• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.69-72
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• 2006

The objective of this study is to find out the shear capacity of URM wall and the variables that affect the shear capacity of URM wall such as the opening and the aspect ratio, considering four kinds of failure modes, sliding shear failure, toe crushing failure, and diagonal shear failure. The main varialble is the shape of opening of URM walls. First URM has one door, second has one window, third hase one door and one window, the last has two windows. The test results of URM with openings show that the specimens are governed by rocking failure mode.

• Computers and Concrete
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• 제19권2호
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• pp.179-189
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• 2017

Concrete shear walls are one of the major structural lateral resisting systems in buildings. In some cases, due to the change in the occupancy of the structure or functional requirements like architectural and even mechanical ones, openings need to be provided and installed in structural walls after their construction. Providing these openings may significantly influence the structural behavior of the constructed wall. This paper considers the results of a nonlinear finite element analysis of shear walls with opening strengthened by carbon fiber reinforced polymer (CFRP) strips with different configurations. Details of bond-slip constitutive model of link elements to simulate the connections of FRP strips to concrete surface is presented. The proposed model in this research has been validated using experimental results available in the literature. The results indicated that the proposed configuration of CFRP strips significantly improved the lateral resistance and deformation capacity of the shear walls with opening.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.244-247
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• 2004

This study proposes the design method of the shear walls with openings using strut-and-tie models. Strut-and-tie models are constructed for opening near the middle of the wall and for opening near a wall boundary. These enables an admissible load path for the horizontal earthquake force. These models consider the size and position of opening effectively. Each model is suitable for the seismic response corresponding with lateral forces in a given direction to be considered. The proposed models are good agreements with nonlinear finite element analysis(DIANA) results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.234-237
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• 2006

A series of three shear wall specimens was tested under constant axial stress and reversed cyclic lateral loading in order to evaluate the seismic retrofit that had been proposed for the shear wall with the opening induced by remodeling. One of these specimens was tested in the as-built condition and the other two were retrofitted prior to testing. The retrofit involved the use of carbon fiber sheets and steel plates (thickness of 3mm) over the entire face of the wall. The test results show that the ultimate failure modes of the specimens were found to be shear fracture of the wall around the opening and two difference types of retrofitting strategy make the different effects of a rise in the strength of each specimen.

• Earthquakes and Structures
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• 제22권4호
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• pp.355-372
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• 2022

The study is part of an experimental program on full-scale Un-Reinforced Masonry (URM) wall panels strengthened with Textile reinforced mortars (TRM). Eight brick walls (two with and five without central opening), were tested under the diagonal tension (shear) test method in order to investigate the strengthening system effectiveness on the in-plane behaviour of the walls. All the URM panels consist of the innovative components, named "Orthoblock K300 bricks" with vertical holes and a thin layer mortar. Both of them have great capacity and easy application and can be constructed much more rapidly than the traditional bricks and mortars, increasing productivity, as well as the compressive strength of the masonry walls. Several parameters pertaining to the in-plane shear behaviour of the retrofitted panels were investigated, including shear capacity, failure modes, the number of layers of the external TRM jacket, and the existence of the central opening of the wall. For both the control and retrofitted panels, the experimental shear capacity and failure mode were compared with the predictions of existing prediction models (ACI 2013, TA 2000, Triantafillou 1998, Triantafillou 2016, CNR 2018, CNR 2013, Eurocode 6, Eurocode 8, Thomoglou et al. 2020). The experimental work allowed an evaluation of the shear performance in the case of the bidirectional textile (TRM) system applied on the URM walls. The results have shown that some analytical models present a better accuracy in predicting the shear resistance of all the strengthened masonry walls with TRM systems which can be used in design guidelines for reliable predictions.

• Computational Structural Engineering : An International Journal
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• 제1권2호
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• pp.117-130
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• 2001

Investigations of low-rice unbounded reinforced concrete shear walls with or without openings are performed with comparison of analytical and experimental results. Theoretical analysis is based on nonlinear finite element algorithm, which incorporates concrete failure criterion and nonlinear constitutive relationships. Studios focus on the effects of height-to-length ratio of shear walls, opening ratio, horizontal and vertical reinforcement radios, and diagonal reinforcement. Analytical solutions conform well with experimental results. Equations for cracking, yielding and ultimate loads with corresponding lateral displacements are derived by regression using analytical results and experimental data. Also, failure modes of low-rise unbounded shear walls are theoretically investigated. An explanation of change in failure mode is ascertained by comparing analytical results and ACI code equations. Shear-flexural failure can be obtained with additional flexural reinforcement to increase a wall's capacity. This concept leads to a design method of reducing flexural reinforcement in low-rise bounded solid shear wall's. Avoidance of shear failure as well as less reinforcement congestion leer these walls is expected.

• Structural Engineering and Mechanics
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• 제57권4호
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• pp.641-656
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• 2016

Reinforced concrete frame buildings with masonry infill walls are one of the most popular structural systems in the world. In most cases, the effects of masonry infill walls are not considered in structural models. The results of earthquakes show that infill walls have a significant effect on the seismic response of buildings. In some cases, the buildings collapsed as a result of the formation of a soft story. This study developed a simple method, called corner opening, by replacing the corner of infill walls with a very flexible material to enhance the structural behavior of walls. To evaluate the proposed method a series of experiments were conducted on masonry infill wall and reinforced concrete frames with and without corner openings. Two 1:4 scale masonry infill walls with and without corner openings were tested under diagonal tension or shear strength and two RC frames with full infill walls and with corner opening infill walls were tested under monotonic horizontal loading up to a drift level of 2.5%. The experimental results revealed that the proposed method reduced the strength of infill wall specimens but considerably enhanced the ductility of infill wall specimens in the diagonal tension test. Moreover, the corner opening in infill walls prevented the slid shear failure of the infill wall in RC frames with infill walls.

• 한국구조물진단유지관리공학회 논문집
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• 제11권5호
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• pp.71-80
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• 2007

기존 시멘트에 비해 우수한 인장변형성능을 가지는 고인성 시멘트 복합체(HPFRCC)를 보수, 보강에 적용 시키려는 연구가 최근 활발히 진행되고 있다. 본 연구에서는 HPFRCC의 일종인 ECC와 초속경 숏크리트인 MDF의 보강성능을 알아보고자 한다. 실험체는 실존하는 철근콘크리트 구조물의 전단벽을 1/2 축소하여 제작하였으며 개구부를 가지고 있다. 실험결과 WB-MDF, ECC는 WB-0.23에 비해 각각 28.4%, 48.4%의 강도증가를 보였으며, 특히 WB-ECC가 WB-MDF에 비해 연성면에서 우수하게 나타났다.

• 한국구조물진단유지관리공학회 논문집
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• 제11권4호
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• pp.51-61
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• 2007

건축의 증가나 자원의 효율적인 활용의 관점으로부터 기존 건축물에 대한 리모델링이 주목을 받고 있다. 리모델링 공사로 인해 기존벽에 개구부를 설치하는 경우 보강 방법을 검토 하는 것을 목적으로 철근콘크리트벽의 정적가력 실험을 실시하였다. 보강 방법은 개구부 주위의 탄소섬유시트 강판 부착으로 했다. 실험체는 실존하는 철근콘크리트 구조물을 1/2 축소 모델로 제작하였다. 실험결과 개구부 주위의 전단 파괴로 최종 파괴되었으며 보강 방법에 따라 내력의 상승 효과는 다르게 나타났다.

• 한국구조물진단유지관리공학회 논문집
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• 제11권3호
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• pp.77-86
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• 2007

건축물의 증가와 자원의 효율적인 활용의 목적으로 기존 건축물에 대한 리모델링이 주목을 받고 있다. 리모델링 공사로 인해 세대간 병합을 위해 기존 벽에 개구부를 설치하는 경우 개구부의 영향을 파악 하는 것을 목적으로 철근콘크리트 전단벽의 정적가력 실험을 실시했다. 그 결과 개구부 유무에 따른 파괴현상은 벽판에 형성된 압축지주의 단면적이 감소함으로써 다르게 나타났다. 특히 최대 내력은 개구부 설치에 따라 약 35%정도 감소되는 특성을 보였다. 이러한 경향은 강성 및 에너지 소산능력에서도 유사하게 나타났다.