• 한국지하수토양환경학회지:지하수토양환경
• /
• 제15권4호
• /
• pp.1-12
• /
• 2010

Well production by a riverbank filtration facility with multi-radial collector well systems in Jeungsan-ri, Changnyeong gun, Korea was evaluated. In this study, the drawdown at collector wells due to pumping and groundwater inflow rates along the horizontal arms of the collector wells were computed through numerical simulations. Sensitivities of the well production to hydraulic conductivity and well flow coefficient, which represents the resistance to the flow from the aquifer to the horizontal arms, were analyzed. Simulation results showed that, with given proposed pumping rate conditions, the drawdown in the caisson exceeded maximum drawdown constraints in the study site and the adjustment of the pumping rate at each well is needed. The drawdown is affected by the hydraulic conductivity of the main aquifer and the well flow coefficient, which means the profound field investigation of the study site is needed to accurately estimate the efficiency of riverbank filtration through radial collector wells.

• 지질공학
• /
• 제27권3호
• /
• pp.255-265
• /
• 2017

상주시 임곡리에 굴착된 심도 100 m 지하수공(PW-2)의 적정양수량을 산정하였다. 시추코아와, 물리검층 자료에 의하면 지하수 산출 심도는 26.1~26.5, 28.0~30.0, 33, 58, 71 m로 해석된다. 단계양수시험에 의하면 40, 55, 70, 90, $132m^3/d$의 양수량으로 70일간 양수시 수위강하량은 각각 6.48, 11.56, 18.07, 28.99, 60.26 m로 예상되었다. $117m^3/d$으로 250분간 실시한 일정량양수시험에서는 양수 경과시간 120~150분에 영향추가 불투수층 경계조건에 도달하여 급격한 수위강하가 일어나 PW-2의 한계채수량은 $90m^3/d$로 산정하였으며 이때의 수위강하량은 28.82~31.27 m이다. 적정양수량은 한계채수량의 범위내의 정류상태여야 하기 때문에 PW-2의 적정양수량은 $70{\sim}90m^3/d$로 제시하였다. 불투수층 경계조건에서 직선의 기울기가 급해지며 지하수의 DO와 ORP가 증가하는 것으로 보아 PW-2를 중심으로 한 기반암지하수의 발달은 제한적인 것으로 추정된다.

• 농업과학연구
• /
• 제39권1호
• /
• pp.97-110
• /
• 2012

This study was carried out for safety evaluation, the practical application and improvement of design method of the agricultural reservoir embankment according to backside extension. Seepage analysis, slope stability analysis and finite element analysis were performed for steady state and transient conditions. Also, the pore water pressure, seepage quantity, safety factor and stress-strain behavior according to high water level and rapid drawdown were compared and analyzed. The pore water pressure at contact region between backside extension and old embankment was kept high after rapid drawdown. Therefore, backside extension is recommended that design method is required to be improved and reinforced more than the others raising embankment. The hydraulic gradients before and after backside extension showed high value at the base of the core, but they showed stable state at the upstream slope and downstream slope. The seepage quantity per 1 day and the leakage per 100 m for the steady state and transient conditions appeared to be safe against the piping. The safety factor of slope stability showed high at the steady state, and transient conditions did not show differences depending on the rapid drawdown. The safety factor was appeared high at the upstream slope before backside extension and downstream slope after extension. The excess pore water pressure for steady state and transient conditions showed negative(-) at the upstream slope, it was small at the downstream slope. The mean effective stress (p') showed high at the base of the core and to be wild distribution after the extension. The displacement after extension showed 0.02-0.06 m in the upstream slope, the maximum shear strain after extension was smaller than that before extension.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2011년도 학술발표회
• /
• pp.36-36
• /
• 2011

일반적으로 저수지 퇴사는 연간 저수지의 유효용량의 0.5~1%을 감소시키고 홍수 시에는 홍수위를 상승시키는 등 저수지에 여러 가지 문제를 일으킨다. 따라서 댐 설계시 장기적으로 저수지 퇴사를 적절히 예측하고, 유지 관리 중에는 주기적인 퇴사 조사를 하여 퇴사의 진행 상황과 분포 등을 분석하여 필요시 댐 조작 방법의 개선이나 나아가 배사와 같은 적극적인 대책이 요구된다. 이에 본 연구는 저수지 배사작업의 지침을 제시하기 위하여 1차원 저수지 퇴 배사 모형을 제시하였다. 1차원 배사수치모의는 수위하강(drawdown)에 의한 배사를 고려하였으며, 준정류가정을 적용한 비연계 모형으로 구현하였다. 소류사량 산정을 위해서는 MPM 공식을 사용하였다. 모형의 적합성을 검증하기 위해 기존 선행 연구에서 수행한 수리실험의 제원 및 실험조건들을 적용하여 수치모의를 수행하였고, 수치모의 결과와 실험결과를 비교하였을 때, 본 연구에서 제시한 1차원 배사 수치모형의 적용성을 확인할 수 있었다.

• 터널과지하공간
• /
• 제4권1호
• /
• pp.24-30
• /
• 1994

Although a dry-system tunnel is not good for reasons fo economy and construction, it has been applied to some tunnels under construction owing to the advantages of good long-term maintenance of tunnel, prevention of consolidation settlement due to the drawdown of groundwater, preservation of the ecosystem, cutailment of operation cost, and so on. The stability of groundwater and the change of the applied water pressure after water proofing were analysed by the finite element method. Using this result, an example of designing the secondary lining for the dry-system tunnel which is to be constructed in low-permeability hard rock was presented.

• 미생물학회지
• /
• 제29권6호
• /
• pp.361-370
• /
• 1991

Physical and chemical environmental factors influencing on the outbreak of freshwater red tide by Peridinium bipes (dinoflagellate) in Soyang Reservoir were studied. Red tide occured in the site of inflowing of tributary streams annually, but the extent and severity of red tide varied from year to year. Several environmental factors such as water level, nutrient releasing from sediment, cyst resuspension, and concentrations of $Ca^{2+}$ and $Mg^{2+}$were studiedin relation to development, extent, and duration of red tide. In June of 1989 and 1991, the red tides of Peridinium bipes were very severe, and these red tides coincided with notable and rapid drawdown of lake water in late spring. Nutrient releasing and cyst resuspension by turbulence during drawdown were suggested as main causes of red tide. The quanity of nutrient releasing from sediment and hydrometeorological factors such as run-off and wind may determine the extent and duration of red tide.

• 자원환경지질
• /
• 제28권2호
• /
• pp.165-176
• /
• 1995

Dongrae is one of the most famous hot spring resort area in the Republic of Korea. The water temperature ranges $50^{\circ}C{\sim}66$. The chemical composition of the thermal water is quite different from normal groundwater. $Na^+$ and $Cl^-$ are the main components, measured more than 75%, $Ca^{+{+}}$ is contained about 22% and the other ions such as $SO_4$ or $HCO_3$ are the minor components. The heat source is uprising along the fracture zone of granite which is indicated as a subsurface high temperature belt. During the research period of 1991~1992, the groundwater table was lowered down to the depth of about 100 m according to continuous increase of daily use of thermal water. The groundwater table was fluctuated with an amplitude of day, weak or seasion. The groundwater table was the lowest at 18:00 h in a day and also lowest at the weekend for the week period. There was a relavent relationship between drawdown and the amount of thermal water use on a long term base. To protect such a rapid drawdown of groundwater table, Dongrae resort area is now asked to take strong municipal control for the daily use of thermal water.

• 한국수자원학회논문집
• /
• 제37권4호
• /
• pp.283-292
• /
• 2004

과거에는 신규댐 건설 여건이 비교적 양호하였으므로 기존댐의 용량 재할당을 고려할 필요가 없었다. 그러나 신규댐의 건설이 어려운 현 상황에서 기존댐의 효율적 이용이 절실히 필요하게 되어, 다목적댐의 용량 재할당에 대한 연구가 필요하게 되었다. 본 연구에서는 금강유역의 대청다목적댐을 대상으로 여러 가지 저수용량 재할당 대안에 대하여 현재 금팜강유역 수문상황의 변화를 적절히 반영할 수 있는 저수지 재할당 기법을 적용하고, 수위하강 빈도, 발전량, 신뢰도, 복원도 및 취약도 분석을 통하여 이수능력의 변화를 평가하였다. 그 결과 용담댐으로 인한 유입량 감소에 따른 대청댐 이수능력의 감소는 홍수조절용량을 이수용량으로 재할당 함으로써 일부분 증가시킬 수 있다는 것을 확인하였다.

• 한국터널지하공간학회 논문집
• /
• 제9권4호
• /
• pp.361-375
• /
• 2007

본 논문에서는 터널시공시 지하수 저하를 동반하는 시공조건에서 발생하는 지표침하 특성에 관한 연구내용을 다루었다. 이를 위해 먼저 지하수 저하로 인한 지반침하 문제에 대한 국내외 기존 연구내용을 살펴보았으며, 지하수 유동시 응력-간극수압 상호작용이 고려된 유한요소해석 모델을 구축하고 이론적 검증을 통해 유한요소해석 모델의 타당성을 검토하였다. 구축된 유한요소해석 모델을 토대로 다양한 시공조건에 대한 매개변수 연구를 수행하고 그 결과를 토대로 지하수 유동시 지반침하에 영향을 미치는 주요 인자를 검토하였으며, 아울러 터널시공이 지하수 저하를 동반하는 시공조건에서의 지표침하 특성을 기존의 이론과 연계하여 고찰하였다.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
• /
• pp.76-80
• /
• 1998

In order to identify the cause of ground water drawdown of a piezometer installed around the LPG storage cavern, parameter estimations were conducted by inverse and forward numerical models. An inverse model, SK-EST developed by SK Engineering & Construction Co., Ltd.(SKEC,1997) was performed to estimate the change of the hydraulic conductivity. It was verified by the commercial forward model, AQUA3D (VATNASKIL,1995). The simulation results showed that the hydraulic diffusivity of the rock mass between the piezometer and the cavern had been increased and the change rate of the hydraulic head had been abruptly increased in response to the change of the operation pressure. Finally the statistical analysis for observed data showed the increase of the change rate of the hydraulic head and thus proved the applicability of SK-EST.