• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.2 s.25
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• pp.35-44
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• 2007

Plowable fill is generally a mixture of sand, fly ash, a small amount of cement and water. Sand is the major component of most flowable fill mixes. Marine dredged soil was adopted for flowable fill instead of fly ash. Natural sea sand and in-situ soil were used for comparison. The flow behavior, hardening characteristics, and ultimate strength behavior of flowable fill were investigated. The unconfined compression test necessary to sustain walkability as the fresh flowble fill hardens was determined and the strength at 3-days appeared to correlate well with the water-to-cement ratio. The strength parameters, like cohesion and internal friction angle, was determined along the curing time. The creep test for settlement potential was conducted. Also, potable falling weight deflectometer(PFWD) test has been carried out for elastic modulus of each controlled low strength materials(CLSM). The data presented show that marine dredged soil and in-situ soil can be successfully used in CLSM.

• Magazine of RCR
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• v.11 no.4
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• pp.53-58
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• 2016

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

• Journal of the Society of Disaster Information
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• v.7 no.4
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• pp.247-258
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• 2011

In this study, both domestic ground and maritime environmental standard and treated method for beneficial use of dredged materials were investigated. To suggest beneficial use of dredged material, cemented bricks and light-weighted bricks were made. The strength of bricks was satisfied with the standard(50kPa), which is the strength for the reclamation work on the reclaimed land.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2006.09a
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• pp.105-108
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• 2006

본 준설토 투기장은 국제도시 부산의 관문이 될 부산신항만 입구부에 위치한 관계로 아름답고 튼튼한 호안이 될 수 있도록 하였다. 본 사업은 부산신항만 개발 중 발생하는 준설토를 수용하는 호안 축조공사로서, 적용된 설계사례 및 설계특화내용을 설명하고자 한다. 지형적 특성상 복잡한 형태의 고파랑작용으로 수리학적으로 월파, 반사파, 연파를 제어하는 경사호안 구조물을 도입하였고, 개선된 S.C.P 연약지반 처리공법을 적용하여 기초굴착 없는 친환경적이고 배수기능을 향상시킨 융기토 유용형 S.C.P공법을 적용하였다. 호안전구간은 친수 개념을 도입하였으며, 호남도 주변 해양생태계 보호를 위하여 미티케이션 개념을 도입하여 환경복원 계획 및 생태형 친수호안을 구상하였다.

• Proceedings of KOSOMES biannual meeting
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• 2007.05a
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• pp.15-20
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• 2007

In this study, the authors investigated the change of marine environment by dumping dredged materials generated by construction of Busan New Port. There are lots of possibilities to impact an ocean ecosystem by toxic materials in the dredged material dumped in the open seas. As a result of analysis of environmental monitoring in the study areas 12 times a year, COD is II grade, T-N is I grade, T-P is between II and III grade. This result is same as another results of offshore in Korea. It seems unclear that it results from the change of water quality by dumping dredged material. However, according to the result of this investigation, it is not effected extensively to the marine environment by dumping dredged materials. We need further environmental monitoring in the interest sea areas, also need to keep on investigating the impact on the marine ecosystem by dumping dredged materials.

• Journal of the Korean Geotechnical Society
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• v.27 no.9
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• pp.47-53
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• 2011

Marine dredged soils taken from navigation channels or construction sites of coastal area usually have a lot of salt in pores of clayey soils. This paper investigates effect of salt on mechanical characteristics of non-salt and salt-rich stabilized dredged soil. The stabilized dredged soil (SDS) consisted of dredged soil and cement. Several pairs of SDS with non-salt and salt-rich dredged soils, noted as N-SDS and S-SDS, respectively, were prepared to compare their strengths and compressibility characteristics. The microstructures, strength and compressibility characteristics of N-SDS and S-SDS specimens at 7 and 28 days of curing time were evaluated using scanning electronic microscope (SEM), unconfined compression test, and oedometer test. It was found that salt concentration of clayey soil affected not only the formation of soil structure but also the strength development of mixture. The compression index and swelling index of S-SDS were also greater than those of N-SDS, which indicated that the compressibility of mixture increased due to salt concentration. Salinity in clayey soil had a negative effect on the strength development and compressibility characteristics of stabilized dredged soils.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.619-626
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• 2014

In this paper, it was constructed the halophyte Mesocosm experimental which was used tidal flat and dredged sediment as a substrate material. Depending on the vegetation and substrate material of Mesocosm, Mesocosm A(tidal flat sediment + Salicornia herbacea), Mesocosm B (only dredged sediment), Mesocosm C(dredged sediment + Salicornia herbacea). Monitoring was carried out of Warter quality factots(Chemical Oxygen Demand(COD), Total Nitrogen(T-N), Total Phosphorus(T-P), water temperature, salinity), Sediment factors(Chemical Oxygen Demand(COD), Total Nitrogen(T-N), Total Phosphorus(T-P)) and growth of Salricornia herbacea. Habitat Stability Index of vegetation was calculating by using the monitoring results. HSI of Mesocosm C was calculated from 0.87 to 0.95 as compared to the relatively high HSI in Mesocosm A, it was evaluated to be able to be used in the restoration and construction of the coastal salt marsh with dredged sediment.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2001.08a
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• pp.146-151
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• 2001

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.8 no.1
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• pp.114-122
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• 1996

Pipeline transport of dredged soils has been widely used for reclamation. In this case the fluid mixed with soils, so called slurries, has very much different characteristics from pure fluids. As the slurry fluid has a peculiar mode in the viscosity, a proper equation of friction factor has to be used which is pertinent to the characteristics of slurry flow for the estimation of pipeline transport of dredged soils. The slurry fluid has the characteristics of Newtonian fluid or non-Newtonian fluid largely depending on the size of particles. In the present study, new forms of pipe friction factor equations have been suggested for both conditions, and using these forms explicit equations have been developed for the computation of relevant pipe diameter and discharge as well as pumping power.