• Proceedings of the Korean Geotechical Society Conference
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• 1992.10a
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• pp.55-60
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• 1992

Hydraulically filled ground is formed by the settling of soil grains from the mixture of soil grains and water. It was generally known that the settling speed of the soil grains in governed by Stokes low. In the case of clayed dredged material, the shape of soil grains is not round, the surface of the soil grains is relatively large compared to the weight of soil grains and inter-grain ionic force is relatively large compared to the wight of soil grains. By this reason the settling and consolidation behavior of hydraulically filled quite different from that of Stokes law. This study investigated the settling and consolidation behavior of hydraulically filled materials of Yeochon industrial complex by large scale laboratory settling & consolidation container. The test results showed tat actual settling speed of soil grains in quite large compared to that of Stokes law. It was turned out that this phenomenon was due to the aggregation of soil grains. Also, it was truned out that the void ration and water content after the completion of settling process was 8.7 and 322% respectively. The consolidtion settlement of clayey hydraulic fill material was predicated better by "incremental small strain" consolidation concept than classical Terzaghj's consolidation concept (infinitesimal strain).

• Journal of the Korean Society for Advanced Composite Structures
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• v.6 no.3
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• pp.86-94
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• 2015

A series of injection and drainage test were conducted on an circular acrylic tube to investigate the pressure generated by the accumulated fill materials inside a circular acrylic tube structure. The acrylic tube was filled by means of gravity filling with a slurry material having an average water content of 700%. The water head during the filling process was 1.8m and the bottom pressure during initial filling was 20.18kPa. The recorded stress at the sides of the acrylic tube was 17.89kPa during the filling process and was reduced to 13.58kPa during the leaving process. Continuous drainage of the acrylic tube has greatly influenced the stresses around the tube structure. As the water is gradually allowed to overflow, the generated pressure at the topmost pressure sensor of the tube was reduced further to 2.17kPa. Eventually, the initially liquid state slurry material transforms into plastic state after water has dissipated and substantial soil particles are deposited in the acrylic tube. The final water content of the deposited silt inside the acrylic tube after the test was 42%. It was found that the state of stresses(geo-static earth pressures) in the acrylic tube was anisotropic rather than isotropic.

• Journal of the Korean Geotechnical Society
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• v.19 no.3
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• pp.39-44
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• 2003

Centrifuge test was conducted to simulate the effects of consolidation settlement of capped contaminated marine sediment. A fluorescent dye was used to monitor the movement of pore water through the cap layer. Dye tracer study clearly showed the consolidation induced advective transport of contaminants. Thus, the capping layer must be appropriately designed to reduce the effects of consolidation induced advective transport. The results from the centrifuge test were compared to predictions made by the Primary consolidation, Secondary compression, and Desiccation of Dredged Fill (PSDDF) computer program, which can qualitatively estimate the consolidation settlement of capped marine sediment. Although PSDDF approximated closely the secondary compression in the centrifuge test (i.e., compare data points from 18 to 25 prototype years), the maximum deviation between centrifuge test result and PSDDF prediction was 20 % about prototype time 6 years. Thus, designers should utilize PSDDF consolidation settlement results with caution.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.52-62
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• 2008

By analyzing specific plant distributions and physicochemical characteristics of topsoil in a reclaimed dredging area, baseline data was found of natural landscape planting sites, and developing dredged fill ground. The reclaimed dredging area is five different stands (1, 2, 3, 4 and 5) which were examined in this research. They are located from sea level to 15 meters in altitude and exhibited typical characteristics of the salt marsh in Gwangyang Bay. Species with high constancy in the vegetation on the reclaimed soil were classified into four stages. A total of 12, 15, 22, 27 and 35 different plant species were found and also increased in stands 1, 2, 3, 4 and 5, respectively. Moving from stand 1 to 5, halophytes decreased and non-halophytes increased. Desalination at each stage of the reclaimed dredging area was a driving force affecting the performance and distribution of halophytes and non-halophytes. Overall, 35 quadrats of soil were selected and analyzed for specific physicochemical characteristics of topsoil between O${\sim}$20cm. Results of the physicochemical analysis such as altitude, slope, vegetation and kind of reclaimed dredging soil, exhibited irregular increases or decreases. As survey areas moved from stand 1 to 4, desalination areas, soil acidity, electric conductions, content of salinity, available phosphorus, potassium, chlorine, calcium, and magnesium indicated decreasing patterns; however, total nitrogen, silt, and clay content increased. Cluster analysis and PCA by environmental data within the stands clearly showed five distinct vegetation patterns on the tested reclaimed area. These results indicate that the differences of performance and distribution of vegetation are due to the SAR in the reclaimed soil and related to the natural survival strategy at the given hostile habitat.

• Journal of the Korean Geotechnical Society
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• v.18 no.5
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• pp.251-260
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• 2002

Geotextile tribes are made of sewn geotextile sheet and hydraulically or mechanically filled with dredged materials. They have been applied in hydraulic and coastal engineering in recent years(shore protection structure, detached breakwater, groins, and jetty). Therefore, it is composed of geotextile and confined fill material. Recently, new preliminary design criteria supported by model and prototype tests, and some stability analysis calculations have been studied. The stability analysis of geotextile tube is composed of geotechnical and hydrodynamic analysis. The stability check points are sliding failure, overturning, bearing capacity failure against the wave attack. In this paper are presented the stability analysis method by empirical equation and 2-D equilibrium analysis for geotextile tube. Also, the hydraulic model tests were performed to verify the theoretical stability analysis with geotextile tube shape, filling ratio, significant wave height, and so on. The results of this study show that the stability of geotextile tube depends on the tube shape, contact area, projection area. The theoretical analysis and hydraulic model test show almost the same results.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.2
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• pp.94-108
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• 2010

The purpose of this study is to provide data for the restoration of 'Yongyun(龍淵)' and 'Hwahongmun(華虹門)' through an investigation of the vicinity of their original landscapes at the time of construction of Hwaseong in Suwon and through tracing the transformative process of the environments of this vicinity. The results are as follows; As identified by 'Yongyunjung(龍淵亭)' and 'Yongdugak(龍頭閣)', other names of Yongyun, 'Banghwasuryujung(訪花隨柳亭)', which was built on 'Yongduam', is a facility whose place identity is highlighted with a sense of unity with Yongyun. The south lakefront of Yongyun, bordering Banghwasuryujung, has boundaries that make the best use of the natural geographical features of Yongduam while the current circumference of Yongyun is comparatively shorter than its original state. The size of 'Joongdo(中島)', however, seems to be an example of apparent over-design complement and reorganize 'Joongdo', which had been restored larger than its original state at the time of restoration in the 1970s. The depth of 'Yongyun' was created to be lower than the actual depth, without consideration for its initial depth, as soil was accumulated through continuous flooding after it was created. It is assumed that the original drains which were installed about 10m inside the lake were created facing the stream. As regards the planting environment, a circular planting of willows was made in the outskirts of 'Yongyun', except the 'Yongduam' which is a pure forest, and a mix of 'Pinus densiflora', shrubbery and deciduous broad leaf trees was planted in 'Joongdo'. Of the plants growing in the area of this study, plant species introduced to Korea after Hwaseong was constructed are found, most of which provide interest and attraction. The old pine trees growing in a group once grew in the castle areas of the vicinity even in the 1920s, the period of Japanese occupation, but they disappeared from the area in the aftermath of subsequent urban development and the Korean War. Although restored to the site, the number and space taken up by these trees are insignificant compared to those of the original environment. On the basis of these results, the following is considered necessary for the true restoration of the vicinity of 'Yongyun' and 'Hwahongmun': First, the grounds of 'Yongyun' should be dredged deeply enough to expose the bedrock and should be recreated in the rough outline of a half moon by extension to the southwest toward 'Yongduam' and 'Hwahongmun', and the size of 'Joongdo' should be significantly reduced. Secondly, considering that most plant species, except the pine trees and wild trees in 'Yongduam', are non-native plants introduced in order to provide such attractions such as the appreciation of scenic areas, they should be replaced with native species, mainly with the pine trees which were utilized during the construction of Hwaseong. The weeping willows planted in the 'middle-island' should be relocated to the outskirts of 'Yongyun', and replaced with pine trees as the major trees and maple trees or deciduous broadleaf trees to fill in the gaps. Thirdly, exotic species such as the 'Pinus rigida' planted in a group around 'Banghwasuryujung' and 'Bugammun' and 'Pinus strobus' planted in the vicinity of Hwahongmun' should be removed.