• 농약과학회지
• /
• 제9권4호
• /
• pp.330-337
• /
• 2005

토성(미사질식양토, 태백; 사양토, 횡성; 양토, 춘천) 및 자갈 함량(0%, 20%, 40%, 60%)에 따라 7종 (carbendazim, carbofuran, chlorpyrifos, cypermethrin, dimethomorph, diniconazole, endosulfan)의 농약을 토양 컬럼에 처리한 후 증류수로 담수상태를 유지하며 수거한 용탈수와 용탈수 수거 후 채취한 토양 중 농약 잔류량을 파악하여 수계 및 토양으로의 농약 이동특성을 평가하였다. 토성 별 용탈수 중 농약은 수용해도가 가장 높은 carbofuran이 세 토양 모두에서 총 검출량의 87% 이상 초기 $2{\sim}4$ L 채취시료에서 검출되었으며, 토양중 carbendazim과 carbofuran을 제외한 5종의 농약 검출량은 미사질식양토 > 양토 > 사양토 순이었다. 컬럼의 상, 중 및 하단의 토양 중 농약 검출량은 carbofuran을 제외한 6종의 농약이 clay 함량이 유사한 미사질식양토 및 양토의 컬럼 상단에서 $50{\sim}92%$ 수준으로 검출되는 경향을 보여 수계로의 농약 이동성 및 토양잔류성은 각 농약의 수용해도와 토양 중 clay 함량에 의존하는 것으로 파악되었다. 자갈함량에 따른 농약의 잔류경향은 토성별 실험과 유사한 결과를 얻었으며, 이동특성 또한 큰 차이를 볼 수 없었으나 자갈함량이 증가할수록 용탈수의 이동 속도 증가와 함께 시간당 농약의 이동량도 증가하였다.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 추계 학술발표회
• /
• pp.1258-1263
• /
• 2010

Backfill material of buried electrical transmission cable should dissipate the heat as rapidly as it is generated, or high temperatures will lead thermal runaway. These problems could raise thermal resistance and recude trasmission efficiency. So Backfill material of buried electrical transmission cable should have not only structual safty but good thermal property. So, in this study, we performed thermal resistancy test for various materials such as sand, weathered soil, clay and mixed soil to analyze the thermal characteristics of CLSM(controlled low strength materials) for water content.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2002년도 가을 학술발표회 논문집
• /
• pp.561-568
• /
• 2002

PFA(Paper Fly Ash) are reclaimed mainly or used in cement industry field as mixture agent in terms of materials recycling. Recently, research for recycling PFA as embankment materials or soil stabilization agent are undergoing in geotechnical engineering field. In this study, physical characteristics of PFA stabilization agent-soil admixtures are examined in change of water content, void ratio, consistency, grain distribution, specific gravity and density. Futhermore, the physical characteristics are compared with unconfined strength as engineering characteristics. Test results showed that unconfined strength and density are increased with increasing of PFA stabilization agent mixed ratio. On the other hand, specific gravity, void ratio and water content are decreased with increasing of PFA stabilization agent mixed ratio. It would be concluded that natural high water content ratio weak soil could be highly improved engineering and physical characteristics with PFA stabilization agent

• 한국해양학회지
• /
• 제13권1호
• /
• pp.19-28
• /
• 1978

To estimate the chemical mass balance of several kinds of trace metals in sea water, suspended matter and bottom sediments, sixty samples from the Kum and Mankyung estuaries were analyzed. In both estuaries, the distribution patterns of leachabl suspended trace metals and of bottom sediments were established to be similar. The relationship between the metal concentration and clay content of the sediments was found to be such that the metal concentration increases with an increase in clay content. A linear correlation ws determined between pairs of leachable metals (Fe-Zn, Fe-Mn and Zn-Mn) in the Kum estuary. However, in the Mankyung estuary linear relationship does not exist. Finally, it is suggested that the trace metals are reworking in the Kum estuary and those in the Mankyung estuary are sinking.

• 대한토목학회논문집
• /
• 제14권4호
• /
• pp.953-963
• /
• 1994

연약 점토 지반의 처리 기술은 고도의 토목공학적인 기술을 요한다. 특히 준설매립토는 액성한계가 크고 자연함수비가 매우 높아 매립재료는 부적합하지만 기술의 발달로 재료의 거동을 예측하여 안정한 재료로 활용할 수있는 단계에 있다. 본 연구에서는 초연약 준설 점토의 침강거동 및 자중 압밀거동의 특성을 알아보고 현장의 상황을 재현한 모형실험으로 얻어진 결과를 현장에서 활용할 수 있는 방안을 모색하고자 하였다. 이를 위해 압밀시험기는 대형으로 제작하였으며 높이와 직경의 변화에 따른 압밀거동의 특성을 고찰해 보고 수치모델로 자중압밀의 거동을 예측하였다.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 1997년도 총회 및 춘계 학술발표회 논문집
• /
• pp.47-52
• /
• 1997

The experimental investigations considered in this paper are similar in many respects to those of Lee$^1$, with some key differences. First, there is no layering of the soils in a heterogeneous liner. The only soil investigated is the clay component of the cover liner. This ensures that the clay is exposed to freezing and that frost propagation in the clay can be investigated separate from other processes. Second, a closed system approach to the simulation was adopted. According to Jones$^2$, closed-system freezing occurs when there is no source of water available beyond that originally present in the soil voids. Freezing under such conditions results in very thin or non-existent ice lenses. One of tile objectives of the experiments described in this paper was the moisture migration and the changing of moisture contents of the compacted clay liner in landfill. The closed-system was used to limit tile variables in the experimental simulation to make these calculations more direct, although the final results could be applied to an open system also. As a result, the moisture content decreased about 45%-46% after two freeze/thaw cycles.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2006년도 춘계 학술발표회 논문집
• /
• pp.1173-1180
• /
• 2006

In this study, aluminum electrodes were put in marine clay which was taken from the south coast in Korea to increase the undrained shear strength by inducing the densification and cementation between clay particles and precipitates which were developed by electric decomposition in an electrode. To raise the cementation rate and reduce treatment time, high electric current (2.5A) was applied in each electrode at a semi-pilot scale soil box with marine clay. After the tests, the undrained shear strength was measured at designated points using a static cone penetration test device and sampling was conducted simultaneously in order to measure water content, pH and electric conductivity which would be the key for configuring the cementation effects indirectly. In the results of electric decomposition in aluminum electrode, the measured shear strength was increased considerably compared to the initial shear strength because of the cementation effect between iron ions and soil particles.

• Geomechanics and Engineering
• /
• 제27권6호
• /
• pp.595-604
• /
• 2021

With the advantages of high permeability and strength, pervious concrete piles can be suitable for ground improvement with high water content and low bearing capacity. By comparing the strength and permeability of pervious concrete with different aggregate sizes (3-5 mm and 4-6 mm) and porosities (20%, 25%, 30% and 35%), the recommended aggregate size (3-5 mm) and porosity (30%) can be achieved. The model tests of the pervious concrete piles in soft soil (silt and clay) foundations were conducted to evaluate the bearing characteristics, results show that, for the higher consolidation efficiency of the silty foundation, the bearing capacity of the silty foundation is 16% higher, and the pile-soil stress ratio is smaller. But when it is the ultimate load for the piles, they will penetrate into the underlying layer, which reduces the pile-soil stress ratios. With higher skin friction of the pile in the silty foundation, the pile penetration is smaller, so the decrease of the pile axial force can be less. For the difference in consolidation efficiency, the skin friction of pile in silt is more affected by the effective stress of soil, while the skin friction of pile in clay is more affected by the lateral stress. When the load reaches 4400 N, the skin friction of the pile in the silty foundation is about 35% higher than that of the clay foundation.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2021년도 가을 학술논문 발표대회
• /
• pp.19-20
• /
• 2021

In order to reduce the emission of harmful substances that degrade indoor air quality, the Ministry of Environment strengthened the standards for the content of VOCs in paints to supply and sell eco-friendly paints. In this related study, an eco-friendly paint mixed with a powder-type absorbent material was prepared and its characteristics were reviewed. As the amount of powder-type absorbent material increased, the workability (viscosity, peeling, etc) decreased. Accordingly, this study aims to examine which particle size is suitable according to the particle size of the granular adsorbent while improving the problem of the powdery adsorbent by using the granular adsorbent. As an experimental plan, the particle size of granular activated clay is selected to be 0.250, 0.425, 0.710(mm), and the decrease rate of VOCs concentration and impact resistance are reviewed. As a result of the experiment, as the particle size of the granular activated clay increased, the decrease rate of the VOCs concentration increased and the impact resistance improved. Therefore, considering the problems that occur after actual painting, the particle size of granular activated clay of 0.425mm is suitable.

• 자원환경지질
• /
• 제28권5호
• /
• pp.455-467
• /
• 1995

In order to investigate the dispersion patterns and speciations of Cu, Pb, Zn and Cd in soils, stream sediments and stream waters, geochemical studies of soil, stream sediment and stream water samples collected in the vicinity of the Shi-Heung Cu-Pb-Zn mine was carried out Cation exchange capacity measurement, size analysis, X-ray diffraction analysis and batch test were performed to select applicable soil for adsorption treatment The average content of Cu, Pb, Zn and Cd in soils collected from tailings and ore dressing plant is 1084 ppm, 2292 ppm, 3512 ppm and 29.2 ppm, respectively, and therefore, tailings and ore dressing plant site may be the major contamination sources in this study area. The mean content of Cu, Pb, Zn and Cd in stream sediments is extremely high up to 794 ppm, 1633 ppm, 2946 ppm and 25.2 ppm, respectively. Tailing particles and heavy metal ions are dispersed along the tributary system. Results from the sequential extraction analysis indicate; (1) most of Cu is bound to organic matters and sulphides, (2) fraction of Pb is mainly bound to Fe and Mn oxides. Most of Zn is largely bound to Fe and Mn oxides and residual fraction. Ion exchangeable fraction of Cd is relatively higher than those of Cu, Pb and Zn. Batch test on soils collected from the kaolinite and/or pyrophyllite mines and from the control areas was carried out to select an applicable soil samples for adsorption treatment The sample, S10, collected from the control area 2 (clay content 33.2%) shows the highest $K_d$ (distribution coefficient). Organic content in soils and several clay minerals shows relatively good correlation with $K_d$. It means that applicable soils for adsorption treatment of heavy metals show high organic and clay content.