• Journal of the Korean GEO-environmental Society
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• v.15 no.3
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• pp.49-55
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• 2014

Characteristics of sedimentation of dredged soil is depended on the field condition and characteristics of dredged soil because dredged fill ground was formed by various field condition, sedimentation and self-weight consolidation process of dredged soil. Dredged fill ground is formed as separated sedimentary layer by characteristics of dredged soil. Therefore, it requires some special test method to consider a various field condition, characteristics of sedimentation and self-weight consolidation of dredged soil. In this study, in order to identify the characteristics of sedimentation of dredged soil with disposing velocity geo-centrifuge test and laser particle size analyzer were performed. As a results, river and mixed dredged soil show the separation sedimentation by soil particle size. And sedimentation of clayey dredged soil is parallel to the bottom surface of dredged fill space.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.922-929
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• 2004

In some port construction, a case of reclamation with dredged soil for land use can be found. Even though this is not a new technology, there are some problems on the test method and analysis. The design parameters are still remained to be solved to get accurate prediction. Sedimentation of particle and self-weight consolidation are the most important design parameters in reclamation by dredged soils. The design parameters are influenced by properties of the physical and sedimentation of dredged soils. This influencing factors can be determined depend on the history of long term sedimentation and particle characteristics. Thus, properties of the sedimentation and consolidation are varies depend on the regional geologic formation. In this paper, three different sites with different regional soil properties will be compared in design parameters of sedimentation and self-weight consolidation.

• Journal of the Korean GEO-environmental Society
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• v.18 no.2
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• pp.59-65
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• 2017

The costal reclamation construction is for making reclaimed land by dredging marine clay with seawater, and then bringing the dredged soil into the reclaimed land. During the process, the dredged soil in the reclaimed land undergoes the sedimentation-consolidation process. Among the processes, the consolidation is a very critical factor when planning reclaimed land because of its requiring time and settlement. In order to predict the requiring time and settlement, the Column test, which was suggested by Yano, has been usually used in the nation. However, the test method needs a very long time to identify the characteristic of sedimentation-consolidation of dredged soil. Therefore, in this study, in order to supplement the weakness of the Column test which needs such a long time, and in order to identify the characteristic of the sedimentation-consolidation for dredged soil in a short time, the Geo-centrifuge test was examined as an alternative method. The result considered that Geo-centrifuge test would be useful to identify the characteristic of sedimentation-consolidation for dredged soil efficiently.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.1190-1197
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• 2009

Design parameters related to Yano's method(1984, 1985), one of experimental approaches having been used widely in Korea to estimate sedimentation and consolidation of dredged and reclaimed ground, were analyzed and their propriety were reassessed in this paper. Data analyses were performed on the basis of the settling test results using samples from the west coastal area of Korea. From analysis of results, for specific characteristics of these dredged and reclaimed marine soft clays, co-relations of initial water content - coefficient of sedimentation/ consolidation - initial setting velocity were evaluated. Relation between height of soil solid and surface height of slurry at the stages of initiation and termination of consolidation was also assessed. Finally ranges and average values of these design parameters were evaluated and typical empirical equations between these design parameters were also proposed.

• 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 GEO-environmental Society
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• v.17 no.2
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• pp.13-22
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• 2016

Accurate settlement estimation of dredged soft soil deposits is significantly important to prevent potential disasters during land reclamation. An application of the non-linear finite strain consolidation theory is inevitable in dealing with a very soft ground formation such as dredged fill. In this paper, a series of the sedimentation-consolidation test, self-weight consolidation test and CRS test were conducted to clarify sedimentation and consolidation characteristics of dredged fill in the Songdo area, Incheon. In addition, the settlement of dredged fill was numerically simulated using the PSDDF program. The dredged soil obtained from the Songdo area was classified as low-compressible silt (ML) based on USCS (Unified Soil Classification System), and the final bulking factors were estimated to be 1.56 and 1.17 by Yano's method and the numerical simulation, respectively. This difference is attributable to relatively high reclaimed height and large permeability of dredged soil in this region.

• Journal of the Korean Geotechnical Society
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• v.23 no.8
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• pp.129-135
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• 2007

In order to analyze the effect of fines content on sedimentation and self-weight consolidation characteristics of dredged soil, a series of self-weight consolidation tests with different fines content were conducted. From the experimental test results on dredged soils, it was found that the coefficient of sedimentation and consolidation is correlated with water content. And it is related to fines content as well. So, in this study, correlation between fines content and the coefficient of sedimentation and consolidation has been proposed. And it is expected that the coefficient of sedimentation and consolidation can be estimated by the percentage of fines content.

• Journal of the Korean GEO-environmental Society
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• v.13 no.3
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• pp.71-76
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• 2012

Since sediment in a stable state is disturbed during the process from sediment in a natural state to dredged soil, the turbidity of water is not good. When the dredged soil settles again, the volume change in the sediment occurs. Coagulant and flocculant are added for turbidity mitigation of the water and faster settling process of suspended solid, and the amount of the substances affects the characteristics of the dredged soil. This study is to investigate the characteristics of the dredged soil depending on the amount of three chemical products added to the wet dredged soil and the dry dredged soil through measuring the suspended solids (SS), volume change and sedimentation velocity. The experimental measurements show that the SS decreased, the volume change rate increased, and the sedimentation velocity increased, as the chemical amount increased. In addition, it was found that the dry dredged soil reacted even with little quantity of the chemicals because derelict and microorganism are removed due to the drying process at $100{\pm}5^{\circ}C$.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.559-562
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• 2001

There are many engineering applications that demand settling acceleration and volume reduction of fine solid suspensions. It is a matter to Improve the dredged soil thickening as well as the dewatering characteristic, because settling acceleration of dredged soil decreases the scale of industrial process and volume reduction of dredged soil decreases environmetal challenge to the disposal sites. Direct electric current induces the movement of fine solid particles suspended in water. Upon formation of a soil structure, the current further induces the movement of water and contaminant in the soil skeleton. Theses phenomena are known as electrokinetics. This study investigates the viability, of using the technique of electrokinetic dewatering to river dredged soil for settling acceleration and volume reduction. The aspect, such as sedimentation velocity, final volume and current variation are discussed.

• Journal of the Korean Geotechnical Society
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• v.16 no.4
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• pp.149-156
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• 2000

Sedimentation and self-weight consolidation tests in cylinder and large model tank and field measurement such as settlement and pore water pressure at each layer by wireless automatic instrumentation system were carried out to investigate the behaviour of dredged marine clay fill. The consolidation behaviour for each reclaimed layer was analyzed from these measured data and numerical analysis result using finite strain consolidation theory. It was fond from this study that the consolidation behaviour of dredged clay fill is heavily dependent on the filling process.