• 한국지반공학회논문집
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• 제24권2호
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• pp.5-14
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• 2008

국내 석산에서 생산되는 골재를 사용하여 대형삼축시험과 대형직접전단시험을 동시에 수행한 후 전단특성을 비교하였다. 비교를 위하여 시험조건을 가능한 일치시켰으며, 상대밀도를 50%, 70%, 90%의 세 가지로 변화시켜 시험을 수행하였다. 시험결과 응력-변형률 거동은 두 가지 시험에서 동일하게 나타나며, 전단강도는 상대밀도의 크기에 따라 시험방법별로 추세가 달라진다. 즉, 낮은 상대밀도에서는 대형직접전단시험의 내부마찰각이 대형삼축압축시험 결과 값에 비하여 작게 나타나고, 높은 상대밀도에서는 이 현상이 역전됨을 확인하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 봄 학술발표회 논문집
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• pp.503-508
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• 2003

In this study, we peformed ahead a field geological investigation, boring investigation for slope stability analysis in large scale slope failure area. But the geological stratum was not clearly grasped, because ground was very disturbed by large scale Granite intrusion. Furthermore, the existing test data was not pertinent to the large scale Granite intrusion site like here. Therefore, various kind of field test were performed to grasp clearly for geological stratum. And the results of back analysis, various kind tests used to slope stability analysis.

• Geomechanics and Engineering
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• 제9권5호
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• pp.601-618
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• 2015

Soil-reinforcement interaction mechanism is an important issue in the design of geosynthetic reinforced soil structures. This mechanism depends on the soil properties, reinforcement characteristics and interaction between these two elements (soil and reinforcement). In this work the shear strength of sand/geotextile interfaces were characterized through direct and simple shear tests. The direct shear tests were performed on a conventional direct shear device and on a large scale direct shear apparatus. Unreinforced sand and one layer reinforced sand specimens were characterized trough simple shear tests. The interfaces shear strength achieved with the large scale direct shear device were slightly larger than those obtained with the conventional direct shear apparatus. Notwithstanding the differences between the shear strength characterization through simple shear and direct shear tests, it was concluded that the shear strength of one layer reinforced sand is similar to the sand/geotextile interface direct shear strength.

• 콘크리트학회논문집
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• 제16권6호
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• pp.867-873
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• 2004

It has been known that debonding failures between CFS(Carbon Fiber Sheet) and concrete in the strengthened RC beams are initiated by the peeling of the sheets in the region of combined large moment and shear forces, being accompanied by the large shear deformation after flexural cracks. These shear deformation effects are seldom occurred in small-scale model tests, but debondings due to the large shear deformation effects are often observed in a full-scale model tests. The premature debonding failure of CFS, therefore, must be avoided to confirm the design strength of full-scale RC beam in strengthening designs. The reinforcing details, so- called 'U-Shape fiber wrap at mid-span' which wrapped the RC flexural members around the webs and tension face at critical section with CFS additionally, were proposed in this study to prevent the debonding of CFS. Other reinforcing detail, so called 'U-Shape fiber wrap at beam end' were included in this tests and comparisons were made between them.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.287-292
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• 2003

The large-scale direct tension tests of plain concrete were performed and then the complete load-CMOD(crack mouth opening displacement) curves with a stable postpeak descending part were presented. Two independently controlled actuators were used to ensure a homogeneous increasing of CMOD in both notches of a specimen and to avoid secondary flexural stresses. It was compared the fracture energies from the test results with them from a classical prediction equation by Bazant and Oh (983), The results are indicated that the fracture energies from these large-scale direct tensile tests are large as 1.5-2 times on average against them from the Bazants prediction equation. But the tensile strength for large-size specimens was about half of the values determined from the splitting tensile strength tests for 10 by 20mm cylindrical specimens due to size effect.

• 한국지반환경공학회 논문집
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• 제10권1호
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• pp.25-34
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• 2009

댐이나 항만 건설시 재료로 사용되는 조립재는 입자크기가 일반 토사에 비해 매우 크기 때문에 이러한 재료에 대해서 전단시험을 수행할 때에는 가급적 대형 전단시험장치를 사용하는 것이 보다 정확한 결과를 얻기 위해 바람직하다. 대형 전단시험장치로는 일반적으로 대형 직접전단시험장치와 대형 삼축압축시험장치가 있으나 일반 토질시험장치와 비교해 제작과 보급, 운영 등의 어려움 때문에 현재까지 국내에서 두 시험장치를 사용하여 시험을 수행한 실적은 많지 않은 편이다. 본 연구에서는 댐 축조재로 사용되는 입경이 큰 조립재료를 대상으로 시료의 평균 입자크기와 공시체 크기, 연직응력(구속압) 조건 등에 차이가 있는 총 6개 case에 대해서 대형 직접전단시험과 대형 삼축압축시험을 수행하고 두 시험간 전단강도 특성의 차이를 비교하였다. Mohr-Coulomb 강도규준에 의한 전단강도를 기준으로, 대형 직접전단시험을 통해 산정된 전단강도가 대형 삼축압축시험을 통해 산정된 전단강도보다 전체적으로 크게 나타났으며 또한, 1,000kPa 수직응력에 대해 두 시험간 산정된 전단강도를 비교한 결과 대형 직접전단시험에 의한 전단강도가 대형 삼축압축시험에 의한 전단강도보다 약 10~70% 크게 나타나 입경이 작은 일반 토사와 비교해 그 차이가 크고, 대형 직접전단시험결과의 분산도가 상대적으로 높은 것으로 나타났다.

• 한국압력기기공학회 논문집
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• 제13권1호
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• pp.16-39
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• 2017

This paper reviewed and summarized the experimental studies conducted during last three decades to evaluate the structural integrity and to establish the acceptance criteria for piping system of nuclear power plants (NPPs) under seismic loading condition. These experimental studies contain the results of large-scale piping system tests under excessive seismic loading as well as standard specimen tests, simplified piping specimen tests, and piping components tests under simplified dynamic and cyclic loading. These would be useful as a basis for establishing integrity assessment procedure and acceptance criteria for piping systems of NPPs under beyond design basis earthquake (BDBE) conditions, and also could be used in planing the scope and direction of further related researches.

• Advances in Computational Design
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• 제8권2호
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• pp.133-145
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• 2023

Scaling and similitude large scale structural member to small scale model is considered the most important matter for the experimental tests because of the difficulty in controlling, lack of capacities and expenses, furthermore that most of MSc and PhD students suffering from choosing the suitable specimen before starting their experimental study. The current study adopts to take large scale slab with opening as a case study of structural member where the slab is squared with central squared opening, the boundary condition is fixed from all sides, the load represents by four concentrated force in four corners of opening, as well as, the study adopts Buckingham theorem which has been used for scaling, all the parameters of the problem have been formed in dimensionless groups, the main groups have been connected by a relations, those relations are represented by force, maximum stress and maximum displacement. Finite element method by ANSYS R18.1 has been used for analyzing and forming relations for the large scale member. Prediction analysis has been computed for three small scale models by depending on the formed relations of the large scale member. It is found that Buckingham theorem is considered suitable way for creating relations among the parameters for any structural problem then making similitude and scaling the large scale members to small scale members. Finally, verification between the prediction and theoretical results has been done, it is observed that the maximum deviation between them is not more than 2.4%.

• 한국터널지하공간학회 논문집
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• 제9권4호
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• pp.331-341
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• 2007

기존터널에 근접 굴착 할 때 발생하는 흙막이벽체의 수평변위를 억제시키기 위해 버팀대에 선행하중을 가했다. 이러한 목적으로 흙막이벽체에 큰 선행하중을 가할 수 있는 새로운 선행하중 시스템을 모형시험에 적용하였다. 대형 시험은 폭 2.0m, 높이 6.0m, 길이 4.0m인 모형 토조에서 수행하였고 시험지반은 모래로 조성하였다. 직경 1.2m인 모형 터널은 시험지반 굴착 전에 설치하고 지반을 조성한 후에 모형터널에 근접해서 흙막이벽체를 설치하고 시험지반을 굴착하면서 모형 터널과 흙막이벽체 및 지반의 거동을 측정하였다. 이때에 선행하중 재하효과를 확인하기 위하여 선행하중을 가하지 않는 시험은 물론 선행하중을 가하여 흙막이벽체의 수평변위를 억제하는 시험을 실시하였고 수치해석을 실시하여 대형 시험결과와 비교하였다. 그 결과 선행하중을 설계축력 이상으로 적용시켜 흙막이벽체의 수평변위를 감소시켰을 때 벽체 배면에 있는 기존 터널의 안정성이 크게 향상되는 것을 확인할 수 있었다.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 추계학술논문발표회 논문집
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• pp.86-92
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• 2008

On this study, modeling works using Cone tools simulation method were made for the prediction of real fire test results such as small to large scale fire tests including ISO 5660-1, EN 13823 and ISO 13784-1. For those simulation prediction, three real fire tests were performed in advance. In addition, Real data from ISO 5660-1 test were applied to this simulation modeling. Finally, the comparative analysis between Real fire tests and Simulation results were made out. Also, the Classifying evaluation by EURO Class using EN 13501-1 were taken off.