• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.383-385
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• 2012

Confined Disposal Facilities(CDF) are an effective and commonly used management option for contaminated dredged material. CDF is an engineered contstruction for containment of contaminated dredged material to control potential releases to the environment. Although the concept is simple, constructing a CDF is a complex and non-standard process. In the process of planning a CDF, many different fields of expertise have to be considered, such as civil engineering, landscaping, chemistry, legislation, social impact, and environmental engineering. This paper provides the concise overview of common guidance on CDF.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.185-192
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• 2000

Recently, the hydraulic fill method is commonly used in many reclamation projects due to lack of fill materials. The method of hydraulic fill in reclamation is executed by transporting the mixture of water-soil particles into a reclaimed land through dredging pipes, then the dredged soil particles settle down in the water or flow over an out flow weir with the water. In the present study, practice each three method in order to suggest method of determining the loss rate of the dredged fills. The first sieve and hydrometer analysis were performed with the soil samples obtained before and after dredging and then apply theory of particle breakage, the second compare with the volume of dredged soil between at the dredging area and the target pond and the last compare with weight of dredged soil between before and after dredging at the dredging area and in the target pond for estimating the amount of soil particles residual at the reclaimed area and the loss of soil particles passed through the weir. In addition to compare with the loss ratio between as using Marsal's modified theory of particle breakage and measured weight and volume in the field.

• 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.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.1183-1189
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• 2009

The sedimentation rate of particles in a suspension is a function of particle size, initial slurry water content and salinity. Many researches conducted on the behavior of dredged soils have centered on such factors. However, there have been few attempts to assess another important influence factor of seasonal water temperature on designing the placement of dredged materials. In this paper, the effect of seasonal water temperature on sedimentation characteristics of dredged clay was investigated with consideration of three different water temperatures, that are $5^{\circ}C$, $15^{\circ}C$, $35^{\circ}C$, which represent critical water temperatures in winter, spring or fall, and summer, respectively. A series of experimental results reveal that the sedimentation rates for the water temperature of $15^{\circ}C$ and $35^{\circ}C$ are very similar each other, but that of $5^{\circ}C$ that represents a winter season leads to a considerably delayed sedimentation compared to the others. This may be attributable to the retardation of ion-leaching from clay particles at low water temperature.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.3
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• pp.129-135
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• 2011

EAF dust from steel industry used as primary materials for the production of lightweight aggregates. Fe compounds in EAF dust plays an important role in the bloating reaction. This study was conducted to evaluate the feasibility of using bottom ash and dredged soil from coal power plant and EAF dust. The effect of different raw material compositions and sintering temperatures on the lightweight aggregate properties were evaluated. The characteristic of thermal bloating of bottom ash and dredged soil were mainly influenced by ferrous materials. The specific gravity of aggregate was decreased with the addition of EAF dust and kerosene was reduced sintering temperature on the bloating formation. Lightweight aggregate containing 10% EAF dust having apparent density under 1.0 g/$cm^3$ were produced at $1150{\sim}1200^{\circ}C$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.212-223
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• 2022

For the remediation and restoration of contaminated sediment at the West Sea-Byeong dumping site, dredged materials was dumped in 2013, 2014, 2016, and 2017. The physicochemical properties and benthic fauna in surface sediments of the capping area (5 stations) and natural recovery area (2 stations) were analyzed annually from 2014 to 2020 to evaluate the capping effect of the dredged materials. The natural recovery area had a finer sediment with a mean particle size of 5.91-7.64 Φ, while the sediment in the capping area consisted of coarse-grained particles with a mean particle size of 1.47-3.01 Φ owing to the capping effect of dredged materials. Considering that the contents of organic matters (COD, TOC, and TN) and heavy metals in the capping area are approximately 50 % lower (p<0.05) than that in the natural recovery area, it is judged that there is a capping effect of dredged materials. As a result of analyzing macrobenthic assemblages, the number of species and ecological indices of the capping area were significantly lower than that of the natural recovery area (p<0.05). The number of species and ecological indices at the capping area were increased for the first four years after the capping in 2013 and 2014 and then tended to decrease thereafter. It is presumed that opportunistic species, which have rapid growth and short lifetime, appeared dominantly during the initial phase of capping, and the additory capping in 2016 and 2017 caused re-disturbance in the habitat environment. In the natural recovery and capping areas, Azti's Marine Biotic Index (AMBI) was evaluated as a fine healthy status because it maintained the level of 2^nd grades (Good), whereas Benthic Pollution Index (BPI) remained at the 1^st and 2^nd grade. Therefore, capping of dredged materials for remediation of contaminated sediment in the dumping site has the effect of reducing the pollution level. However, in terms of the benthic ecosystem, it is recommended that the recovery trend should be monitored long-term. Additionally, it is necessary to introduce an adaptive management strategy when expanding the project to remediate the contaminated sediment at the dumping area in the future.

• Journal of the Korean GEO-environmental Society
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• v.4 no.4
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• pp.53-59
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• 2003

Phosphogypsum is a by-product resulting from the phosphoric acid process for manufacturing fertilizers. It consists mainly of $CaSO_4{\cdot}2H_2O$ and contains some impurities such as $P_2O_5$, $F^-$, and organic substances. Recycling research of phosphogypsum is very limited to a field of study, especially, civil engineering. This study describes an application of phosphogypsum as dredged materials. For this purpose, experiments are performed to evaluate the physicochemical properties and environmental characteristics of dredged clay with phosphogypsum ; sedimentation test, pH, and leaching test. The result of this study are as follows : the settling velocity is increased due to the activity of phosphogypsum. And leaching and radioactive test results are far below than those of regulatory requirement of Waste Management Act in Korea. Therefore phosphogypsum can be used as dredged materials in reclamation.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.495-508
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• 2010

Vertical drains are commonly used to accelerate the consolidation process of soft soils, such as dredged materials. The installation of vertical drain provides a radial drainage path to water in the deposit soil in addition to the vertical direction. An estimation of time rate of settlement is considerably complicated when vertical drains are installed to enhance consolidation process of dredged material because the vertical drains are commonly installed before self-weight consolidation is ceased. In this paper, the vertical drain theory developed by Barron(1948) is applied to analyze the non-linear consolidation behavior considering radial drainage. The overall average degree of self-weight consolidation of the dredged soil under the condition that the water is drained in both radial and vertical directions is estimated using the Carillo(1942) formula. In addition, the Morris(2002) theory and the one-dimensional non-linear finite strain numerical model, PSDDF, are applied to analyze the self-weight consolidation in case of only the vertical drainage is considered. The new analysis approach proposed herein can simulate properly the time rate of the self-weight consolidation of dredged materials that is facilitated with vertical drains.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5230-5236
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• 2013

In this paper, the influencing factors for the decision of the embankment construction method utilizing geotextile tube were studied by analyzing the application and economic considerations based on the construction practices of the geotextile tube filled with dredged soil in the domestic and international. In the domestic case, cost savings of 40 to 50% is attained by applying geotextile tubes in the embankment construction and in the international case, the amount of quarry materials was reduced from 20 to 70% by replacing the core of the embankment with geotextile tube. As a result, utilization of geotextile tube filled with dredged soil should be considered in a very large construction site with a quarry-to-site delivery distance of more than 16~25km. The construction scale and delivery distance were found to be important influencing factors for the decision of the embankment construction method utilizing geotextile tube filled with dredged soil.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2C
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• pp.119-131
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• 2010

In this study, beneficial use of ocean contaminated sediments were investigated by laboratory and environmental tests, and their prototypes were released. Dredged material from Ulsan port is used for making cement treated samples and lightweight foamed samples, and various engineering tests were performed to identify the compressibility and stress-strain behaviors. Environmental tests were also performed for the beneficial uses. The values of Cu are a little higher than the suggested standard possible for reusing dredged material and equal to the suggested standard alarming for reusing dredged material, which shows environmental harmfulness for the reuse of construction material. In addition, particle size distribution, compaction test, Atterberg limit tests, specific gravity test, and unit weight test were performed to investigate the use of landfill cover materials. The shear strengths of cement treated soils were found to be enough for reclamation works.