• Journal of Soil and Groundwater Environment
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• v.12 no.4
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• pp.8-15
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• 2007

Geotechnical and environmental properties of stone fillers are analyzed by several laboratory experiment to identify the possibility of recycling fillers and sewage dredged soils as construction materials. The result of geotechnjical test shows that the sewage dredged soil is a sandy soil which contains 70-80% sand and is useful as an aggregate of construction site. Stone filler has large fine content, which may disqualifies the use as construction materials. However, this material is still useful as a filler in stone quarries or finished mines. From the environmental test, the liquids leached from two types of materials have satisfied the standard of chemical substances in the soil environment law and no harmful effect in ground pollution is expected when recycling.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.101-111
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• 2000

This research is results of experimental and numerical works on characteristic of strength increase and bearing capacity in dredged and reclaimed soil due to desiccation shrinkage. For a soil sampled from southern coastal area in Korea, basic soil property tests and standard consolidation test with falling head permeability tests were carried out to obtain consolidational characteristics of soil. Double cone penetration test, laboratory vane test and unconfined compression test were also performed to investigate the change of shear strength with degree of desiccation. Model tests were performed in 1G environment and 30G level artificially accelerated condition by using the centrifuge model test facilities to investigate the bearing capacity of desiccated ground. Test results were analyzed by using the theoretical and load-settlement characteristics method proposed by Meyehof & Hanna(1978). On the other hands, the numerical technique, using the finite strain consolidation theory considering the effect of desiccation was used to estimate the appropriate time of using heavy construction equipments in field with respect to strength increase due to desiccation.

• Journal of Ocean Engineering and Technology
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• v.24 no.3
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• pp.52-58
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• 2010

This study investigated the engineering properties of waste tire powder-bottom ash added composite soil, which was developed to recycle dredged soil, bottom ash, and waste tire powder. Test specimens were prepared using 5 different percentages of waste tire powder content(0%, 25%, 50%, 75%, and 100% by weight of the dry dredged soil), three different percentages of bottom ash content (0%, 50%, and 100% by weight of the dry dredged soil), and three different particle sizes of waste tire powder (0.1~2 mm, 0.9~5 mm, and 2~10 mm). Several series of unconfined compression tests, direct shear tests, and flow tests were conducted. The experimental results indicated that the waste tire powder content, particle size of waste tire powder, and bottom ash content influenced the strength and stress-strain behavior of the composite soil. The flow value increased with an increase in water content, but decreased with an increase in waste tire powder content.

• Geomechanics and Engineering
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• v.15 no.4
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• pp.957-964
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• 2018

In this study, a method of electrochemical consolidation is applied. This method utilizes electro-osmosis, which is an effective ground improvement technique for soft clays, and soil treatment using lime, which is the oldest traditional soil stabilizer. The mechanism of lime treatment for soil involves cation exchange, which leads to the flocculation and agglomeration. Five representative laboratory tests-an electro-osmotic test and four electrochemical tests with various proportions of lime-were performed on dredged marine clay. The objectives of this study are to investigate the effect of electrochemical treatment and to determine the optimum dose for optimal consolidation performance of dredged marine clay. The results show that a better consolidation effect was achieved in terms of current, temperature, and vane shear strength by using electrochemical treatment. The best results were observed for the electrochemical test using 4% lime content.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2891-2898
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• 2015

The new developed long distance transport technology uses the effect of electro-magnetic energy. But it's difficult to estimate the new technology. We monitored the velocity profile and pressure drops in pipes and estimated the technology quantitatively from data analysis. Laboratory test and field test gave us that the effects of electro-magnetic energy changed the flow properties and increased the velocity, especially at the slip layer. When transporting the dredged soil, electro-magnetic field generation reduces the frictional resistances at the slip layer, increases the velocity of flow. Furthermore, it would be possible to transport the dredged materials up to 15km long with one pump station.

• Journal of the Korean Geotechnical Society
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• v.21 no.10
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• pp.27-39
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• 2005

A finite difference program with 3-D governing equation expanded from 1-D self-weight consolidation is developed to analyze the consolidation behavior of surface dredged soil with horizontal drains. Various boundary conditions with horizontal drains and seepage pressure of pore water infiltrated to the drains are considered in the program. A laboratory soil chamber experiment for the consolidation of dredged soil is performed to validate the program and the measured settlement-time result is compared with the one predicted by the program. The influence of design conditions of horizontal drains such as horizontal installation spacing, installation depth and number of drain layers, on the consolidation is analyzed.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.155-165
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• 2003

A series of one-dimensional cylinder sedimentation test, seepage consolidation test and two-dimensional deposition model test were conducted to examine the characteristics of deposition and volume change of dredged soils containing the high water content, and these experimental results were compared with the sedimentary conditions of actual dredged-reclaimed fields to obtain the relations of a volume change by settling what is required for design. In addition, the change of water content and the distribution of fine grained soils after sedimentation were investigated. Thus, it was concluded that deposition height increased lineary as substantial soil volume increased, and also the elevation of interface increasea proportionately at both the starting time and the finishing time of virtual self-weight consolidation in one-dimensional sedimentation. Furthermore, the two-dimensional model test results were shown to describe the plain distribution of water content and fine grained silt where dredged soil was deposited by two dimensional flowing, and the water content was distributed to wide range from the minimum water content 30% to maximum 180% according to the passed amount of №200 sieve percentage.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.6 s.107
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• pp.95-102
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• 2005

This study was carried out to find out the heavy metal contents and the physico-chemical properties for the improvement of dredged soils which widely exist in lowlands of Korea. At first all the average heavy metal contents were close to background level and were much lower than concern level of the Soil Environment Conservation Act of Korea. And the results of physical analyses of soils showed on the average $2.46\~2.74 Mg/m^3$ in Particle density, $0.45\~2.45 kg/kg$ in soil water contents, $0.34\~0.90 Mg/m^3$ in bulk density, $0.67\~0.87m^3/m^3$ in porosity, $2.18\times10^{-5}\~1.20\times10^{-8} m/s$ in saturated hydraulic conductivity, R0.12\~0.65 m^3/m^3$ in available water contents. Finally the results of chemical analyses of soils showed on the average $6.5\~8.2\;in\; pH,\;5\~48 g/kg\;in\; OM,\;0.48\~4.51g/kg\;in\;T-N,\;19\~25mg/kg$ in available phosphate, $0.28\~11.80 dS/m\;in\;EC,\;8.7\~38.1cmol/kg$ in CEC, respectively Accordingly, the physicochemical properties of soils ought to be analyzed accurately before dredging for effective using of dredged soils. And it will be more effective, if the dredged soils are used with proper balance among each content of components with consideration to the physicochemical properties of common soils.

• Journal of the Korean GEO-environmental Society
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• v.12 no.9
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• pp.71-78
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• 2011

Cement treating technique, such as deep mixing method, has been used widely to stabilize the dredged clayey soil for many years. Despite of its effectiveness in treating soil by cement, several efforts have also been made to try to reduce the side effect of the cement that used to stabilize the dredged clay. However, authors considered that more detailed study on the physical and mechanical properties of lean-mixed soil-cement has been required to establish the design procedure to apply the practical problems. Therefore, in this study, the curing time and mixing ratio was used as key parameters to estimate the physical and mechanical properties including long-term behavior. The unconfined strength of lean-mixed soil-cement increase continuously during curing period, 270 days, while increasing rate becomes low in ordinary cement-treated dredged clay. We also concluded that cement-treated dredging clay shows apparent quasi overconsolidation behavior even in low cement proportion. By this study, fundamental approach was carried out for effective reuse of very soft dredged clayey soil both in mechanical and environmental aspect. It can be also expected that this study can propose a basic design data to use the lean-mixed soil cement.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.1
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• pp.99-109
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• 2015

In the construction industry, the interest for recycling aggregates is rising as more people demand for alternatives due to lack of supply of natural aggregates and environmental problems. However, in order for recycled aggregates to be used in infrastructures, stability and other factors need to be verified. Therefore, the objective of this study is to analyze the sensitivity of soil properties to secure slope safety according to various heights of embankment when bottom ash and dredged soil mixture is applied in the embankment. In most cases, all heights were safe for the slide for the embankment whether the water level is full or sudden draw down. The result of the sensitivity analysis revealed that the unit weight of embankments is highest among all factors to be considered. However, the sensitivity of the unit weight became smaller and the sensitivity of the friction angle of embankments increased with the height of embankments. The sensitivity of factors of core materials is very small because the core has weaker physical properties than those of the embankment. The effect of the height for each factor is different for each slope and water levels. The sensitivity of the unit weight of embankments is most affected when the height is 60m in the upstream slope. To conclude, bottom ash and dredged soil mixture can be applied in the embankment and different factors must be considered in different scale because the sensitivity depends highly on the height of embankments.