• 한국토양비료학회지
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• 제44권2호
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• pp.316-319
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• 2011

Biopiles which offer the potential for cost-effective treatment of contaminated soils are above-ground, engineered systems that use oxygen to stimulate the growth and reproduction of aerobic bacteria for degradation of the petroleum constituents adsorbed to soil in excavated soils. This technology involves heaping contaminated soils into piles and stimulating aerobic microbial activity within the soils through the aeration and/or addition of minerals, nutrients, and moisture. Inside the biopile, microbially mediated reactions by blowing or extracting air through the pipes can enhance degradation of the organic contaminants. The influence of a aeration system on the biopile performance was investigated. Air pressure made to compare the efficiency of suction in the pipes showed that there were slightly significant difference between the two piles in the total amount of TPH biodegradation. The normalised degradation rate was, however, considerably higher in the aeration system than in the normal system without aeration, suggesting that the vertical venting method may have improved the efficiency of the biological reactions in the pile.

• Computers and Concrete
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• 제6권1호
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• pp.79-93
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• 2009

In the present paper, a methodology has been presented for the reliability assessment of concrete barriers that lie at a certain depth in the soil, and a missile (a rigid projectile) impacts the top of the soil cover normally, and subsequently after penetrating the soil cover completely it hits the barrier with certain striking velocity. For this purpose, using expressions available in the literature, striking velocity of missile at any depth of soil has been derived and then expressions for the depths of penetration in crater and tunnel region of concrete barrier have been deduced. These depths of penetration have been employed for the derivation of limit state functions. Using the derived limit state functions reliability assessment of underground concrete barrier has then been carried out through First Order Reliability Method (FORM). To study the influence of various random variables on barrier reliability, sensitivity analysis has also been carried out. In addition, a number of parametric studies is conducted to obtain the results of practical interest.

• Geomechanics and Engineering
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• 제4권1호
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• pp.67-78
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• 2012

Soil foundations exhibit significant creeping deformation, which may result in excessive settlement and failure of superstructures. Based on the theory of viscoelasticity and fractional calculus, a fractional Kelvin-Voigt model is proposed to account for the time-dependent behavior of soil foundation under vertical line load. Analytical solution of settlements in the foundation was derived using Laplace transforms. The influence of the model parameters on the time-dependent settlement is studied through a parametric study. Results indicate that the settlement-time relationship can be accurately captured by varying values of the fractional order of differential operator and the coefficient of viscosity. In comparison with the classical Kelvin-Voigt model, the fractional model can provide a more accurate prediction of long-term settlements of soil foundation. The determination of influential distance also affects the calculation of settlements.

• 한국방사선학회논문지
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• 제9권2호
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• pp.117-120
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• 2015

주5일 근무제와 여가 생활의 증가로 인하여 캠핑을 하는 사람들이 지속적으로 증가 하고 있다. 따라서 다양한 캠핑장시설이 증가하고 있다. 사설 캠핑장의 경우 파쇄석이라 불리는 자갈 사이트와 일반 흙으로 된 사이트 등 다양한 사이트가 존재한다. 캠핑장은 야외 활동이 많은 곳이기 때문에 캠핑장내에서 측정되는 방사선량을 각각 다른 싸이트 별로 자연방사선량을 측정한 후에 분석하였다. 파쇄석으로 만들어진 장소보다는 흙으로 만들어진 싸이트에서 자연방사선량이 적게 측정되었으며, 인위적으로 만든 타프 그늘보다는 자연적으로 형성된 나무그늘이 자연 방사선량이 적게 측정되었다. 결론적으로 캠핑장소 선택시에서 자연방사선량을 피하려면 인위적으로 만든 캠핑장 보다는 나무가 많은 자연휴양림 장소가 캠핑하기 좋은 곳 이라고 알리고 싶다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2002년도 추계학술발표회
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• pp.179-182
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• 2002

Geosynthetics are widely used in landfill for filtration, drainage, separation and so on. For many landfill failure cases, interfaces of geosynthetics can be potential failure surfaces. Therefore, it is very Important to estimate the interface properties of geosynthetics. In this study, shaking table tests were peformed between smooth geomembrane and geotextile. From the test results, it was found that there is a limited acceleration that can be transmitted from smooth geomembrane to geotextile. And the influence of normal stress and frequencies of excitation were discussed.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.262-265
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• 2004

The purpose of this study is to investigate environmental characteristics and in-situ hydraulic conductivity by eco cone penetration system. The underground environments and permeability of site was investigated and analyzed by this eco cone system. The electrical resistivity, pH, ORP, temperature and hydraulic conductivity were measured by eco cone penetration system. This eco cone penetration system provides a continuous environment and permeability profiles in underground, and provides reliable results for investigation of normal and contaminated ground.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.192-199
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• 1999

In order to make the reasonable irrigation planin the reclaimed paddy fields, the estimation of irrigation water requirements by soil textures and water management methods for the normal growth of crops is very important. This study was carried out to determine leaching water requirements before cultivating crops. For the purposes of this study, the physical and chemical properties of soil sampels used in the desalinication experiments were analyzed and change of salinity by supplying water and leaching water were investigated in the experimental field with lysimeters.

• 한국토양동물학회지
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• 제5권1호
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• pp.5-7
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• 2000

중국 광동지방에서 채집한 농발거미과 농발거미속에 속하는 Heteropoda guangdongensis sp. nov.(신칭)를 채집하였기에 이를 신종으로 기재 보고하는 바이다.

• 한국토양동물학회지
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• 제5권1호
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• pp.9-11
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• 2000

저자들은 중국 후안상 수인닝현, 우이산, 통상현, 시멘현, 등지에서 채집한 게거미과의 꽃게거미속에 속하는 Misumenops hunanensis sp. nov. (신칭)을 신종으로 기재 발표하는 바이다.

• 한국지반공학회논문집
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• 제27권10호
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• pp.13-23
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• 2011

동토기반 말뚝기초의 지지력은 말뚝구조물 표면과 주변 토사의 접촉면에서 발현되는 동착강도에 의해 산정되며, 이는 동착-강도가 동토지반 기초설계를 위한 가장 주요한 설계정수임을 의미한다. 동착강도는 토사종류, 동결온도, 말뚝표면에 수직방향으로 작용하는 지중응력, 재하속도, 말뚝구조물의 표면 거칠기 등 다양한 인자들에 동시다발적인 영향을 받는 것으로 보고되고 있다. 1960년대부터 동토지반 기초설계를 위한 동착강도 산정방법들이 제안되어 왔으나, 대부분 동결온도와 말뚝구조물 표면특성에 대한 영향은 고려하고 있는 반면 동착강도의 주요 영향인자 중 하나인 지중응력에 의한 영향을 고려하지 않고 있어 소정깊이 이상의 말뚝기초 설계를 위한 동착강도 산정방법으로 활용되기에는 한계가 있는 것으로 판단된다. 본 연구에서는 동결온도뿐 아니라 지중응력이 동착강도에 미치는 영향을 파악하기 위하여 직접전단시험기를 활용한 동결토 전단강도 및 동착강도 측정실험을 각각 수행하였다. 실험결과 전단강도와 동착강도는 모두 동결온도 조건이 낮아질수록, 혹은 수직응력 조건이 커질수록 증가하는 경향을 보였다. 전단강도와 동착강도의 정량적 관계분석을 위해 정의된 전단강도와 동착강도의 비 $r_s$는 초기 동결온도에서는 급격하게 감소하는 경향을 나타냈으나, 동결온도가 낮아질수록 증가하며 수렴구간을 형성해가는 경향을 보였다. 본 연구에서는 최종적인 연구결과로서 동결온도 및 수직응력 조건을 바탕으로 결정된 $r_s$값을 이용하여 동결토의 전단강도로부터 동착강도를 예측할 수 있는 방법을 제안하고 있다.