 강도증가형 내진보강공법이 주를 이루고 있어 다양한 내진보강기법의 개발 및 적용이 필요한 실정이다. 따라서 본 연구에서는 지진입력하중 저감형 내진보강기법으로서 강재댐퍼시스템을 제안하여 구조적 성능을 파악하고, 이를 적용한 보강 실험체와 비보강 실험체를 제작하여 정적가력실험을 통하여 그 성능을 비교하였다. 제안된 강재댐퍼시스템은 입력에너지를 소산시키는 내부의 슬릿형 댐퍼와 이를 지지하는 기둥 및 외부 프레임으로 구성되며, 내부 댐퍼는 먼저 항복하여 에너지를 소산시키기 위하여 지지기둥 및 프레임에 사용된 강재보다 강성 및 강도가 적게 계획되었다. 강재댐퍼의 성능실험 결과, 비교적 안정적 거동을 하며, 강성과 강도 및 에너지 흡수능력이 우수하게 나타났다. 보강 및 비보강 실험체의 골조는 기존 학교 건축물의 표준도면을 기준으로 하여 골조의 일부를 대상으로 60% 축소율을 적용하여 계획하였으며, 보강 실험체는 미리 제작된 강재댐퍼시스템을 골조 내에 설치하여 에폭시 주입법으로 부착시공 하였다. 보강 및 비보강 골조 실험체의 정적가력 실험결과 비보강 실험체는 기둥의 휨 항복 후 변형의 증가에 따라 휨 및 전단 균열이 증가하면서 최종적으로 기둥이 전단파괴 되었으며, 보강 실험체는 비보강 실험체에 비하여 기둥 및 보의 균열이 적고, 골조에 골고루 분포되어 파괴 규모가 감소하였다. 최대 강도면에서 보강 실험체는 비보강 실험체에 비하여 약 3.4배 우수하였으며, 초기강성은 약 7배 가량 유리한 것으로 평가되어 제안된 강재댐퍼시스템이 강도면에서 우수한 성능을 나타냄을 알 수 있었다. 또한 두 실험체의 기둥 주근 및 띠철근의 변형률을 비교한 결과, 비보강 실험체는 대부분의 철근이 항복하여 큰 변형을 일으킨 반면, 보강실험체에서는 철근의 항복현상이 나타나지 않았고 댐퍼가 항복을 하면서 큰 변형을 일으켰다. 이를 통해 지진하중 입력 시 댐퍼에서 입력 에너지를 흡수하여 큰 하중을 부담하며, 기존의 구조부재에는 입력 에너지가 낮아 손상이 보다 적게 발생함을 확인하였다.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.6
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• pp.55-65
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• 2010

The purpose of this experimental study is to evaluate the seismic performance of a 2 story RC shear wall system by the static reversal loading test. The lower 2 stories of the prototype structure were selected, and the specimens of this study were comprised of a T-type wall with an opening. The specimens were reduced to about 60% of the full scale size and were constructed to measure the result of the experimental variable regarding the existence of a lintel beam. To perform this study, the static repeated loading test was performed. According to the existence or absence of a lintel beam, the structural capacities and behavioral differences of the shear wall system were compared. The test results of this study showed that the specimen with a lintel beam underwent the seismic performance with an ultimate strength and ductility capacity better than the specimen without a lintel beam.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.30-30
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• 2011

국내의 내진설계 기준은 1988년에 처음 도입되었으며, 최근 점차 강화되고 있는 실정이다. 공동주택에 주로 적용되는 전단벽식 구조시스템에서 증가된 지진력에 저항하기 위해서는 벽량과 철근이 증가하게 되어 공사비가 상승하게 된다. 이러한 단점을 보완하기 위한 제진설계의 필요성이 대두되고 있는 실정인데, 기존의 제진장치는 주로 가새형 또는 벽체형을 대부분이라 평면계획에 제약이 있다. 따라서 전단벽식 구조의 공동주택의 제진설계 시에는 우리나라와 같은 중 약진 지역에 적합하고 저렴한 비용으로 충분한 내진성능과 평면의 가변성을 확보할 수 있는 댐퍼의 선택이 필요하다. 본 연구의 목적은 기존의 가새형 및 벽체형 제진장치의 국내 공동주택 적용시의 문제점인 평면의 가변성 확보에 유리하고, 수동형 제진장치의 장점을 추구할 수 있는 마찰댐퍼를 삽입한 커플링보 제진시스템의 내진성능을 조사하는 것이다. 내진성능을 평가하기 위해서 실대형 커플링보 실험체를 계획하고 제작하였다. 실험체는 2개로 구성되어 있으며, 하나는 기존의 철근배근 상세를 갖는 철근콘크리트 커플링보 실험체와 커플링보에 마찰댐퍼가 삽입된 실험체이다. 횡하중에 대한 성능을 평가하기 위해서 유사정적 반복가력실험을 실시하였다. 엑츄에이터로부터 실험체 상보의 가력지그를 통해 하중이 전달되도록 하였으며, 가력은 최초 0.25%의 층간변형각부터 변위제어를 통해 목표 층간변형각인 1.5% 이상까지 진행되도록 하였다. 실험결과, 두 실험체의 이력곡선과 에너지 흡수능력을 평가하였다. RC 실험체는 핀칭현상이 관찰되었고, 가력이 진행됨에 따라 커플링보와 벽체에서의 균열이 확산되어 종국적으로 취성적인 커플링보의 전단파괴가 발생하였다. 마찰댐퍼를 삽입한 실험체는 계획된 마찰거동이 잘 발휘되어 목표 층간변형각인 1.5%까지 이선형거동이 잘 나타났다. 최대 내력은 RC 실험체가 3배 이상 크지만, 누적층간변형각에 따른 에너지 흡수능력은 마찰댐퍼 실험체가 2배 이상 우수한 결과를 보였으며, 커플링보 및 벽체에서의 균열이 매우 저감되었다.

• Magazine of the Korea Concrete Institute
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• v.9 no.3
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• pp.137-147
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• 1997

Interface shear strength of' concrete under static loading and deterioratiion of interface strength by fatigue loading in shear were experimentally investigated using composite beam test specimens. Thirteen beams were constructed. Five composite beams were tested statically until interface delaminations were observed in the static tests. Seven composite beam and one monolithically cast beam were subjected to two to three million cycles of fatigue load. Test variables were interface roughness, interface shear reinforcement, and presence of interface bond. The average interface shear strength of the composite beams with bonded-rough interface was 6, 060 kPa. No interface delamination was observed after cycling for the composite beams with bonded - rough interface and interface bond was not influenced by repeated application of the shear stress of 2.000 kPa(about 1/3 of the static interface shear strength). Smooth interface and unbonded-rough interface with shear reinforcement deteriorated under repeated shear loading.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.165-170
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• 2008

This study discusses the inelastic behavior of single-layer latticed dome, composed of tubular truss member and newly proposed joint sections, through loading test on the scale-down structure. The loading test was performed under displacement control conditions, using loading transfer system for the same value of point loads on all joints. Maximum applied load was nearly 1.6 times of the design load, and inelastic buckling occured beyond compressive yeilding in some members. The displacement of structure was maimtained upto the limit of oil jack. The behavior of latticed dome from the loading test was analyzed on the view of structural design practice.

• Journal of Korean Society of Steel Construction
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• v.18 no.5
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• pp.607-614
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• 2006

The composite metal deck plate system has been widely used of late for office structures. However, composite floor decks are bored imprudently for installation in building equipment. In this study, experimental investigations of bored composite steel deck slabs were performed to evaluate the flexural capacity of each specimen. The variables set were the shapes and positions of the openings in the composite slabs. The results were analyzed in the form of load-displacement graphs and with respect to the ductility and energy dissipation capacity ofeach specimen to evaluate its structural capacity.

• Journal of Korean Society of Steel Construction
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• v.21 no.2
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• pp.145-154
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• 2009

This study discusses the inelastic behavior of single-layer latticed dome, which consists of a tubular truss member and newly proposed joint sections, through a loading test on a scaled-down structure. The loading test was performed under displacement control conditions, using loading transfer system for the same value of point loads on all joints. The maximum applied load was nearly 1.6 times of the design load, and structural failure occurred after exceeding the compressive yielding in some members. Structural displacement was maintained up to the limit of the oil jack. The behavior of the latticed dome from the loading test was analyzed according to the order of loading steps.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.5
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• pp.23-32
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• 2012

Research on steel plate concrete (SC) structures for the modularization of nuclear power plants have been performed recently in Korea. In this study, the seismic capacity and stiffness characteristics of unstiffened SC shear walls under the effects of earthquakes were investigated through static pushover tests. Failure modes, sectional strength, and stiffness characteristics of SC structures under lateral loads were inspected by analyzing the experimental results. The strengths obtained by the experiments were also compared with those derived by the design code of the SC structures. One of the main failures of unstiffened SC shear walls was found to be the type of bending shear failure due to the debonding of the steel plate at the concrete interface. The ductility capacity of SC structures was also confirmed to be improved, which is considered to be a confining effect on steel plates in the longitudinal behavior of SC structures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.341-347
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• 2018

The purpose of this study is to develop a new type of hybrid artificial reef that can solve the problems of construction, installation and operation of existing concrete type and steel type artificial reef, and to evaluate basic structural performance through static loading test. For this purpose, we evaluated the strengths and weaknesses of concrete type and steel type artificial reef in literature, and developed a new type of hybrid artificial reef which can effectively overcome the problems of each artificial reefs while maintaining the advantages of two artificial reefs as an alternative respectively. In order to evaluate the merits of the proposed hybrid artificial reef, it was confirmed that the possibility of securing the convenience of the proposed hybrid artificial reef in the field and the possibility of securing the desired advantages were confirmed. Also, the static loading test was performed to evaluate the basic structural performance of the artificial reef. Through the above study, it was confirmed that the developed hybrid artificial reef exhibited proper structural performance while securing easiness of making and assemble.mm) can be predicted to have a low value up to 60% of the strength of cylinders without reinforcement.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.4
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• pp.81-90
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• 2020

A textile and capillary tube composite panel(TCP) was developed to simultaneously retrofit the seismic performance and the energy efficiency (e.g. heating or insulation performance) of existing unreinforced masonry (URM) buildings. TCP is a light-weight mortar panel in which carbon textile reinforcements and capillary tubes are embedded. Textile reinforcements plays a role of seismic retrofit and capillary tubes that hot water circulates contribute to the energy retrofit. In this paper, the static cyclic loading tests were performed on the masonry walls with/without TCP to understand the seismic retrofit effect of TCP retrofit and the results were summarized. The results of the test showed that the TCP contributed to increase the capacity of the Shear strength and ductility of the URM walls. In addition, the deformation of the wall after cracking was substantially controlled by the carbon textile.