• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.10a
• /
• pp.1717-1726
• /
• 2008

Vibration triaxial compression test was put in influence for liquefaction strength of fine grained soil of dredged and reclaimed ground and consideration for fine fraction content, relative density, overconsolidation ratio and plasticity index in this study. By the results of these test, the liquefaction strength increased with fine fraction content and the relative density, overconsolidation ratio incresed with liquefaction strength too. However, in the case of nonplastic silt was the smalist liquefaction strength which influenced by dilatancy and interlocking when silt content was 34.7%(average grading 0.12mm). Therefore, liquefaction strength of fine grained soil of dredged and reclaimed ground increased with fine fraction content so it will help to make lower liquefaction.

• Journal of Industrial Technology
• /
• v.20 no.A
• /
• pp.93-100
• /
• 2000

This research is to investigate the self-weight consolidation settlement and desiccation shrinkage settlement of soft marine dredging clay by performing numerical and experimental works. Large column test were carried out investigate the consolidation settlement considering effect of the self-weight and desiccation shrinkage, and centrifuge model test was also carried out investigate self-weight consolidation settlement. Results of centrifuge model and large column experiments about changes of settlement with time were analyzed by using the numerical technique of explicit finite difference method considering effect of the self-weight and desiccation based on the finite strain consolidation theory. Centrifuge model test results were in relatively good agreements with analyzed results in terms of self-weight consolidation settlement with time. Large column test results showed quite different values from the numerically estimated one, carried by experimental conditions.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.1126-1133
• /
• 2005

The effects of mean particle size and uniformity coefficient of dredged soils to the liquefaction resistance strength and dynamic characteristics are experimentally studied in this paper. Representative 4 mean particle sizes and 3 uniformity coefficients were selected and 12 representative particle size distribution curves which have different mean particle sizes and uniformity coefficients, were artificially manufactured using the real dredged river soil. Cyclic triaxial tests and torsional shear tests were carried out to analyze the effect of mean particle size and uniformity coefficient to the liquefaction resistance strength and dynamic characteristics of soils.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11a
• /
• pp.615-620
• /
• 2000

The strength properties of Light-Weighted Soils(LWS) mixed with Expanded Polystrene(E.P.S) are studied. Test results show that when the initial water contents of dredged soils are under 135% and the cement contents are above 1%, Light-Weight Soils are in the appropriate strength range of 2.0 to 4.0kg/㎠. However, E.P.S contents had a little affects on the strength properties of LWS. In the view of E.P.S diagram's effects on LWS, which have expand ratio of 25, 35, 45 and 60, further studies considering of physical properties of original E.P.S beads are needed.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.20 no.4
• /
• pp.185-191
• /
• 2010

To effectively utilize resources of reject ash and dredged soil, globular shape-formed artificial lightweight aggregate were manufactured in 8~10 mm size. Starting materials were changed various grading and composition, sintered at $1050{\sim}1250^{\circ}C$. The specific gravity, water absorptance of artificial lightweight aggregates were measured on the basis of the KS. In this study could make a prediction about application of bloating mechanism by ferrous materials and alkali/alkali-earth oxide at high temperature.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2002.10a
• /
• pp.345-348
• /
• 2002

The dredged soils of rural streams can be treated with cement for recycling. It is very important to know whether the treated soils have achieved some required qualities for further treatments if the soils are mixed with cement. In this study, fall-cone test was used to examine changes in workability and compactibility during an curing time of soil-cement mixture. Test results showed that fall-cone apparatus can be satisfactorily used for this purpose. Although there was some difference of initial curing time and cement contents, the engineering properties of treated soils were little affected.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.09a
• /
• pp.355-358
• /
• 2002

A sediments are Integral called as gravel, sand, clay, mineral materials which are settling in bottom layer of reservoir, stream, and oceans from land. In practical problems relations of sediments are flood by decreed of flow capacity and down of water quality. Dredged sediments are composed with constructed material and variety of pollutant compounds. Therefore, it is very much of cost effects in nationally, if development for use of constructed material separated only constructed material within sediments. And it will be continue to the dredge operation of stream sediment for retrofit of water environment and sustainable's after the years. The following results could be obtained : In case of high concentration sediments, sample for design of CDF was shown property of flocculent settling. Assuming that average inflow rate is 1, 000㎥/hr, mean residence time( $T_{d}$), average ponding depth( $H_{pd}$ ), and design surface area for flocculent settling( $A_{df}$ ) were 5 hr, 0.6m, and 15, 750 $m^2$ respectivelyrespectivelyy

• Journal of Soil and Groundwater Environment
• /
• v.9 no.2
• /
• pp.41-47
• /
• 2004

This research in the degradation of polychlorinated biphenyls(PCB) has focussed on the use of experimental enrichment cultures to obtain PCB-deading communities and identification of PCB-degrading bacteria accor야ng to pure culture. During 180 days, enrichment culture was performed to obtain PCB-degrading bacteria and initial concentration was injected 1.6 ppm,0.7 ppm, respectively. After 180 days of enrichment culture, PCBs was removed 80-87% and 57-71%. Biodegradation of PCBs was studied according to dominated PCB-degrading bacteria. Biodegraddation of PCBs was 80% in initial concentration of PCBs for 20days, enrichment cultured PCB-degrading bacteria was isolated by pure culture and it was verified to Pseudoxanthomonas sp.

• Journal of the Korean Geotechnical Society
• /
• v.17 no.2
• /
• pp.113-122
• /
• 2001

소성이 높은 고함수비를 갖는 준설점토에 대한 침강 및 자중압밀 특성에 대한 연구는 국내외에서 활발하게 진행되고 있는 반면, 비소성 준설토에 대한 침강, 퇴적 특성에 대한 연구는 국내뿐만 아니라 국외에서도 거의 진행되지 않고 있는 실정이다. 일반적으로 비소성 준설토는 침강 및 퇴적 단계에서 고소성의 준설점토와 다른 거동 특성을 나타낸다. 본 논문에서는 비소성 준설토에 대한 실내 침강압밀실험을 실시하여 비소성 준설토의 퇴적 및 침강 현상을 제시하였다. 또한 퇴적고 관찰이 이루어진 준설토에 대한 퇴적특성 분석을 통하여 계면고 관찰이 이루어진 준설토에 대한 퇴적 현상을 해석하였으며, 이를 통하여 비소성 준설토에 대한 침강 및 퇴적 거동을 예측하였다. 또한 초기 및 최종 퇴적고에 대한 상관관계, 최종 퇴적고 및 최종 계면고에 대한 상관관계 분석을 통하여 비소성 준설토의 거동 특성을 분석하였다.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.11 no.2
• /
• pp.63-69
• /
• 2008

As a basic study on the creation of artificial tidal flats using dredged sediments, the pilot-scale artificial tidal flats with 4 different mixing ratio of ocean dredged sediment were constructed in Nakdong river estuary. The phragmites australis was transplanted from the adjacent phragmites australis community after construction, and then the survival and growth rate of the planted phragmites australis were measured. Also the changes of soil chemical oxygen demand (COD), ignition loss (IL), and the heterotrophic microbial numbers were monitored. The survival rate of the planted phragmites australis decreased as the mixing ratio of dredged sediment increased but there was little difference of length and diameter of the shoots. 30% of COD and 9% of IL in the tidal flat with 100% dredged sediment decreased after 202 day, however, fluctuations of COD and IL concentrations were also observed possibly due to the open system. It was suggested that the construction of tidal flats using ocean dredged sediment and biological remediation of contaminated ocean dredged sediment can be possible considering the growth rate of transplanted phragmites australis, decrease of organic matter and increased heterotrophic microbial number in the pilot plant with 100% dredged sediment. However, the continuous monitoring on the vegetation and various environmental factors in the artificial tidal flat should be necessary to evaluate the success of creation of artificial flats using dredged sediments.