• Journal of the Korean Geotechnical Society
• /
• v.24 no.5
• /
• pp.5-13
• /
• 2008

This paper proposed an environmental standard far beneficial use of dredged materials currently considered as waste materials. In Korea, even though chemical analysis of sediments are carried out frequently, their analysis results were not interrelated with the effects of biological lives due to a shortage of data, which may result in difficulty to develope Korean standards for reusing dredged materials. For these, this paper first searched existing foreign standards, analyzed local contaminated sediment data, identified their main components of contaminations and then compared clean-up standards of sediments consisting of lower and higher level. From these analyses new environmental standards considering Korean domestic circumstances are proposed. It is judged that newly proposed standards are appropriate in terms of both Korean national sedimental environments and economical recycling aspects because environmental standard levels proposed are higher than background level of sediments in Korea and foreign country's standards, where many experiences and environmental monitoring works have been already performed.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.13 no.4
• /
• pp.309-318
• /
• 2001

A zero-dimensional simple model is presented to predict the currents in the opening channel of tide embankment and the sea-level response of the interior basin to ocean sea level. In general, a tidal embayment has wide tidal flats so that the effect of tidal flats has been taken into account by formulating the volute variation vs. depth. The model has been verified through the comparison with the 2-dimensional depth-integrated model which can resolve the small area by using the multigrid method. As the results applied to the storage of dredged material of Incheon North Harbour, the results indicate that both models adequately describe the sea-level and current fluctuations in the storage.

• Journal of the Korean GEO-environmental Society
• /
• v.2 no.1
• /
• pp.5-13
• /
• 2001

The purpose of this paper is to present the pressuremeter test result and analysis for Yulchon Combined Cycle Power Plant(CCPP) site. The CCPP site is old backfill area with the hillcut materials obtained from the borrow sources near the mountains. The geology of this area consists of 6-layers from the ground level such as hillcut material, dredged clay fill, silty sand, original marine clay, weathered rock, soft rock, etc.. The pressuremeter test has been carried out with three different probe, in size and membrane type for all layers except the clay layers. The cone penetration test has been also carried out to collaborate with the pressuremeter test in the hillcut material layer.

• Journal of Korean Port Research
• /
• v.14 no.4
• /
• pp.451-461
• /
• 2000

The design and maintenance of navigation channel and water facilities of an harbor which is located at the mouth of river or at the estuary area are difficult due to the complexity of estuarial water and sediment circulation. Effects of deepening navigable waterways, of changing coastline configurations, or of discharging dredged material to the open sea are necessary to be investigated and predicted in terms of water quality and possible physical changes to the coastal environment. A borad analysis of the transport mechanism in the estuary area was made in terms of sediment property, falling velocity, concentration and flow characteristics. In order to simulate the transport processes, a two-dimensional finite element model is developed, which includes erosion, transport and deposition mechanism of suspended sediments. Galerkin’s weighted residual method is used to solve the transient convection-diffusion equation. The fluid domain is subdivided into a series of triangular elements in which a quadratic approximation is made for suspended sediment concentration. Model could deal with a continuous aggregation by stipulating the settling velocity of the flocs in each element. The model provides suspended sediment concentration, bed shear stress, erosion versus deposition rate and bed profile at the given time step.

• Journal of Industrial Technology
• /
• v.19
• /
• pp.391-402
• /
• 1999

The numerical model predicting the behaviours of submerged mound constructed by dredged material is developed in this paper. The model is based on the Bailard's sediment transport formula, Stokes' second-order wave theory and the sediment balance equation. Nonlinear partial differential equation which is the same form as convection-dispersion equation which represents change of bed section can be obtained by substituting sediment transport equation for equation of sediment conservation. By this process, the analytical solution by which the characteristic of the behaviours of submerged mound can be estimated is derived by probably combining the convention coefficient and the dispersion coefficient governing the behaviours of submerged mound and the probability density function representing the wave characteristics. The validity of the analytical solution is verified by comparing the analytical solution which is assumed to estimate the movement rate submerged mound by bed-load with the field data of the past and its characteristic is analyzed quantitatively by obtaining the mean of the dispersion coefficient representing the extent of the decrease rate of the submerged mound height.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.11a
• /
• pp.72-84
• /
• 2001

In order to utilize mass of oyster shells for a partial substitute material for reclamation, we investigate the shear characteristics of dredged sluge mixed with oyster shells. the apparent modulus of elasticity of the this mixture are obtained from the triaxial compression tests and is utilized to characterize the apparent modulus of elastic of the oyster shells by carrying out some numerical analysis based upon the homogenization theory. We got the conclusion by a series of experiment, 1) It is verified that modulus of elasticity of dredged clay is improved by mixing with oyster shells. 2) The homogenization method for deducing apparent modulus of elasticity of oyster shells, which can consider micro-structure of mixed soil, is introduced. The elastic modulus is affected from the skeleton structure of oyster shell. The effect of 49kPa is bigger than that of 98kPa.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1992.10a
• /
• pp.75-86
• /
• 1992

The elevation of reclamation work in the coastal area for the industrial complex is determined through the investigation and review of marine conditions, drainage plan and fill materials. The embankment to be constructed with crushed stone on the soft soil should be safe against the wave force, immediate and long term consolidation settlement, overturning and sliding due to self-weight and other forces. Because of lack of fill material from the borrow pit, the soft marine clay to be dredged shall be used as the reclamation material. And Paper Drain Board is used as the improvement method for the deep soft clay strata.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2006.04a
• /
• pp.230-233
• /
• 2006

국내에서는 매년 60만 톤의 하수슬러지가 준설된다. 현행법상 하수 준설토는 산업폐기물로 정의되며, 재활용되도록 강조되어진다. 그럼에도 불구하고 매입에 의한 처리로 낭비되고 있는 실정이다. 본 연구에서는 하수 준설토의 재활용 방안을 모색하기 위하여 지반 공학적 실험을 실시하였다. 실험 결과 준설된 순수한 하수 준설토의 경우 국내 건설용 성토재료 요구기준에 충분히 안정적인 것으로 나타났다.

• Journal of the Korean Applied Science and Technology
• /
• v.30 no.4
• /
• pp.575-585
• /
• 2013

This research was performed to evaluate the recycling feasibility as a construction material of dredged harbor soil mixed with clay and glass frit. Concentration of heavy metals of the dredged soil from D harbor was severly high, showing Zn of 526.0~13,150.1 mg/kg. The dredged soil was maily composed of 48.30 wt% $SiO_2$, 16.60 wt% $Al_2O_3$, 10.10 wt% CaO, 7.75 wt% $Fe_2O_3$. The clay and the glass frit contained 70.82 wt% $SiO_2$ and $Al_2O_3$ 18.78 wt%, and 71.75 wt% $SiO_2$, 13.99 wt% CaO, 8.51 wt% $Na_2O$, respectively. After adding 10~40 wt% to the clay and sintering them at $1,000^{\circ}C$ or $1,100^{\circ}C$, the compressive strength of the sintered specimens showed $132.6{\sim}178.5kgf/cm^2$ or $581.2{\sim}793.7kgf/cm^2$, respectively. In case of SC46 with the addition 40 wt% of the dredged soil to the clay, the compressive strength ($793.7kgf/cm^2$) of specimen sintered at $1,100^{\circ}C$ was over 5 times higher than that at $1,000^{\circ}C$. The specimen mixed with 40 wt% of dredged soil, 60 wt% of clay and 1 wt% of glass frit satisfied the 1st grade standard for clay brick by KS L 4201. The results of all specimens by Korean Standard Leaching Test also satisfied the standard criteria.

• Journal of Korean Society of Environmental Engineers
• /
• v.38 no.5
• /
• pp.236-241
• /
• 2016

This study conducted a screening-level ecological risk assessment for heavy metals in dredged sediment for recycling in terrestrial environment. Toxicological information of six heavy metals (i.e., Cu, Zn, Cd, Pb, Cr, and Ni) was collected from ECOTOX of US Environmental Protection Agency, and screened and qualified for the use in the screening-level ecological risk assessment. According to the number of terrestrial ecological receptors for which toxicological information is available, PNEC (Predicted No Effect Concentration) of each heavy metal was derived using either stochastic approach (for Cu, Zn, and Cd), or deterministic approach (for Pb, Cr, and Ni). Hazard quotients of the six heavy metals were derived for a field-collected dredged sediment using the PNEC derived and the PEC (Predicted Environmental Concentration) determined for the dredged sediment. The HQs of Cu, Zn, Cr, Pb and Ni were higher than unity indicating a possibility of ecological risk of the five heavy metals when the dredged sediment is applied in terrestrial environment. Accordingly, remediation processes or a higher-level ecological risk assessment would be needed for the recycling of the material.