최근에 상용화된 SWRO 막은 플럭스 감소만으로 파울링을 평가하기 어렵다. 따라서 본 실험에서는 열역학 모델식을 통해 유기막오염과 세정에 따른 투수계수(Lp)와 농도분극계수(fcp), 파울링에 의한 여과저항(Rf) 변화를 분석해보았다. 파울런트 미주입시, 원수 TDS농도별, 압력별로 Lp와 fcp를 분석하였고 그 후, 유기 파울런트를 주입하여 막오염 진행에 따른 Lp와 fcp 변화를 분석하였다. 실험 결과, 파울런트를 주입하지 않은 경우, Lp와 fcp는 동일한 원수의 TDS 농도에서 압력이 증가함에 따라 증가하고, 동일한 운전 압력에서 원수의 TDS 농도가 증가할수록 감소하였고, 막오염 진행에 따른 Lp와 fcp의 감소 경향은 플럭스 감소 경향과 일치하지 않으며 막오염 물질 별로 다른 양상을 보였다.

The changes of rainfall pattern and impervious covers have increased disaster risks in urbanized areas. Impervious covers such as roads and building roofs have been dramatically increased. So, it is falling the ability safety of flood defense equipments to exist. Runoff coefficient means ratio of runoff by whole rainfall which is able to directly contribute at surface runoff during rainfall event. The application of accurate runoff coefficients is very important in sewer pipelines design.This study has been performed to estimate runoff characteristics change which are applicable to the process of sewer pipelines design or various public facilities design. It has used the SHER model, a long-term runoff model, to analyze the impact of a rising impervious covers on runoff coefficient change. It thus analyzed the long-term runoff to analyze rainfall basins extraction. Consequently, it was found that impervious surfaces could be a important factor for urban flood control. We could suggest the application of accurate runoff coefficients in accordance to the land Impervious covers. The average increase rates of runoff coefficients increased 0.011 for 1% increase of impervious covers. By having the application of the results, we could improve plans for facilities design.

PURPOSES : This study is to construct the regression models of drainage asphalt concrete specimens and to provide the appropriate coefficients of hydraulic conductivity prediction models. METHODS: In terms of easy calculation of the hydraulic conductivity from porosity of asphalt concrete pavement, the estimation model of hydraulic conductivity was proposed using regression analysis. 10 specimens of drainage asphalt concrete pavement were made for measurement of the hydraulic conductivity. Hydraulic conductivity model proposed in this study was calculated by empirical model based on porosity and the grain size. In this study, it shows the compared results from permeability measured test and empirical equation, and the suitability of proposed model, using regression analysis. RESULTS: As the result of the regression analysis, the hydraulic conductivity calculated from the proposal model was similar to that resulted from permeability measured test. Also result of RMSE (Root Mean Square Error) analysis, a proposed regression model is resulted in more accurate model. CONCLUSIONS: The proposed model can be used in case of estimating the hydraulic conductivity at drainage asphalt concrete pavements in fields.

The relationship between hydrologic processes and scale is one of the more complex issues in surface water hydrology. Disturbances that change vegetation and/or soil properties have been known to subsequently alter the landscape. The primary objective of this study was to estimate the grain size of soils with different properties from the hydraulic conductivity using pedotransfer functions. The double ring infiltrometer method was used to measure the vertical hydraulic conductivity of three soils under different soil planar surface treatments. Seven selected pedotransfer functions were used to estimate percentile diameters and the reduction in infiltration caused by compaction was misconstrued as caused by changes in percentile diameter. Results showed that compaction on the sandy loamy foot paths reduced the hydraulic conductivity by about 50%. The study showed that perceptual models of infiltration processes and appreciation of scale problems in modeling are far more sophisticated than normally presented in texts. Hydraulic measurement methods are still relevant and will provide significant information of grain size of the soils.

In this study, the crack healing performance of concrete containing microbial - based self - healing agent for the purpose of crack crack healing was evaluated by the permeability test. As a result of the addition of the microbial culture solution to the mixed water at an alternative ratio, the permeability recovery rate increases as the substitution rate increases. It is necessary to develop a microbial concentrate and to study the application of mixed microorganisms for the purpose of increasing the rate of permeability recovery and decreasing the substitution rate of microbial solution.

The purpose of this study is to estimate the permeability coefficient of concrete using mass hydrophobation agent. Experiments were carried out by making concrete specimens with different amounts of mass hydrophobation agent. It is considered that the pores are filled in the internal structure of the concrete by the expansion of the mass hydrophobation agent.

The purpose of this study is to estimate the permeability coefficient of concrete using mass hydrophobation agent. Experiments were carried out by making concrete specimens with different amounts of mass hydrophobation agent. It is considered that the pores are filled in the internal structure of the concrete by the expansion of the mass hydrophobation agent.

As hydrogeologic parameters such as hydraulic conductivity and specific yield are estimated by aquifer test , these are dependent on specific points at which field test was conducted. To overcome these site-specific limitations, a method of estimating transmissivity of aquifer using distribution features for parameters in Water table fluctuation model is newly suggested. Distribution features in reaction factor, specific yield and transmissivity having the function of pore space in aquifer are used to derive empirical equation for estimating transmissivity. From the result for applying the equation for 10 groundwater stations in Northeast Jeju Island, this equation is available for estimating transmissivity compared to the value estimated by existing equations. The estimated transmissivity ranged from 14.2 to 3,716.9 m2/day, and its average was 821.8 m2/day.

투수계수는 지반의 안정성 평가에 중요한 인자로 사용되며, 다양한 실험방법을 통해 유추되고 있다. 본 연구는 기존 방법 외에 물리탐사 기법 중에 하나인 탄성파 속도로 투수계수를 산정할 수 있는 방법을 제시하고자 한다. 탄성파 속도를 이용한 투수계수는 기존에 활용되고 있는 Hazen과 Kozeny-Carman 방정식을 이용하였으며, 각각의 수식에 대입되는 입력변수는 문헌값을 선택하였다. 기존방법과 탄성파 속도를 함께 측정 후 결과값을 비교하기 위하여 탄성파 센서가 장착된 새로운 압밀셀(oedometer)을 활용하였다. 새로운 압밀셀은 탄성파 센서가 추가로 장착되어 기존 압밀셀보다 직경은 확장되었지만 시료 직경 대 높이 비율을 2.5로 고정하여 ASTM에서 추천하고 있는 비율을 만족시켰다. 시료는 원형성이 높은 글라스비즈를 선행적으로 선택하였으며, 측정 데이터의 신뢰성을 확보한 후 주문진사와 점토도 함께 적용하였다. 압밀실험 결과 하중이 증가함에 따라 시료의 침하량은 감소하였으며 탄성파 속도는 증가하는 것으로 나타났다. 탄성파 속도는 일반적으로 입자의 접촉면에 의존하므로 재하 응력이 증가할수록 접촉면적이 커져 그 값이 크게 나타난 것으로 판단된다. 압밀실험에 의해 도출된 투수계수와 탄성파 속도를 도출된 투수계수 값을 비교하였으며, 그 결과 거의 유사한 값을 보이는 것으로 나타났다. 따라서 본 연구는 물리탐사기법을 활용하여 지반의 설계상수를 도출한 것에 의의가 크며, 추후 다양한 조건을 변화하여 현장의 적용성을 극대화 시키고자 한다.

유사발생 잠재성 및 토양침식으로 인한 유사발생 위험성이 높은 것으로 평가된 내성천유역을 대상으로 강우-유출-토양침식-유사이송으로 이어지는 유역단위의 분포형 모형을 구축하였으며 유출과 유사농도 모의 결과에 주요한 영향을 미치는 조도계수 및 투수계수의 민감도 분석을 실시하였다. 모의결과, 내성천유역의 토지 피복이 숲인 지역의 조도계수를 0.4에서 0.45로 변경하여 지표수 유출 유속을 감소시킴으로써 향석 지점에서의 유출곡선에 미치는 영향을 분석하였으나 유출수문곡선의 변화에 영향을 미치지 않는 것으로 나타났으며 평균 유사농도 값과 유사농도의 범위에 있어서도 모의 결과가 근소하게 증가하나 유의한 변화는 없는 것으로 나타났다. 투수계수에 대한 민감도 분석 결과, 투수계수 값을 저감 시킬수록 총 유출량 및 첨두 유출량은 점차 증가하는 것으로 나타났다. 유사농도 모의의 경우에도 투수계수를 저감시킬수록 모든 지점에서 평균 유사농도 및 유량에 따른 유사농도 범위가 증가하였으며, 향석 지점의 경우 투수계수를 50% 저감하였을 때 유사 농도 모의 값이 유량-유사량 관계식에 의해 계산된 값과 가장 근사한 것으로 나타났다.

Fundamental approach to compute gas and water permeability of concrete is suggested. For several compositions of cement pastes, the permeability coefficients were calculated with the analytical formulation, followed by a microstructure-based model. As the result of calculation of permeabilities for concrete, hydration leaded to the significant reduction of the coefficients. Meanwhile, the relationship between gas permeability and water permeability has a linear function for cement paste based on Klinkenberg effect, however, which is not effective for concrete.

강변여과는 원수를 강변의 대수층에 통과시켜 지층의 자체 정화능력을 이용하여 원수 중의 오염물질을 상당량 저감한 후 상수를 공급하는 방식이다. 본 연구에서는 지질정수를 추정하는 방법 중 하나인 역해석을 이용하여 강변여과 지역의 투수량계수를 추정하였다. 역해석이란 현장에서 직접 측정한 값과 프로그램을 통해 계산된 값의 차를 목적함수로 두고 이를 최소로 하도록 미지의 매개변수를 결정하는 것이다. 최적화 기법으로 BFGS(Broyden-Fletcher-Gold