• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.667-675
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• 2008

As a large construction such as highway, dam, reclaimed land etc. increase in number more and more, large amount of fill materials are required. However, it's difficult to obtain it because of environmental problems and economical efficiency. A alternative plan is to utilize a gypsum which is a by-product yielded from chemical plants and verify suitability to use gypsum as fill materials. Therefore, a characteristic of compaction for gypsum is analyzed and construction methods are given regard to this characteristic from construction of dike using gypsum. Based on the results obtained, it is found that moisture of gypsum in compaction should to be more dry side of O.M.C(optimal moisture content) because of sponge phenomenon. When gypsum is used to fill materials, standards of compaction should be decided from laboratory test.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.205-210
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• 1994

This study was conducted to evaluate performance of asphalt concretes under various densities, using Marshall specimens before and after freezing-and-thawing treatment. Six different compaction blows per side (20, 30, 40, 50, 60, 70 blows) were applied to specimens to produce different densities. Test results showed that the lower density specimens had the weaker resistance to freezing-and-thawing treatment. The density was an index of retaining fatigue life and displacement after freezing-and-thawing. Therefore, poor compaction in pavement was considered to be a major cause of early distress mechanisms such as rutting, ravelling and cracking, which were resulted in a reduced service life.

• Geotechnical Engineering
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• v.11 no.4
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• pp.63-74
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• 1995

Much of Taegu and Kyungpook areas are composed of sedimentary rocks. This paper is concerned with the engineering characteristi os of weathered shale soils and mudstone soils. In this study, the engineering characteristics of weathered shale soils and mudstone soils are investigated by performing tests such as compaction, gradation, CBR permeability and crushability according to compaction energy and water content. The experiments were carried out to obtain the relationships of the ratio of surface area(Sw'/Sw) and the indez of crushing(IC) The results are found as follows : (1) Weathered shale soils are larger than weathered mudstone soils in maximun dry den sixty, but weathered shale soils are smaller than weathered mudstone soils in OMC. (2) Minimum permeability is found in OMC's 1~2% wet side, and the more compaction energy is high, the more the change's range of permeability becomes narrow. (3) There is linear correlation between the ratio of surface area and the indez of crushing. IC : 14.286sw'/Sw -8.429(r=0.9937) (4) Soaked CBR value becomes maximum in OMC's dry side, and it decreases as the water content increases. Whereas the more compaction energy is high the more unsoaked and soaked CBR values are high in OMC's dry side, unsoaked and soaked CBR values are opposed to that in OMC's wet side.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.6
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• pp.80-87
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• 1997

A series of tests was performed to determine a threshold concentration of water-soluble organic permeant(ethanol) for permeability to be increased in clay and to estimate long-term permeability behaviors, effects of overburden pressure and compaction conditions on permeability in clay. Results of study are as follows ; 1. A threshold concentration of water-soluble organic permeant(ethanol) in clay was about 7O~8O% and its dielectric constant was 40, and dielectric constant seems to be closely related with absolute permeability. 2. Permeability of long-term tests was more or less larger than that of short-term tests. 3. Overburden pressures applied for a long time elapsed have little effects on the restriction of permeability increase. 4. Since water content has no effects of compaction capability when it is compacted with OMC or wet side of OMC, its permeability is to be estimated as same level of dry side of OMC. 5. Clays matured in the humid chamber are increased in permeability 2 times larger than unmatured ones. Thixotropy, therefore, should be considered in the design procedures because field conditions of construction would be quite similar to this..

• Journal of the Korean Geosynthetics Society
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• v.13 no.3
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• pp.21-30
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• 2014

In this study, the applicability of the lightweight dynamic cone penetrometer in the domestic slope site was investigated using the weathered granite soil sampled form the Namwon slope site. And then, the lightweight dynamic cone penetration tests according to the change in the degree of compaction and water content were performed and it was analyzed with the correlations between the degree of compaction, the void ratio, the degree of saturation and the value of cone resistance. From the laboratory test results, the cone penetration resistance was rapidly increased in the dry side of the optimum moisture content, and it was largely decreased in the wet side of the optimum moisture content. Moreover, when the degree of compaction and the degree of saturation are large, the cone resistance is increased linearly. And a high correlativity was shown between water content, void ratio, the degree of saturation and the cone resistance. From these results, it is judged that the lightweight dynamic cone penetrometer can be applied to the investigation on the site slope.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.472-485
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• 2008

In this study, sand compaction pile method was adopted to improve the soft ground under the permanent dyke, namely west sea dyke of Incheon New Port. The row replacement ratio 30% was applied to consider the ground condition, environmental side and the construction cost of the site. The stability and displacement analysis was carried out by respectively SLOPE/W and PLAXIS 2D program. Based on this analysis, it is found that the safety factor and displacement is within an allowable criteria. The model experiment was carried out using the acryl soil box with $400(H){\times}1200(L){\times}250(W)mm$ to show the displacement of the dyke and behavior of soft ground. Based on this experiment results, it is found that the settlement does not occur from 1 and 2 loading phases and horizontal displacement of 0.0075% occurs from 2 phases. It is also found that the differential settlement occurs 0.05mm corresponding respectively 0.02% and 0.03% of the dyke height(15cm).

• Geomechanics and Engineering
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• v.14 no.2
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• pp.175-185
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• 2018

Sand Compaction Piles (SCPs) are constructed by feeding and compacting sand into soft clay ground. Sand piles have been installed with irregular cross-sectional shapes, and mixtures of both sand and clay, which violate the design requirement of circular shape according to the replacement area ratio due to various factors, including side flow pressure. Therefore, design assumptions cannot be satisfied according to the conditions of the ground and construction and the replacement area ratio. Two case histories were collected, examined, and interpreted in order to study the effect of the shape of SCPs. The effects of the distortion of SCP shape and the mixture of sand and clay were studied with the results of large direct shear tests. The design internal friction angle was secured with the irregular cross-sectional sand piles regardless of the replacement area ratio. The design internal friction angle was secured regardless of mixed condition when the mixture of sand and clay was higher than the replacement area ratio of 65%. Therefore, systematic construction management is recommended with a replacement area ratio below 65%.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.2
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• pp.109-117
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• 1983

Dynamic shear modulus of the compacted clayey soil was determined by the resonant column test to study the parametric effects of confining pressure, shear strain amplitude, molding water content, compaction energy, void ratio and the degree of saturation. The effect of each of these parameters on the dynamic shear modulus found to be significant and can be explained in terms of the changes in soil by compaction. Dynamic shear modulus of the compacted soil is increased significantly by compaction and compaction at the dry side of the optimum moisture content is much more effective. It is also found that the dynamic shear modulus showes a good correlation to the static shear strength of the compacted soil. Therefore the dynamic shear modulus of the compacted soil for a certain confining pressure may be obtained ea8i1y from the unconfined compression strength.

• Journal of the Korean GEO-environmental Society
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• v.11 no.6
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• pp.47-55
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• 2010

The recycled fine aggregates were mixed with weathered granite soils typically used for fill materials and tested engineering properties, physical properties, and compaction characteristics according to the mixing ratio of the mixed soils. The results of this study were as follows. For the results of A-type compaction test, the recycled fine aggregates showed low effects compared to the weathered soils, but the mixed soils which were mixed with the weathered granite soils and the recycled fine aggregates showed good compaction effects. Especially, the mixing ratio of 70:30 by weight showed for maximum compaction result. From the results of the direct shear test, the cohesion was ince csed according to proportion of the weathered granite soils. The weathered granite soils neared the optimum moisture content showed for maximum shear strength paramcoers, while the cohesion of the mixed soil was relatively ince csed in the wet side of the optimum moisture content. This trend was seemed to remained cence composition in the recycled fine aggregates. The internal friction angle of the recycled fine aggregates and the mixed soils showed maximum value near dry side of the optimum moisture contents. And the internal friction angles of the mixed soils were increased according to higher proportion of the recycled fine aggregates.

• Journal of the Korean GEO-environmental Society
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• v.12 no.10
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• pp.83-90
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• 2011

A series of centrifugal model test was conducted to investigate the distribution of vertical earth pressure on circular ductile underground corrugated steel plate waterway culvert with considering the compaction degree of the backfill in the high landfilled embankment section. The compaction degree of backfill was varied to 80, 85, 90, and 95% at the 53g-level gravity considering the similarity of the site. As a result of this test, the load reduction factor by the arching effect of the top of corrugated steel plate showing ductile behavior nearly agreed with the load reduction factor according to the compaction degree of backfill specified in the AISI(2002) design method. The vertical earth pressure measured at the top of the corrugated steel plate was linearly decreased as the compaction degree increased. The greater the compaction degree of backfill was, the greater the reduction of surface loading on the top of the corrugated steel plate by arching effect. The load decreased by arching effect on top of the corrugated steel plate was transferred to the side backfill of the corrugated steel plate(EP 1) and the outside of backfill(EP 3).