• Journal of Ocean Engineering and Technology
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• v.18 no.4 s.59
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• pp.46-51
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• 2004

The surface layer in dredged and reclaimed marine clay is improved by mixing of shallow soils and hardening agents, which is made of cement, containing some other special admixtures. Tests in both laboratory and field settings are performed to investigate the improvement effect and strength properties of cement-stabilized soils. The test results show that the hardening agent sufficiently improves the soil properties of the surface layer, while increasing the load-carrying capacity. The strength of cement-stabilized soils depends, primarily, on water-to-cement ratio and curing temperature. That is, the higher curing temperature and the longer curing time, the higher the strength in cement-stabilized soils. The high ratio of water-ta-cement results in a lower strength.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.201-204
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• 2004

Immobilization is seen as a promising technology for lead remediation. In a laboratory experiment, immobilization of lead with soluble P was tested as a function of reaction time and P concentration. The P treated with an acidic solution to enhance heavy metal immobilization was worked into the soil, and within 7 days, lead was stabilized. Different molar ratios of soluble phosphates (super-phosphate and KH$_2$PO$_4$) would be considerably effective to accelerate the formation of highly insoluble minerals due to the lack of leachable Pb in the contaminated soil. Although it was demonstrated that the addition of soluble phosphates with an acidic solution significantly reduced available lead in soil up to over 95%, remaining phosphorus in soil matrix might cause a possible groundwater eutrophication in the near future.

• Geomechanics and Engineering
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• v.6 no.4
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• pp.403-418
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• 2014

There are around 6700 millions tons of perlite reserves in the world. Although perlite possesses pozzolanic properties, it has not been so far used in soil stabilization. In this study, stabilization with perlite and lime of an expansive clayey soil containing smectite group clay minerals such as montmorillonite and nontronite was investigated experimentally. For this purpose, test mixtures were prepared with 8% of lime (optimum lime ratio of the soil) and without lime by adding 0%, 10%, 20%, 30%, 40% and 50% of perlite. Geotechnical properties such as compaction, Atterberg limits, swelling, unconfined compressive strength of the mixtures and changes of these properties depending on perlite ratio and time were determined. The test results show that stabilization of the soil with combination of perlite and lime improves the geotechnical properties better than those of perlite or lime alone. This experimental study unveils that the mixture containing 30% perlite and 8% lime is the optimum solution in stabilization of the soil with respect to strength.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.30-33
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• 2002

In this study, feasibility of using hydrogen peroxide as a chemical oxidant for in-situ treatment by EK-Fenton technology were investigated. Kaolinite, kaolinite/sand mixture and illitic soil spiked by phenol and phenanathrene were used and variation of electrochemical characteristics were examined by EK-Fenton test. For kaolinite that having low buffer capacity, hydrogen peroxide was injected effectively from anode reservoir. However illitic soil that having relatively higher buffer capacity had low hydrogen peroxide introducing efficiency. The test results showed that Hydrogen ions generated by current increased during the treatment decreased under pH 3 in the most of kaolinite specimen. Therefore, stabilized hydrogen oxide was injected more effectively in the kaolinite specimen. This study suggests that efficiency of hydrogen peroxide injection by EK-Fenton thechnoloty is dependent of variation of pH in the soil

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.17-24
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• 2000

Hardening agent has been the traditional material for surface soil stabilization of soft ground. This study aims at determining optimal mixture ratio of hardening agent in accordance with the required design specifications. Hardening agent is properly mixtured with Fly ash, Gypsum, Slag and Cement for the ettringite hydrates which is effective for early stabilization of unconsolidated soil. The treated soil is the clay which are widely found here and there in Korea. In this study, preliminary tests were performed to get optimal mixture ratio of stabilizer ingredient, and marine clay in Jin-Hae was used to get physical and chemical properties. Laboratory tests of 50 stabilized soil were peformed to get optimal mixture ratio for 16 stabilizer material of 6 type, and stabilizer mixing was determined.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.735-738
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• 2005

The purpose of this study is the infiltration characteristics of soil cut-slope by rainfall. Stability analysis of soil cut-slopes has been conducted by limit equilibrium method on Seep/w and finite element method on Slope/w. Result is same as following. First. the hour when seepage line and groundwater in contact is proportionate from rainfall rate condition and upper natural slope gradient condition which is identical. Second, when seepage line and groundwater is contact, seepage line moves gradually at soil cut-slope surface. Finally, seepage line is formed similarly with soil cut-slope gradient. Third, when rainfall is ended, from the recording upper natural slope where the hour will pass it is stabilized

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.129-134
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• 2000

Hardening agent has been the traditional material for surface soil stabilization a sat ground This study aims at determining optimal mixture ratio of hardening agent in accordance with the required design specificutions. Hardening agent is properly mixed with Fly ash, Gyosum, Slag and Cement for the etmmngite hydrates which is dective for early stabilization of unconsoliokrred soil. \ulcornerhe treated soil is the clay tint is widely found here and there in Koresz In this study, preliminary tests were performed to get optirml mixture ratio of stabilizer ingredient, and mrvine clay in Jin-Hae was used to get physid and Md properties. Labomtory tests of 50 stabilized soil were performed to get optimal mixture mtio for 16-stabilizer merial a 6 types, a d stabilizer mixing was determined

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.381-386
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• 2005

In order to have compressive strength tests and frost heaving tests, two sorts of soil samples at Chonbuk-Do area were used. According to this research, the compressive strength of soil which was mixed by quick lime, was largely increased until 28 days but after 28 days, the increment of strength was seldom found and its maximum compressive strength increasing rate for content of quick lime was $10{\sim}15%$ scope. In the mixed rates of quick lime and briquette ash, the compressive strength of soil which was mixed by quick lime and briquette ash, was increased by increasing mixed rates of quick lime and its compressive strength was increased by additional quantity. The compressive strength of mixed soil within freezing-thawing 1 cycle was diminished around 30% compared to non-freezing soil's 28 days compressive strength but there were no movements after 2 cycle.

• Geomechanics and Engineering
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• v.10 no.6
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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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• 2003.04a
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• pp.184-187
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• 2003

The preliminary data from the application of the ultrasound to the degradation of TCE were shown. The first order degradation coefficients were are 0.0134 s$^{-1}$ and 0.0151s $^{-1}$ with saturating gas of air and argon, respectively. The pH of the solution went down to 3 and stabilized in each case.