• 한국환경생태학회지
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• 제17권4호
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• pp.360-365
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• 2004

충청북도 충주지역에서 생육하는 굴참나무림에서 세근에 의한 지하부에서의 연간 탄소축적량을 조사하기 위하여 2001년 4월부터 11월까지 매달 토양샘플러를 사용하여 0-30cm, 30-60cm, 그리고 60-90cm 토양 깊이에서 샘플을 채취하였다. 세근에 의한 탄소생체량(fine root carbon biomass)은 다른 두 개의 조사 토양깊이에서 보다 0-30cm 토양깊이에서 가장 많은 것으로 나타났다. 세근에 의한 순탄소생산량 (kg/㏊/yr)은 0-30cm에서 671kg, 30-60cm에서 599kg, 그리고 60-90cm토양깊이에서 479kg로 나타났으며, 0-90cm토양깊이에서 세근에 의한 총 순탄소생산량은 1749kg이었다 세근고사율은 0-30cm에서 0.43, 30-60cm에서 0.96. 그리고 60-90cm에서 1.03로 나타났다. 세근고사율에 의한 토양으로의 연간 양분투입량은 N의 경우 33.9kg/㏊/yr, P의 경우 1.8kg, K의 경우 11.4kg, 그리고 Ca의 경우 20.1kg으로 나타났다.

• The Korean Journal of Ecology
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• 제17권2호
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• pp.113-119
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• 1994

Vertical and horizontal distribution and seasonal changes of fine roots as well as inorganic nitrogen content in soil were determined in Quercus mongolica and Quercus acutissima stands in Mt. Taemosan, Seoul. The vertical distribution of fine rooth phytomass showed a power-functional decrease as descending soil depth. Fine root phytomass was 170 g $DM/m^2$(46%) and 225 g $DM/m^2$(47%) in top soil of 5 cm depth, and 370 g $DM/m^2$ and 480 g $DM/m^2$ from soil surface to 50 cm depth in Q. mongolica and Q. acutissima stands, respectively. Fine roots in relation to the distance from the nearest tree were evenly distributed horizontally in both stands. Fine roots phytomass in top soil of 5 cm depth reached a peak in June, and thereafter decreased gradually in both stands. Patterns of seasonal changes in fine root phytomass were closely related to inorganic nitrogen and moisture content.

• 한국조경학회지
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• 제31권6호
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• pp.77-84
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• 2004

This study was carried out to analyze the vertical and horizontal distribution of fine root biomass of Pinus thunbergii transplanted in reclaimed land from the sea near Gwangyang Bay. The fine-root biomass according to 6 planting ground types were as follows: 98.5 g DM/$m^2$ for P2, 51.1 g DM/$m^2$ for P6, 47.8 g DM$m^2$ for P5, 44.6 g DM/$m^2$ for P3, 38.2 g DM/$m^2$ for P4, 31.8 g DM/$m^2$ for Pl, respectively. The vertical distribution of fine root biomass decreased at descending soil depths of the 6 mounding types. Fine root biomass was 31∼55% in the topsoil of 20cm depth. Fine root biomass that were related to the Spatial distance from the nearest tree were unevenly distributed horizontally in 6 stands. distribution patterns of fine root biomass were closely related to soil hardness and alkalic cation (Ca++, Mg++, Na+, K+) concentrations. Therefore, in order to have good condition for the growth of landscaping plants, we suggest that there is a need for the construction of planting grounds as well as a need for soil improvement in bad soil environments.

• Geomechanics and Engineering
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• 제1권2호
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• pp.169-178
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• 2009

Due to the enormous amount of fills required, broken rock-fine grain soil mixtures have been increasingly used in the construction of high-fill foundations for airports, railways and highways in the mountain areas of western China. However, the compressibility behavior of those broken rock-fine grain soil mixtures remains unknown, which impose great uncertainties for the performance of those high-fill foundations. In this research, the mixture of broken limestone and a fine grain soil, Douposi soil, is studied. Large oedometer tests have been performed on specimens with different soil content. This research reveals the significant influence of fine grains on the compressibility of the mixture, including immediate settlement, creep, as well as wetting deformation.

• 한국지반환경공학회 논문집
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• 제16권11호
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• pp.39-43
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• 2015

본 연구에서는 압밀 배수를 촉진하기 위한 공법에서 사용되는 조립토나 골재로의 세립토 관입 정도를 다양한 조건에서 실험을 통해 확인하여 세립토의 조립토나 골재로의 관입특성을 규명하였다. 지중응력에 대응하는 압력의 크기나 세립토 함수비의 변화에 상관없이 해성점토가 해사나 표준사로는 관입되지 않아 모래 배수/말뚝 체에서의 배수저항 현상은 전혀 발생하지 않은 것으로 확인되었고, 오히려 물다짐에 의한 모래 배수/말뚝 체의 전단강도가 크게 증대한 것으로 보인다. 골재의 경우에는 골재의 입경이 클수록 해성점토의 관입깊이는 증대하고, 같은 골재라도 압력이나 함수비가 클수록 해성점토의 관입깊이는 증대함을 알 수 있었으며, 액성한계보다 작은 함수비를 갖는 해성점토는 입자가 작은 편인 13mm 골재로의 관입깊이가 현저하게 줄어들어 그 관입깊이가 상당히 적다 하더라도 일단 관입된 세립토에 의해 배수/말뚝 체에서의 배수저항 현상이 발생할 것으로 사료된다. 따라서 자연함수비가 액성한계보다 큰 매우 연약한 세립토층에서는 모래보다 큰 입경을 갖는 쇄석이나 자갈 등 골재를 사용하는 gravel drain 공법 및 gravel compaction pile 공법 등의 적용을 지양해야 하고, 자연함수비가 액성한계보다 작은 연약한 세립토 지반에서도 gravel drain 공법 및 gravel compaction pile 공법 등과 같은 연직배수공법을 적용할 경우 그 효용성은 크게 저하할 것으로 사료된다.

• Advances in concrete construction
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• 제10권4호
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• pp.311-317
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• 2020

Performance of Sustainable materials continues through using of recycled waste construction materials to minimize the utilization of the natural resources. The cement industry is a major source of CO₂ in the atmosphere which is the main cause of global warming. Replacement of OPC with other sustainable cementitious materials has been the most interesting area of researches. This investigation focuses on the properties of alkali-activated mortar with the different replacement ratios of ceramic tile powder (CTP) by fine soil powder (FSP) (0 to 100)% and different molarities of sodium hydroxide concentrations. The experimental program was conducted by examining the compressive strength, water absorption, and water sorptivity. The results showed that the compressive strength of the specimens at age of (28, 56, and 90 days) increases with an increase in the amount of fine soil powder content and decreases at the age of 120 days. Also, minimum water absorption at the age of 90 days was found in the mixes containing 100% fine soil powder. However, fine soil powder replacement had a negative effect on the sorptivity and water absorption values at the age of 120 days. On the other hand, the 12M sodium hydroxide concentration was considered the optimum concentration compared to other concentrations.

• Geomechanics and Engineering
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• 제6권1호
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• pp.33-45
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• 2014

Use of geotextile as reinforcement material to improve the weak soil is a popular method these days. Tensile strength of geotextile and the soil-geotextile interaction are the major factors which influence the improvement of the soil. Change in fine content within the sand can change the interface behavior between soil and geotextile. In the present paper, the bearing capacity of unreinforced and geotextile-reinforced sand with different percentages of fines has been studied. A series of model tests have been carried out and the load settlement curves are obtained. The ultimate load carrying capacity of unreinforced and reinforced sand with different percentages of fines is compared. The interface behavior of sand and geotextile with various percentages of fines is also studied. It is observed that sand having around 5% of fine is suitable or permissible for bearing capacity improvement due to the application of geosynthetic reinforcement. The effectiveness of the reinforcement in load carrying capacity improvement decreases due to the addition of excessive amount of fines.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.181-188
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• 2004

Composite soil methods among granular pile merhods that we could improve soft ground of fine soil particles by, have permeability as one of fundamental principals. The catual state, that voids of sand or gravel, etc. of granular soil as drainage materials are clogged by fine soil particles, is 'clogging'. In this study, it is analysed that using sand or gravel, etc. of granular soil as drainage materials, experiment are made by clogging tester on several condition.

• The Korean Journal of Ecology
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• 제26권2호
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• pp.59-64
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• 2003

We examined the effects of fertilization [control (C), 200 kg N ha^{-1} + 25 kg P ha^{-1}$ (LNP), and 400 kg N $ha^{-1} + 50 kg P ha^{-1}$ (HNP)] on fine root (＜ 2 mm diameter) dynamics using monthly soil coring method in a 39-year-old Pinus rigida plantation of central Korea. The average fine root biomass (live + dead) (kg $ha^{-1}$ $\pm$ SE) during the first growing season for C, LNP, and HNP was 1301 $\pm$ 54, 1084 $\pm$ 47, and 1328 $\pm$ 22, respectively. The fine root production (kg $ha^{-1}$ $\pm$ SE) was 2394 $\pm$ 128 for C, 2048 $\pm$ 101 for LNP, and 2768 $\pm$ 150 for HNP, respectively. Over the same period, fertilization treatments had impact on N and P concentrations of live fine root. Nitrogen and P inputs (kg $ha^{-1}$ $yr^{-1}$) into the soil through fine root turnover for C, LNP, and HNP were 16.6 and 0.9, 17.2 and 0.9, and 24.1 and 1.6, respectively. There were no significant differences in fine root biomass and production during the first growing season after fertilization. However, fertilization increased fine root N and P concentrations, and in consequence resulted in increased N and P inputs into soil through fine root turnover.

• 한국환경복원기술학회지
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• 제5권3호
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• pp.1-8
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• 2002

Clayey paddy soils should be mixed with other good coarse soils to be used as a material for the lining, or, embankment. However, it has been difficult to separate soil particles from each other because of the internal cohesion in the soil gradation(separation) characteristics of the fine soil were investigated by various laboratory tests including the slaking durability test. Degradation rate of the soil were dependent upon the clay content and the initial water content before the submergence. The amount of degradations decreased as initial water content increased with exponential functions. The dried specimens separated into the particles after 24 hours of the submergence and specimens which water contents were less than 10% also separated into the particles after 2, or 3 days of the submergence. Compaction curves and the unconfined strength were not varied before and after the submergence. However, unconfined strength decreased as water content increased.