• Journal of Navigation and Port Research
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• v.36 no.8
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• pp.613-618
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• 2012

For the tug-barge simulation, captive model test(Horizontal Planar Motion Mechanism) of the barge model is carried out. From the result of HPMM test, a resistance coefficient, maneuvering coefficients of the barge are obtained. A mathmatical model of the barge is validated by turning simulations with different angle of towing line applied a simple towing line model and the tactical diameter compared to sea trial data. As a result, the tactical diameter of the barge is smaller as the angle of towing line is bigger. The tactical diameter from simulations is smaller than that from sea trial data, may be caused by increased displacement of the barge.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.128-130
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• 2010

예선과 부선으로 이루어진 예부선의 예인 운항 상태에 대한 수학모델을 개발하기 위하여, 먼저 예선에 대한 수학모델을 개발하였다. 이를 위하여 예선모형을 이용하여 4자유도의 수학모델에 대한 구속모형시험을 수행하였고, 그 결과를 이용하여 선회, 지그재그 시뮬레이션을 수행하였다. 또한 예선실선에 대한 예선시운전 실험을 통하여 선회, 지그재그 결과를 얻고, 이를 시뮬레이션 결과와 비교하여 예선의 수학모델을 검증하였다.

• Magazine of the Korea Concrete Institute
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• v.10 no.2
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• pp.167-178
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• 1998

횡방향철근에 의하여 적절히 구속된 콘크리트 기둥은 강도증가 및 연성의 확보면에서 유리하다. 본 연구의 목적은 횡방향철근에 의하여 구속된 코아콘크리트의 크기,횡방향철근의 간격비 및 체적철근비 등의 변화에 따른 콘크리트 기둥의 극한강도를 포함한 최대하중 이전의 거동 및 최대하중 이후의 거동을 실험적, 해석적으로 고찰함으로써 콘크리트 기둥의 구속효과정도를 규명하려는데 있다. 본 연구에서는 횡구속된 콘크리트 기둥모형의 압축재하실험을 수행하였으며, 최대하중 이전의 거동에 대하여 연속체적 파괴와 소성을 고려한 3차원 모델링을 통한유한요소해석을 실시하였다. 또한 횡구속된 콘크리트 기둥의 변형률국소화 모델에 의한 파괴해석을 통하여 구속된 콘크리트 기둥의 최대하중 이후의 거동을 재현하였다. 해석결과는 압축재하실험의 결과와 비교, 분석되었으며, 이에 따른 구속효과를 규명하였다.

• Journal of the Korean GEO-environmental Society
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• v.14 no.2
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• pp.43-50
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• 2013

In this study, the tests were carried out for the behavior according to method of constrained nail head of slope reinforced with soil nail under dynamic loading, by using shaking table. Shaking table tests were carried out by applying Hachinohe seismic wave having the long-period characteristics and Ofunato seismic wave having short-period characteristics, as changing constrained and unconstrained condition of nail head, and so on. Failure mode, ground acceleration characteristics, vertical displacement and horizontal displacement of slope were compared and analyzed on the basis of results obtained from the test. Results of carrying out shaking table test showed that both short-period wave and long-period wave had large effects on slope, and constraint of nail head was found to have large shear resistance for dynamic load. And it was confirmed that stability of slope under seismic loading was largely improved by constrained head of soil nail.

• Journal of the Korean Geosynthetics Society
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• v.22 no.4
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• pp.27-34
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• 2023

This paper describes the results of a pile pullout test considering the confine pressure and fines content of the ground. The Pullout tests were conducted under various ground conditions using model piles. The effect of ground confine pressure on the pullout resistance and the pullout resistance parameters of the pile were evaluated based on the experimental results. The results of pullout test showed that the maximum pullout resistance occurred at a pullout displacement of about 7mm to 9mm, regardless of the fines content and the confine pressure of the ground. The maximum pullout resistance of the pile decreased as the fines content of the ground increased, and this trend became clearer as the confine pressure increased. The pullout resistance calculated by theoretical formula was compared with the experimental results in order to ensure the reliability of the pullout test results. The comparative results showed that the experimental and theoretical values showed a tendency to decrease the pullout resistance as the fines content increased, in all confine pressure conditions. The analysis result of the pullout resistance parameters confirmed that the pullout resistance was greatly influenced by the adhesion compared to the interface friction angle, as the fines content of the ground around the pile increased.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1018-1022
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• 2007

본 연구는 친수공간 확보에 따른 경관호안 블록의 개발과 홍수시 수리적 안정성을 가져올 수 있는 블록의 규격은 물론 블록의 형상에 따른 상호 맞물림과 블록간의 고정 등 수리적으로 안정성을 제공해 주는지를 수리모형실험을 통해서 분석하였다. 바닥 사석공에서는 아무런 맞물림이 없는 상태에서보다는 맞물림을 주었을 경우가 안정성이 크게 나왔고 그 맞물림의 량이 많은 조건으로 실험한 육각형 다이아몬드블록의 결과가 안정성이 더 크게 나왔다. 사석의 경사시공에서는 횡적구속만 주었을 경우보다는 종·횡적구속을 주었을 경우가 안정성이 크게 나와 두방향의 구속이 필요함을 보여주었다. 이러한 실험결과는 블록의 크기, 형상 및 맞물림에 따른 유속, 수심, Froude수, Shields수, 바닥전단응력, 입자 Reynolds수의 분석을 통해 얻었다.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.884-891
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• 2003

이 논문는 지오신텍스 보강토 구조물의 보강 메카니즘을 수치계산을 통해 규명하고자 하는 목적으로 쓰여졌다. 이 연구에서는 보강 메카니즘은 전단에 의한 다짐토의 체적 팽창(부의 다일렌탄시)을 지오신텍티스에 의해 구속 억제하는 과정에서 생성되는 효과로 간주하고 있다. 보강 메카니즘의 규명을 위해 1992년 일본 Kanazawa에서 실시된 실모형 실험과 실내 실험 결과를 이용하였으며. 수치계산에서는 다짐토의 다일렌탄시 특성을 표현 가능한 탄소성 구성모델을 이용하여 유한요소(FEM)을 이용하고 있다. 수치 계산에 의해 실모형, 실험 실내실험 결과를 비교 분석하였다.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.387-395
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• 2003

Model tests were conducted to study the behavior of the piled raft foundation system on sands. Especially in this study, the method using the triaxial compression apparatus was devised and used to apply the confining pressure which is considered difficult in the existing model test on the soil. Steel rods (6mm dia.) and aluminum plates (8mm thickness, 50mm dia.) were used to simulate piles and rafts respectively. Jumunjin standard sands were used to ensure the homogeneity of the sample. After the sample with the piled raft model was laid inside the triaxial cell, the confining pressure was applied and then the compressive force was applied. The increase and/or decrease ratio of the bearing capacity, the load distribution ratio between raft and piles and the effect of settlements decrease depending on the confining pressure, the number of piles and the length of piles were analyzed and the bearing capacity and skin friction of the pile was calculated. By the results of these experiments, the bearing capacity increased and the settlement decreased with this piled raft foundation system. Especially the effect was larger with the increase of the number of piles than with the increase of length of piles. Hereafter, the study of the load transfer mechanism of piles under confining pressure would be made possible using these small model tester like triaxial compression apparatus.

• Journal of the Korean Geosynthetics Society
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• v.8 no.4
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• pp.41-46
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• 2009

In this paper, a series of laboratory chamber tests were performed to evaluate the effects of clays mixed into compaction piles due to confining stress of ground on consolidation promoting. For the tests, various compaction piles such as SCP, GCP, and RAPP (Recycled-Aggregate Porous concrete Pile) were used. The ground condition was simulated at 50% and 100% of degree of consolidation. Also, confining stresses were applied to the composite ground corresponding to those of 5m depth. The amount of mixed clays into each compaction pile were estimated by measuring the drainage from the saturated compaction piles. From the test result, it was shown that the drainage area of compaction pile was changing according to the consolidation condition. GCP showed the most change of drainage area as it has relatively large void ratio; however, the amount of change was decreased by progressing consolidation of ground.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.239-249
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• 1999

In this study, experimental work has been carried out to investigate the effect of lateral soil movement on passive piles. This paper consists mainly of two parts: the first, performance of a series of laboratory experiments on a single pile and one-row pile groups, and the second, comparison between the measured and the predicted results. In the laboratory experiments, a quadrilateral soil movement profile was imposed on model piles embedded in both sandy soils and weathered soils. The maximum bending moment and pile deflection induced in passive piles were found to be highly dependent on pile stiffness, pile spacing, relative densities and pile head fixity condition. It was shown that the group effect might either increase or decrease the maximum bending moment and pile deflection, depending on the aforementioned influence factors. Based on the results obtained, a spacing-to-diameter ratio of 7.0 seems to be large enough to eliminate the group effect, and a pile in such a case behaves essentially the same as a single pile.