• Journal of Korean Society of Coastal and Ocean Engineers
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• v.14 no.1
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• pp.65-75
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• 2002

The changes of sea bottom configuration, which may cause the coastal disasters, have been considered as social problems. It is obvious that the beach deformation is attributable to the sediment transport associated with erosion and siltation in coastal areas such esturies, channel and harbors. The prediction method and countermeasures far them, however, are not on the level of satisfaction, which indicates that make efforts should be made on developing them. Groin was constructed at Hak-Dong gravel beach to embark ship at 1996, as a result region of right of groin, severe erosion of beach is proceeding till now 1999. In this study, based on the field measurements, involved the one-line theory model which was selected for the prediction of shoreline change to prepare coastal protection methods of Hak-Deng gravel beach. Author found that the storaged sediment estimation model by Sonu and Beek(1971) is useful model at the Hak-Dong gravel beach by the use of topographical survey data from September, 1998 to September, 1999.

• Journal of the Korean Society for Railway
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• v.18 no.6
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• pp.552-557
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• 2015

Ballast gravel in a railroad field is often polluted by grease and heavy metals. In this paper, the performances of a dry cleaning method for polluted ballast gravel in which pollutants on the gravel surface can be physically removed was extensively studied. A polluted ballast cleaning device able to shoot emery blasting media onto the surface using compressed air was prepared. Polluted ballast gravel was put into this device for cleaning, with the treatment time varied from 1 to 10 min. The cleaning efficiency of the total petroleum hydrocarbons and heavy metals were studied. The total petroleum hydrocarbon removal efficiency was 70-80% for gravels sampled from a locomotive waiting line, while it was 40-60% for gravels sampled from a turnout area. The heavy metal removal efficiency exceeded 90% for copper and lead, while it was 65-80% for nickel and zinc. This system was found to be effective for the remediation of polluted ballast gravels.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.460-467
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• 2009

This research was conducted for the purpose of investigating the influence substrates addition such as germanium or Granite porphyry gravel have on the growth of foliage, on the inorganic compositions of leaves as well as on root activity, in order to discover effective means of introducing plants to the indoors. Syngonium podophyllum, Dracaena sanderiana, Epipremnum aureum and Hedera helix were used as study subjects to which soil (mixed top-soil: Sunshine Mix No. 2, USA), tap water, tap water with germanium (300g), tap water with Granite porphyry gravel (300g) were added respectively and formulated. Studies on growth variations according to substrates addition indicate that growth of Syngonium podophyllum was most sluggish under tap water only treatment. Plant growth was most active under geranium-gravel treatment. In the case of Dracaena sanderiana, treatment of substrates addition had no meaningful influence on plant growth. However, the growth of Epipremnum aureum and Hedera helix was also shown to be most active under geranium-gravel treatment. Geranium-gravel treatment was shown to be particularly beneficial for root length, number of roots and dry weight. Root activity was analyzed on ten day intervals and there was discernable difference in the root activity of all the plants according to the varying treatments. In the case of the Syngonium podophyllum, the root activity was sluggish in all three types of treatment on the 10th day but improved gradually. On the 30th to the 50th day of the experiment, the root activity was found to be best under the Granite porphyry gravel treatment. In the case of the Dracaena sanderiana, the root activity was most active under the geranium-gravel treatment from the 10th to the 40th day but deteriorated from the 50th day. However, there was no significant different in all three treatments from the 60th day onwards. Analysis of the inorganic components of the leaves indicates that, while Ca and Mg were higher in the geranium than in the Granite porphyry gravel, they do not directly influence the content of inorganic components in the leaves. The results indicate that Epipremnum aureum and Hedera helix grow better under hydro-culture than when grown in soil and growth under hydro-culture is shown to increase when germanium is added to tap water.

• The Journal of Engineering Geology
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• v.16 no.1 s.47
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• pp.97-107
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• 2006

Or this study, prevailing design and construction methods of dam under various unfavorable conditions are summarized. for example, foundation treatment with large scale alluvium site or weathered rock mass, dam constructing techniques with unfavorable topographic conditions are studied for the better understanding of relating engineers. Also, zoning by using weak rocks and sand-gravel fill techniques are summed up.

• Journal of Environmental Science International
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• v.17 no.11
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• pp.1203-1210
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• 2008

Flow resistance in a natural stream is caused by complex factors, such as the grains on the bed, vegetation, and bed-form, reach profile. Flow resistance in a generally stable gravel bed stream is due to protrudent grains from bed. Therefore, the flow resistance can be calculated by equivalent roughness in gravel bed stream, but estimation of equivalent roughness is difficult because nonuniform size and irregular arrangement of distributed grain on natural stream bed. In previous study, equivalent roughness is empirically estimated using characteristic grain size. However, application of empirical equation have uncertainty in stream that stream bed characteristic differs. In this study, we developed a model using an analytical method considering grain diameter distribution characteristics of grains on the bed and also taking into account flow resistance acting on each grain. Also, the model consider the protrusion height of grain.

• Journal of the Korean earth science society
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• v.27 no.7
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• pp.757-767
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• 2006

Alluvial-plain deposits in the southeastern part of the Eumsung Basin (Cretaceous) are characterized by coarse-grained channel fills encased in purple siltstone beds. It represents distinct channel geometry, infill organization, and variations in facies distribution. The directions of paleocurrent, sedimentary facies changes, and channel-fill geometry can be used to reconstruct a channel network in the alluvial system developed along the southeastern margin of the basin. The channel-fill facies represent downstream changes: 1) down-sizing and well-sorting in clast and martix of channel fills and 2) internal organization of scour fill or gravel lag and overlying cross-stratified, planar-stratified beds. These findings suggest multiple stages of channel-filling processes according to flooding and subsequent stream flows. In the small-scale pull-apart Eumsung Basin (${\sim}7{\times}33km^2$ in area), vertical-stacked alluvial architecture of the coarse-grained channel fills encased in purple siltstone is expected to result from episodic channel shifting under a rapidly subsiding setting.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.84-90
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• 2009

The gravel ballast in the ballasted track has the function to not only transfer/scatter the train loads to subgrade through rail and sleeper but also elastically support the train loads. Because track irregularities results inevitably from the repetitive train loads, the track maintenance should be undertaken for correcting them. By analyzing the track maintenance history in the Gyeongbu high speed railway, this study tries to choose the local two spots in the railway in which the repair frequencies are maximum and relative small; to analyze their dynamic characteristics as well as grade; and to compare them with maintenance history. As the dynamic characteristics of track, the vertical displacement and vibrating acceleration of sleeper as well as acceleration of ballast are measured/analyzed. Furthermore, by collecting soil and gravel on the reinforced roadbed and undertaking ballast screening test, the size distributions are compared with grade distribution standards of high speed railway.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.1
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• pp.116-121
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• 2001

This study is performed to examine the physical and mechanical properties of eco-concrete with polypropylene fiber. Test results show that the strengths are increased with increase of the content of natural gravel, excellent soil compound and polypropylene fiber. The coefficient of permeability is increased with increase of the content of the polypropylene fiber but it is decreased with increase of the content of natural gravel and excellent soil compound. The lowest coefficient of permeability is achieved by eco-concrete which it is 100 times lower than that of the control. The durability factor is increased with increase of the content of natural gravel and excellent soil compound, and decreased with increase of the content of polypropylene fiber.

• Cement Symposium
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• no.14
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• pp.87-91
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• 1986

• Journal of the Korean GEO-environmental Society
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• v.16 no.11
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• pp.39-43
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• 2015

In this study, the infiltration quantity of fine-grained soil into coarse-grained soil or aggregate for methods to accelerate consolidation drainage is checked by laboratory tests under various conditions and those characteristics on infiltration are examined closely. Irrespectively of pressures to fine-grained soil corresponding to stresses in a soil mass or moisture contents of fine-grained soil, fine-grained soil does not infiltrate into standard sand and marine sand, so it is verified that drain-resistance into sand mass of drainage / pile does not occur entirely and its shear strength would increase highly by water compaction. It is known that the infiltration depth of fine-grained soil into aggregate increases according that those size is larger in case of aggregates and it increases according that the pressure or the moisture contents is higher in case of same size aggregate. It is thought that drain-resistance into aggregate mass of drainage / pile would occurs by infiltrated fine-grained soil in advance though the infiltration depth of fine-grained soi of lower moisture content than liquid limit into 13 mm aggregate is low quietly. So gravel drain method or gravel compaction pile method, etc. using aggregate of gravels or crushed stones, etc. larger than sand particle size should be not applied in very soft fine-grained soil mass of higher natural moisture contents than liquid limit, and it is thought that its applying is not nearly efficient also in soft fine-grained soil mass of lower natural moisture contents than liquid limit.