• 한국지진공학회논문집
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• 제10권3호
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• pp.77-84
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• 2006

비보강 조적조는 비균일 재료로 이루어진 합성재료에 가까우므로 그 거동이 하중종류와 구조물의 손상 정도에 따라서 매우 달라지게 된다. 본 연구에서는 여러 차례의 모의 지진을 받는 구조물의 손상거동이 어떻게 전개되어 가는지 살펴보는 간단한 방법을 제시한다. 특히, 시간영역 자료를 여러 구간으로 나누어서 주파수가 어떻게 변화해 가는지 살펴보는 부분 FFT방법을 이용하였다. 또한, 주파수와 강도와의 관계식을 이용하여 단자유도계의 이선형모델도 유도하였다. 본 연구에서 제시하는 이러한 방법들을 이용하여 비보강 조적조의 비탄성 성질들을 합리적으로 구할 수 있었다.

• Earthquakes and Structures
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• 제10권2호
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• pp.351-366
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• 2016

The structural collapse of masonry structure under dynamic loading displays many possible failure mechanisms often related to interaction between structural components. Roof collapse is one of the major damage mechanisms observed in masonry structures during an earthquake. Better connection between the roof diaphragm and walls may be preventing roof collapse, but it can affect other failure mechanisms. In spite of this fact, less attention has been paid to the influence of the roof diaphragm effect on masonry structures and little research has been implemented in this field. In the present study, the roof diaphragm effect on the unreinforced masonry structure under dynamic loading has been experimentally investigated. Three one-quarter scale one-story adobe masonry house models with different roof conditions have been tested by subjecting them to sinusoid loading on a shaking table simulator. Phenomena such as failure pattern, dynamic performance of masonry structure were examined.

• 콘크리트학회지
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• 제7권4호
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• pp.71-83
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• 1995

• Earthquakes and Structures
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• 제2권3호
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• pp.233-256
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• 2011

This paper investigates the applicability of newly developed Cu-Al-Mn shape memory alloy (SMA) bars to retrofitting of historical masonry constructions by performing quasi-static tests of half-scale brick walls subjected to cyclic out-of-plane flexure. Problems associated with conventional steel reinforcing bars lie in pinching, or degradation of stiffness and strength under cyclic loading, and in their inability to restrain residual deformations in structures during and after intense earthquakes. This paper attempts to resolve the problems by applying newly developed Cu-Al-Mn SMA bars, characterized by large recovery strain, low material cost, and high machinability, as partial replacements for steel bars. Three types of brick wall specimens, unreinforced, steel reinforced, and SMA reinforced specimens are prepared. The specimens are subjected to quasi-static cyclic loading up to rotation angle enough to cause yielding of reinforcing bars. Corresponding nonlinear finite element models are developed to simulate the experimental observations. It was found from the experimental and numerical results that both the steel reinforced and SMA reinforced specimens showed substantial increment in strength and ductility as compared to the unreinforced specimen. The steel reinforced specimen showed pinching and significant residual elongation in reinforcing bars while the SMA reinforced specimen did not. Both the experimental and numerical observations demonstrate the superiority of Cu-Al-Mn SMA bars to conventional steel reinforcing bars in retrofitting historical masonry constructions.

• 한국전산구조공학회논문집
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• 제31권6호
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• pp.283-291
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• 2018

본 연구는 지진에 저항하는 부재인 비보강 조적벽체로 구성된 건물의 내진성능평가에 활용되는 비선형 정적해석을 위한 비보강 조적벽체의 해석모델을 수립하고자 하였다. 본 연구의 해석모델은 비보강 조적벽체의 휨거동을 모사하기 위한 파이버 요소와 비보강 조적벽체의 전단에 대한 응답을 예측하기 위한 전단스프링 요소로 구성된다. 본 논문은 먼저 제안하고 있는 모델의 형상에 대해서 설명하고, 기존에 행해진 조적조 프리즘의 실험결과로부터 얻은 응력-변형률 곡선을 근거로 파이버와 전단스프링 요소의 물성치에 대한 결정 방법을 설명한다. 제시하고 있는 모델은 비선형 정적 해석결과와 다른 연구자들에 의해 수행된 실험결과를 비교하여 타당성을 검증한다. 해당 모델은 최대강도, 초기강성, 그리고 이들로부터 얻어지는 비보강 조적벽체의 하중-변위 곡선을 적절하게 모사하고 있다. 또한, 해석모델이 비보강 조적벽체의 파괴모드를 예측할 수 있는 것으로 나타난다.

• Structural Engineering and Mechanics
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• 제42권5호
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• pp.609-629
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• 2012

This study deals with the assessment of low and mid rise multi-story buildings made of stone and /or brick, composite steel and masonry slabs from the sixties, known to be vulnerable to seismic hazard using the "vulnerability index" method based on buildings survey following Ain Temouchent (1999) and Boumerdes (2003) earthquakes, from where vulnerability curves are constructed using the translation method. The results obtained for the case study confirm what has been observed in situ.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.178-185
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• 2000

A set of tests were accomplished in order to get better insight of the basic material properties of masonry made of normal concrete brick and different type of mortar compositions. Three different types of test were performed. Masonry unit and prism were tested by compressive strength test, Masonry wallets were tested by compressive strength test. Masonry wallets were tested in diagonally under tension. A significant influence of different mortar compositions on compression strength of masonry prism was observed, The tests have shown that for diagonal compression three different mode of failure were possible : tension crack along the loaded diagonal sliding along a mortar joint and combined sliding and diagonal crack according to the adhesive strength of a mortar.

• Earthquakes and Structures
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• 제26권5호
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• pp.363-382
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• 2024

In India's north-eastern region, low-strength autoclaved aerated concrete (AAC) blocks are widely used for constructing masonry structures, making them susceptible to lateral forces due to their low tensile and shear strengths and brittleness nature. The absence of earthquake-resistant attributes further compromises their resilience during seismic events. An economically viable solution to enhance the structural integrity of these masonry structures involves integrating steel wire mesh within the masonry mortar joints. This study investigates the in-plane shear behaviour of AAC masonry by employing two approaches: incorporating steel wire mesh within the masonry bed joint "BJ" and the masonry bed and head joint "BHJ". These approaches aim to augment strength and ductility, potentially serving as earthquake-resistant attributes in masonry structures. Three distinct variations of steel wire mesh and three reinforcing arrangements, i.e. (-), (L) and (Z) arrangement were employed to reinforce the two approaches. The test result reveals a significant enhancement in structural performance upon inclusion of steel wire mesh in both reinforcing approaches, with the "BHJ" approach outperforming the "BJ" approach and the unreinforced masonry, along with increase in capacity as the wire mesh size increases. Furthermore, the effectiveness of the reinforcing arrangement is ranked with the (Z) arrangement showing the largest performance, followed by the (L) and (-) arrangement.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.182-185
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• 2006

The objective of this study is to evaluate residual seismic capacity of Unreinforced Masonry(URM) walls which were damaged by earthquake through the measurement of frequency. Three URM walls which made the shape ratio(1/h, 1.0, 1.5, 2.0)to be a variable were tested for the objective. It was seen that the natural frequency decreased with growing at rotation angle. Also, this study found out that residual seismic capacity and natural frequency of URM walls is correlative.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.210-213
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• 2006

The objectives of this study is to find out the relationship of crack width and residual seismic capacity of Unreinforced Masonry(URM) walls which were damaged by earthquake. Three URM walls which made the shape ratio(1/h, 1.0, 1.5, 2.0)to be a variable were tested for the objective. It was seen that the crack width increased with growing at rotation angle. Also, this study found out that failure mode affects crack type of URM. In other words, horizontal and vertical crack was increased in rocking and sliding failure mode respectively.