Background : This study examined EC in soil depending on leaking water rate of sun shading facilities and conducted experiments to establish the proper leaking water rate for ginseng depending on rainfall. Methods and Results : For leakage examination, rainfall flowing into a ridge. As sun shading facilities of ginseng to examine leakage, four kinds such as Blue-Pe-sheet, Pe4 (four–layered polyethylene net) + Pe2 (two–layered polyethylene net), Pe4, Pe2 were installed. As for leakage, a plastic box (23 × 30 × 30 ㎝) was installed on the ridge of ginseng field and outside, rainfall into the box during precipitation was examined, and the leakage quantity was calculated as the ratio of the quantity into the ginseng field regarding rainfall outside. The leakage quantity was examined a total of six times on July 2, July 3, August 24, August 30, August 31, and September 4. Regarding EC in soil, WT–1000n (www.rfsenser.co) which is a EC measuring instrument was used, and the average was calculated through 3 repeated examinations. There are little differences in the leakage quantity depending on the sun shading with 0.1% of the Blue-Pe-sheet, 2.3% of Pe4 + Pe2, 4.3% of Pe4, and 30.7% of Pe2. At the leakage rate of 0.1%, EC decreased from 1.52 ds/m on July 3 to 1.04 ds/m on August 8, and increased again to 1.54 ds/m on September 3 At the leakage rate of 2.4%, EC changes were lower than that of the leakage quantity of 0.1%, and similar results depending on periods were found. At the leakage rate of 4.3%, salt concentration was measured at 0.92 ds/m on July 3, decreased since then, increased to 0.90 ds/m on September 3, and overall concentration was less than 1.0 ds/m. At the leakage rate of 30.7%, EC was the lowest at 0.46 ds/m and similar results were found since then. Conclusion : The differences in leakage quantity depending on sun shading facilities of ginsengs affected EC in soil, and EC became lower with more leakage quantity. As for the leakage quantity to maintain the EC in soil proper for ginseng growth and development lower than 1.0 ds/m, it was found to be effective to control the leakage quantity at 30% in May - June, and September - October when there are less rainfall, and at 2 - 5% in July - August when there are heavy rainfall.

Background : Ginseng sometimes develops physiological disorders as EC of soil accumulates in sun shading facilities with no leaking water. In addition, it is difficult to make moisture content of soil and EC stably suitable for ginseng growth and development in the same sun shading facility. Accordingly, this study examined EC in soil depending on leaking water rate of sun shading facilities and conducted experiments to establish the proper leaking water rate for ginseng depending on rainfall. Methods and Results : For leakage examination, rainfall flowing into a ridge. As sun shading facilities of ginseng to examine leakage, four kinds such as Blue-Pe-sheet, Pe4 (four–layered polyethylene net) + Pe2 (two–layered polyethylene net), Pe4 , Pe2 were installed. As for leakage, a plastic box (23 × 30 × 30 ㎝) was installed on the ridge of ginseng field and outside, rainfall into the box during precipitation was examined, and the leakage quantity was calculated as the ratio of the quantity into the ginseng field regarding rainfall outside. The leakage quantity was examined a total of six times on July 2, July 3, August 24, August 30, August 31, and September 4. Regarding EC in soil, WT-1000n which is a EC measuring instrument was used, and the average was calculated through 3 repeated examinations. There are little differences in the leakage quantity depending on the sun shading with 0.1% of the Blue-Pe-sheet, 2.3% of Pe4 + Pe2, 4.3% of Pe4, and 30.7% of Pe2. At the leakage rate of 0.1%, EC decreased from 1.52 ds/m on July 3 to 1.04 ds/m on August 8, and increased again to 1.54 ds/m on September 3 At the leakage rate of 2.4%, EC changes were lower than that of the leakage quantity of 0.1%, and similar results depending on periods were found. At the leakage rate of 4.3%, salt concentration was measured at 0.92 ds/m on July 3, decreased since then, increased to 0.90 ds/m on September 3, and overall concentration was less than 1.0 ds/m. At the leakage rate of 30.7%, EC was the lowest at 0.46 ds/m and similar results were found since then. Conclusion : Differences in leakage quantity depending on sun shading facilities of ginseng affected EC in soil, and EC became lower with more leakage quantity. For the leakage quantity to maintain the EC in soil proper for ginseng growth and development lower than 1.0 ds/m, it was found to be effective to control the leakage quantity at 30% in May - June, and September - October when there are less rainfall, and at 2 - 5% in July - August when there are heavy rainfall.

Measurement items of phenomena reflecting the overall condition of the structure during the measurement for safety management in the dam include water volume and displacement depending on the number of water leaks. Leakage measurements, which are important indicators to be measured on a dam, require significant accuracy and reliability. However, the dam design basis includes general measurement equipment, but the lower the limit for calculating the water leakage, and the lack of accuracy and reliability is a phenomenon. Therefore, in order to improve accuracy and reliability of the dam's major measurement items, the standards of the dam water measuring meter and the suitability of the water leak calculation formula (based on USBR) are reviewed to elicit problems and suggest solutions.

수도의 인구가 급증함에 따라 수원확보에 어려움을 겪고 있는 실정이다. 상수도시설은 준공 후 관의 매설로 인하여 관의 부식 및 노후화를 파악하기가 어렵다. 이러한 이유로 수도관로의 누수 파악과 누수로 인한 경제적 손실을 막기가 어렵다. 본 연구에서는 S대교의 누수량을 조사하고 시축관 설치 후의 누수량과 비교하여 누수감소량을 조사하였다. 그 결과 누수감소율이 약 98 %로 나타났으며, 이는 신축관을 설치하여 누수량을 감소하고 경제적 손실을 줄일 수 있는 것으로 판단된다.

본 연구는 중력댐 하부에서, 침투류에 의한 양압력과 누수량을 산정을 위한 방법론 제시를 그 목적으로 한다. 이를 위하여, 유한차분법을 이용한 3차원 부정류 수치모형을 개발하였다. 개발된 모형은 비균질 매체에서 Darcy 방정식을 만족하는 포화흐름을 모의할 수 있다. 모형의 검증을 위하여 우물이 있는 대수층에서 질량 이동을 산출하였고, mass balance 오차는 3%를 상회하지 않는 것이 확인되었다. 개발된 모형을 이용하여 중력댐 하부 대수층에서, 차수벽과 배수공의 존재에 의한 양압력과 누수량의 변화를 산출하였다. 유선망 방법과 비교한 양압력은 서로 유사한 결과를 나타내었으며, heel에서 toe까지의 양압력은 선형적인 분포를 보인다. 차수벽의 길이가 증가함에 따라서 heel에서의 양압력 강도는 선형적으로 감소하지만, 대수층을 통과하는 누수량은 비선형적으로 감소한다. 또한, 댐 설계 기준에서 제시되는 양압력 계산 공식의 계수들을 분석한 결과, 감소계수 α = 1/3 은 차수벽의 길이가 전체 대수층 높이의 약 70%일 경우에 해당하는 값으로 산출되었다. 배수공 주위에서 양압력은 연직 혹은 수평방향으로 급격한 곡률을 나타낸다. 본 연구에서 개발된 수치모형은 중력댐 설계에서 하부 침투류에 의한 영향, 특히 비균질성을 반영하여 양압력과 누수량을 평가하는데 활용될 수 있을 것으로 기대된다.