• 한국지반공학회논문집
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• 제20권3호
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• pp.75-83
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• 2004

인디아나주 도로국 (INDOT, Indiana Department of Transportation)에서는 부분적으로 1990년대 초반부터 토사개량(지반 안정화는 아님)에 대한 저비용의 건설재료로서 석회노분을 사용해왔다. 그러나 석회노분을 포함한 흙의 강도향상은 설계과정에서 노상의 안정화계산에 반영되지 않았다. 따라서 본 연구는 석회노분이 수화된 석회와 유사한 공학적 성질을 지닌 재료인지를 평가하기 위하여 수행되었으며, 인디아나주에서 흔히 접할수 있는 A-4, A-6, A-7-6와 같이 세립분이 우세한 다양한 흙과 조합하여 석회노분의 역학적 장점들을 평가하기 위해 일련의 실내실험들을 수행하였다. 본 연구에서는 아터버그한계, 표준다짐, 일축압축, CBR, 체적 안정성과 회복탄성계수등의 실험들을 수행하였으며 그 결과 비처리토에 비해 처리토의 경우 60-400% 정도의 범위로 일축압축강도가 증가하였다. 비혼합토에 대한 CBR 값의 범위가 3-18인 것에 반하여, 혼합토에 대한 CBR 값들은25-70의 범위내에 있다. 또한, 일반적으로 혼합토의 회복탄성계수도 상당히 증가하는 것으로 관찰되었다. 이상의 결과는 석회노분은 수화된 석회에 대한 대안으로서 실용적이고 경제적인 재료이며 세립토의 강도를 향상시키며 작업성을 향상시킬 수 있음을 암시한다.

• 한국토양비료학회지
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• 제34권2호
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• pp.98-104
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• 2001

가. 우수 토양관리농가의 토성은 대부분 SiL이나 SL이었으며 점토함량은 7%~15%범위이었다. 토양의 용적밀도는 우수 토양관리농가 0.89, 인근농가 1.10이었고, 작토심은 평균 23.1cm로 인근농가 17.8cm 보다 깊었으며, 토양입단함량은 우수 토양관리 농가 61.6, 인근농가 54.2%이었다. 나. 토양의 화학성은 우수토양관리농가가 인근농가에 비해 pH, OM, $NO_3-N$가 양호한 편이었다. 다. 토양선충밀도는 우수 토양관리농가가 인근농가에 비해 뚜렷한 경향이 없었으나, 방선균의 밀도는 우수 토양관리 농가가 인근농가나 노지에 비하여 많은 편이었고, 토양병원성세균인 후사리움밀도는 두 농가를 제외하고는 우수토양관리농가가 인근에 비해 적었다. 라. 우수 토양관리농가의 공통특징은 정식전에는 담수+심경, 거친유기물을 시용하고 화학비료를 지양했으며, 정식 후에는 정적판수와 자가액비(+영양제)위주로 양수분을 공급하며, 휴한기에는 담수+태양열소독이나, 우기시 피복물제거, 옥수수 등 제염작물 재배 및 논으로의 환원 등이었다.

• 한국초지조사료학회지
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• 제11권2호
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• pp.108-115
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• 1991

A field experiment was conducted to evaluate the effects of cattle compost application on the change of soil physical properties and their relationship to yield performance of selected main forage crops. Maize(CV. Suweon 19) and sorghum hybrids(CV. Pioneer 9'31) as a summer crops and winter rye were grown on newly reclaimed red yellow soils(Fine loamy, Typic Hapludults) under different application rate of cattle compost associated with chemical NPK fertilization, from Oct. 1986 to Sept. 1989. Experimental field was laid down as a split plots design with four replications. The results obtained are summarized as follows: 1. Cattle compost application reclaimed soil physical propeties, such as formation of granular structure and water holding capacity, and it result in a great increase of plant growth and the rate of dry matter accumulation. 2. While cattle compost treatment reduced the portion of soild phase of the three phase constituents of soils, it increased the portion of air phase and liquid phase comparatively. 3. Organic matter, N, P, K, and mineral content in soil were markedly increased in the plot treated with compost. 4. Cattle compost application increased fodder production both in maize-rye and sorghum hybrids-rye cultivation. Annual dry matter yield of maize-rye cropping was 2183(NI'K only), 2425(NPK+compvst 3000 kg) and 2800kg/lOa(NPK + compost 6000kg/10a).

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.819-835
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• 2009

In order to investigate the field application of selected stabilization methods(cover soil method, surface and total interval treatment of embankment method) on rice paddies contaminated by heavy metals, column test was carried out with heavy metal-contaminated soils collected from rice paddies around abandoned mine site. Columns were made by acrylic and filled with untreated soil, treated soil mixed with amendments(lime stone and steel refining slag) and uncontaminated cover soil according to the design report. Distilled water was discharged into the columns with the velocity of 1 pore volume/day. During test, pH, EC, and heavy metal concentration were measured in the regular term. The column test result showed that the selected stabilization methods were effective remediation method to stabilize heavy metals in paddy soils, but it was also expected that application of surface treatment methods was required the careful observation on pH variation due to the lowest increment.

• Journal of Forest and Environmental Science
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• 제26권2호
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• pp.117-129
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• 2010

The present study was undertaken in moist temperate forest of Mandal-Chopta area in the Garhwal region of Uttarakhand, India. The aim of the present study was to assess the physical properties of soils in relation to the forest structure and composition. Twelve forest types according to the altitude, slope aspect and species compositions were selected for the study. Physical properties of soil i.e., soil colour, soil texture (per cent of sand, silt and clay), moisture content, water holding capacity, porosity, bulk density (gm/$cm^3$) and void ratio were analyzed for three different depths viz., (i) 'upper' (0-10 cm), (ii) 'middle' (11-30 cm) and (iii) 'lower' (31-60 cm) in all the selected forest types. Phytosociological and diversity parameters viz. total basal cover ($Gha^{-1}$), stem density ($Nha^{-1}$), tree species richness, Simpson concentration of dominance and Shannon-Wiener diversity index were also calculated for each forest type. This study also provides the comparisons between the results of physical analysis of the present study with numerous other previous studies in the temperate Himalayan region of the Uttarakhand.

• 한국도로학회논문집
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• 제20권4호
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• pp.21-26
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• 2018

PURPOSES : The objective of this study is to evaluate the application of soil stabilization method for soft shoulder construction in the iRoad Project of Sri Lanka. METHODS : Firstly, the quantitative analysis of soil strength improvement due to soil stabilization was done for soil samples collected from iRoad construction sites. Two types of soils were selected from iRoad Project sites and prepared for soil stabilization testing by the Road Development Authority. Secondly, the appropriate stabilizer was selected at given soil type based on test results. Two different stabilizers, ST-1 and ST-2, produced in Korea were used for estimating soil strength improvements. Finally, the optimum stabilizer content was determined for improving shoulder performance. The uniaxial compressive strength (UCS) test was conducted to evaluate the strength of stabilized soil samples in accordance with ASTM D 1633. The use of bottom ash as a stabilizer produced from power plant in Sri Lanka was also reviewed in this task. RESULTS : It is found from the UCS testing that a 3% use of soil stabilizer can improve the strength up to 2~5 times in stabilized soft shoulder soils with respect to unstabilized soils. It is also observed from UCS testing that the ST-1 shows high strength improvement in 3% of stabilizer content but the strength improvement rate with increase of stabilizer content is relatively low compared with ST-2. The ST-2 shows a low UCS value at 3% of content but the UCS values increase significantly with increase of stabilizer content. When using the ST-2 as stabilizing agent, the 5% is recommended as minimum content based on UCS testing results. Based on the testing results for bottom ash replacement, the stabilized sample with bottom ash shows the low strength value. CONCLUSIONS : This paper is intended to check the feasibility for use the soil stabilization technique for shoulder construction in Sri Lanka. The use of soil stabilizer enables to improve the durability and strength in soft shoulder materials. When applying the bottom ash as a soil stabilizer, various testings should be conducted to satisfy the specification criteria.

• 대한토목학회논문집
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• 제4권4호
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• pp.137-145
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• 1984

타일랜드 북동부(北東部) 세 지역(地域)에서 나타나는 이산토(離散土)에 대한 물리적(物理的) 화학적(化學的) 특성(特性)에 대(對)한 시험(試驗)이 실험실(實驗室)과 현장(現場)에서 수행(遂行)되었다. 이산토(離散土)의 점토함량(粘土含量)과 이산성(離散性)과의 관계(關係)를 구명(糾明)하기 위(爲)하여 실내(室內)에서 이산토중(離散土中)의 점토(粘土) 분리(分離)한 후(後) 인위적(人爲的)인 점토함량비(粘土含量比)로 흙을 다시 만들어서 pinhole 시험(試驗)을 수행(遂行)하였는데, 이산토(離散土)는 점토함량비(粘土含量比)에 관계(關係)없이 쉽게 이산(離散)되었다. 또한 흙의 추출수(抽出水)와 저수지(貯水池) 물에 대한 화학적(化學的) 특성(特性)을 밝히기 위하여 SA,R, ESP 및 pH 값들이 결정(決定)되었는데, 이산토(離散土)는 1.8~6.7 SAR, 1.4~7.9 ESP 및 5.4~9.0의 pH 값을 나타내어서 일반적(一般的)인 흙에 비(比)하여 높은 SAR, ESP 및 pH 값을 보였다.

• 한국토양비료학회지
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• 제47권4호
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• pp.290-298
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• 2014

A bacterial strain with the potential ability to solubilize heavy metals was isolated from heavy metal contaminated soils collected from abandoned mines of Boryeong area in South Korea. The bacterial strain with the highest degree of metal resistance was shown to have close proximity with Shewanella xiamenensis FJ589031, according to 16S rRNA sequence analysis, and selected for investigating the mobilization of metals in soil or plant by the strain. The strain was found to be capable of solubilizing metals both in the absence and in the presence of metals (Co, Pb and Cd). Metal mobilization potential of the strain was assessed in a batch experiment and the results showed that inoculation could increase the concentrations of water soluble Co, Pb and Cd by 48, 34 and 20% respectively, compared with those of non-inoculated soils. Bacterial-assisted growth promotion and metal uptake in sunflower (Helianthus annuus) was evaluated in a pot experiment. In comparison with non-inoculated seedlings, the inoculation led to increase the growth of H. annuus by 24, 18 and 16% respectively in Co, Pb and Cd contaminated soils. Moreover, enhanced accumulation of Co, Pb and Cd in the shoot and root systems was observed in inoculated plants, where metal translocation from root to the above-ground tissues was also found to be enhanced by the strain. Plant growth promotion and metal mobilizing potential of the strain suggest that the strain could effectively be employed in enhancing phytoextraction of Co, Pb and Cd from contaminated soils.

• 한국토양비료학회지
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• 제47권4호
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• pp.242-248
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• 2014

We have five soil series of pan soils in South Korea out of 391 series: Gangreung, Bugog, Yeongog, Jangweon, and Pogog. Productivity decreases in pan soils as pan horizons impede percolation and capillary rise of water and interrupt root extension. This study was performed to investigate pedogenic processes of pan soils mainly located in footslope and river terrace by analyzing physicochemical properties and soil micro-morphology. Korean pan soils belong to Alfisols, Ultisols, or Inceptisols and have udic or aquic soil moisture regime, mesic temperature regime, and mixed mineral substances. Texture of pan horizons selected for the present study was mainly silty clay loam with clay contents ranging from 26.3 to 45.3%. Bulk density of the pan horizons ranged from 1.4 to $2.1Mg\;m^{-3}$ and their soil structure were subangular or angular structure. In terms of micro-morphological structure, Bt horizon of Gangreung series was formed as platy and striated b-fabric structure possibly affected by uplift of coastal terrace following clay sedimentation by flood. Jangweon series showed micro-morphology of massive structure and crystallic b-fabric as macropores between coarse debris established by debris fall in slope were filled with silt-sized particles. The Bt horizons having massive structure and striated b-fabric in Yeongog, Pogog, and Bugog series implies that those horizons experienced horizontal mass flow after clay accumulation.

• 한국토양비료학회지
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• 제48권4호
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• pp.255-261
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• 2015

Soil catena can be characterized by some properties, such as drainage levels and soil textures. Characteristics of soil catena are different drainage levels from a summit to the direction of gravity and similar soil textures. Therefore this study was performed GIS (Geographic information system) and statistical analyses using perimeters from soil series in order to characterize quantitatively and objectively soil distributional properties in Korea. The total of 16 soil series from representative granite and granite gneiss originated soils were selected among inland soils from detailed soil maps (1:25,000 scale) in Rural Development Administration (RDA) and analyzed. After the detailed soil maps were merged by soil series unit, perimeters were measured from one soil series to neighboring soil series using functions of table join, merge, dissolve, buffer, and clip in ArcGIS (10.1). The covering ratio of each soil series unit was calculated from neighboring perimeters by soil series and applied to clustering analysis. Soils that were analyzed were the total of 16 soil series; 7 of sandy loam and 9 of clay loam. As a result, analyzed soil series adjoined complicatedly such as Hyocheon series adjoined 26 series and Jisan did 276 series. The results of the clustering analysis showed that soils were clustered by soil textures except a few soil series. This study applied only one property that was a length of neighboring soil series to GIS and statistical analyses. These results were compared to existing soil groups that were classified by new-soil taxonomy, texture, soil type and drainage level. It showed that these analyses can provide soil characteristics by soil texture. Based on this study, there is a need to investigate further objectively and quantitatively in statistical analyses of soil series.