• 자원환경지질
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• 제11권3호
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• pp.99-108
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• 1978

The Gum-Ho river basin is one of the densely populated area having more than 35% of the total population and it was also well irrigated since earlier days in the Nackdong river basin. Most of the easily developed source of surface water are fully utilized, and at this moment the basin is at the stage that no more :surface water can be made available under the present rapid development of economic condition. Since surface water supplies from the basin have become more difficult to obtain, the ground water resources must be thoroughly investigated and utilized greatly hereafter. In economic ground of the basin what part could ground water play? In what quantities and, for what uses could it be put? The answer to these questions can be relatively simple;the ground water resources in the basin can be put at almost any desired use and almost anywhere in the basin The area of the basin is at about $2088km^2$ in the middle part of Nackdong river basin and it is located along the Seoul-Pusan express highway. The mean annual rainfall is about 974.7mm, most of which falls from June to September during the monsoon. Accumulated is appeared approximately after every 8 year's accumlated dry period with the duration of 5 years. The water bearing formation in the basin include unconsolidated alluvial deposits in Age of Quaternary, saprolite derived from weathered crystalline rocks, Gyongsang sedimentary formations of the period from late Jurassic to Cretaceouse, and igneouse rocks ranging of the Age from Mesozoic to Cenozoic. The most productive ground water reservoir in the basin is calcareous shale and sandstones of Gyongsang system, which occupies about 66% of the total area. The results of aquifer test on Gyongsang sedimentary formation show that average pumping capacity of a well drilled into the formation with drilling diameter and average depth of $8{\frac{1}{2}}$ inch and 136m is $738m^3/day$ and also average specific capacity of those well is estimated $77.8m^3/D/M$. Total amount of the ground water reserved in the basin is approximately estimated at 37 billion metric tons, being equivalent 18 years total precipitations, among which 7 billion metric tons of portable ground water can be easily utilized in depth of 200 meters.

• 한국터널지하공간학회 논문집
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• 제15권2호
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• pp.161-173
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• 2013

도심지와 같이 개발가능한 지역이 제한되어 있으면 기존 건물에 인접하여 지반을 굴착하는 경우가 종종 발생한다. 이러한 경우 지반은 이완되고 따라서 토압에 따라 가시설 벽체에 변형이 발생하므로 인접 구조물의 안정성에 문제가 발생할 수 있다. 따라서 본 연구에서는 실내 모형실험을 통하여 여러 가지 형태의 지반 굴착방법에 따른 인접 지반의 지표면 변위를 산정하고, 이를 수치해석에 적용하여 지표면 침하에 따른 구조물의 변형 양상을 연구하였다. 이렇게 얻어진 구조물 변형 형상 중에서 각 변위와 수평 변형율을 추출하여 최종적으로 인접 구조물의 손상 정도를 평가하였다.

• 한국터널지하공간학회 논문집
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• 제11권3호
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• pp.229-242
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• 2009

본 논문에서는 터널굴착으로 발생한 지표면에서의 최대 침하 및 수평변위와 총 침하부피량을 추정하기 위하여 서로 상이한 지층에서 다양한 깊이 및 직경, 서로 다른 시공조건(지반손실량)을 가진 터널에 대해 수치해석을 수행하였다. 수치해석 결과로부터 얻어진 지표면에서의 최대 침하량은 터널 굴착부 천단에서의 최대 침하량과 지층별, 터널직경 및 깊이, 시공조건(지반손실량)별로 비교되었으며, 또한 지표면에서의 최대 침하량은 지표면에서의 최대 수평변위량과도 비교하였다. 뿐만 아니라, 터널굴착부에서 발생한 지반손실량($V_L$)과 지표면에서 형성된 총 침하부피량($V_s$)을 지층 및 터널깊이와 직경을 달리하여 상호 비교하였다. 수치해석을 통해 얻어진 결과는 그 적용성과 타당성을 검증하기 위하여 기존 현장계측자료와의 비교가 수행되었으며, 이를 통해 본 연구의 수치해석 결과가 향후 터널굴착으로 발생된 주변 지반의 거동을 파악하고 분석하는 실무자료로서 활용될 수 있다는 것을 파악하였다.

• 한국안전학회지
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• 제7권4호
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• pp.55-61
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• 1992

An engineer designing a tunnel in an urban area should be to predict the magnitude and distribution of ground movements which are important to Investigate the potential damage to the existing structures around tunnel. The present study examines available theories and emprical equations, and tries to investigate quantativily ground movements around tunnel with tunnel progressing. Approcaches to the problem of ground movements associated with twin tunnel was and elasto - plastic finite element method. Typical section in Seoul Subway were selected in numerical study. The analysis and study was done with respect. to surface, subsurface and crown settlements with varying ground conditions, tunnel geommetry and construction conditions.

• 한국환경과학회지
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• 제5권6호
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• pp.727-738
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• 1996

An one dimensional atmosphere-canopy-soil interaction model is developed to estimate of the heat budget parameter in the atmospheric boundary layer. The canopy model is composed of the three balance equations of energy, temperature, moisture at ground surface and canopy layer with three independent variables of Tf(foliage temperature), Tg(ground temperature), and qg(ground specific humidity). The model was verilied by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HAPEX-MOBILHY experiment. Also we applied this model in two dimensional land-sea breeze circulation. According to the results of this study, surface characteristics considering canopy acted importantly upon the simulation of meso-scale circulation. The factors which used in the numerical experiment are as follows ; the change for a sort of soil(sand and peat), the change for shielding factor, and the change for a kind of vegetation.

• Journal of Mechanical Science and Technology
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• 제20권7호
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• pp.1043-1050
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• 2006

The aerodynamic interaction between a wing and a rail is investigated using a boundary-element method. The source and doublet singularities are distributed on the wing and its guide-way rail surface. The unknown strengths of the singularities are determined by inverting the aerodynamic influence coefficient matrices. Present method is validated by comparing computed results with the other numerical data. Rail width and rail height affect the aerodynamic characteristics of the wing only if the rail is narrower than the wing span. Although the present results are limited to the inviscid, irrotational flows, it is believed that the present method can be applied to the conceptual design of the high speed ground transporters moving over the rail.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1360-1361
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• 2008

This paper presents the surface potential rise distribution near grounding electrodes produced by ground fault currents. The small-scale model with the foundation pedestal in hemispherical tank was used to simulate the ground fault condition of the electrical installations for street lamps. When entering the fault current through the test ground electrode, surface potential rise, potential gradient, touch and step voltages for different grounding electrode shapes were measured, and the results obtained were discussed.

• 한국해양공학회지
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• 제15권1호
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• pp.92-97
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• 2001

Hardening agents have been the traditional material for surface soil stabilization of soft ground. This study aims at determining the optimal mixture ratio of the hardening agent in accordance with the required design specifications. Hardening agents which consists of fly ash, gypsum, slag and cement for the ettringite hydrates is effective for early stabilization of unconsolidated soil. The raw ground material is the clay that is widely found in Korea. In this study, preliminary tests were performed to get an optimal mixture ratio of the stabilizer ingredient and marine clay from Jinhae was used to get physical and chemical properties. Laboratory tests of 50 stabilized soils were performed to get an optimal mixture ratio for 16-stabilizer materials of 6 types, and a mixture ratio of the stabilizer ingredient and marine clay was determined.

• 한국환경복원기술학회지
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• 제7권4호
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• pp.17-31
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• 2004

How far of natural regeneration of the city and improvement on the urban environment will be possible in the replanting on the impermeable surface? The replanting of what kind of form will be obtained in order to realize it? The regeneration of the nature is possible, if it can be realized at the thin soil layer in which the result of being equivalent to the natural soil function. Using the light artificial soil with the water retentiveness, it is possible that green on the artificial ground reinforces the green skeleton of the city. The green of artificial ground improves the thermal ambience of the city and demonstrates stormwater runoff depression effect. It is necessary to built the landscape which continues with the surrounding green. Ecologically stabilizing green has the high amenity. The development of replanting technology of the artificial ground which fosters the city culture is desired.

• 한국군사과학기술학회지
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• 제10권3호
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• pp.71-78
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• 2007

We suggest a multi-path propagation analysis method using DTM(Digital Terrain Map). Generally, the total signal strength at a target is calculated by adding the field propagated in free space and the field reflected from the ground surface. In this paper, we also consider the vertical reflections associated with the vertical surfaces such as precipitous cliffs and electricity pylons in the mountain area. In addition, we primarily take account the main slope of the ground surface to improve the accuracy of the total field density at the target.