• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.153-162
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• 1997

시간평균된 해안의 지하수위는 내륙쪽에 강우가 없는 경우에도 평균해수면 (Mean Sea Level)보다 1내지 2미터 정도 높은 것으로 관측되었다. 이러한 해안의 지하수위상승현상은 주로 파랑과 조석의 작용에 의해 나타난다. 본 연구에서는 지하수위상승에 미치는 조석 및 파랑의 효과를 현장관측결과를 통해 정량적으로 보여주었으며, 또한 이들 각각의 작용에 기인한 지하수위상승에 대한 해석해 및 최근 이론들을 제시하였다. 특히, 최근 지하수의 수리학적 모델링에 관한 연구에서 파랑의 침투 (wave runup infiltration)효과의 중요성이 강조되었는 바, 본 연구를 통해 종래에 보고된 바 없는 swash zone (shoreline과 runup limit사이)에서의 파랑의 침투속도(분포)를 지하수위관측자료를 이용해 간접적으로 산정함으로써 해안의 지하수위예측모델링을 보다 정확히 수행할 수 있으리라 사료된다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.4
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• pp.503-515
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• 2021

In this study, rainfall infiltration in vault of the second near-surface disposal facility was evaluated on the basis of various disposal scenarios. A total of four different disposal scenarios were examined based on the locations of the radioactive waste containers. A numerical model was developed using the FEFLOW software and finite element method to simulate the behavior of infiltrated water in each disposal scenario. The effects of the disposal scenarios on the infiltrated water were evaluated by estimating the flux of the infiltrated water at the vault interfaces. For 300 years, the flux of infiltrated water flowing into the vault was estimated to be 1 mm/year or less for all scenario. The overall results suggest that when the engineered barriers are intact, the flux of infiltrated water cannot generate a sufficient pressure head to penetrate the vault. In addition, it is confirmed that the disposal scenarios have insignificant effects on the infiltrated water flowing into the vault.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.12
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• pp.1106-1111
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• 2006

To improve warpage, delamination and the chemical reaction between 2 different co-fired materials, the bonding behavior with common glass was studied. As shown in the previous paper, the phenomenon of the infiltration is different with the composition of the glass. In particular, in the case of low temperature melting glass, infiltration is experimented in this study. GA-1 glass is infiltrated among $BaTiO_3$ particles below $800^{\circ}C$ and is made by glass/ceramic composite. Until the laminate is fired under $850^{\circ}C$, provskite phase is observed. Although in the case of GA-12 glass, the temperature of the glass infiltration is lower than it of GA-l glass, the perovskite phase already disappears at $800^{\circ}C$. As a result, GA-1 and GA-12 glasses are infiltrated among particles at low temperature, however, the chemical reactivity of the glass/ceramic and sintering temperature should be considered.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.177-177
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• 2009

이동통신 시스템의 소형화 경량화 다기능화 추세에 따라 세라믹 모듈의 정밀도 및 집적도가 중요한 요소로 부각되고 있다. 이러한 모듈의 고집적화 추세에 대응하기 위하여 세라믹 소성시 수축율 제어가 필수적인 요소로 부각되고 있으며, 이에 따라 X, Y축의 소성 수축율을 0에 근접하게 제어하는 무수축 소성 기술이 요구되고 있다. 선행연구를 통하여 $Al_2O_3$/Glass/$Al_2O_3$ 구조의 glass infiltration법에 의한 무수축 소성 기술 구현 가능성을 확인하였으나, 아직 해결해야 할 문제점들이 있다. glass가 $Al_2O_3$층으로 infiltration되는 과정에서 glass층이 de-lamination 되는 결함이 발견되었으며 이는 유전체 기판의 Q값을 낮추고 기판의 신뢰성에 악영향을 줄 수 있어 이에 대한 개선이 필요한 실정이다. 본 연구에서는 $Al_2O_3$/Glass/$Al_2O_3$ 구조의 glass infiltration법에 의한 선행 실험에서 관찰된 기판 내부의 de-lamination 현상에 대한 원인을 규명하고 해결책을 제시하고자 하였다. glass 유동과 바인더 burn-out이 동시에 진행됨에 따라 기공이 생성되며 glass가 점성유동함에 따라 이 기공이 glass층으로 모이게 되어 de-lamination 현상이 발생하는 것으로 사료된다. 이를 해결하기 위하여 de-lamination층에 $Al_2O_3$의 tamping을 시도하여 glass층의 기공이 빠져 나갈 수 있는 channel 을 형성하고, 남아있는 기공을 $Al_2O_3$로 채우는 효과를 얻을 수 있었다. 이에 따라 기판의 밀도와 Quality factor 값이 향상되었으며 미세구조가 치밀한 무수축 기판을 제작할 수 있었다.

• Journal of the Korean Geotechnical Society
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• v.40 no.3
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• pp.7-18
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• 2024

In this study, slope stability was evaluated in consideration of unsaturated soil behavior to predict landslides. Samples were collected from a landslide site due to heavy rainfall during Typhoon Hinnamnoh. Soil moisture characteristic tests were performed based on the evaporation method using a swelling undisturbed sample and a remolded sample. Based on the hydraulic-mechanical behavior, two-dimensional infiltration and stability analyses were performed. As a result, from the two sample types, it is found that both behaviors exhibited clear differences in the results, and the behavior of the swelling undisturbed sample was able to predict the actual slope failure appropriately.

• Composites Research
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• v.12 no.3
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• pp.36-44
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• 1999

The fabrication process of $Al_2O_{3p}/Al$ composite by in-situ process was investigated. The effects of processing variables such as addition type and content of Mg, processing temperature and time on the infiltration behavior of molten Al, microstructure and hardness were investigated. When the pure Al was infiltrated into mixtures of Mg and $Al_2O_3l$ powder, processing temperature required to spontaneous infiltration was decreased, and the content of Mg was the most powerful variable for infiltration of molten Al. But when the Al-Mg alloy was infiltrated into $Al_2O_3l$ particles, infiltration ratio indicated nearly same value regardless of Mg content in alloy and processing temperature, and critical processing temperature required to spontaneous infiltration was $800^{\circ}C$. The $Al_2O_{3p}/Al$ composites which were fabricated by mixtures of Mg and $Al_2O_3l$ powders resulted in high hardness value, but hardness values were scattered due to non uniform dispersion of $Al_2O_3l$ particles by excessive reaction of Mg.

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.51-64
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• 2000

This paper presents a procedure of calculating a safety factor of the unsaturated slope suffering from the rainfall infiltration. The process of infiltration into a slope due to rainfall and its effect on the behavior of the soil slope are examined by using a two dimensional finite element flow-deformation coupled analysis. A factor of safety is calculated at various elapsed times after the commencement of rainfall as in the following procedure. First, stresses are estimated at each Gaussian point from the coupled finite element analysis. Then, the global stress smoothing method is applied to get a continuous stress field. Based on this stress field, a factor of safety is calculated for a specified slip surface by a stress integration scheme. Then, a search strategy is used to find out a critical slip surface which is associated with the minimum factor of safety. Some numerical examples are analyzed in order to study the effect of hydraulic conductivity on the slope stability during rain-induced infiltration. According to the results, local failure zone can be formed near the slope surface due to inhomogeneous distribution of hydraulic conductivity If the failure zone is once formed, then the region extends until a large amount of slide activates. Therefore the local failure can be neglected no longer in the stability analysis.

• Journal of the Korean Geotechnical Society
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• v.21 no.8
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• pp.45-53
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• 2005

Shallow slope failures in residual soil during periods of prolonged infiltration are common over the world. Therefore, this study examines an approximate method to estimate the influence of infiltration on surficial stability of slopes by one-dimensional infiltration model. Modified GAML model based on the Green-Ampt model was extended to predict the infiltration behavior of two-layered slope. Then, the model has been considered to evaluate the likelihood of shallow slope failure which is induced by a particular rainfall event that accounts for the rainfall intensity and duration for various return periods in two-layered soil profile. The results obtained from the approximate method were compared with those obtained from numerical analyses. According to the results, with the use of properly estimated input parameters, the proposed method was found to give good results that agree reasonably well to those of the more rigorous finite element analyses.

• Journal of the Korean GEO-environmental Society
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• v.24 no.10
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• pp.15-23
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• 2023

In this study, the infiltration behavior of slopes composed of mixed soils with clay contents of 0%, 5%, and 10% in weathered Gneiss soil, which is a representative weathered soil in Korea, was investigated, and the stability of unsaturated slopes due to rainfall infiltration was examined. For this, in this study, the soil water characteristic curve was obtained through the water retention test, and the strength constant was obtained through the triaxial compression test. Based on the obtained results, the influence of clay content and antecedent rainfall effect (i.e., initial suction) on the formation of saturated zone (i.e., wetting band) and slope stability due to rainfall infiltration was examined through infiltration and stability analyses. As a result, it was found that the hig her the initial suction, the slower the formation of the saturated zone on the slope. In addition, it was found that as the clay content increases, the shear strength of the ground increases and the resistance to rainfall infiltration increases, and eventually the slope stability is greatly improved.

• Journal of the Korean Geotechnical Society
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• v.29 no.12
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• pp.25-34
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• 2013

This paper presents the results of a reduced-scale physical model investigation into the behavior of retaining walls subject to cycles of wetting and drying due to rainfall infiltration. Reduced-scale model walls equipped with a water spraying system that can simulate the wetting process were first constructed and a series of tests were conducted with due consideration of different rainfall intensities and backfill soil types. The results indicate that cycles of wetting and drying process have adverse effects on the wall behavior, increasing wall deformation as well as earth pressure acting on the wall, and that the first cycle of wetting and drying process has more pronounced effect on the wall performance than the ensuing cycles. It is also shown that the degree to which the wetting and drying cycles affect the wall behavior depends greatly on the backfill soil type, and that the larger the fine contents, the greater is the effect of cycles of wetting and drying on the wall behavior. Practical implications of the findings from this study are discussed in great detail.