• Steel and Composite Structures
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• 제22권1호
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• pp.79-89
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• 2016

Cold formed steel shear panel is one of the main components to bearing lateral load in low and mid-rise cold formed steel structures. This paper uses finite element analysis to evaluate the stiffness, strength and failure mode at cold formed steel shear panels whit steel sheathing and nonlinear connections that are under monotonic loading. Two finite element models based on two experimental model whit different failure modes is constructed and verified. It includes analytical studies that investigate the effects of studs and steel sheathing thickness changes, fasteners spacing at panel edges, one or two sides steel sheathing and height-width ratio of wall on the lateral load capacity. Dominant failure modes include buckling of steel sheet, local buckling in boundary studs and sheet unzipping in the bottom half of the wall.

• 한국지반환경공학회 논문집
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• 제23권9호
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• pp.25-31
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• 2022

Attaching shelf to retaining structure leads to a decrease in the total lateral earth pressure. This decrease enables the retaining structures to become more stable, to have small displacement, and to exhibit lower bending moments, the relief shelves effects are analyzed using FEM in order to understand how they stabilize cantilever wall in this study. Several models are varied by changing location and width of shelves to realize earth pressure and displacements of retaining wall. The displacement is getting smaller because earth pressure acting on shelf increases as shelves locations are lower and width is longer. The ground settlement variation effects caused by relief shelves are studied also. The ground settlement increases abruptly where shelf location is between of 0.5H and 0.625H, and settlement decreases suddenly where shelf width is between b/h=0.375 and b/h=0.500. The shelf significantly reduces earth pressure and movement of the wall. This decrease in the lateral pressure increases the retaining structure stability.

• 치과방사선
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• 제21권2호
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• pp.157-163
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• 1991

The author has evaluated the panoramic image of the maxillary sinus according to the skull position. The lead foils were attached to the five walls of the maxillary sinus and the inferior turbinate individually. The skull was located in three positions; standard position, 20㎜ forward position and chin-down position. The obtained results were as follows: 1. In standard position, the medial wall was superimposed upon most of the panoramic antral image. The anterior wall and the posterolateral wall were superimposed upon the medial half and the lateral third respectively. 2. In forward position, the width of the panoramic antral image was diminished generally. The anterior wall was superimposed upon most of the panoramic antral image and the posterolateral wall appeared narrowly at the most lateral portion of the panoramic antral image. 3. In chin-down position, there was no significant difference in comparison to the standard position. 4. Inferior turbinate was not superimposed upon the panoramic antral image.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.65-70
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• 2001

The compression toe of structural wall is designed to resist the axial compression and shear force caused by wind or earthquake. The performance of shear wall used in tall building is highly influenced by combined shear and axial force. For this reason, it is possible to result in local brittle failure because of concentrated damage in the potential plastic hinge region under severe earthquake. Thus, it is necessary to establish the lateral confinement details at the plastic hinge of shear wall so that shear wall can behave a ductile manner, The objective of this study is to evaluate the seismic performance of L-shaped walls with different confinement details. For this purpose, three wall specimens were tested experimentally and also analyzed using Nonlinear FEM package.

• Earthquakes and Structures
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• 제7권6호
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• pp.909-935
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• 2014

The seismic characteristics of two semi-gravity reinforced concrete cantilever retaining walls are examined via an experimental program using an outdoor shake table (one with and the other without concrete masonry sound wall on top). Both walls are backfilled with compacted soil and supported on flexible foundation in a steel soil container. The primary damages during both tests are associated with significant lateral displacements of the wall caused by lateral earth pressure; however, no collapse occurs during the tests. The pressure distribution behind the walls has a nonlinear trend and conventional methods such as Mononobe-Okabe are insufficient for accurate pressure estimation.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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• pp.521-526
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• 2002

The seismic performance of structural walls subjected to the cyclic lateral loads are influenced by various factors, like sectional shape, aspect ratio, reinforcement ratio, arrangement of reinforcement, and axial load ratio etc. In this research, reinforced concrete structural walls with the T-shaped cross section were selected. The seismic performance of T-shaped wall was affected by the many (actors because T-shaped wall is irregular wall composed to two rectangular walls. Especially the seismic performance of T-shaped wall varies with the flange condition and the various factors including the flange condition were determined. Therefore, the objective of this study is to understand the factors to improve seismic performance of RC T-shaded tv using sectional analysis.

• Geomechanics and Engineering
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• 제6권2호
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• pp.117-138
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• 2014

The main focus of the current study is to evaluate the dynamic behavior of a cantilever retaining wall considering backfill and soil/foundation interaction effects. For this purpose, a three-dimensional finite element model (FEM) with viscous boundary is developed to investigate the seismic response of the cantilever wall. To demonstrate the validity of the FEM, analytical examinations are carried out by using modal analysis technique. The model verification is accomplished by comparing its predictions to results from analytical method with satisfactory agreement. The method is then employed to further investigate parametrically the effects of not only backfill but also soil/foundation interactions. By means of changing the soil properties, some comparisons are made on lateral displacements and stress responses. It is concluded that the lateral displacements and stresses in the wall are remarkably affected by backfill and subsoil interactions, and the dynamic behavior of the cantilever retaining wall is highly sensitive to mechanical properties of the soil material.

• 한국지반신소재학회논문집
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• 제22권2호
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• pp.85-92
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• 2023

본 연구에서는 제주 지역에서 어스앵커로 지지된 흙막이벽의 측방토압 적용을 평가하기 위하여, 2개의 현장 시공 사례를 기반으로 수평변위에 대한 계측값과 예측값을 비교하였다. 흙막이벽에 작용하는 측방토압의 예측은 Rankine 토압, Hong & Yun 측방토압, Terzaghi & Peck 수정측방토압, Tschebotarioff 측방토압을 이용하여 탄소성해석을 실시하였다. 그 결과, A현장에 대한 최대 수평변위의 예측값은 계측값에 비하여 약 10배~12배로 화인되었으며, B현장의 경우에는 예측값이 계측값보다 약 9배~12배로 평가되었다. 즉, 2개 현장 모두 계측값에 비해 예측값에 의한 최대 수평변위가 유사한 증가율을 보였다. 모든 현장 사례에서 계측값에 의한 최대 수평변위는 퇴적층, 연암층 및 클링커층에서 발생하였고, 수평변위 형상은 사다리꼴 형태에 나타냈다. 그리고 예측값에 의한 최대 수평변위는 클링커층 주변에서 발생하였으며, 수평변위 형상은 타원형으로 나타났다. 클링커층이 혼재되어 있는 지반에서 계측값이 예측값과 매우 다른 수평변위 경향을 보이는 원인으로는 클링커층이 암반층과 연속된 지층의 형태로 존재하기 때문으로 판단되었다. 즉, 예측되는 토압 분포와 상당히 다른 경향을 보이는 제주 지역의 토압 분포 특성을 고려하면 과다하게 평가되는 기존의 예측방법을 적용하는 것은 다소 무리가 있을 것으로 판단되기 때문에, 보다 경제성을 확보할 수 있는 현실적인 제주 지역의 측방토압에 관한 연구가 수행될 필요가 있다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.697-704
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• 2002

This paper presents the results of instrumentation of a two-level of soil-reinforced segmental retaining wall. Instrumentation items include the lateral wall displacements and the geogrid strains at several locations. The instrumentation is still long carried in order to examine long-term behavior. The result indicate that the upper wall has a significant effect on the behavior of the lower wall doubling the wall moved. The wall also exhibits significant post-construction movements that had ceased several months after the wall completed. The implication of the findings from this study was discussed in great detail.

• 대한토목학회논문집
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• 제31권2C호
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• pp.75-82
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• 2011

최근 콘크리트 블록을 전면판으로 주로 사용하고 있는 기존의 블록식 보강토 옹벽과는 달리 경량의 강재를 지주로 이용하여 전면판의 자중을 감소시켜 안정성을 높이고 시공이 쉬운 보강토 공법이 개발되었다. 이 연구에서는 새로 개발된 보강토 옹벽의 안정성을 확인하기 위해 실제 크기의 현장시험을 수행하여 전면판에 발생하는 수평변위, 수평토압, 그리고 옹벽의 침하량 등을 계측기를 이용하여 측정하였다. 또한, 3차원 수치해석을 수행하여 현장시험결과와 수치해석결과를 비교 분석하였다. 현장계측결과 전면판 최대수평변위는 46mm(0.009H), 최대침하량은 21.5mm로 나타나 FHWA 기준을 만족하는 것으로 나타났다. 또한 현장계측결과를 수치해석결과와 비교 분석한 결과 새로운 보강토 공법은 충분한 안정성을 확보하는 것으로 나타났다.