• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.9 no.1
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• pp.1-12
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• 2004

Sedimentary facies and high-resolution echo facies were analyzed to elucidate sedimentation pattern of the late Quaternary glacial-marine deposits in the northern continental margin of the South Shetland Islands. Six sedimentary facies are classified, based on grain texture and sedimentary structures in gravity cores. The high-resolution (3.5 ㎑) echo characters are classified into 6 echo facies on the basis of clarity, continuity, and shape of bottom and subbottom echoes together with seafloor topography. Distribution of the echo and sedimentary facies suggest that there was a significant change in sedimentation pattern between the Last Glacial Maximum (LGM) and subsequent glacier-retreating period. When the grounded glaciers extended to the present shelfbreak during LGM, coarse-grained subglacial tills were widespread in the shelf area, and deep troughs in the shelf were carved beneath the fast-flowing ice steam. As the glacial margin retreated landward after LGM, dense meltwater plumes released from the retreating ice-front were funneled along the glacier-carved troughs, and accumulated channel- or cannyon-fill deposits in the shelf and the upper to mid slope. At that time, slope sediments seem to have been reworked by slope failures and unsteady contour currents, and further transported by fine-grained turbidity currents along the South Shetland Trench. After the glacial retreat, sediments in the shelf and slope areas have been mainly introduced by persistent (hemi) pelagic settling, and fine-grained turbidity currents frequently occur along the axis of the South Shetland Trench.

• Journal of the Korean Geotechnical Society
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• v.20 no.4
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• pp.29-38
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• 2004

A finite element nonlinear stress-deformation model with multi-interface element is applied to the stability analysis of waste landfill slope. Strength parameters of waste and geosynthetic materials are obtained from the triaxial test of waste and the direct shear test of geosynthetics, respectively. The landfill models used for the numerical models are fit to regulations of the Korean waste management law. The results of the strength tests showed linear behavior for the waste and nonlinear behavior for the eosynthectic materials. The stability analysis with multi-interface element for the geosynthetic materials in the liner system showed large shear stress and slippage at the boundary of the foundation and the slope of the waste fill. This analysis verified the necessity of multi-interface analysis for waste landfills with composite liners.

• Geotechnical Engineering
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• v.12 no.5
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• pp.41-54
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• 1996

In this paper, the consolidation settlement of the landfill foundation during and after the period of disposal is analyzed using the program CONSOL which can include the influence of waste load and the leachate level into the analysis. the stability analysis of the embankment is also performed under the varied strength of foundation soil which results from the increase of effective stress due to consolidation of the clay under the landfill. The predicted settlement from CONSOL is compared with the field measured settlement. The results show that, when the leachate level increases with the increase of waste height, the increase of the effective stress of foundation clay is negligible and the stability of the slope of the landfill may not be secured as the disposal of the waste proceeds. Several complementary repairworks, e. g. the reduction of current slope of the fill, application of drain methods to stop or reduce !he leachate level are recommended. The predicted settlement consists moderately with the field measured settlement.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.1
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• pp.55-64
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• 1985

This thesis, intended to establish the design criteria of core wall of a Fill Dam, has determined after a series of twenty one analytic experiments on the seepage flows in various types of core wall that the rates of rise and fall of the seepage flow changing in accordance with the variation of core wall cross section, which is to say, the transformation of slope inclination. Particularily the appropropriate design inclination was examined for the sloped core wall. Putting the resulting values into the existing approximate theoretical function has revealed the volume of theoretical seepage flows. With this result, the experiment values was compared and interestingly enough, a theoretical formula was found which is considered to be the nearest one to the resulting values of the experiment. It is also discussed in the papers that the seepage alignment and flows in the sloped core wall section that inclined to the upstream and the adoptability of the theoretical function which has been known up to present. Based on the above mentioned study it is anticipated that thesis should be available for determination of the cross section in the core wall design of a Fill Dam as large amount of references as it can be.

• Journal of the Korean GEO-environmental Society
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• v.23 no.2
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• pp.25-36
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• 2022

In this study, seepage control effect of relief well was evaluated quantitatively on embankment of small fill dam and levee. Seepage analysis of dam and levee were carried out according to the permeability of fill material and foundation and to analyze behaviour characteristics of seepage. The up-lift pressure at toe of embankment was analyzed which is generated by seepage according to relief well installation condition. The relief well could reduce pore water pressure which is to cause piping or up-lift pressure at foundation ground of embankment and it does not be influenced on geometric condition such as dam height and slope incline. In case of relative low permeable ground, the pore water pressure reduction effect of relief well was decreased compare with high permeable ground but it shows pore water pressure reduction effect compare with no relief well condition. The reduction effect of relief well shows relative gap according to diameter and penetration length of relief well and the installation length of relief well is the most effective factor for seepage control.

• Geotechnical Engineering
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• v.13 no.5
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• pp.19-34
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• 1997

Classical earth pressure theories normally assume that ground condition remains uniform for considerable distance from the wall, and that the movement of the wall is enough to result in the development of an active pressure distribution. In the case of many low gravity walls in cut, constructed, for example, by using gabions or cribs, this is not commonly the case. In strong ground a steep temporary face will be excavated for reasons of economy, and a thin wedge of backfill will be placed behind the wall following its construetion. A designer then has the difficulty of selecting appropriate soil parameters and a reasonable method of calculating the earth pressure on the w리1. This paper starts by reviewing the existing solutions applicable to such geometry. A new silo and a wedge methods are developed for static and dynamic cases, and the results obtained from these are compared with two experimental results which more correctly mod el the geometry and strength of the wall, the fill, and the soil condition. Conclusions are drawn concerning both the magnitute and distribution of earth pressures to be supported by such walls.

• The Korean Journal of Petroleum Geology
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• v.2 no.2 s.3
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• pp.71-81
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• 1994

Alluvial fan delta often extends into deep water, forming steep-faced delta front. Depositional features of modern steep-faced fan-delta slope and prodelta are characterized by slump scar, chute/channel, swale, lobe, splay and debris fall. These features largely originate from sediment failure or sediment-laden underflows (sediment-gravity flows) off river mouth. Sedimentary facies of equivalent ancient systems comprise sheetlike and/or wedged bodies of gravelstone and sandstones, slump-scar and -fill, chute/channel-fills, and sheetlike, lobate and slump mass on steeply-inclined fan-delta foreset and prodelta.

• Journal of the Korean earth science society
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• v.31 no.6
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• pp.563-572
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• 2010

Both multi-channel temperature monitoring and geophysical electric survey were performed together for an embankment to assess the leakage zone. Temperature variation according to space and time on the inner parts of engineering constructions (e.g.: dam and slope) can be basic information for diagnosing their safety problem. In general, as constructions become superannuated, structural deformation (e.g.: cracks and defects) could be generated by various factors. Seepage or leakage of water through the cracks or defects in old dams will directly cause temperature anomaly. This study shows that the position of seepage or leakage in dam body can be detected by multi-channel temperature monitoring using thermal line sensor. For that matter, diverse temperature monitoring experiments for a leakage physical model were performed in the laboratory. In field application of an old earth fill dam, temperature variations for water depth and for inner parts of boreholes located at downstream slope were measured. Temperature monitoring results for a long time at the bottom of downstream slope of the dam showed the possibility that temperature monitoring can provide the synthetic information about flowing path and quantity of seepage of leakage in dam body. Geophysical data by electrical method are also added to help interpret data.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.130-137
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• 2012

This study has conducted to develop new gabion wall systems with vegetation base materials for stream bank stability and rapid rehabilitation. Vegetation base materials are primarily compounded with fine soil, organic composts and peat moss as plant fibers, a water retainer and a soil improver. Normally gabion wall systems resist the lateral earth pressures or stream power by their own weight. Therefore, fill material must have suitable weight, compressive strength and durability to resist the loading, as well as the effects of water and weathering. In this project, 100 to 200-mm clean, hard stones are basically specified, and about 50-mm rubbles are also used. Test application of new gabion wall system carried out in the stream bank of a small stream in the Gwangreung experimental forest, belonging to Korea Forest Research Institute (KFRI) in December 16th, 2006. As a result of the analysis of hydraulic stability of new gabion wall system, gabion wall system has highest threshold shear stress when the gabion wall covered by vegetation. New gabion wall system is highly resistant to sliding and overturning because safety coefficients exceed 1.5. As a result of term of slope stability analysis of new gabion wall system by Bishop and Fellenius methods, stability of stream bank was highly increased after the construction of gabion wall. Therefore, new gabion wall system is effective to stabilize unstable stream bank.

• Journal of Korean Society of Forest Science
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• v.13 no.1
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• pp.67-78
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• 1971

The measures of contour-terracing with sod has been executed as a major measures for hillside erosion control works for a long time in Korea. It is, however, recognized that pair terracings make a new slope-face having the more steeper degree of slope between the upper and the lower terraces on hillsides and it also does not contribute for establishing the natural vegetation-cover by penetration of pioneer seeds on the slope faces or cut-faces of hillsides. The study was therefore conducted in connection with the above problems on the cut-face having slope of $40^{\circ}$ and 1.6 meter in slope length with clay soils. Plot allocation for the experiment consists of 3 kinds of 3 replica plots having each $1.6m^2$ of slope area, i. e., the control plot with direct seeding on slopes only ($T_1$), the covering plot with the straw-mats after seeding on slopes ($T_2$) and the seeding plot after covering with the straw-mats. ($T_3$). The main results obtained may be summarized as follows : 1. Effects of the straw-mat mulchings on surface soil loss control:-The total amount of soil losses from each treatments are measured as 4,651 gr from $T_1$, 163 gr. from $T_2$ and 2,891 gr. from $T_3$ treatment respectively. (Refer to table No. 2, 3 and 4). In short, it is recognized that effect of $T_2$ treatment is compared as 28.5 times than that of $T_1$ treatment and 17.7 times than that of $T_3$ treatment respectively. Effect of $T_3$ treatment compared with $T_1$ treatment is also such recognizable as 1.6 times in control of surface soil losses on a slope face. 2. Effect of the straw-mat mulchings on soil moisture content on slopes; -Average per cent of surface soil moisture content by treatments show as 21.60 at the $T_1$, 23.04 at the $T_2$ and 22.21 at the $T_3$ treatment respectively and that of subsurface soil moisture content by treatment show as 23.81 at the $T_1$, 26.16 at the $T_2$ and 24.81 at the $T_3$ treatment respectively. The variance of soil moisture content by treatments was highly significant (Refer table No. 7, 8 and 9). 3. Effect of the straw-mat mulchings on vegetation establishment;-Average numbers of germination by treatments are counted as 237 Nos. at the $T_1$, 246 Nos. at the $T_2$ and 262 Nos. at the $T_3$ treatment plots and the vegetation coverage on ground was almost same as about 90% of covers in all treatments. This effect is more or less lower than that of surface soil erosion control. 4. Regarding the effect on surface soil erosion control, the straw-mat mulchings would be effective as a new measures for control of soil erosion on erosion susceptible lands such slope-faced bare-lands as cut-fill faces, mass-movement faces and bare hillsides.