• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1378-1382
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• 2009

This study is conducted to investigate the possibility of the utilization of the mixed soil formed by mixing stone sludge, bentonite, and residual soil as a soil sealant sustaining both stability and capacity in the barrier system. And the mixed soil formed by mixing stone sludge, river sand is conducted to investigate the possibility of recycle. A series of tests were performed on the mixed soil(stone sludge, bentonite, Cement and residual soil) to evaluate basic properties such as compaction, compressive strength, permeability of these materials. and the stone sludge-river sand mixed soil were performed the discharge capacity tests.

• Geomechanics and Engineering
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• 제29권3호
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• pp.281-290
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• 2022

The direct shear test is commonly used to evaluate the shear behavior of frozen soil-structure interfaces under normal stress. However, failure criteria, such as the Mohr-Coulomb failure criterion, are needed to obtain the unconfined shear strength. Hence, the punch shear test, which is usually used to estimate the shear strength of rocks without confinement, was examined in this study to directly determine the adfreezing strength. It is measured as the shear strength of the frozen soil-structure interface under unconfined conditions. Different soils of silica sand, field sand, and field clay were prepared inside the steel and concrete ring structures. Soil and ring structures were frozen at the target temperature for more than 24 h. A punch shear test was then conducted. The test results show that the adfreezing strength increased with a decrease in the target temperature and increase in the initial water content, owing to the increase in ice content. The adfreezing strength of field clay was the smallest when compared with the other soil specimens because of the large amount of unfrozen water content. The field sand with the larger normalized roughness showed greater adfreezing strength than the silica sand with a lower normalized roughness. From the experiment and analysis, the applicability of the punch shear test was examined to measure the adfreezing strength of the frozen soil-structure interface. To find a proper sample dimension, supplementary experiments or numerical analysis will be needed in further research.

• 아시안잔디학회지
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• 제17권1호
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• pp.13-17
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• 2003

본 실험은 종합 토양개량재 KOB-Soil이 한지형 잔디의 생육에 미치는 영향을 구명하기 위해 Creeping bentgrass 및 Kentucky bluegrass (KB) 75%+perennial ryegrass(PR) 25%로 조성된 잔디면에서 실험을 수행하였다. 실험기간은 2001년 9월 1일∼2002년 8월 31일까지 강원도 정선군 사북읍, 강원카지노 리조트 실험포 화절령 지구에서 수행하였다. 처리는 USGA 지반의 혼합층에 모래 80%+피트 20%, 모래80%+KOB-Soil 1호 20% 및 모래 80%+KOB-Soil 2호 20%로 하였다. 조사항목으로 잎 길이(mm), 잎 수, 잔디품질, 뿌리길이(mm)를 조사하였다. 종합 토양개량재 KOB-Soil은 한지형 잔디인 크리핑 벤트그래스와 Kentucky bluegrass (KB) 75%+perennial ryegrass(PR) 25%의 잎 길이, 잎 수, 잔디품질, 및 잔디 뿌리 생육을 촉진하는 것으로 나타났다. 특히 KOB-Soil에 있어 크리핑 벤트그래스와 KB 75%+PR 25%의 생육은 KOB-Soil 1호가 2호보다 우수한 것으로 나타났다. 이는 KOB-Soil 1호는 BFS-1000이 ㎥당 2.76L 수량 및 Root grow(황산고토를 주성분으로 하는 천연 토양개량제)가 ㎥당 0.48L 의 수량이 함유되어 있기 때문으로 판단된다.

• 한국환경농학회지
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• 제41권2호
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• pp.101-107
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• 2022

BACKGROUND: Soil amendment was necessary applied for the sand that had been used to root zone of green ground in golf course because of its low water retention power and cation exchangeable capacity. This study was conducted to evaluate the effect of the mixed ratio of peat moss and coconut coir as soil amendment materials on the soil physicochemical properties applied to rootzone based on sand. METHODS AND RESULTS: The soil amendments were blended at 0, 3, 5, 7 and 10% by soil volume. The pH in the peat moss treatment was lower than that of control (0% soil amendment), and pH and electrical conductivity (EC) in the coconut coir were higher. The blending ratio of peat moss was negatively correlated with pH of rootzone soil (p<0.01), and that of coconut coir positively with EC (p<0.01). As compared with control, capillary porosity, the physical factors such as air-filled porosity, total porosity, and hydraulic conductivity of rootzone soil were increased by applying peat moss and coconut coir. For correlation coefficients between percentage of soil amendments and soil physical factors, peat moss and coconut coir were positively correlated with porosity and hydraulic conductivity (p<0.01). CONCLUSION(S): These results indicated that the application of peat moss and coconut coir affected on the change of physicochemical properties of rootzone soil, and improved soil porosity and hydraulic conductivity.

• 한국해양공학회지
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• 제22권2호
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• pp.42-49
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• 2008

Recently many countries have become interested in the development of cold or arctic regions. The construction of engineered structures in those regions demands an understanding of the deformation characteristics of frozen soil. However, an understanding of frozen soil behavior poses difficult problems owing to the complex interaction between the soil particles and the ice matrix. In this research, a series of laboratory tests was performed to investigate the variations in the unconfined compression strength and split tensile strength of weathered granite soil and mixed soil (standard sand and kaolinite) in 15 degrees below zero environments. In the frozen soil tests, specimens were prepared with various water and clay contents, and then the interrelationships between four factors (water content, clay content, unconfined compression strength, split tensile strength) were analyzed. The test results were summarized as follows; as the water content was increased, the unconfined compressive and split tensile strengths also increased in frozen soil. However as the clay content was increased, the unconfined compressive and split tensile strengths were lowered. In the case of frozen soil that contained little clay content, the strength decreased rapidly in mixed soil (standard sand and kaolinite) when the frozen specimen was broken. On the other hand, in the cases of mixed soil that contained a high clay content and weathered granite soil, the strength decreased relatively slowly.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.241-252
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• 2010

This study investigates the application of dilatometer test for evaluating the deformation characteristics of granular soil. $K_D$ is the most sensitive to the stress history among CPT and DMT measurements, and $E_D$ and $q_c$ are observed to be similarly affected by the stress history. The coefficient of at-rest earth pressure($K_0$) is an indirect measure evaluating the stress history of granular soil. A relation using only DMT indices provides appropriate prediction of $K_0$ values. Although penetration of dilatometer inevitably induces the failure of cementation bonds, $E_D$ reflects the deformation characteristics of undamaged cementation relatively well. Therefore, a slightly better prediction of M value for cemented sand is achieved by using $E_D$ rather than $q_c$. Because of the weaker particle strength of calcareous sand compared than quartz sand, the majority of sand particles adjacent to dilatometer probe will be crushed during penetration. The particle crushing will induce the less contraction of the dilatometer membrane during penetration, consequently, the smaller $K_D$ and $E_D$ of calcareous sand.

• 환경위생공학
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• 제17권1호
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• pp.41-51
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• 2002

This research was carried out using Anderson air sampler which were set up on the roof of the Engineering College of Konkuk University at Hwayang-Dong, Kwangjin-Gu, Seoul from Aug. 1992 to foul. 1999. The results are as follows: The major component of yellow sand is soil particles based upon the observation that particles ranging from $3.3~7.0{\mu}m$ occupy 36~63%. It is certain that the increase of fine particles of respirable dust during yellow sand phenomenon in Seoul area affects the human body. The trace metals from natural sources like Al, Ca, Fe, K, Na, and Si show larger mass median diameter(MMD) values during yellow sand phenomenon than in normal situations while the values of MMD for Mn and Pb rarely changes. Noticeably, the changes in value of MMD of water soluble elements like ${NO_3}^{-}$ and ${SO_4}^{2}$ are 2.3 and 6.6 times higher during the yellow sand phenomenon compared to normal situations, respectively. This fact is regarded as decisive evidence showing that ${NO_3}^{-}$ and ${SO_4}^{2}$ in the air are attached to yellow sand and move together.

• 한국방재학회 논문집
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• 제8권2호
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• pp.105-110
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• 2008

Flowable fill is generally a mixture of sand, fly ash, a small amount of cement and water. Sand is the major component of most flowable fill with waste materials. Various materials, including two waste foundry sands(WFS), an anti-corrosive waste foundry sand and natural soil, were used as a fine aggregate in this study. Natural sea sand was used for comparison. The flow behavior, hardening characteristics, and ultimate strength behavior of flowable fill were investigated. The unconfined compression test necessary to sustain walkability as the fresh flowable fill hardens was determined and the strength at 28-days appeared to correlate well with the water-to-cement ratio. The strength parameters, like cohesion and internal friction angle, were determined for the samples prepared by different curing times. The creep test for settlement potential was conducted. The data presented show that by-product foundry sand, an anti-corrosive WFS, and natural soil can be successfully used in controlled low strength materials(CLSM), and it provides similar or better properties to that of CLSM containing natural sea sand.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.533-538
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• 2009

Ultimate lateral loaded pile capacity is influenced by soil conditions. Methods of calculating ultimate lateral loaded pile capacity in homogeneous soil were suggested by a lot of previous researchers.(Broms 1964, Petrasovits & Award 1972, Prasad & Chari 1999) There is only few homogeneous soil in actual condition, however, it could be not conviction that the methods from previous researchers are correct in multi-layered soil. In this study, ultimate lateral capacities were estimated from artificial multi-layered soils and were measured from lateral load test that were composed by various soil conditions. The influence of layered soil conditions were confirmed by comparing with two results.

• 한국초지조사료학회지
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• 제27권4호
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• pp.229-234
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• 2007

버즈풋 트레포일의 줄기에서 뿌리를 유도함에 있어, 최적의 유도조건을 확립하고자 배양토 종류별, 복합희토 처리 농도별, IBA 처리 농도별로 뿌리 유도율을 조사하였다. 원예농상토, 마사토, 강모래 등 3종류의 배양토에서 뿌리 유도율을 조사한 결과, 마사토(77.8%), 강모래(70.0%), 원예용 상토(41.1%) 순으로 높게 나타났다. 마사토와 강모래에서 복합희토 용액을 농도별로 처리하여 뿌리 유도율을 조사한 결과, 마사토에서는 복합희토 용액 60 ppm 처리에서 90.0%로 높게 나타났고, 강모래에서는 복합희토 용액 20 ppm 처리에서 80.0%로 높게 나타났다. 마사토와 강모래에서 IBA 용액을 농도별로 처리하여 뿌리 유도율을 조사한 결과, 마사토와 강모래를 사용한 두 처리 모두 40 ppm에서 뿌리 유도율이 96.7%로 동일하게 최고로 높게 나타났다. 이상의 결과로부터 포장에서 재배하고 있는 버즈풋 트레포일의 영양체증식을 하기 위해서는 버즈풋 트레포일 줄기를 절단하여 강모래나 마사토에 삽지 후 IBA 용액을 40 ppm 농도로 처리하여 30일 이상 배양하는 방법이 가장 효율적인 것으로 밝혀졌다.