• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.120-123
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• 2001

To evaluate the biodegradability of contaminants in an aquifer, computer modeling with RT3D model (Clement, 1997) was used. The RT3D model simulates the biodegradation of organic contaminants using a number of aerobic and anaerobic electron acceptors. The RT3D model was applied to a well-studied petroleum hydrocarbon plume in a shallow unconfined aquifer in Uiwang, Korea. The results of this study demonstrate tile importance of biodegradation processes in the monitored natural attenuation and in reducing contaminant concentrations in a shallow aquifer. The modeling results tell that the amount of electron acceptors is the key factor affecting biodegradation of TEX, the petroleum hydrocarbon contaminant in shallow groundwater

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.05a
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• pp.70-73
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• 1997

Recycling of$\boxUl$ useful industrial waste is highly recommended by the government. Some geotechnical properties such as specific gravity, dry density, unconfined compressive strength, pH. compressibility, permeability were determined to evaluate the feasibility of waste lime use in the landfill as an admixture clay liner. Various types of environmental tests on waste lime were conducted to compare the results with the EPA requirements. Laboratory test results indicate that admixture soil(waste lime/decomposed granite soil) is a promising material its an admixture clay liner in the sanitary landfill.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.219-222
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• 2003

Bech scale tests were performed to evaluate the adaptability of industrial wastes, especially bottom ash, salg and phosphogypsum among others, for constructing the surface layer of a landfill or reclamation, which function is a vegetation base layer. In the test, columes test were used to check the extraction characteristics of wastes and small PVC soil-box that equipped the drainage device was used to model a performance of layers and to monitor the growth of plants at the composite layer of those. Tests have been continued during one and half year and It has been verified that bottom ash and phosphogypsum look like as a valuable material to safely reuse as the vegetation base layer even though some unconfined factors are remain.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.183-186
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• 2003

This study was conducted to evaluate effects by adding oil to clay soil and influences of remained oil in soil as time elapsed. Unconfined compression test and direct shear test were performed to analyze strength properties of contaminants in clayey soil. As a results of $q_u$ test for kerosene and diesel contaminated clayey soil indicate that were decreased from near 5% oil content rapidly and the declination of strength were blunt as oil content over 10%. The cohesions(c) and internal friction angle(${\psi}$) of kerosene contaminated clayey soil were not varied as quantities of kerosene in clayey soil increased. In the case of diesel contaminated clayey soil, the cohesions(c) were decreased and the internal friction angle(${\psi}$) were increased.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.447-450
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• 2005

The purpose of this study is to investigate properties of compressive strength of concrete using the shale rock as coarse aggregates. To evaluate properties of compressive strength of concrete using crushed shale rock, we performed the expriment according to the proportioning strength of $10MPa\~40MPa$ and the slupm of $12\%\~15\%$. The result of this study is as follow. The compressive strength of concrete using crushed shale rock is lower than those of granite aggregates. The proportioning strength is higher, the reduction of comperssive strength of concrete using the shale rock is higher.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.49-54
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• 2000

Several soil parameters can be calculated for results of Piezocone test; sensitivity, soil classification, OCR, undrained shear strength, coefficient of consolidation etc., and used to analysis geotechnical problems. Particularly, the coefficient of consolidation which is related to degree of consolidation varies according to rigidity index(I/sub r/). In this study, rigidity index(I/sub r/) was analyzed by Roy's formula. Trixial tests and unconfined compression tests data in the ten sites was analyzed. In conclusion, rigidity index(I/sub r/) was suggested such as rigidity index(I/sub r/) = 15∼60, average rigidity index value(I/sub r/) of approximately 33 within a country.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.443-446
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• 2000

The feasibility study on paraffin binder as a solidifying agent of digested sewage sludge cake was peformed. The availability of paraffin binder as a solidifying agent was investigated by several tests. Based on the tests, it is ascertained that paraffin binder with a small amount of quicklime and fly ash enhances the solidification of digested sewage sludge cake. Paraffin binder shortened the drying time of digested sewage sludge cake and solidified sludge with paraffin was not dissolved in water again. Also, the unconfined compressive strength of solidified sludge with paraffin increases.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.494-505
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• 2006

In this study, using constant normal stiffness(CNS) direct shear tests, side shear load distribution were analyzed by the influencing parameters of unconfined compressive strength, surface roughness, confining stress, and material properties. Based on the CNS tests, side shear load transfer function of drilled shafts in rock is proposed using geological strength index(GSI), which indicates discontinuity and surface condition of rock mass in Hoek-Brown criterion. Though comparisons with results of nine drilled shafts's load tests, it is found that the load-transfer curve by this study is in good agreement with the general trend observed by in situ measurements, and thus represents a significant improvement in the prediction of bearing capacity of drilled shaft.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.906-909
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• 2005

The purpose of this paper is to study on the construction of roadbed with environmental friendly soil amendment agent and reinforced fiber. The special amendment agent and fiber used in this study has a function of soil-cement-agent solidification and reinforcement. A series of laboratory experiments including unconfined compressive strength, tensile strength, compaction test were carried out to investigate the physical and mechanical characteristics of roadbed treated by solidifying agent and fiber. The results of this research showed that the roadbed using poor soil could be efficiently constructed by treatment of this amendment agent and fiber.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1390-1395
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• 2005

To analyze the effects of oyster shell particles, inserted in the self-hardening matrix such as cement paste, on strength, homogenization analysis using micro structure was used to estimate and assess the apparent elastic modulus of oyster shell particle. DIB modeling technique was used to represent of the micro structure of oyster shell mixed concrete. The results showed that the apparent elastic modulus of LOS (large oyster shell particle) was changed with the amount of LOS inserted. In particular, when the amount of LOS was 200% of the weight of cement, the apparent elastic modulus of LOS tended to decrease rapidly. This could mean that the strength of oyster shell mixed concrete is much affected by LOS inserted material in mixed ratio of 200%.