• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.6
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• pp.107-115
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• 2015

The objective of the this study is to find the breakage index and changes in permeability of Bottom ash from thermoelectric power plants in Korea. Bottom ash was crushed by compaction according to compaction energy from 0 to $1661.4\;kN/m^2$. The particle size distribution was estimated by sieve analysis. The various breakage indexes were used for analyzing the change in particle size distribution and effect of compaction energy. In the result, breakage indexes were increased as compaction energy and initial upper 4.75 mm diameter ratio, but values and tendencies of breakage indexes appeared in different as calculation method of breakage indexes. The coefficient of permeability was decreased with particle breakage, but decreasing ratio of permeability was very small. Bottom ash has a higher permeability than the weathered soil and it is considered high usability as a permeable materials.

• Coupled systems mechanics
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• v.11 no.2
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• pp.93-106
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• 2022

The total embankment settlement consists of three stages: the initial settlement, the primary consolidation settlement, and the secondary consolidation settlement. The total embankment settlement is largely controlled by the primary consolidation settlement, which is usually computed with numerical models that implement Biot's theory of consolidation. The key parameter that affects the primary consolidation time is the coefficient of permeability. Due to the complex stress and strain states in the foundation soil under the embankment, to be able to predict the consolidation time more precisely, aside from porosity-dependency, the strain-dependency of the coefficient of permeability should be also taken into account in numerical analyses. In this paper, we propose a two-dimensional plane strain numerical model of embankment primary consolidation, which implements Biot's theory of consolidation with both porosity-dependent and strain-dependent coefficient of permeability. We perform several numerical simulations. First, we demonstrate the influence of the strain-dependent coefficient of permeability on the computed results. Next, we validate our numerical model by comparing computed results against in-situ measurements for two road embankments: one near the city of Saga, and the other near the city of Boston. Finally, we give our concluding remarks.

• The Journal of Engineering Geology
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• v.16 no.1 s.47
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• pp.31-43
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• 2006

As a result of calculating bearing capacity of soft silt soil(ML) and soft silt soils(ML', SM, SM') mixed with sand, all kinds of soils showed smaller values than existing expressions and when theoretical values are applied, considerable review is required. It was found that ultimate surcharge(bearing capacity) of soft silt soil was $q_{ult}=1.34C_u$ that of ML' soil in soft silt soils mixed with 3 kinds of sand $q_{ult}=1.40s$, that of SM soil $q_{ult}=1.73s$ and that of SM' soil $q_{ult}=2.72s$, Consequently, as content of sand having greater permeability than silt soil in creased, soil was stabilized gradually.

• Journal of the Korean Geosynthetics Society
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• v.6 no.1
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• pp.33-38
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• 2007

PVD (Prefabricated Vertical drain) consists of filter and core. An effective PVD has two basic filtration functions ; first to retain soil particle ; and second, to allow water to pass from the soil into the PVD core without clogging or blinding. Clogging which reduces the permeability of the geotextile filter jacket is caused by fine particles penetrating into the geotextile filter jacket in relatively low permeability soil conditions. As clogging performance increases gradually, excess pore water flow from soil is resisted and finally consolidation delays. Current soil-geotextile filter system criteria are generally based on relationships between a representative pore size of the geotextile and particle size of the soil. In Korea, PVD geotextile filter system criteria have been applied by only testing AOS (Apparent Opening Size) of filters without evaluating the filtration and clogging performance on soil-geotexile filter systems. Therefore, the filtration tests on soil-geotexile filter systems were conducted in order to evaluate the filtration and clogging performance with 3 kinds of geotextile filters. On these tests, we have applied geotextile filter system criteria on PVD in ${\bigcirc}{\bigcirc}$ sites.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.6
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• pp.50-59
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• 2014

This experiment was performed in order to study the relationship between physical properties of soil and the growth characteristics of Sedum reflexum. A correlation analysis and multiple regression analysis were performed using SPSS Ver 19.0 for Windows. The multiple regression analysis results of soil physical properties and growth characteristics were as follows. The regression equation: The length=$.993-14.070^*$(soil bulk density)+$.233^*$(solid phase)+$.038^*$(liquid phase)+$.068^*$(permeability). The significance of soil bulk density and solid phase was great. The width=$2.931-33.925^*$(soil bulk density)+$.566^*$(solid phase)+$.206^*$(liquid phase)+$.027^*$(permeability). The significance of soil bulk density and solid phase was great. The wet weight and dry weight of the upper and lower and soil physical properties did not have a direct relationship.

• Geotechnical Engineering
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• v.10 no.4
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• pp.5-16
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• 1994

This paper is concerned with the engineering characteristics weathered mudstone soil in Pohang area. The crushability of weathered Boil can be described in terms of the ratio of surface area(Sw'/Sw). In this study, the characteristics of weathered mudstone soil was investigated by performing teat such as compaction. CBR, permeability, and grain size according to compaction energy. The results are found as follows : (1) In generally, the specific gravity of weathered mudstone soil is very small and optimum moisture content (OMC) is large and maximum dry density is small (2) The CBR value increases as the compaction energy increases, but this value decreses from D -2 compaction(26kg.cm/cm3). the swelling ratio increases the npaction energy to 20.6kg.cm/cm" and decreases in all compaction energy from 20.6kg.cm/cm3 (3) As the compaction energy is small, the change of permeability due to water content is large and the difference between minimum coefficient of permeability and coefficient of permeability at OMC is large, but the difference is small as the compaction energy increases (4) The decrease of permeability due to the decrease of void ratio and the increase of ratio of surface area is caused by the crush of particle due to the increase in compaction energy. Especially, the compaction energy is smaller, the change of the ratio of surface area to the coefficient of permeability is larger.rger.

• Journal of the Korean Society of Groundwater Environment
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• v.7 no.1
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• pp.24-31
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• 2000

Soil air permeability and influence of radius in air injection/extraction tests were estimated. These are important factors in the determination of optimal design for SVE or bioventing system. For evaluation of the effects of air leakage from the ground surface on those factors, Theis (1935) and Hantush (1960) methods were used in the data analysis. The air permeability of the studied area was in the range of 1.64$\times$$10^{-7}$~5.66$\times$$10^{-6}$ $\textrm{cm}^2$, and this result would be used for the design of SVE or bioventing system.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.140-143
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• 2003

Air permeabilities in unsaturated fractured tuff at the Apache Leap Research Site (ALRS) near Superior, Arizona, exhibit a self-affine behavior, thus renders a field random fractal. Based up fractal scaling, the observed scale effect has been interpreted [Hyun et al., 2002]. Recently, Frantziskonis and Hansen [2000] presented that fractal scaling can be represented based on wavelets. This study deals with the way of using wavelets for fractal scaling. A numerical study is presented to examine the applicability of wavelet-based approach to determining upscaled air permeability values on various data supports at the site. To characterize the scaling property of self-affine fields generated based upon wavelets, Hurst coefficient, H. was inferred by applying the average wavelet coefficient (AWC) method. The result yielded H = 0.24, which is very close to the result of geostatistical analysis using a power variogram (H = 0.22). The study concludes that wavelet-based scaling is a useful way of determining parameter values on different data supports, which is an essential task for modeling of subsurface flow and mass transport in a numeric grid with different resolutions (grid size).

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.3
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• pp.75-84
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• 2013

The seepage quantity analysis of reservoir embankment is very important for assessment of embankment safety. However, the conventional analysis does not consider uncertainty of soil properties. Permeability is known that the coefficient of variation is larger than other soil properties and seepage quantity is highly dependent on the permeability of embankment. Therefore, probabilistic analysis should be carried out for seepage analysis. To designers, however, the probabilistic analysis is not an easy task. In this paper, the method that can be performed probabilistic analysis easily and efficiently through the numerical analysis based commercial program is proposed. Stochastic response surface method is used for approximate the limit state function and when estimating the coefficients, the moving least squares method is applied in order to reduce local error. The probabilistic analysis is performed by LHC-MCS through the response surface. This method was applied to two type (homogeneous, core zone) earth dams and permeability of embankment body and core are considered as random variables. As a result, seepage quantity was predicted effectively by response surface and probabilistic analysis could be successfully implemented.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.536-539
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• 2003

This study area has been contaminated by oils. To identify contaminated ranges and to assess the possibility of contamination dispersion, monitoring wells were installed and slug test, field soil permeability test, automatic or manual measurement of groundwater table, and groundwater quality analyses in field and laboratory were performed. In addition, a groundwater modeling program was used to assess the possibility of oil contamination dispersion, based on field data and groundwater quality data. The results showed that concentration of oil contaminants in groundwater have been decreased by dispersion and adsorption.