• Journal of the Korean GEO-environmental Society
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• v.13 no.5
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• pp.41-49
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• 2012

In this study, laboratory test, in-situ vane shear test and piezocone penetration test in the study area were conducted to investigate the engineering characteristics of soft soils at Cheongra District, Songdo District in Incheon City, the west coast of Gyeonggi province, and Sihwa District in Ansan city. The correlations among compression index, and in-situ vane shear test, and cone resistance were obtained. The variations of liquid limit, plasticity index, water content and compression index with respect to depth exhibit strong similarity. This means that they have strong correlations, which can be used to evaluate the local characteristics of the study area. Thus, the correlations between compression index and physical properties were analysed to investigate the engineering characteristics of soft soil in the study area. The relationships between the measured piezocone factor by empirical methods, and undrained shear strength obtained by triaxial compression test or in-situ vane shear test were compared. It shows the significant correlation and piezocone factors, $N_{kT}$are suggested for the study area.

• Journal of the Korean Geotechnical Society
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• v.17 no.4
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• pp.331-339
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• 2001

인산석고(phosphogypsum)는 비료생산과정에서 발생되는 산업부산물로, 주요구성성분은 이수석고(CaSO$_4$.2$H_2O$)의 성분이 대부분이고 여기에 인(P$_2$O$_2$), 철(F)와 유기물질 등으로 이루어져 있다. 전 세계적으로 인산석고 발생량은 현재 1억8천만톤이고 향후 약 3억8천만톤 발생될 것으로 추정되며, 국내에는 약 157만톤이 발생되고 있다. 본 연구는 성토재료로 인산석고를 활용할 경우 이에 대한 물리적 환경적 특성을 분석하였다. 이를 위하여 인산석고와 화강토 혼합비율에 따른 입도분석, 비중시험, 다짐시험, CBR시험, pH시험 및 용출시험 등 일련의 실험을 실시하였다. 실험결과, 인산석고 혼합재료를 성토재료로 활용할 경우 환경적으로 유해한 영향이 적으며, 산업부산물의 자원화 차원에서 대체 성토재료로 활용이 가능한 것으로 나타났다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.267-270
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• 2002

금정터널 굴착 공사의 실시 설계를 위하여 굴착시 발생하게될 터널내로의 지하수 유출과 관련된 수리지질학적 특성을 연구하였다. 단열들에 대한 정보를 얻기 위하여 지표지질조사 및 지질구조조사를 실시하였다. 연구지역의 투수성을 파악하기 위하여 토양의 물리적, 공학적 특성을 규명하였고, 또한 정압주입시험을 실시하였다. 선구조선의 우세방향은 북북동-남남서 방향으로 동래단층 및 동래단층과 관련된 단층군들이 포함된다. 토양시료의 시험결과, 산정된 수리전도도는 2.l9E-05 m/sec ~ 2.11E-04 m/sec 로서 투수성이 빠름 ~ 매우 빠른 범위 값을 갖는 것으로 나타났다. 주입시험에 의해 산정된 수리전도도는 2.28E-10 m/sec ~ 1.49E-06 m/sec 로서 최대값과 최소값은 4 차수(four order)의 차이를 보였다.

• Journal of the Korean GEO-environmental Society
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• v.6 no.2
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• pp.21-30
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• 2005

The purpose of this study was to evaluate the effect of vegetation on the cutting slope applied by vegetation system in the whole land. The engineering characteristics of slopes were investigated using the face mapping and physical tests. From the statistical methods, a relationship between a geologic stratum and degree of covering was independent. Therefore, the afforestation of slope was affected more by condition of vegetation as direction and opening of joints, and a topsoil state than by conventional classification of layer. It was concluded that the adjustable vegetation on the slope considering condition of geometric shape of slope, joint data and spontaneous type could make useful early afforestation.

• Journal of the Korean Geotechnical Society
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• v.23 no.4
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• pp.101-112
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• 2007

This paper presents the results of an investigation on the ways of utilizing bed sediment as levee materials by laboratory tests. A series of laboratory tests were performed to asses the improved engineering characteristics of bed sediment using admixture cement and weathered granite soils. In this study, several tests such as the grain size analysis test, direct shear test, permeability test, unconfined compression test were peformed. The results of the analyses indicated that the treated bed sediment with cement and weathered granite soils can have the adaptability to the fill material for levee.

• Journal of the Korean GEO-environmental Society
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• v.14 no.4
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• pp.29-37
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• 2013

In order to recycle both water sludge and waste fishing net(WFN), it was investigated in this paper the engineering characteristics of mixtures that consisted of different content of water sludge(0%, 10%, 30%, 50%) and reinforced with waste fishing net(unreinforced, untreated WFN, glue treated WFN). WFN or glue treated WFN(1&2 layers) was also added to the mixture to improve the interlocking between the soil particle and WFN. Several series of laboratory tests such as compaction test, triaxial test, oedometer test, permeability test and leaching test were carried out. The experimental test results indicated that, as water sludge content increases, maximum dry unit weight, cohesion, friction angle, and permeability of the mixture decrease, while optimum moisture content, compression index, expansion index and compressibility increase. For the case of reinforced mixture, its cohesion and friction angle are increased due to the inclusion of WFN and glue treated WFN. Leaching result of mixture was satisfied with standard of ministry of environment.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.4
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• pp.450-457
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• 2020

In this study, engineering characteristics such as flowability, segregation and compressive strength by age to derive fast hardening material mixing proportion using excavated soil. And based on optimal mixing proportion, field simulation experiment conducted in laboratory to examine the effectiveness of the method such as kelly ball drop test and soil penetration test for reviewing the following process. As as a result of evaluation, in case of kelly ball drop test and soil penetration test were securing the following process initiation time 3 hours after place CLSM. As results of these assessments, kelly ball drop test and soil penetration test were applicable for revewing following process in construction field besides unconfined compressive strength method.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.432-445
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• 2018

Vegetation and water characteristics of an eco-technological water purifying biotope were investigated at five years after the wetland construction. A total of 91 vascular plant species in 36 families were recorded. Initially planted emergent macrophytes such as Phragmites australis, P. japonicus, Zizania latifolia, Typha latifolia, and T. angustifolia mainly comprised the vegetational components of the wetland. The effect of water purification was observed markedly in most indicators such as electric conductivity (P < 0.01), $NO_3-N$ (P < 0.05), $NH_4-N$ (P < 0.001), $K^+$ (P < 0.05), $Na^+$ (P < 0.01), and $Mg^{2+}$ (P < 0.01). In particular, $NO_3-N$ and $NH_4-N$ concentrations decreased to about 60% and 30%, respectively, via the purification process of the wetland. Separativeness and curvature from the meandering structure of 15 units (multi-cell wetland system) seemed likely to make the wetland continuously play a role as an eco-technological water purifying biotope. We recommend that eco-technological design factors should be included in wetland constructions for efficient and continuous functioning, thus enhancing ecological values of wetlands.

• Journal of the Korean GEO-environmental Society
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• v.2 no.1
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• pp.23-30
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• 2001

A Series of laboratory tests were conducted to investigate the engineering characteristics for organic soil widely distributed in Yong-dong region which always makes problems in construction works. Physical characteristics of Yong-dong organic soil area were measured in terms of such categories as nature water content, organic content, specific gravity, liquid limit, and plasticity index. As a result, it was found that nature water content was $50.8^{\circ}-343.5%$, organic content 12.1-42.5%, specific gravity 1.76-2.71, liquid limit 46.6-440.2%, and plasticity index 9.2-557.2%. Also, as consolidation load increases, consolidation coefficient slightly decreases with small up and down. The ratio of secondary consolidation coefficient to compression index is 0.001-0.091 $C_a/C_c$, secondary coefficient tends to increase greatly when organic content is in the range of 11-22%.

• Journal of the Korean Geotechnical Society
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• v.26 no.1
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• pp.63-73
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• 2010

The supply of high quality filling materials for pavement base course or reclamation is getting harder. So, there is an attempt to use soft mudstones as an earth filling material in Pohang area. But the engineering properties of the soil deposit placed with soft mudstones have not been clearly evaluated yet. We investigated the water absorption and softening, the slaking behavior and the geological mechanism in order to obtain an effective way of estimating the magnitude of land subsidence and the reduction of soil strength. The applicability of soft mudstones is examined by a variety of laboratory tests and pilot-scale field tests. In addition, it is necessary to consider the environmental characteristics of soft mudstones as a reclaiming material, Consequently, the results from the current study can be used to prevent any construction defects due to the careless use of soft mudstones for the pavement base course or reclamation.