• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.606-611
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• 1999

Recently , the hydraulic fill method is commonly used in many reclamation projects due to lack of fill materialss. The method of hydraulic fill i recalmation is executed by transporting the mixture of water -soil particles into a relcaimed land through dredging pipes, then the dredged soil particels settle down in thewater orflow over an out flow weir with the water. The amount of the volume reductions of dredged soil is considered the sum of the overall settlement by descication shrinkage and self-weigth consolidation and the loss of soil particles flow over a weir. In the present study, hydrometer analysis was performed with the soil samples obtained bofore and after dredging to estimate the amount of soil particles residual at reclaimed area and the loss of soil particles , then it was suggested the method of determining the loss ratio of dredged soils from the tests results. The hydrometer analysis of in-situ soil samples showed that the loss ratio of dredged soils is lowest at the nearest point to dredge pipe and highest at the nearest point of out flow weir.

• Korean Journal of Environmental Agriculture
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• 제33권4호
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• pp.298-305
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• 2014

BACKGROUND: The utilization of green manures as alternatives to reduce the use of chemical fertilizers is considered a good agricultural practice. Effect of incorporation of green manure to soil on change of inorganic nitrogen (N) is well literatured. However, there have been few studies on examining entire dynamic of N including inorganic N and N gases in soil incorporated with green manure. The objective of this study was to examine the changes of inorganic N and N gases with single and mixture applications of hairy vetch and barley in the soil. METHODS AND RESULTS: Hairy vetch(H) and barley (B) were applied at the mixture ratio of B:H=0:0, B:H=100:0, B:H=0:100, and B:H=50:50 in soil. The soil-green manure mixtures were incubated in the dark at $25^{\circ}C$ for 17 weeks under aerobic conditions. Cumulative emission of $NH_3$ and $N_2O$ from soils amended with mixture of barley and hairy vetch(B:H=50:50) were less than those from amended with mono hairy vetch(B:H=0:100). Incorporation of single hairy vetch or mixture of barley and hair vetch application could significantly increased concentration of plant available N ($NH_4{^+}$) in early stage of plant growth and plant available N ($NO_3{^-}$) in later stage. However, high concentration of $NO_3{^-}$ in soil could cause adverse environmental impact through $NO_3{^-}$ leaching from soil. CONCLUSION: Conclusively, it might be a good soil management practice to incorporate mixture of barely and hairy vetch in the view point of increase in plant available N concentration and decrease in N losses through volatilization, denitrification, and leaching.

• Journal of Soil and Groundwater Environment
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• 제6권4호
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• pp.61-72
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• 2001

A barrier liner system is placed at the bottom and side slope in landfill to protect a leaking of leachate that the hydraulic conductivity of this system should be less than It 107cm/sec. In this study, the soil-bentonite mixture for the bottom liner system was evaluated in two point of views : changing characteristics of the hydraulic conductivity according to the different mixing ratio of soil-bentonite with the effect of bentonite swelling and the difference method (A & D type) of compaction on the hydraulic conductivity. As the results, maximum dry density (${\gamma}$$_{dmax}$) of SC group mixture was higher than of CL group mixture. However, the result of optimum moisture contents(OMC) of both groups were the contrary. In case of ${\gamma}$$_{dmax}$ by different compaction method, D type was higher than A. But the OMC were the contrary. The difference of ${\gamma}$$_{dmax}$ according to the Compaction energy, “SC” group mixture W3S higher than the “CL” group. In case of OMC of “CL” group was higher than “SC” group. The effecting of swelling was a little bit different on the two factors. According to the result of compaction test, the use of site soil only could not meet the criteria on hydraulic conductivity, but could find a solution for the mixing ratio of bentonite mixture were satisfied to the standard of barriation. The increased in bentonite mixing ratio and degree of swelling, the values of hydraulic conductivity were decreased. Especially the “CL” group with “D” type compaction measured the lowest value with the same conditions. Also, the bentonite mixing ratio has more influenced on the hydraulic conductivity compare with swelling effect. The “SC” group mixture with “A” typo compaction got a big difference from others. The evaluation of economic for the construction cost on the two cases, the lower bentonite mixing ratio of soil-bentonite mixed soil is more economically because of bentonite cost.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.127-130
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• 2001

This paper presented to phenanthrene removal of electrokinetic(EK) remediation and enhanced EK remediation with bench scale test. The experiments were carried out on mixture soil with phenanthrene as the test compound. The EK remediation experiments were conducted under controlled voltage. Surfactant solution was constantly supplied at the anode reservoir with constant concentration. Results showed that phenanthrene was removed little in EK remediation. Surfactant helped phenanthrene moving and cumulated in cathode region. Moving effect was increased with surfactant concentration.

• Computers and Concrete
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• 제12권6호
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• pp.785-802
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• 2013

Ready-mixed soil material, known as a kind of controlled low-strength material, is a new way of soil cement combination. It can be used as backfill materials. In this paper, artificial neural network and nonlinear regression approach were applied to predict the compressive strength of ready-mixed soil material containing Portland cement, slag, sand, and soil in mixture. The data used for analyzing were obtained from our testing program. In the experiment, we carried out a mix design with three proportions of sand to soil (e.g., 6:4, 5:5, and 4:6). In addition, blast furnace slag partially replaced cement to improve workability, whereas the water-to-binder ratio was fixed. Testing was conducted on samples to estimate its engineering properties as per ASTM such as flowability, strength, and pulse velocity. Based on testing data, the empirical pulse velocity-strength correlation was established by regression method. Next, three topologies of neural network were developed to predict the strength, namely ANN-I, ANN-II, and ANN-III. The first two models are back-propagation feed-forward networks, and the other one is radial basis neural network. The results show that the compressive strength of ready-mixed soil material can be well-predicted from neural networks. Among all currently proposed neural network models, the ANN-I gives the best prediction because it is closest to the actual strength. Moreover, considering combination of pulse velocity and other factors, viz. curing time, and material contents in mixture, the proposed neural networks offer better evaluation than interpolated from pulse velocity only.

• Journal of the Korean Society of Environmental Restoration Technology
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• 제5권2호
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• pp.34-38
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• 2002

This studies were performed to determine the effects of indoor relative humidity conditions on the growth of Arachniodes aristata and Pyrrosia lingua in native fern and investigate an applicable possibility of indoor plants. The response of Arachniodes aristata and Pyrrosia lingua was evaluated in growth chamber (KG-8407-87) to 3 relative humidity and 3 soils. Relative humidity was applied to 25%, 50%, 90%; soils were prepared based on soil mixture(SM), top field soil(TF), masa soil(MS). Results of experiments are as follows ; 1. Under a low humidity condition, such as 25%, Water contents, chlorophyll content, ornamental value of Arachniodes aristata and Pyrrosia lingua decreased much more a 50-90%. 2. The growth of Arachniodes aristata were best in pots under a soil mixture(SM) but Pyrrosia lingua were field top soil(FT) under 25%. It seemed that Pyrrosia lingua due to tolerance of desiccation more than Arachniodes aristata. Though these studies, coefficient of relative humidity and soil was plays an important role in Arachniodes aristata and Pyrrosia lingua growth in indoor environments.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제54권3호
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• pp.327-331
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• 2009

Korean government has promoted the policy of chemical fertilizer reduction by 40% reduction from 2003 to 2013. Hairy vetch (Vicia villosa Roth) fixes nitrogen from the atmosphere and rye (Secale cerale L.) accumulates soil nitrogen to reduce potential nitrogen loss. The objective of this research was to identify optimum seeding rates of hairy vetch-rye mixtures in the central regions of Korea. The experiment of mixture rate was carried out for maximum production in 2006 and 2007. The best seeding rate mixture for maximum biomass production was 6.75 kg hairy vetch and 5 kg rye per 10a. Pure hairy vetch and rye were used as control. The nitrogen production of mixture treatments were higher than pure rye. The hairy vetch and rye mixture can scavenge potentially leachable nitrogen, while maintaining soil fertility by adding fixed nitrogen to the cropping system.

• Geomechanics and Engineering
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• 제10권6호
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• pp.793-806
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• 2016

The pozzolanic characteristics of a sludge incinerated into ash were determined in this study. Lime is commonly used as a stabilizer for the treatment of soils, whereas sewage sludge ash (SSA) is often applied with lime to improve soft subgrade soil. In this study, a cohesive soil categorized as A-4 (low-plasticity clay) by AASHTO classifications was mixed with SSA/lime with a 3:1 ratio. Nano-$SiO_2$ was also added to the soil. To identify changes in the workability, strength, permeability, and shear strength of the soft subgrade soil, basic soil tests were conducted, and the microstructure of the treated soil was analyzed. The results indicate that SSA/lime mixtures improve the properties of soft subgrade soil and transform the soil from "poor subgrade soil" to "good to excellent subgrade soil" with a CBR > 8. Additionally, the addition of 2% nano-$SiO_2$ increases the unconfined compressive strength of soft subgrade soil treated with SSA/lime mixture by approximately 17 kPa. However, the swelling of the treated soil increased by approximately 0.1% after the addition of nano-$SiO_2$ and lime. Thus, soil swelling should be considered before lime and nano-$SiO_2$ are applied to soft subgrade soil.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.47-51
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• 2004

The purpose of this research was to evaluate the effect of mixed surfactant solution for removal of perchloroethylene (PCE) in soil. Ten different surfactant solutions were used in column studies. Mixed surfactant solutions (anionic and nonionic) were most effectively worked in the sandy soil for removal of PCE as a result of synergism between the two types of surfactants. The effectiveness of the mixture of surfactants was 35 % greater than that for the anionic or nonionic surfactant alone. The results indicate that mixed surfactant solution leaching is a promising candidate for the remediation of PCE contaminated sandy soil.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 한국지하수토양환경학회 2000년도 창립총회 및 춘계학술발표회
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• pp.3-8
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• 2000

A simple and rapid simultaneous analysis method of BTEX and TPH in soil was developed. 5g of soil sample were mixed with sodium sulfate and then extracted with 10 mL of mixture of acetone and dichloromethane (1:1). Extraction was performed for 10 min in sonicator and analysis was with GC-FID. The detection limits of BTEX and TPH was 0.8 and 10 mg/kg, respectively. The analytical recoveries were >90% for all BTEX and TPH. Low boiling point fuels and high boiling point fuels are consistently reproduced within RSD 7%. The analysis results show very simple and rapid quantitation of BTEX and TPH in soil sample with low RSD.