• Structural Engineering and Mechanics
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• 제52권6호
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• pp.1177-1191
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• 2014

Reinforced concrete (RC) shear walls are one of the most commonly used lateral-load resisting systems in high-rise buildings. RC Parallel redundancy walls studied herein consist of two parts nested to each other. These two parts have different mechanical behaviors and energy dissipation mechanisms. In this paper, experimental studies of four 1/2-scale specimens representing this concept, which are subjected to in-plane cyclic loading, are presented and test results are discussed. Two specimens consist of a wall frame with barbell-shaped walls embedded in it, and the other two consist of a wall frame and braced walls nested each other. The research mainly focuses on the failure mechanism, strength, hysteresis loop, energy dissipation capacity and stiffness of these walls. Results show that the RC parallel redundancy wall is an efficient lateral load resisting component that acts as a "dual" system with good ductility and energy dissipation capacity. One main part absorbs a greater degree of the energy exerted by an earthquake and fails first, whereas the other part can still behave as an independent role in bearing loads after earthquakes.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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• pp.90-94
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• 1992

ACI318-89 Recommened that when the specified compressive strength of concrete in a column is greater than 1.4 times that specified for a floor system, top surface of the column concrete shall extend 2ft (600mm) into the slab from the face of column to avoid unexpected brittle failure. The major variables are extension distance, compressive strength of concrete (f'c), shear confinement ratio(Vs), and loading types. The test results showed that the load capacity of the specimen subjected to monotonic loading had more than that of the specimen subjected to one way cyclic loadings. The failure models of specimens under cyclic loading were concentrated at 5∼20cm apart region from beam-column joint face. Ducility index(μf) are increased with increasing of shear confinement ratio. The specimen with 2ft extension distance shows more ductility than specimen with lft extension distance.

• Earthquakes and Structures
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• 제7권5호
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• pp.753-777
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• 2014

This study investigates the behavior of precast concrete cantilever wall systems with new vertical connections under cyclic loading. C-type steel connections for PC wall systems are proposed for the transfer of bending moments between walls in the vertical direction, whereas a shear key in the center of the wall is prepared to transfer shear forces by bearing pressure. The proposed connections are assembled easily because the directions of the slots are different at the edges of the walls. Structural performance characteristics such as the strength, ductility, and failure modes of test specimens were investigated. The longitudinal reinforcing steel bars, which are connected to the C-type connections, yielded first. Ultimate deformation was terminated owing to premature failure of the connections. The strength and deformation obtained from the cross-sectional analysis were generally similar to experimental data.

• Steel and Composite Structures
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• 제28권2호
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• pp.123-138
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• 2018

Eccentrically braced frames (EBF) represent an optimal structural solution for seismic prone areas, being able to provide high dissipative capacity and good elastic stiffness, to withstand strong seismic events without significant loss of bearing capacity and to avoid damage to non-structural elements in case of low and moderate earthquakes. The accurate knowledge of the cyclic behaviour of the dissipative links, characterizing the whole performance of EBFs, is required to optimize the structural properties and to refine the design techniques adopted for multi-storey buildings' analysis. Reliable numerical models for the links, at the same time requiring a limited computational effort, are then needed. The present work shows the results of a wide experimental test campaign executed on real-scale one storey/one bay frames with horizontal and vertical links, together with the elaboration of a simple semi-analytical model for the quick representation of the cyclic behaviour of shear links.

• Earthquakes and Structures
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• 제21권6호
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• pp.653-667
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• 2021

In this study, cyclic loading tests were conducted on the precast concrete (PC) wide beam (WB)-column joints. Two beam-column joint specimens were fabricated with the arrangement and anchorage details of the reinforcing bars penetrating the beam and column as variables. Through a cyclic loading test, the lateral load-story drift ratio responses, seismic performance characteristics (e.g., ductility, overstrength factor), energy dissipation, strength and stiffness degradations of each specimen were compared and analyzed based on the various indices and the current structural codes (ACI 318-19 and ACI 374.1-05 report). In addition, the shear lag effect was confirmed through the gauge values of the PC beam, and the differences in seismic performance between the specimens were identified on that basis.

• 국제초고층학회논문집
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• 제10권3호
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• pp.211-218
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• 2021

A new type of earthquake resilient reinforced concrete (RC) shear wall structure, installed with replaceable coupling beams and replaceable corner components at the bottom of wall piers, is proposed in this study. At first, the mechanical behavior of replaceable components, such as combined dampers and replaceable corner component, is studied by cyclic loading tests on them. Then, cycling loading tests are conducted on one conventional coupled shear wall and one new type of coupled shear wall with replaceable components. The test results indicate that the damage of the new type of coupled shear wall concentrates on replaceable components and the left parts are well protected. Finally, a case study is introduced. The responses of one conventional frame-tube structure and one new type of structure installed with replaceable components under the wind and the earthquake are compared, which verify that the performance of new type of structure is much better than the conventional structure.

• 한국지반신소재학회논문집
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• 제10권1호
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• pp.19-28
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• 2011

본 논문에서는 동결-융해 반복작용이 화강풍화토의 압축강도 특성에 미치는 영향에 관한 내용을 다루었다. 이를 위해 세립분 함유량을 변화시켜 다양한 시료조건을 조성한 후 동결-융해 시험 환경을 조성한 후 동결-융해 반복작용 사이클을 강제 부가하였다. 시료에 대한 평면변형률압축시험 및 미세입자구조의 변화를 가시적으로 확인할 수 있는 전자주사현미경(SEM) 촬영 및 분석을 수행하였다. 먼저, SEM 분석 결과 화강풍화토는 동결-융해 반복작용에 노출될 경우 입자들이 뭉쳐 간극이 증가하는 추세를 보였다. 한편, 압축강도 특성의 경우 세립분 함유량에 따라 다소 차이를 보이는 것으로 나타났는데 세립분 함유량이 적은 경우에는 강도저하 현상을, 세립분 함유량이 많은 경우에는 강도 증가 현상을 보임을 확인할 수 있었다.

• 콘크리트학회논문집
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• 제22권6호
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• pp.805-816
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• 2010

축소모델의 지진모의실험을 위해서는 실물 실험체의 구조거동을 축소모델 실험체가 잘 모사하는지 상사성 확인이 필수적이다. 본 논문에서는 2층 RC 벽식구조 실험체의 반복 횡가력 실험을 통해 강도, 연성과 같은 전체거동과 휨, 전단, 들뜸과 같은 국부거동의 결과를 나타내었다. 인방보의 유무에 따른 3 : 5 실물 실험체와 1 : 7 축소모델 실험체를 비교 분석 하였으며, 1 : 7 축소모델 실험체가 실물 실험체의 전체거동과 국부거동에 대해서 대체로 잘 모사하고 있음을 확인하였다.

• 한국전산구조공학회논문집
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• 제25권6호
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• pp.525-532
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• 2012

근래에 지어진 건축물의 경우 지진에 대한 안전성을 확보하고 있지만 1983년 개정이전의 건축물은 내진설계가 미반영 되어 있어 지진에 대해 매우 취약하다. 본 연구에서는 내진성능이 부족한 기존 건축물의 지진 발생 시의 안전성 확보를 위한 내진보강 방안으로 격자강판 내진보강벽을 제안한다. 축력과 반복수평력을 받는 성능실험을 수행하였으며, 실험체는 벤치마크 용도로 순수 철근콘크리트 프레임(BM-RC)과 프레임 내부에 격자강판 내진보강벽(SW-RC)을 설치한 2개의 실험체를 제작하여 실험을 수행하였고, 축력과 횡하중 가력을 위하여 500kN용량의 엑츄에이터 2대와 2,000kN용량의 엑츄에이터 1대를 사용하였다. 실험결과를 통해 벤치마크 실험체와 비교하여 강도, 강성, 연성 및 에너지소산능력을 평가하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 봄 학술발표회 논문집
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• pp.154-159
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• 1993

To develop the detailing methods at the ends of flexural shear walls. which are satisfying the ductility requirement corresponding to R = 3.5 and capable of improving the consturctibility, tests of ten isolated cantilever shear walls were carried out under the load condition comprising the cyclic lateral and constant vertical loads. major test parameters include the way of detailing and arrangement of transverse reinforcement in the boundary elements at the ends of walls, and placement of vertical reinforcement. From tests, comparable ductile behavior in test specimens incorporating the channel type of open hoops, compared with those incorporating the regular type of closed hoops, was observed.