• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.129-151
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• 2022

In the current work, a series of three-dimensional finite element analyses have been carried out to understand the behaviour of piles when the adjacent tunnelling passes underneath grouped piles with a reinforced pile cap. In the current study, the numerical analysis studied the computed results regarding the ground reinforcement condition between the tunnel and pile foundation. In addition, several key issues, such as the pile settlements, the axial pile forces, the shear stresses and the relative displacements have been thoroughly analysed, and the IoT platform based preliminary design guidelines were also presented. The pile head settlements of the nearest pile from the tunnel without the ground reinforcement increased by about 70% compared to the farthest pile from the tunnel with the maximum level of reinforcement. The quality management factor data of the piles were provided as API (Application Programming Interface) of various forms by the collection and refinement. Hence it has been shown that it would be important to provide the appropriate API by defining the each of data flow process when the data were created. The behaviour of the grouped piles with the pile cap, depending on the amount of ground reinforcement, has been extensively analysed, and the IoT platform regarding the quality management of piles has been suggested.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.151-158
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• 2000

The lateral deformation of one row pile groups was investigated based on analytical study and a numerical analysis. The emphasis was on quantifing the load transfer of pile groups subjected to lateral soil movement. An analytical method to consider pile-soil interaction in weathered soil was developed using load-transfer curve methods. Through the comparative study, it is found that the prediction by present approach is in good agreement with the general trend observed by in-situ measurements.

• 보일러설비
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• no.11 s.142
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• pp.118-121
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• 2005

아침 · 저녁으로 기온이 뚝 떨어지면서 '월동준비'에 나서는 소비자들이 급증하면서 각 유통업체의 겨울 난방용품 판촉전이 후끈 달아오르고 있다. 본격적으로 난방용품판매가 시작된 할인점의 경우 지난달보다 판매량이 15~30% 늘었으며, 특히 전기장판과 전기요의 매출은 150%, 온풍기, 원적외선 전기 히터 등의 매출은 200% 이상 신장하는 등 적은 비용으로 간편하게 실내 온도를 높일 수 있는 가전제품이 특수를 누리고 있다. 요즘처럼 일교차가 클 때는 집 안 전체를 난방은 비효율적으로, 전기장판, 온풍기, 매트, 히터 등 적은 비용으로 난방효과를 볼 수 있는 부분 난방용품이 인기를 끌고 있다.

• KOREAN POULTRY JOURNAL
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• v.4 no.11 s.37
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• pp.23-26
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• 1972

[ $\lcei$ ]여기 시골에 한 나뭇꾼이 있다. 그는 매일 산에 올라 나무를 베어 시장에 내어 그 수입으로 생계를 유지한다. 그는 '어떻게 하든지 해가 지기전 조금이라도 더 많은 나무를 베어야겠다' 하며 열심히 일을 한다. 나무를 베는 사람에게는 이말이 지상과제이며 부지런하게 나무를 벨수록 그는 돈을 많이 벌것이며 땔감인 이 나무중 어느 하나가 더 길거나 짧아도 상관없을 것이다. 그러나 양계가가 이 중요한 사양 관리부문을 이런식의 태도로 임하였다면 그는 그에게 돌아올 이익을 뚝 잘라버린 것이다. 적절한 디비킹은 철저한 기술의 숙달이 요구되며 기대와 인내를 가지고 진행해야 되며 실시하는 시기와 방법에 대한 정확한 지식을 가져야 한다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.27 no.5
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• pp.435-443
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• 1998

물은 인체 조직의 70%를 점유하고 있으며 만일 5%정도의 수분을 상실하게 되면 인간은 혼수상태가 되며, 12%정도를 잃으면 생명을 유지할 수 없다. 따라서 물은 신체의 유지는 물론 인간생활에 있어서 없어서는 안될 중요한 자원으로서 그 사용량과 수질은 문화 생활의 정도를 가늠하는 척도로 여겨져 왔다. 기존의 풍부한 물은 단순히 자유재로 생각되어 왔으나, 최근 들면서 귀중한 자원이며 경제재라는 인식이 확산되고 있으며 물을 수자원이라고 부르는 것이 세계적 추세이다.

• Journal of the Korean Geotechnical Society
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• v.15 no.1
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• pp.79-98
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• 1999

In the present study, a simple finite element method of analysis to predict non-uniform settlements at the interface between the mat foundation and foundation soils is proposed. Based on the proposed finite element method of analysis, the method to evaluate load sharing ratios of the foundation soils adjacent to the granular group piles is also presented. Further proposed is a procedure to estimate ultimate bearing capacity of the skirted granular group piles in a square pattern. To verify validity of the proposed methods and the estimated ultimate bearing capacity of the skirted group piles, comparisons are made with the results analyzed by using the PENTAGON3D FEM program. Finally, behavior characteristics with different reinforcement patterns of the skirts and the effect of an increase of ultimate bearing capacity due to the skirts are analyzed in connection with the design parameters.

• Journal of the Korean Geotechnical Society
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• v.18 no.3
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• pp.43-50
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• 2002

This paper describes a simplified numerical procedure for analyzing the response of bridge pier foundations due to riverbed scouring. A computationally efficient algorithm to analyze the behavior of a pile group is proposed by considering soil-pile, pile-cap, and pile-fluid interactions. The complex phenomenon of the pile-soil interaction is modeled by discrete nonlinear soil springs (p-y, t-z and q-z curves). The pile-cap interaction is considered by geometric configuration of the piles in a group and connectivity conditions between piles and the cap. The pile-fluid interaction is incorporated into the procedure by reducing the stiffness of the soil-pile reactions as a result of nonlinearity and degradation of the soil stiffness with river bridge scouring. Through the numerical study, it is shown that the maximum bending moment increases with increasing scour depth. Thus it is desirable to check the stability elf pile groups based on soil-pile and pile-cap interactions by considering scouring depth in the riverbed.

• Journal of the Korean Geotechnical Society
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• v.19 no.3
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• pp.65-74
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• 2003

The dragload on pile groups in consolidating ground was investigated based on a numerical analysis. The case of a single pile and subsequently the response of groups were analyzed by 2D and 3D finite element studies. Conventional continuum elements and special slip elements were used in the analyses for comparison. Based on a limited parametric study, it is shown that dragload for a single pile and group effect are normally overestimated by continuum analyses, compared with the predictions by the slip analyses. The group effect was examined from the slip analysis by considering various factors such as pile configurations, surface loading, interface friction coefficient, and axial loading on piles. An examplary analysis and one previous experimental observation of dragload and group effects were back-analysed. The case histories demonstrated that the slip analysis might predict a better estimate of dragload and group effect compared to the no-slip continuum analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.3
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• pp.175-181
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• 2003

In this reseach, a seepage test is carried out for three kinds of soil using a upward seepage equipment. Reliability about the existing method of pipining investigation were verified making an estimate of the critical velocity, the critical hydraulic gradient, and hydraulic conductivity and so on. Also, sensitive analyses were carried out using Plaxis that is FEM Program about design factors of scour. The height of core had a big infulence on the hydraulic gradient of the embankment's lower part in the result of sensitive anaylsis. Also, second only to the height of core, and the slope of embankment, the width of crest had influence on scour. However, the change of hydraulic gradient in the effluent gateway had a little influence on the crest width of core. Using these results of sensitive analysis on designing, hydraulic gradient in the effluence gateway turned out to be reducing by altering design factors that change of sensitiveness is big, in case of the hydraulic gradient bigger than the standard hydraulic gradient.

• Journal of the Korean Geotechnical Society
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• v.38 no.1
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• pp.17-33
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• 2022

This study describes the effect of ground water table on the dynamic analysis of single piles subjected to earthquake loading. The dynamic numerical analysis was performed for different dry and saturated soils with varying the relative densities of surrounding weathered soils (SM). The test soil was a weathered soil encountered in the engineering field and bender element tests were conducted to estimate the dynamic properties of test soil. The Mohr-Coulomb model and Finn model were used for soil, dry and saturated conditions, respectively. These models validated with results of centrifuge tests. When compared with the results from the soil conditions, saturated cases showed more lateral displacement and bending moment of piles than dry cases, and this difference caused from the generation of excess porewater pressure. It means that the kinematic effect of the soil decreased as the excess pore water pressure was generated, and it was changed to the inertial behavior of the pile.