• 한국지진공학회논문집
• /
• 제16권6호
• /
• pp.37-46
• /
• 2012

In Korea, most existing school buildings have been constructed with moment frames with un-reinforced infill walls designed only considering gravity loads. Thus, the buildings may not perform satisfactorily during earthquakes expected in Korea. In exterior frames of the building, un-reinforced masonry infill walls with window openings are commonly placed, which may alter the structural behavior of adjacent columns due to the interaction between the wall and column. The objective of this study is to evaluate the seismic performance of existing school buildings according to the procedure specified in ATC 63. Analytical models are proposed to simulate the structural behavior of columns, infill walls and their interaction. The accuracy of the proposed model is verified by comparing the analytical results with the experimental test results for one bay frames with and without infill walls with openings. For seismic performance evaluation, three story buildings are considered as model frames located at sites having different soil conditions ($S_A$, $S_B$, $S_C$, $S_D$, $S_E$) in Korea. It is observed that columns behaves as a short columns governed by shear due to infill masonry walls with openings. The collapse probabilities of the frames under maximum considered earthquake ranges from 62.9 to 99.5 %, which far exceed the allowable value specified in ATC 63.

• 한국주거학회:학술대회논문집
• /
• 한국주거학회 2005년도 추계학술대회 논문집
• /
• pp.167-170
• /
• 2005

This study aims to develop a detachable 'Infill Components' applicable to open housing. Recently, the need for innovative housing methods is increasing because of the environmental preservation issues and the need for favorable housing stock resulting from the increased housing supply ratio. In order to maintain favorable housing stock, there has to has a to be a shift from typical plans and construction methods for mass production to those with some identity, which may satisfy various needs of dwellers. In this light, the Ramen structure has become popular owing to the growth of remodelling market, and construction companies tend to adopt flexible type multi-family housings to increase sales by appealing to their customers. However, there are few domestic studies on the Infill components for the change of structure. As a result, further studies may have to be based on the case study. The purpose of this research is to provide fundamentals for the development of infill components corresponding to the structural change, especially for the development of partition walls that can be easily moved by dwellers. By reviewing problem of construction, arrangement of the movable partition wall system and door system which has within wring in the first Experimental Open Housing in Korea at KICT(KOHP21), this research provides the fundamentals for developing a movable partition wall acceptable to the dwellers who may want to remodel the interior to meet the needs of themselves.

• Composites Research
• /
• 제35권6호
• /
• pp.463-468
• /
• 2022

상용 FFF (Fused filament fabrication) 3D 프린터로 제조된 탄소 단섬유강화 나일론 복합재료 구조의 내부 채움 패턴(Infill pattern)의 높은 공극률은 프린팅 된 구조의 기계적 성능을 결정한다. 본 연구는 프린팅 된 구조의 내부 채움 패턴의 공극률을 줄여서 기계적 특성을 개선하기 위해 사각형 내부 채움 구조로 제작된 Onyx 복합 재료 시편의 열압밀 조건에 따른 시편의 기계적 성능을 실험적으로 평가하고, 가장 우수한 기계적 물성을 유도하는 열압밀 공정 조건(145℃, 4 MPa, 12 min)을 찾았다. 현미경 관찰결과 열압밀 후처리를 겪은 복합재료 시편의 내부 채움 공극률이 효과적으로 줄어듦을 확인하였다. 후처리된 시편의 기계적 성능을 확인하기 위해, 후처리를 하지 않은 대조군 시편과, 후처리 후 밀도와 치수를 동일하게 설정하여 출력한 시편과 함께 인장시험 및 3점 굽힘시험을 수행하여 기계적 물성을 비교한 결과 열압밀 후처리를 수행한 경우 기계적 물성이 효과적으로 개선되는 것을 확인하였다.

• Earthquakes and Structures
• /
• 제19권3호
• /
• pp.157-174
• /
• 2020

The in-situ pushover test differs from the shake-table test because it is performed outdoors and thus its size is not restricted by space, which allows us to test a full-size building. However, to build a new full-size building for the test is not economical, consequently scholars around the world usually make scale structures or full-scale component units to be tested in the laboratory. However, if in-situ pushover tests can be performed on full-size structures, then the seismic behaviors of buildings during earthquakes can be grasped. In view of this, this study conducts two in-situ pushover tests of reinforced concrete (RC) buildings. One is a masonry-infilled RC building with openings (the openings ratio of masonry infill wall is between 24% and 51%) and the other is an RC building without masonry infill. These two in-situ pushover tests adopt obsolescent RC buildings, which will be demolished, to conduct experiment and successfully obtain seismic capacity curves of the buildings. The test results are available for the development or verification of a seismic evaluation model. This paper uses ASCE 41-17 as the main evaluation model and is accompanied by a simplified pushover analysis, which can predict the seismic capacity curves of low-rise buildings in Taiwan. The predicted maximum base shear values for masonry-infilled RC buildings with openings and for RC buildings without masonry infill are, respectively, 69.69% and 87.33% of the test values. The predicted initial stiffness values are 41.04% and 100.49% of the test values, respectively. It can be seen that the ASCE 41-17 evaluation model is reasonable for the RC building without masonry infill walls. In contrast, the analysis result for the masonry infilled RC building with openings is more conservative than the test value because the ASCE 41-17 evaluation model is limited to masonry infill walls with an openings ratio not exceeding 40%. This study suggests using ASCE 41-17's unreinforced masonry wall evaluation model to simulate a masonry infill wall with an openings ratio greater than 40%. After correction, the predicted maximum base shear values of the masonry infilled RC building with openings is 82.60% of the test values and the predicted initial stiffness value is 67.13% of the test value. Therefore, the proposed method in this study can predict the seismic behavior of a masonry infilled RC frame with large openings.

• 토지주택연구
• /
• 제2권4호
• /
• pp.397-406
• /
• 2011

본 연구는 지속 가능한 주거환경을 구현하기 위한 실천전략의 하나로서 100년의 내구성과 가변성을 갖는 장수명 공동주택 표준모델에 실질적으로 적용할 수 있는 다양한 가변요소 시스템 개발을 주된 목적으로 한다. 연구방법으로는 장수명 공동주택 표준모델을 적용한 '실험주택'을 대상으로 개발한 각종 가변요소 시스템과 기술들을 통합하고 단계별 현장 적용성 평가, 전문가 의견조사 및 설문조사 등을 실시하였다. 본 연구는 총 3단계로 구분하여 수행하였다. 1단계에서는 고정요소인 전체 구조체와 가변요소인 건식외벽, 창호 등을 시공함과 동시에, 전용면적 $84m^2$에 가변요소 시스템을 시공하면서 현장 적용성을 평가하였다. 2단계에서는 전용면적 $50m^2$ 3세대를 대상으로 국내 최초로 수직통합형 세대(전용$50m^2$+전용$40m^2$)와 수평확장형 세대(전용$50m^2$+전용$10m^2$)를 대상으로 다양한 가변요소시스템의 현장 적용성 평가를 실시하였다. 3단계에서는 본 연구에서 개발한 건식 온돌의 현장검증을 위한 각종 성능평가 실험과 기 사용한 주택부품의 해체, 이동 및 재시공을 통한 3R 구현 정도 파악 등 실용성 제고를 위한 다양한 검증 작업도 함께 실시하였다.

• Structural Engineering and Mechanics
• /
• 제16권6호
• /
• pp.675-693
• /
• 2003

In order to consider the modified seismic response of framed structures in the presence of masonry infills, proper models have to be formulated. Because of the complexity of the problem, a careful definition of a diagonal pin-jointed strut, able to represent the horizontal force-interstorey displacement cyclic law of the actual infill, may be a solution. In this connection the present paper shows a generalized criterion for the determination of the ideal cross-section of the strut mentioned before. The procedure is based on the equivalence between the lateral stiffness of the actual infilled frame scheme during the conventional elastic stage of the response and the lateral stiffness of the same frame stiffened by a strut at the same stage. Unlike the usual empirical approaches available in the literature, the proposed technique involves the axial stiffness of the columns of the frame more than their flexural stiffness. Further, the influence of the bidimensional behaviour of the infill is stressed and, consequently, the dependence of the dimensions of the equivalent pin-jointed strut on the Poisson ratio of the material constituting the infill is also shown. The proposed approach is extended to the case of infills with openings, which is very common in practical applications.

• Computers and Concrete
• /
• 제22권4호
• /
• pp.383-393
• /
• 2018

Infill wall strengthening method has been widely used for seismic strengthening of deteriorated reinforced concrete (RC) frame structures with non-seismic details. Although such infill wall method can ensure sufficient lateral strengths of RC frame structures deteriorated in seismic performances with a low constructional cost, it generally requires quite cumbersome construction works due to its complex connection details between an infill wall and existing RC frame. In this study, an advanced seismic strengthening method using externally-anchored precast wall panels (EPCW) was developed to overcome the disadvantage inherent in the existing infill wall strengthening method. A total of four RC frame specimens were carefully designed and fabricated. Cyclic loading tests were then conducted to examine seismic performances of RC frame specimens strengthened using the EPCW method. Two specimens were fully strengthened using stocky precast wall panels with different connection details while one specimen was strengthened only in column perimeter with slender precast wall panels. Test results showed that the strength, stiffness, and energy dissipation capacity of RC frame specimens strengthened by EPCWs were improved compared to control frame specimens without strengthening.

• 교육시설 논문지
• /
• 제19권4호
• /
• pp.21-28
• /
• 2012

This study proposes a procedure for evaluating the seismic performance and retrofit of a typical reinforced building (R/C) school buildings contructed in the 1980s. The procedure is derived from the Japanese Standard for Evaluation of Seismic Capacity of Existing Reinforced Concrete Buildings and Nonlinear Static Procedure (NSP) specified in Federal Emergency Management Agency (FEMA 356). In this study, the Japanese Standard was applied for evaluating the additionally required seismic performance in the existing school building. Cast-in-place (CIP) reinforced concrete infill walls and steel braces were used to seismically retrofit the existing school building located in the region of Hongsung in Chungnam. In the pushover analysis, i.e NSP, the hinge properties of columns, beams, infill walls and steel braces were carefully calibrated based on the existing experiment results in the available literatures. The predicted seismic performance for the retrofitted building was compared to that for the virgin building. Based on the seismic evaluation with the Japanese Standard and the FEMA 356 criteria, the addition of CIP reinforced concrete infill walls and steel braces have superior constructablility and can improve effectively the seismic performance of the existing school buildings constructed in 1980s.

• 한국주거학회논문집
• /
• 제21권3호
• /
• pp.67-76
• /
• 2010

The purposes of this study are to understand residents' needs in regard to living space and to suggest how to provide layout options for the infill, based on their needs, so that the residents can change their living space to suit their own need. This study analyzed residents' needs in terms of living spaces through literature reviews on apartment remodeling and related previous studies. The results are as follows: First, the residents remodeled the various infill, and remodeling works are then classified into five infill groups according to the flexible features: 1) structural elements, such as flooring, ceilings, interior walls, and windows/doors; 2) equipment elements, such as lighting and electricity, electrical wiring, heating arrangements, and water supply & drainage systems: 3) finishing material elements, such as finishing materials for floors, walls, and ceilings, skirting boards, moldings, and art walls; 4) furniture elements, such as built-in wardrobes, storage closets, and kitchen cabinets; and 5) bathroom facility elements such as faucets and sinks. Second, based on the remodeling features, four ways to provide options can be suggested. 1) options are provided for each room; 2) options are provided in connection with structural elements; 3) options are provided for each finishing material element; and 4) options are provided with the combinations of different bathroom facilities.

• Steel and Composite Structures
• /
• 제26권3호
• /
• pp.361-373
• /
• 2018

This paper presents the development of finite element (FE) models to simulate the behavior of diagonally stiffened steel plate shear wall systems (SPSWs) with differently shaped openings subjected to a cyclic load. This walling system has the potential to be used for shear elements that resist lateral loads in steel-framed buildings. A number of $\text\tiny{^1/_2}$-scale one-story buildings that were un-stiffened, stiffened and stiffened with opening SPSWs are modeled and simulated using the finite element method based on experimental data from previous research. After validating the finite element (FE) models, the effects of infill plate thickness on the cyclic behavior of steel shear walls are investigated. Furthermore, triple diagonal stiffeners are added to the steel infill plates of the SPSWs, and the effects are studied. Moreover, the effects of a number of differently shaped openings applied to the infill plate are studied. The results indicate that the bearing capacity and shear resistance are affected positively by increasing the infill plate thickness and by adding triple diagonal stiffeners. In addition, the cyclic behavior of SPSWs is improved, even with an opening in the SPSWs.