• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.229-236
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• 2002

In this study, the characteristics of chemical grouting, such as solidification, penetrability, were analyzed experimentally by grain size of grout materials and permeability, relative density of the ground. For evaluating applicability of grout material, solidification tests and permeability tests were peformed. From the results of the tests, effective solidification ratio and penetrability ratio of Micro Cement were 75% and 86% respectively when ground permeability was in the range of 10$^{-4}$ to 10$^{-2}$cm/sec. On the other hand, effective solidification ratio and penetrability ratio of Ordinary Portland Cement (OPC) were both lower than 50%. When penetrability of grout material is needed for improvement of dam foundation and soft ground, application of Micro Cement is much superior to that of the other materials. The results of the grouting tests in the hydrodynamic ground show that the solidification effect of long gel-time grout material is excellent as injection pressure increases when groundwater velocity is relatively low. But when groundwater velocity is relatively high, the solidifcation effect of long gel-time grout material is very poor because most grout materials are outflowed.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.340-349
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• 1995

Effects of the zeolite particle size on the soil chemical properties and on rice growth was investigated on the pot with the loamy sand (Sadu series) and silty clay loam(Paju series) soils. All the zeolite treatments brought the increase of unhulled grain yield on the both loamy sand and silty clay loam soils. Unhulled grain yield increased with increasing the amount of zeolite applied and with decreasing the amount of particle size of zeolite applied on both soils. Unhulled grain yield increased significantly by 11.1% (22.79g/head) with 2ton/10a of smaller than $106{\mu}m$ size zeolite on the loamy sand soil and on the silty clay loam soil, yield increased by 9.3% (24.98g/head) with 1.5ton/10a of smaller than $106{\mu}m$ size zeolite. CEC, pH and contents of exchangeable cations of the soil after experiment were raised by increasing the amount of zeolite and also by decreasing the particle size of zeolite at both soil. At the heading stage, the zeolite treatments improved the growth of rice plant compared to control. The nutrient contents(T-N, Ca, Mg, K, Na), except phosphorus, in the rice plant grown on the zeolite treated soils were higher than control plot.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.200-204
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• 1998

Physical and chemical properties of artificial soil produced by firing process were analyzed and compared with normal dry field soil and soil quality standards. Material used for production was water and wastewater treatment sludge, chabizite, and lime. The mixed material was thermally treated in the firing kiln at about $300^{\circ}C$ and $1,000^{\circ}C$, respectively, as per designed process. General properties of the artificial soil were classified as sand by unified soil classification method and similar to the dry-field soil, and even soil conditioning effect were expected when it is mixed properly with normal soil. The artificial soil is high in pH and permeability compared to the dry-field soil. Heavy metal concentrations of the artificial soil met the soil quality standards for the farmland. Overall, the artificial soil was thought to be an appropriate soil which can be returned safely to the nature without significant adverse effect. The cost for the artificial soil production process needs to be lowered for practical application as a sludge treatment, therefore, commercializing of the artificial soil is under review.

• Journal of Conservation Science
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• v.29 no.3
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• pp.209-221
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• 2013

This study is to interpret the construction characteristics and the provenance of soil layers from the Dongnamri site in Baekje Kingdom of Buyeo, Korea. The soil layers is divided into present age layer, Baekje layer and lower part layer, and the soils formed in the Baekje Kingdom period is divided into the Baekje 1st layer and the Baekje 2nd layer according to temporal intervals. The soil layers gradually becomes darker in color and higher in mineral content towards the lower part layer. However, the particular distinction between layers of the soils could not be identified. Additionally, the soil layers show a similar characteristics of mineralogy and geochemical evolution regardless of the layers. This indicates that the sites were made with weathered soil from an identical bed rock, and the site show a similarity to the surrounding soil, indicating its possibility of being the original materials. However, through the analysis of particle size, the first and second Baekje layers occurred that these layers were formed by setting up the soil with high content of sand on the bottom and stacking the soil with high content of silt on top of it.

• Journal of the Korean GEO-environmental Society
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• v.14 no.10
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• pp.49-57
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• 2013

Recently, recycling of the industrial by-products has been an important issue of the Yeosu bay, where large industrial complex is located. Major industrial by-products which are produced from Yeosu industrial complex area are phosphogypsum and flyash, which are about 82% and 10% of the 1.6 million tons industrial by-products. Moreover since the Yeosu industrial complex is located at seaside, phosphogypsum has been pointed as cause of serious environmental contaminant from the regional society. Therefore recycling study can't be delayed anymore. In this paper, artificial aggregate was manufactured by non-sintering process from industrial byproducts - e.g., phosphogypsum and slag - as a geotechnical drainage material. To show the feasibility of the artificial aggregate as a geotechnical drainage material, geotechnical experiments including particle size analysis, permeability test, and large scale direct shear test were carried out. Test results show that the permeability of the artificial aggregates range from $6.94{\times}10^{-1}cm/sec$ to $8.86{\times}10^{-1}cm/sec$, which is much larger value than those are required for the drainage material from the construction specification in Korea, and the friction angle of the artificial aggregate is as large as that of sand in water immersion conditions. From the test results, it was concluded that artificial aggregate made from industrial by-products can be used successfully as a geotechnical drainage material.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.1-12
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• 2018

This study was conducted to analyze the openness of erosion control dams situated near mountain stream. The ecological functions of erosion control dams analyzed by such openness for adequately protect and manage the diversity of species and to prevent disasters. The obtained results were as follows. When structurally modifying or changing non-permeable, gravity type dams with a passing rate of less than 1% into open-type dams, the passing rate increased by about 77 times more from 0.72% to 55.8%. Except for closed, gravity type erosion control dams that are constructed with a special purpose such as creating sand deposits and reservoirs, there is a need to construct and improve the dams into permeable type dams that can relatively satisfactorily perform various functions such as carrying soil and sand to the downstream region and create a ecological corridor upstream and downstream for fish and amphibians. The openness based on the blocking height of the erosion control dam varies depending upon the height of the base part and the depth of the substructural part. It must be designed based on the on-site conditions and the purpose of the construction. The functional types of erosion control dams based on the open form of the cross-section as follows: the fish traffic type, flood control type, reservoir type for forest fire control), non-permeability type for soil and rock blocking, net type for blocking the rock flow and the particle screen type.

• Journal of the Korean Geosynthetics Society
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• v.14 no.4
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• pp.59-77
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• 2015

In order to meet the new requirements for landfill materials, this study planned a study to apply mixed soil of mixing bottom ash and coastal dredged soil to the dredged ground. Coal ash generated from thermal power plant is divided into fly ash and bottom ash. In the case of fly ash, many studies have been conducted because small particles causes permeability coefficient to be small during recycling so no problem has been raised in the environmental area but the utilization of bottom ash has been limited because environmental problems have been raised during recycling due to its larger particle size and greater permeability coefficient. According to recently published studies, however, the results of the study that conducted the water analysis of leachate generated in the ground improvement section using bottom ash showed that heavy metal contamination levels were found to be within the reference value and no significant environmental problems were found so utilization of bottom ash is evaluated to increase significantly in the future. This bottom ash has the particle size of sand and only transportation costs need to be considered when providing materials because the majority has been disposed and it is judged as the most suitable material in dredging landfill in the economic aspect because most thermal power plants are located in the coast and transportation costs can be reduced by ship. Also, research on mixed soil that can maximize the effect of the construction period and construction cost savings than dredged soil is determined as needed because the demand for coastal dredging reclamation is increasing such as Saemangeum project etc. Therefore, we studied self-weight consolidation characteristics depending on sample processing and mixing method of mixed soil by carrying out interior self-weight consolidation experiments on mixed soil of mixing bottom ash and Kaolinite according to the new development needs of recent coastal reclaimed ground and these result findings are expected to be used as basic data when applying the large coastal dredged ground in the future.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.350-355
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• 1995

This study was conducted to use oyster shells, which have caused environmental problems in the coastal of Korea, as an agricultural material after processing. Physico-chemical components and neutralizing amount on the Ihyun silt loam of crushed oyster shell and slaked lime were examined. In field experiment, the properties of the soil, growth and yield of lettuce, cabbage, spinach, onion, red pepper and soybean were examined by the treatments of the shell(3.68ton/ha) or the lime (2.76ton/ha) with a randomized block design. Particle size of crushed oyster shell consisted of 73.4% of 1~60mesh and 26.6% larger then 61 mesh and contents of CaO, OM, and $P_2O_5$, etc. were 55.5%, 1.3%, and 0.29%, respectively. The requirement of the shell to neutralize the soil was 130~135% of the lime, but after 24months, it was the same. The application of the shell increased the contents of available $P_2O_5$ and $SiO_2$ exchangeable Ca in used soil. The shell tratment increased the leaf height, leaf width, etc. of the examined plants, and the yields 6~154% according to examined plants, as compared with the nonliminged, indicating that the shell possesses a great potential as an agricultural material with the same effectiveness as the lime.