• 한국환경복원기술학회지
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• 제23권6호
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• pp.187-200
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• 2020

Despite the eco-friendly route plan, road slopes were collapsed due to road construction, resulting in human and property damage. To solve this problem, the Ministry of Land, Transport and Maritime Affairs established guidelines in 2009 to conduct a test-bed for slope recording considering the conditions of the site and the ecological environment, and divided them into recording quality and economic evaluation. The following results were obtained by analyzing 183 construction methods of cut-soil sections at 60 sites from 2012 to 2018 for road slope afforestation research. Straw net+seedspray, vegetation media spray method 1T, 3T were used the most, and vegetation media spray method 3T(patent) was excellent in quality, and straw net+seedspray was excellent in economics. As a result of analyzing the market unit price and the construction unit price, vegetation media spray method submitted the construction unit price at up to 60% lower than the market unit price. As a result of the analysis of the key factors of the greening method evaluation, the economic assessment had the greatest influence on all evaluation items. Problems in the evaluation method of revegetation were first identified as problems in the allocation of points and secondly as problems in the evaluation criteria. As for the improvement of the economic assessment criteria, the method was proposed to evaluate the same method based on market unit price when the same method was constructed, and not to conduct an economic assessment if there was a difference in market unit price between methods, or to add weight to the scores. Based on the monitoring data of 60 road slopes, this study drew up problems and improvement measures. However, with regard to scoring, research on appropriate scoring is needed by examining the current status.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권3호
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• pp.1-13
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• 2021

Groundwater monitoring is commonly practiced with real-time sensors placed in several depth spots in aquifer. However, this method only provides monitoring data at the point where the sensors are installed. In this study, we developed a vertical line monitoring system (VLMS) that can provide continuous data of groundwater parameters along the vertical depth. The device was installed in a well located on the coast of the eastern part of Jeju island to monitor electrical conductivity, temperature, salinity, pH, dissolved oxygen, and oxidation-reduction potential over approximately 3 months from September 11 to December 3, 2020. The results indicated that the groundwater levels fluctuated with the tidal change of seawater level, and the upper and lower boundaries of the freshwater and saltwater zone in the groundwater were located at below 16 m and 36 m of mean sea level, respectively. There was a large variation in EC values during the high tide and temperature change was the greatest during flow tide. Although further investigation is needed for improvement of the device to obtain more accurate and reliable data, the device has a potential utility to provide fundamental data to understand the seawater intrusion and transport mechanisms in coastal aquifers.

• 한국지반신소재학회논문집
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• 제19권1호
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• pp.75-82
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• 2020

보강토 옹벽이 붕괴되는 사례가 종종 발생되면서, 붕괴된 옹벽의 보강 및 복구에 대한 사회적인 관심은 날로 커지고 있으나 이에 대한 연구는 미미한 경향이 있다. 이와 같은 배경 아래, 본 연구에서는 Plaxis 2D프로그램을 이용한 일련의 수치해석을 수행하여 설계부실로 전면블록의 전도와 배면 침하 피해가 발생된 기존 보강토 옹벽을 복구할 수 있는 방안에 대한 사례연구를 수행하였다. 복구방안으로는 기존 피해 보강토 옹벽에 쏘일네일링과 보강콘크리트(RC) 전면벽체를 보강하는 방안(Case 1)과 기존 피해 보강토 옹벽을 제거하고 재시공하는 방안(Case 2)으로 검토하였다. 보강토 옹벽의 내적안정검토결과는 파단에 대해서는 Case 1이 Case 2보다 크고 인발에 대해서는 Case 2가 Case 1보다 안전율이 크게 나타났다. 수치해석에 의한 외적거동과 전단강도감소법에 의한 전체사면안정 안전율은 Case 1이 Case 2보다 안정적으로 나타났다. 본 연구에서는 보다 안정적인 외적거동을 나타내는 Case 1로 기존 피해 보강토 옹벽을 보강하도록 하였다.

• 분석과학
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• 제21권4호
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• pp.304-315
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• 2008

한라산 1100 고지에서 채취한 대기 부유분진의 조성은 인위적 기원의 성분들이 가장 높고, 다음으로 해양 기원 성분과 토양 기원 성분들이 높은 함량을 나타내었다. 계절별로는 봄철에 토양 성분인 nss-$Ca^{2+}$, Al, Fe, Ca 성분의 농도가 크게 증가하였고, 인위적 기원의 $NH{_4}^+$, $K^+$, nss-$SO{_4}^{2-}$은 6월에 가장 높은 농도를 보였다. 반면에 $NO{_3}^-$은 봄철에 nss-$Ca^{2+}$과 함께 농도가 상승하였고, 이는 중국으로부터 장거리 이동에 의한 영향으로 추정된다. 황사와 비황사 때의 농도를 비교해 본 결과, 황사 때에 nss-$Ca^{2+}$, Al, Ca, Fe 농도가 7.2~9.5배 증가하였고, nss-$SO{_4}^{2-}$과 $NO{_3}^-$은 각각 1.3, 3.8배 정도 더 증가한 것으로 확인되었다. 요인분석법으로 분진성분의 발생기원을 조사해 본 결과, 한라산 1100 고지 부유분진은 토양의 영향을 가장 많이 받고, 다음으로 인위적 영향과 해염 영향을 많이 받고 있는 것으로 추정된다. 역궤적분석에 의해 분진 성분의 유입경로를 조사한 결과, 공기덩어리가 중국대륙을 거쳐 제주지역으로 이동한 북서풍 계열의 풍향일 때 주요 인위적 기원의 성분과 토양 성분의 농도가 상승하고, 공기가 북태평양을 거쳐 제주지역으로 유입되었을 때 이들 성분들의 농도가 상대적으로 감소하는 경향을 보였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.354-361
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• 2005

Physical parameters such as porosity and effective porosity are important physical parameters that determine the transfer and movement of water and solutes in porous media. Various methods of determining these parameters have been developed, with varying degrees of accuracy and applicability. Most of the existing methods produce static results. They do not produce instantaneous and real time of porosity and effective porosity in a porous media. In this study, a new permittivity method called Frequency Domain Reflectometry with Vector analyzer (FDR-V) is proposed to determine the porosity and effective porosity of some sand samples in the laboratory. The advantage of the FDR-V method is that it instantaneously determines the temporal variation of dielectric constants of porous media. Then, the porosity and the effective porosity of porous media are computed using well established empirical equations. Results obtained from the FDR-V method compared favorably with results from other permittivity methods such as gravimetric, injection and replacement tests. The ratio of effective porosity to porosity was $85{\sim}92%$, when FDR-V was used. This value compared favourably with 90%, which has been usually quoted in previous studies. Considering the convenience and its applicability, the measurement system of FDR-V permittivity holds a great potential in porous media and contaminant transport studies.

• 환경영향평가
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• 제9권2호
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• pp.127-142
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• 2000

This research was performed for analyzing the transport of suspended solids during the harbor construction. In behalf of the research, we have analyzes the characteristics of suspended solids movement in sand reclamation of breakwater according to age of tide and tidal period at the construction spot of Pusan new harbor. In the process of sand reclamation, soil was dumped by a dumping device which direct soil from the barge to the bottom of the sea. According to the results from this research, suspended solid concentration was very high in the range of 5m from the dumping point right after the dumping. However these suspended solids settled very quickly and the solids concentration was very beyond 10m from the dumping point. It is deduced that the movement of solids dumped from barge has the tendencies as following; 1) Most of the dumped solids precipitated quickly after the dumping 2) The rest of the suspended solids are diffused slowly toward the bottom of the water being figured smoothing curve 3) The diffusion movement of suspended solids tend to proceed toward the shore line in a parallel motion with tidal current at the sea-bottom That is to say, most of the suspended solids precipitated very quickly even though highly concentrated solids produced at the bottom of the solids which did not precipitated spread with the tidal current horizontally along the bottom of the sea.

• Ecology and Resilient Infrastructure
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• 제2권1호
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• pp.99-104
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• 2015

다수의 매토종자를 함유하고 있는 표토는 중요한 생태복원 재료로서 많이 알려져 있으나, 이를 실제로 활용하는 구체적인 방법에 대한 자료는 부족한 실정이다. 본 연구에서 하천복원 재료로서 표토의 가치에 대해 재평가하였다. 또한 실제로 황구지천 하천환경정비사업에서 완경사 호안, 고수부 복원, 식재 등에 표토를 활용한 결과 생태적, 치수적, 경제적 및 시공적 측면에서 자연친화적 하천 복원에 매우 효과적이었다. 결론적으로 표토가 하천복원의 유용한 재료인 것을 확인하였다.

• 한국토양비료학회지
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• 제43권3호
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• pp.275-282
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• 2010

The laboratory column experiments were used to transport of metal elements by infiltration-related dispersion and/or diffusion in mine tailing of the Guryong gold mine. The mine tailing shows the neutral pH (for a pore water) and contains quartz, chlorite, pyrite and calcite. Both a non-reactive solute ($Cl^-$ of 100 mg $L^{-1}$) and a reactive solute (1N HCl), were injected continuously through columns. The breakthrough curve in the non-reactive experiment reached at a maximum under 1.5 pore volumes (PV). The longitudinal dispersion (0.607 cm) and hydrodynamic dispersion coefficient ($1.96{\times}10^{-7}cm^{2}sec^{-1}$) were calculated by the slope. In the reactive experiment, the plateau curve was appeared in the pH values of 5.3, 4.5 and 1.7. The releases of metal elements such as Fe, Mn, Al, Cu, Zn, Pb, and Cd were observed to be related to the pH buffering. High concentrations of Mn, Cd and Zn were observed at the first pH plateau (4 PV and pH 5.3), whereas Fe, Cu, Al and Pb were released as the pH decreased to 4.0 or less. The resulting order of metals mobility, based on the effluent water, is Mn=Cd>Zn>Cu>Fe>Al>Pb.

• 한국미생물·생명공학회지
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• 제37권4호
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• pp.316-321
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• 2009

국내 토양으로부터 Chondromyces crocatus KYC2823을 순수 분리하고, 또 다른 5균주를 동반 세균이 함께 존재하는 상태로 분리하였다. 균주 KYC2823은 경북 청도군에서 채취한 토양시료에서 분리하였으며, 자실체 형태와 특이한 향의 발산을 포함한 여러 특성이 전형적인 C. crocatus임을 보였다. 이에 더해, 16S rDNA 염기서열이 C. crocatus의 새 표준균주로 제안된 Cm c5과 99.8% 유사하였다. 한편, PCR을 이용한 polyketide 생합성 유전자 조각의 클로닝 및 분석은 균주 KYC2823이 전자전달계 저해물질인 ajudazol과 actin cytoskeleton의 기능에 영향을 미치는 물질인 chondramide의 생합성 유전자, 그리고 아직까지 클로닝되지 않은 polyketide 계열 물질의 생합성 유전자를 가지고 있음을 보여주었다.

• 자원환경지질
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• 제39권2호
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• pp.191-212
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• 2006

사금광상은 주로 따까오이 지역에 분포한다. 충적층은 미고화 또는 반고화된 자갈층, 사질층과 토양층으로 구성된다. 이들은 석탄기-페름기 편암과 백악기 화강섬록암위에 부정합으로 놓인다. 상 분석에 의하면 충적층은 하도 충진의 자갈과 모래 퇴적광상 및 범람원 토양광상을 포함하는 전형적인 하성퇴적광상으로 사료된다. 금 입자는 주로 자갈층 내에 함유되어 있으며, 자갈층을 구성하는 역들 중에서 석영맥 기원의 역들만이 금을 함유하고 있다. 이러한 양상은 원암이 석영맥이었고, 이동과 삭박작용 동안 석영맥으로부터 금입자가 분리되었음을 지시한다. 이 지역에서의 금 매장량은 최소 792kg에 달한다.