• Journal of the Mineralogical Society of Korea
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• v.13 no.3
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• pp.115-120
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• 2000

Oxidation of pyrite has caused a serious environmental problem such as the acidification of soil and surface water. The mineralogical change of acid sulfate weathering of hydrothermally altered andesite which contained 11.8% of pyrite and was exposed in atmosphere by lay out works for a residential area and a golf course was studied using X-ray diffraction (XRD) and electronmicroscopes. Ferrihydrite, jarosite, and an unidentified water soluble phase were observed as weathering products of the andesite. Under electronmicroscopes, showed aggregate of platy microcrystals; jarosite was platy morphology: water soluble Phase was columnar. Morphology of fresh Pyrite in the andesite changed from pyritrohedron to cubic in its frequency with increasing its particle size. The drainage water was acidic (pH 3.5) and in an equilibrium state with both ferrihydrite and jarosite.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.7 no.4
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• pp.340-345
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• 1995

Dispersion characteristics of surface discharge heat water in shallow region are investigated for coastal power plant with nearly constant depth of 20 meters by observing the seasonal depthwide temperature in several stations, which give or precise horizontal distribution and vertical structure of heat water. Surface discharged heat water in shallow coast in the Yellow Sea relies mainly on ambient tidal flow. so it behaves as free jet when the ambient now is strong and shows plumelike behavior during stagnant tide. According to observation the neat field region is estimated as 200-300 meters and shows distinct vertical profile and exponentially decreasing pattern from discharge point for this region. But there are no remarkable vertical distortion of temperature beyond 800 meters even though it is discharged from surface. Characteristic length scale model, CORMIX3, is applied and compared with the field date Overall tendency of CORMIX3 results resemble well with field data especially in near field and intermediate region.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1178-1189
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• 2010

낙동강 하구지역 연직배수공법이 적용된 연약지반에서 성토시 발생할 수 있는 지반의 측방변형에 대해 3개소 현장 35개 지점에서 수행한 현장 계측데이터를 분석하였다. 성토과정에서 측방변형 패턴 및 변형량을 파악하는데 가장 우선적으로 파악해야 할 계측항목이 지중경사계이며 지반특성별 측방변형 패턴(최대 측방변위발생 지점, 전단변위 발생지점, 지층에 따른 변위발생 형태 등)의 정밀 분석을 위해서는 지중경사계가 설치된 지점의 지층구성을 파악하는 것이 가장 중요하다는 것을 알 수 있었다. 최대 측방변위량과 성토체 중앙부 침하량과의 관계에서는 Tavenas et al.(1979)이 제안한 ${\Delta}_y=(0.18+0.09){\Delta}_s$이하로 관측되었다. 또한 측방변형 억제 및 인접지반의 동반침하를 차단하기 위해 보강된 D.C.M., C.I.P.구간에서는 Tavenas et al.(1979)이 제안한 ${\Delta}_y=(0.18-0.09){\Delta}_s$이하로 관측되었다. 최대 측방변위량과 성토속도와의 관계에서는 과잉간극수압 소산에 필요한 충분한 시간과 원활한 배수가 될 수 있도록 시공관리(성토속도조절, 배수관리 철저)하는 것이 무엇보다도 중요하다는 사실을 다시 한 번 확인 할 수 있었다. 마지막으로 편재하중 재하에 따른 인접 지반 및 구조물의 침하 및 기울기 변화는 측방유동에 의한 거동과 함께 압밀침하에 의한 제체의 체적감소로 인한 인접지반의 동반침하가 상당기간 동안 발생하고 있는 것으로 관측되었다.

• Journal of the Korean Geotechnical Society
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• v.15 no.5
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• pp.171-191
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• 1999

The final aim of this research is to systematize the reinforced-earth wall system using the geosynthetic composite reinforcement in the weathered granite backfill soils having relatively large amount of fines. As a staged endeavour to accomplish this purpose, laboratory pull-out tests and finite element modeling are carried out in the present study focusing on the analyses of friction characteristics associated with interaction behaviors of the geosynthetic composite reinforcement composed of geogrid with a superior function in tensile resistance and geotextile with sufficient drainage effects. In addition, drainage effects of the geotextile below geogrid are examined based on the analysis of finite difference numerical modeling. From the present investigation, it is concluded that the geosynthetic composite reinforcement in the weathered granite backfills may possibly be used to achieve effects on both a reduction of deformations and an increase of the tensile resistance, together with drainage effects resulting from the geotextile.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.2
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• pp.162-169
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• 2007

This study is focused on the comparison of a 3 dimensional numerical and hydraulic model experiment for the flow phenomenon when a lock gate is opened. The lock gate is designed to discharge the flood flow rate at $218m^3/s$ of Solicheon at the Kun Jang national industry complex. The three dimensional ${\kappa}-{\epsilon}$ turbulent model of ANSYS CFX-10 of the computational fluid dynamics(CFD) program was used. The characteristics of CFX-10 are able to be simulated effectively for turbulent flow, especially the flow separation of the boundary layer of the two phase interface of air and water. The velocity and the flow pattern of the numerical model was showed to be similar to the results of the hydraulic model experiment.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.3
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• pp.276-281
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• 1985

This study was conducted to examine the morphological, physical and chemical characteristics of the Song-jeong (residuum), Dae-gog (local colluvium-alluvium), Ji-san and Og-cheon (local-alluvium) series with fine loamy texture derived from fine granitic parent materials on the drainage catena. 1. These soils consist of a catena, and then a color sequence due to the influence of topography, water table and free iron content. 2. The poorer the drainage, the higher were the silt/clay ratio, soil reaction, organic matter, and available phosphate content in soils but the active iron content was lower.

• Journal of the Korean Geosynthetics Society
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• v.4 no.1
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• pp.7-15
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• 2005

In recent years, the geotextile tubes filled with dredged material have been used in dike and breakwater construction for a number of projects around the world, and their use in this field is growing very fast. One of the most attractive advantages of geotextile tube technology is can be use the in-situ filling materials by hydraulic pumping, it can be also established lower costs and fast construction than other technology. Geotextiles form one of the two largest groups of geosynthetics and it is commonly made by two major types of polymer material(Polypropylene, Polyester). The objective of this paper is to examine several issues associated with drainage function and feasibility of geotextile tube structure such as filtering efficiency, dewatering efficiency, and filling process with polymer materials. Based on the laboratory filtering test and in-situ tests, polypropylene goetextile is more effective for drainage function of geotextile tube technology.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.41-46
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• 2008

After choosing twenty sluice culverts located at national rivers by detailed appearance evaluation, hydraulic response test and acoustic televiewer in addition to surface geophysical explorations were carried out to investigate the cavities which exist at the boundary of sluice culvert and ground. Tapping, GPR, 3-D resistivity surveys and acoustic televiewer imagery obtained successful results in limited conditions according to characteristics of the sites. On the other hand, hydraulic response test successfully detected cavity existing at the lower part of sluice culvert and its continuity. However, hydraulic response test can not supply the quantitative informations on the scale and the shape of cavity. Thus it is very important for accurate investigation to make comprehensive interpretation after supplying various surveys proper to site characteristics.

• Resources Recycling
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• v.25 no.3
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• pp.3-10
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• 2016

The passive treatment was required a large area for the treatment of acid mine drainage (AMD), and pollutants were discharged with mine drainage by the increased flow rate in summer. This study was performed to improve the turbidity and to precipitate the pollutants quickly using coagulants and flocculants in AMD of abandoned mine sites that were difficult to build the passive treatment system. The coagulant PAC (Poly aluminium chloride) and flocculant PAM (Polyacrylamide) were selected to improve turbidity in W mine waters. We also tested the particle size analysis, ICP-OES and/or SEM-EDS for water and sludge samples.

• Journal of the Society of Disaster Information
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• v.13 no.4
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• pp.483-490
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• 2017

Recently, the demand for industrial and residental land are increasing with economic growth, but it is difficult to obtain the area for development with good ground condition. Various kinds of vertical drain technologies such as sand drain, sand compaction pile, packed drain, PVD are commercially available to improve the soft ground. Discharge capacity is the important factor of vertical drains. However, under field conditions, discharge capacity is changed with various reasons, such as soil condition, overburden pressure, and so on. In this paper, the experimental study was carried out to estimate the discharge capacity of four different types of PBD, PBD for double core PBD, deep type PBD, X type PBD, general type PBD. Characteristics of the discharge capacity for the surcharge load and hydraulic gradient were analysed. The double core PBD was excellent for discharge capacity in this study.