• Journal of Soil and Groundwater Environment
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• v.18 no.1
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• pp.57-66
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• 2013

Although the quantity of dredged soils has increased owing to recent new harbor construction, sea course management, polluted sediment dredging, and four-river project, the reuse or recycling of those dredged soils has not done properly in Korea. To develop measures to utilize them in various ways for reuse or recycling, the biophysicochemical properties of dredged soils and sediment were assessed in this study. Samples were classified according to their sources-river and sea-by location, and as dredged soil and sediment depending on storage time. The results showed that dredged materials from the sea have high clay content and can be used for making bricks, tiles, and lightweight backfill materials, while dredged materials from the river have high sand content and can be used in sand aggregates. Separation procedures, depending on the intended application, should be carried out because all dredged materials are poorly sorted. All dredged soils and sediments have high salinity, and hence, salts should be removed before use for cultivation. Since dredged materials from the sea have adequate concentrations of nutrients, except phosphate, they can be used for creating and restoring coastal habitats without carrying out any additional removal processes. The high overall microbial activities in dredged materials from the river suggested that active degradation of organic matter, circulation of nutrients, and provision of nutrients may occur if these dredged materials are used for cultivation purpose.

• Journal of the Korean GEO-environmental Society
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• v.16 no.9
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• pp.5-12
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• 2015

A large amount of dredged soils occur in the marine purification project but dredged fine-grained soils have been abandoned as a waste. The standards as filling materials, banking materials, revetment blocks and concrete blocks were surveyed. Through the geotechnical tests of marine dredged fine-grained soils and the alkali-activation reaction, the usability as banking materials, revetment blocks and concrete blocks were analyzed. Dredged sands could be used as banking materials, and dredged fine-grained soils could be used as filling materials. A mixture of dredged fine-grained soils and dredged sands could be used as banking materials. Materials produced by the alkali-activation reaction could be used as a revetment block and a concrete block.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.299-307
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• 2009

New lake dike in Saemanguem area is 125km length and require a great amount of fill materials, but it's difficult to get the amount of materials and develop a quarry because of environment conservation. Therefore, the solution is to use the dredged soil in project area as the fill materials not to develop quarry. However, characteristic of dredged soil as a silty fined sand is very weak at seepage, sliding, erosion of dike due to infiltration of rainfall, wind etc. So, lake dike using dredged soil must be constructed safely against the unstable problem of dredged sand. The objective of research is to make safe lake dike using dereged soil on construction of Saemangeum new lake dike. So, we analyzed the characteristic of dredged soil and suggested a standard section of lake dike.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.14 no.3
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• pp.192-200
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• 2002

There is a volume change between the sediments and the dredged materials because the dredged materials is fully disturbed by the dredger and settled in the basin from the stabilized condition. The volume of the dredged materials is also affected by the coagulants and flocculants (hereafter C & F) which was used to speed up the settling of the suspended solids. In this study, the volume change of the dredged materials is analysed in detail due to the injection amount of the C & F. The dredged materials were sampled in the lagoon located in the East coastal zone, and the volume change of the samples is quantitatively analysed by the laboratory test due to the change of the clay content and the amount of the C & F. The optimal amounts of the C & F is determined by showing the minimal volume change due to C & F injection. From the experimental results, the volume of the dredged materials is increased 1.68 times on an average and the volume change rate is slightly increased, i.e., negligible, as the clay content increase in the case of the C & F injection.

• Journal of the Korean Geotechnical Society
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• v.24 no.5
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• pp.15-25
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• 2008

Contamination level assessment of harbor dredged materials is carried out for beneficial use, which generated annually due to port construction and maintenance of harbor channel. The basic purpose of environmental risk assessment was a scientific approach to susceptibility of hazard risk to human's health from different dredged materials. And this paper proposes a guideline of safely beneficial use of dredged materials at both industrial area and residental area, generated from major port execution throughout a sound investigation of their contamination levels. Newly proposed guidelines were in general higher levels compared to both current guidelines of treatment and use of dredged materials and soil environment protection levels. Finally, environmental assessment results of dredged material contamination generated in major ports of Korea for beneficial use based on pre-assessment environmental levels show that some port's dredged materials contain heavy metals such as Cd, As, Cr and Zn, more than base levels which requires more precise contamination investigation. Others were found to be very appropriate for beneficial use.

• Journal of the Korean GEO-environmental Society
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• v.14 no.2
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• pp.31-41
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• 2013

The dredged soils of western sea of Korea have been used as the fill materials because it possess the characteristics that constitute silt, silty sand and sand mainly. However, a study on dredged soils as the fill materials is insufficient. Hence, in this present study, the application the dredged soils of western sea of Korea as the fill materials was confirmed. Primary, the composition characteristics of the ground was analyzed to confirm the application on dredged soils as the fill materials by the piezo-cone penetration test. In laboratory test, it was performed the self-weight consolidation test for mechanical characteristics of the dredged soils. The direct shear test using self-weight consolidation test sample for shear strength characteristics was performed after self-weight consolidation test. Additionally, the mechanical characteristics of the dredged soils on elapsed time using self-weight consolidation test sample, which is drained naturally, was evaluated. The dredged soils of western sea of Korea show that unit weight and shear strength is increased as natural drain time elapses.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.54-57
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• 2002

Pretreatment technologies are defined as technologies that prepare or condition dredged material for subsequent, more rigorous treatment processes. The objectives of this study are to test the feasibility of treating dredged sediment using pretreatment process(hydrocyclone, sedimentation basin, and flotation), and to estimate design parameters for a pilot-plant design. The final goal of the project is to recycle the dredged sediment that is otherwise reused as construction materials.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.247-258
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• 2008

Environmental standards for beneficial uses of dredged materials are proposed. Even though chemical analysis of ocean sediments are carried out frequently, their analyses results were not interrelated with the effects of biological lives due to a shortage of biological data. These facts have resulted in difficulty to develope Korean's standards of recycling dredged materials. This paper first searched existing current foreign standards, analyzed local contaminated ocean sediment data, identified their main chemical components of contaminants, and then compared with clean-up standards of sediments consisting of lower and higher levels. From these analysis, new environmental standards considering Korean domestic circumstances are proposed. It is judged that new standards are appropriate to both Korean national sedimental environments and economically recycling aspects because environmental standard levels proposed are higher than background levels of sediments in Korean and foreign standards.

• Journal of Navigation and Port Research
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• v.30 no.9
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• pp.755-762
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• 2006

When we consider to develop a new harbor, the most important factor, we think, is the lowest water depth of waterway and approaching channel for safe navigation of vessel. The existing harbors have been being dredged to meet the international trend of jumbo sized vessels by adopting the new design criteria. As the dredged materials over the expected at the design level were common and there are still lack of land based reclamation area, we have no choice to discharge the dredged materials in open sea area In this study, we analysed the behavior of discharged materials at the dumping area of offshore, which were collected from the dredging work at the waterway in Busan New Port. We measured the tidal currents and analyzed the waters of dumping site after the dumping work. These were used to evaluate the numerical models. Suspended Solids(SS) were introduced to the diffusion model. Because of the characteristic of the dumping site, the speed of initial diffusion and settle down of the discharged materials was so fast. Therefore, we believe that the dumped materials do not cause a significant impact to the marine environment.

• Journal of Environmental Science International
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• v.17 no.1
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• pp.29-36
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• 2008

A large amount of $2.1{\times}10^6m^3$ of polluted sediment was dredged from the Masan Bay and deposited in Gapo confined area, Masan, Korea. The six representative sediments were obtained and analyzed for issue components. The data was discussed with the species of benthos and their distribution. It was judged that toxicological effects of sediment analyzed ranged from ERL to ERM with copper and zinc, and ERL with cadmium, chrome, lead and nickel by the Adverse Biological Effects. The dredging index (DI) of sediments stabilized for 10 years since dumping the confined site was calculated and compared with the DI values of dredged sediment itself. DI values decreased from 0.67 to $0.07{\sim}0.18$, which reflects DI value less than 0.2 is good for benthos in the sediment by the natural recovery of dredged materials. The ecological recovery was confirmed in this confined area as a habitat of benthic organisms.