• 지질공학
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• 제12권1호
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• pp.63-73
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• 2002

누수 보강 저수지의 그라우팅 개선 구간 평가를 목적으로 물-시멘트 배합비별로 제조된 그라우트에 대하여 재령 변화에 따른 전기비저항과 압축강도 변화를 측정하였다. 동일 조건 하에서 그라우트의 농노가 증가할수록 전도도는 높아지고, 대상 매질에 그라우트가 주입되는 경우 주입 이전에 비해 비저항이 상대적으로 낮아지는 효과가 나타나므로 이를 이용한 주입 구간의 판정이 가능함을 확인하였다. 대상 매질이 서로 다른 세 지구에 대한 그라우팅 이후 전기비저항 수직탐사 결과 겉보기 비저항은 수십∼수백 ohm-m 이하로 낮아졌으며, 주입 이후 수 일이 지난 후부터는 점차 증가된 상태로 일정하게 유지되는 것으로 나타나는데, 이는 그라우트가 주입된 이후 대상 지층 내에서 굳어짐에 따른 강도 증가의 결과로 밝혀졌다.

• 한국안전학회지
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• 제32권6호
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• pp.40-45
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• 2017

Chemical accidents generated during maintenance, repair, and normal operation, such as dispersion, fire, and explosions, can cause massive losses like a 2012 hydro fluorine leak in Gumi, South Korea. Since this accident, many researches have studied physical mitigation systems. However, due to many difficulties including potential costs and lack time, it is really hard for many companies to install mitigation systems without prior knowledge. Thus, the efficacy of mitigation system should be evaluated. This study assesses a dike design considering the fluid velocity at an open hole when a leakage accident occurs. It is assumed that leakage materials follow a free fall motion. Throughout case studies, a current KOSHA guide for a dike design was evaluated and new guidelines handling various conditions were proposed.

• 한국농공학회지
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• 제40권4호
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• pp.94-102
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• 1998

This paper aims at developing the prediction technique of the deformation for the embankment such as sea dike and shore protection relevant to reclamation project along the southern coast of the Korean Peninsula. Generally total deformation of a sea dike over clayey foundation are composed of immediate settlement, plastic deformation and consolidation settlement. Plastic deformation occurs when the ultimate bearing capacity is less than overburden pressure containing the stress increment due to the construction of an embankment. The reliable prediction of total settlement is very important since deformed final geometry of sea dike is directly connected for analysing the safety of the long-term slope failure and piping. During this study, plastic deformation, major part of deformation was analysed using the program developed by authors, whereas immediate settlement and consolidation settlement were predicted by Mochinaka and Sena's method and Terzaghi's 1-dimensional theory of consolidation respectively. In order to validate the prediction technique for the deformation, a case study of Koheung Bay reclamation works was carried out. A good agreement was obtained between observation and prediction, which means the applicability of the technique.

• 한국안전학회지
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• 제33권5호
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• pp.35-41
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• 2018

Chemical accidents generated during maintenance, repair, and normal operation, such as dispersion, fire, and explosions, can cause massive losses like a 2012 hydro fluorine leak in Gumi, South Korea. Since this accident, many researches have studied physical mitigation systems. However, due to the lack of potential costs and time, it is really hard for many companies to install mitigation systems without prior knowledge. Thus, the efficacy of mitigation system should be evaluated. This study assesses a dike design considering the fluid velocity at an open hole when a leakage accident occurs. It is assumed that leakage materials follow a free fall motion. Throughout case studies, a current KOSHA guide for a dike design was evaluated and new guidelines handling various conditions were proposed.

• 한국수자원학회논문집
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• 제49권8호
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• pp.707-717
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• 2016

본 연구에서는 직선 개수로 내에 설치된 수제 모형 주위에서 발생하는 난류 흐름의 특성을 알아보기 위하여 수리모형실험을 수행하였다. 실험은 Froude 수가 0.100과 0.185인 두 가지 흐름 조건에서 이루어졌다. 시간평균유속과 난류 응력을 구하기 위하여 초음파 유속계를 이용하여 3차원 순간 유속을 측정하였다. 실험 결과, 수제 하류에서 난류 응력이 큰 재순환 영역이 존재하는 것으로 확인하였다. Froude 수가 큰 경우와 작은 경우의 전반적인 평균 유속 분포는 유사하게 나타났으나, 최대 무차원 난류 응력과 최대 무차원 바닥 전단응력은 Froude 수가 증가할수록 차이를 보였다.

• 한국농공학회지
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• 제34권1호
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• pp.87-99
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• 1992

A mathematical model, UNSATR which predicts the seepage flow through the body of dike especially under the tidal fluctuation has been developed. This model has been revised from UNSAT2 model which was developed on the basis of the saturated-unsaturated theory by Neuman. UNSATR has been verified and applied to the hydraulic model in order to estimated the seepage quantity, the formation of free water surface etc. The results lead to the following conclusions : 1. Seepage rates between the mathematical model and hydraulic model experiment are very similar to each other both in constant and transient water level conditions. 2. The lapsed time to be steady state of the free water surface becomes late as the tidal levels are relatively low mainly due to the seepage flow from the unsaturated zone of the body of dike. 3. Under the transient state of water levels, owing to the flow from the unsaturated domain, streamlines crossing to the free water surface are found and time lag during a falling tide may allow the free water surface inside the body of dike to stand at a high level than the outside water level. 4. The utility and validity of UNSATR model are convinced when the analyses on seepage problems through the porous embankment of the soil structures on the conditions of the steady and unsteady states are carried out.

• 한국농공학회논문집
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• 제57권1호
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• pp.11-23
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• 2015

In this study the laboratory test for hydraulic conductivity and the seepage analysis with finite element method on measurement section of sea dike embankment were performed for the purpose of estimating the relative density of embankment from the measured pore water pressures, and both results of the test and the analysis were coupled with the method of estimating seepage blocking state with the hydraulic head loss rate in sea dike embankment. The relationship of void ratio vs hydraulic head loss rate was obtained by setting hydraulic conductivity as common ordinate on the relationships between the void ratio and the hydraulic conductivity and between the hydraulic conductivity and the hydraulic head loss rate. The void ratio on the segment between measuring points was calculated from the coupled relationship of the void ratio vs the hydraulic conductivity. The allowable upper and lower limits of hydraulic head loss rate and those of void ratio on the safety were generated from the coupled relationship between the laboratory compaction test and the sedimentation test. Current hydraulic head loss rate and void ratio were evaluated in the allowable range between upper and lower limits.

• 지질공학
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• 제31권3호
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• pp.239-255
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• 2021

Kinematic analyses of magmatic intrusions and faults can provide useful information on stress conditions and chronological relationships between dike emplacement and brittle deformation events. We studied structures in rocks exposed on a coastal platform in Geoje Island off the southern Korean Peninsula because of its well-developed dikes and faults. The geology of the study area includes the Cretaceous Seongpo-ri Formation, which is composed mostly of shale, sandstone, and hornfels intruded by magmatic dikes. Most of the dikes are developed along pre-existing structural features (faults and fractures), indicating that their emplacements were structurally controlled. Because dikes commonly open along the direction of the minimum principal stress, the direction of this stress can be obtained from dike geometry and orientation through the matching of piercing points on either side of a dike. In addition, the deformed dikes can give information regarding later deformation. On the basis of the kinematic analyses, we identified five deformation events in the study area, which are kinematically related to changes of the regional maximum principal stress. Results indicate that the structures in the study area have been controlled predominantly by episodes of reactivation of the NNE-trending Yangsan strike-slip fault, located to the northeast of the study area, under different stress regimes. In a wider tectonic context, the brittle deformation of the rocks of Geoje Island was probably induced by interactions among the Philippine Sea, Pacific, and Eurasian plates, including changes in subduction parameters with respect to the latter two plates over time.

• 한국항해항만학회지
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• 제28권10호
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• pp.925-931
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• 2004

목포항 인접해역은 영산강 하구둑과 영암-금호방조제 건설로 인하여 많은 변화를 가져왔다. 특히, 영산강 하구둑과 영암-금호방조제 방류에 의한 영향은 조류속 변화와 퇴적특성 변화와 같은 환경적 영향을 초래하기 때문에 중요하다. 본 연구에서는 영암-금호방조제, 영산강 하구둑 방류현황을 수집${\cdot}$분석하고, 이를 바탕으로 하여 기존의 수치모형실험에서 간과되어 온 방류와 관련된 각종 실험계수를 재조정하여 수치모의론 수행하여 인근 해역 특성을 분석하였다. 영암-금호방조제에서의 방류량에 따른 조류변화를 파악하였으며 이에 기초하여 퇴적특성 변화를 비교한 결과, 조류 순환과 밀접한 관련이 있음을 알 수 있었다.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2006년도 공동학술대회 논문집
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• pp.73-78
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• 2006

저수지 누수구간에 대한 지수를 목적으로 저수지 제체를 대상으로 시멘트 그라우트를 이용한 그라우팅을 수행하였으며, 효과 검증을 위하여 그라우팅 전후에 다양한 수리시험과 전기비저항 탐사를 수행하였다. 효과 검증을 위한 쌍극자배열 전기비저항 탐사 결과 그라우팅 이후 전극 전개별 겉보기 비저항 이상곡선이 양호한 연속성과 주입 구간 전체에서 저비저항대가 수평적으로 발달되는 결과가 나타났다. 또한 장기간의 전기비저항 수직탐사를 이용한 결과 겉보기 비저항을 이용하는 경우 주입 이전에 비해 낮아지는 구간으로 주입 구간 확인이 가능하였다. 검사공을 이용한 전기비저항 토모그래피 탐사 결과 제체 상부에서 수행한 기존의 탐사 결과와 일치됨에 따라 향후 검사공을 이용한 그 라우팅 효과 판정 시 이 방법을 병행하는 경우 제체의 그라우팅 효과에 대한 공간적인 검증이 가능함을 확인하였다.