• International Journal of Highway Engineering
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• v.15 no.5
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• pp.57-64
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• 2013

PURPOSES : It is to evaluate lightweight soil as a subgrade material based on mechanical tests and calculation of pavement performance. METHODS : In this research, various contents of cement and air foam are used to make lightweight soil using wasted dredged soil. Uniaxial compressive strength test is conducted to evaluate strength of 7 and 28 day cured specimens. Secant modulus was calculated based on the stress and strain relationship of uniaxial compressive strength test. Resilient modulus test was measured using by repeated triaxial compression test. The measured resilient modulus was used in layered elastic program to predict fatigue and rutting life at a given pavement structure. RESULTS : Uniaxial compressive strength increases as cement content increases but decrease as air foam content increases. Resilient modulus also increases as cement content increases and decrease as air foam content decrease. CONCLUSIONS : It is concluded that dredge clay soil can be used as subgrade layer material using by lightweight treated soil method.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.151-154
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• 2003

This paper reviews depositional environments and consolidation characteristic of Soft Dredged Clay fill and then analytical solution of self-weight consolidation is made to find consolidated state. It's known that Soft Dredged Clay Ground is in the under-consolidated state under $U{\fallingdotseq}30%$ from analytical solution. It is effective for higher consolidation rate that the time of Dredge is shorter ani the time of leave is longer. It is conclude that the under-consolidated state should be considered in prediction of consolidation settlement.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.355-358
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• 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 the Korean GEO-environmental Society
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• v.3 no.3
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• pp.37-44
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• 2002

Sheet piles are often used to build continuous walls for the waterfront structures, and also used for some temporary structures, such as the braced cuts. Sheet pile walls may be divided into two basic categories that is cantilever and anchored. Stock(1992) developed an expedient format for determining the depth, maximum bending moment and anchor force of sheet pile wall for cantilever and free earth supported anchored wall. But, that is useful only in case that water table exists above the dredge line. In this study, a simplified formulae was developed for the design of the anchored free earth supported sheet pile wall both in sand and clay by solving the derived equations and regression analysis. It can be used whether the ground water table is above or under the dredge line.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.6
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• pp.39-45
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• 2016

In this paper, analyzes the characteristics of self-weight consolidation on the dredged clay according to the fines content and falling height. Research was performed with the dredged clay sampled by Sae-mangeum field site. Classification of fines content was performed by sieve analysis test. After adjusting the fine content, self-weight consolidation tests were carried out focussing on the variation of fines content and falling heights. From the test results of the self-weight consolidation test, samples with high fines content had reached sedimentation completion more later than ones with less fine content samples. In other words, the start of self-weight consolidation was slowing down with increasing of fines content. Also, from the test results of calculating the coefficient of sedimentation consolidation, the coefficient value were increased with the fines content increases. In addition, the change of sedimentation ratio and volume ratio showed more higher changed value as the fine content increases. Thus, it is important to consider the fines content when estimate the settlement time of dredged soil in field dredge work.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.1
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• pp.73-82
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• 2000

Large quantitive of polllutants are washed into reservoirs during storm events. These polllutants contribute to eutrophication, such as algal blooms and fish kills. This study was conducted for the purpose of assessing the pollutant removal possibilities of sedimentation pool formed by deep dredging of a reservoir inlet. Water quality data were collected in the Masan reservoir, whose inlet has been dredged deep like sedimentation pool. The average concentration of chemical oxygen demand(COD) , toatal nitrogen(T-N) and total phosphrous(T-P) in the deep dredged area were 8.7 ~20.5mg/ι (T-N), 0.17~0.84mg/ι(T-P), which were 4.9%(COD), 29.0%(T-N) and 44.8%(T-P) higher than those of middle part of the reservior. The texture of sediment in the dredged area was silty loam, while that of the middle part was sandy clay loam. Organic matter contents, T-N and T-P of the bottom soil in the dredge area showed higher values than the middle part of the reservoirs. From these results, it was considered thedeep dredged area in the inlet of reservoir might play a key role to settle pollutant particulate. Based on the result of water quality analysis, deep dredging of the reservoir inlet could be assessed to reduce T-N and T-P of the reservoir about 6.5% , 8.3%, respectively. However, the effect of the sedimentation pool would be raised if the settled particles were taken into account in assessing water quality improvement for the reservoir. Accordingly, dredging of a reservoir inlet to make a shape of sedimentation pool is recommended for water quality improvement of reservoir in the stage of dredging plan.

• Journal of the Korean Geotechnical Society
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• v.15 no.2
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• pp.129-138
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• 1999

This study is performed for the development of a field monitoring and test technique both of self-weight and hydraulic consolidation by which the soil parameters of dredge-reclaimed clay can be obtained effectively. The field monitoring development and tests mentioned above make it possible to reproduce the process of the self-weight consolidation from settling to reclaimed soft ground. The experimental research is mainly focussed on the characteristics of self-weight consolidation of dredged clayey soil. And theoretical study has pointed out the limits in the application of Terzaghi's one dimensional consolidation theory in interpreting reclaimed clayey ground. Furthermore, a finite difference analysis has been made on the basis of Mikasa s self-weight consolidation theory which takes the problems of Terzaghi's theory into consideration. The relationships between specific volume, effective stress, and the coefficient of permeability of Kunsan reclaimed clayey soil have been obtained by laboratory tests. On the other hand, through the field monitoring, pore pressure, total pressure, and water levels have been measured after pouring. The results of these experiments have been analyzed, and compared with those from Terzaghi's method and the finite difference analysis of Mikasa's self-weight consolidation theory. In conclusion, the measured settlements is comparatively consistent with Mikasa's self-weight consolidation theory rather than Terzaghi's consolidation theory.