• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1998년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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• pp.163-170
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• 1998

The influence of the dam-reservoir interaction on the seismic response of dams is studied. The impounded water is assumed to be inviscid and compressible ideal fluid. Material damping is introduce to simulate the energy loss of wave propagation in the water. The irregular region of the impounded water adjacent to the dam is modeled by boundary element method. The regular region extending to infinity is modeled by the transmitting boundary. The dam body is assumed to behave elastically and modeled by finite element method. The coupled equation of motion is obtained by substructure method.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1997년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
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• pp.132-132
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• 1997

The influence of the dam-reservoir interaction on the seismic response of concrete dam is studied. The dam body is assumed to behave elastically and modeled by FEM. The impounded water is assumed to be inviscid and compressible fluid and modeled by BEM. The seismic response of dam-reservoir system is analyzed by coupling two regions : the dam body and reservoir.

• 한국수자원학회논문집
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• 제43권4호
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• pp.325-336
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• 2010

본 연구에서는 금강유역의 물이용과 댐의 영향에 의한 하천유황의 변화를 평가하였다. 유황변화의 압력지표로서 하천수 이용률과 담수지수를 분석하였다. 유황의 정량적인 변화 분석을 위하여 유황곡선, 유황계수, 홍수 및 갈수 빈도분석과 유량변동분석법을 적용하였다. 8개 분석 대상지점의 결과는 댐 건설전의 유황과 비교할 때 댐과 물이용의 영향으로 고유량 범위에서는 감소하고, 저유량 범위에서는 증가하고 있음을 구체적인 수치로 확인하였다. 금강유역은 연평균유출량의 24%를 저류할 수 있는 139개의 댐과 저수지에 의해 유황이 조절되고 지표수의 이용률이 36%로서 이들의 지표가 유황변화의 압력요인이 되고 있다.

• 한국수자원학회논문집
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• 제44권4호
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• pp.285-293
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• 2011

본 연구에서는 제한된 수자원 부존량을 효율적으로 사용하고 각 댐의 저류량, 수요에 대한 용수공급량 및 하천유지용수를 최대화하기 위해 댐 상 하류간의 연계운영 모형을 이용하여 연계운영 효과를 분석하고 댐과 보의 최적 연계운영을 통한 하류단의 수문학적 거동 특성 변화를 검토하여 댐운영 개선방안 도출 등 다양한 하천관리 개선 방안에 대해 연구하였다. 대상유역은 신뢰성 높은 수문자료를 획득 가능한 금강 수계 유역으로 하였으며 수문자료는 순물소모량을 감안한 '67~'06년(40개년) 유입량(수자원장기종합계획, 2006)을 유역의 일유입량으로 변경하여 적용하였다. 연계운영 시 네트워크상에서 용수공급 가능한 범위는 연평가시 95%를 만족하는 신뢰도를 적용하였으며 기존에 건설된 용담, 대청댐에 의해 구해진 저수지수는 0.292로 산정되었고 향후 추가될 금남, 금강, 부여보에 의해 재산출된 저수지수는 0.297로 나타났다. 결과적으로 29.2%를 저류할 수 있는 상태에서 보가 추가되면서 29.7%로 저류량이 증가됨을 나타낸다. 규암지점의 유황변동특성을 분석한 결과, 각 단계가 증가할수록 저수량 $Q_{275}$과 갈수량 $Q_{355}$은 증가하고 풍수량 $Q_{95}$과 평수량 $Q_{185}$은 감소하여 대상지점의 유황이 전반적으로 개선되는 것을 확인할 수 있다. 특히, 갈수량의 경우 댐과 보에 의해 통제가 되지 않은 수치 보다 댐-보연계 시 $16.3m^3/s$ 증가하였다. 본 연구를 통해 자연상태의 유황보다 댐연계 및 댐-보 연계운영에 의해서 유황이 안정되고 이로 인해 안정적으로 이용할 수 있는 용수가 증가되는 것을 확인할 수 있었다.

• 한국해양공학회지
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• 제27권2호
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• pp.107-113
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• 2013

Most natural river reach are approximately balanced with respect to sediment inflow and outflow. Dam construction dramatically alters this balance, creating an impounded river reach characterized by extremely low flow velocities and efficient sediment trapping. The impounded reach will accumulate sediment and lose storage capacity until a balance is again achieved, which would normally occur after the impoundment has become "filled up" with sediment and can no longer provide water storage and other benefits. This paper aims to investigate the sediment removal process in dam reservoir using simultaneously pressure flushing operation and vibrator machine. The main objective of this study is to identify the effect of vibrator in flushing cone dimensions. To achieve the objectives of present study, laboratory test have conducted under different hydraulic conditions such as two bottom outlets with diameter equal to 2" and 3", five discharges 0.23, 0.53, 1.21, 1.53 and 2.1 lit/s and only one water depth above the center of bottom outlets. Using the vibrator machine mounted into the reservoir and close to the bottom outlet, different frequency e.g. 20, 35 and 50 HZ, have been introduced to the deposited sediment at the vicinity of outlet. The results indicate that the volume and width of flushing cone are strongly affected by frequency of vibrations. The results indicate that the volume and width of flushing cone are strongly affected by frequency of vibrations.

• 한국수자원학회논문집
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• 제48권3호
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• pp.149-158
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• 2015

비상방류시설은 안전한 댐 운영 및 유지관리를 위해서 절대적으로 필요한 시설임에도 불구하고 국내 댐의 경우 이를 고려한 설계가 이루어지지 않아 각 댐의 비상방류 대응 적정성을 판단하기 곤란한 상황이다. 특히 국내 댐의 경우 비상방류시설규모를 산정하는 기준이 일정치 않을 뿐만 아니라 대부분의 용수댐은 별도의 방류시설 조차도 없는 실정이다. 따라서 본 연구에서는 기존댐 방류시설 현황 분석, 국내외 비상방류시설 설계기준 등의 검토와 함께 국내 댐설계기준을 적용한 가상 댐체와 수어댐을 대상으로 수위에 따른 방류능 분석을 수행하였다. 또한 SEEP 프로그램 등을 활용, 수위저하 속도에 따른 제체의 사면 안정성을 검토함으로써 비상방류 시설의 적정규모 산정기준을 제시하고자 하였다. 이를 위하여 수리학적 해석을 통해 저류수심에 따른 제체에 작용하는 힘을 분석하였으며 수위저하 속도 변화에 따른 제체의 안정성을 검토하여 허용수위저하 속도 범위를 제시하였다. 수위 25% 저감은 하중을 50%까지 감소시켜 초기수위 저감이 중요한 것을 알 수 있었다. 가상 댐체는 물론 수어댐에 수위저하 속도 1 m/일을 적용하더라도 제체의 안전성은 보장됨을 확인하였다. 다만, 방류능과 방류 소요일수는 수위별 저류용량 등 저류지 특성과 밀접한 관계가 있어 초기대응을 위해서는 7~10일 이내에 저류수심의 25%를 먼저 방류시키고 나머지 방류량은 1~2개월 이내에 방류할 것을 제안하였다.

• Structural Engineering and Mechanics
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• 제36권3호
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• pp.321-341
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• 2010

The seismic-induced failure of a dam could have catastrophic consequences associated with the sudden release of the impounded reservoir. Depending on the severity of the seismic hazard, the characteristics and size of the dam-reservoir system, preventing such a failure scenario could be a problem of critical importance. In many cases, the release of water is controlled through a reinforced-concrete intake tower. This paper describes the application of a static nonlinear procedure known as the Capacity Spectrum Method (CSM) to evaluate the structural integrity of intake towers subject to seismic ground motion. Three variants of the CSM are considered: a multimodal pushover scheme, which uses the idea proposed by Chopra and Goel (2002); an adaptive pushover variant, in which the change in the stiffness of the structure is considered; and a combination of both approaches. The effects caused by the water surrounding the intake tower, as well as any water contained inside the hollow structure, are accounted for by added hydrodynamic masses. A typical structure is used as a case study, and the accuracy of the CSM analyses is assessed with time history analyses performed using commercial and structural analysis programs developed in Matlab.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.1118-1125
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• 2005

In this study, seismic safety of CFRD(Concrete-Face Rockfill Dam) type "D" dam in operation is evaluated from the results of 1-g shaking table test using similitude laws. Model dam is made by similitude law considering the grain size of prototype dam component. After the model dam is impounded to the normal water level(N.W.L), it is excited by artificial earthquake wave corresponding to standard design respond spectrum of the "D" dam site. Displacement response behavior of the dam is examined through the measurement of vertical and horizontal displacement of dam crest. Also, amplification characteristics of acceleration with dam height is examined through the measurement of acceleration with dam height. Finally, the purpose of this study is to evaluate seismic safety of "D" dam in operation. From the results of acceleration measurement, it was found that acceleration of dam crest was amplified about 1.52 times compared to the acceleration of dam bottom and amplification phenomenon is outstanding at three quarters of dam height from the bottom of dam. From the analysis of displacement behavior, it was estimated that vertical displacement of prototype dam is 6.8cm (0.1% of dam height) and horizontal displacement 12.3cm(0.2% of dam height). These percentages is much lower than 1% of dam height(general stability criteria). Therefore, it was concluded that seismic stability of "D" dam against an estimated earthquake is guaranteed.

• 한국물환경학회지
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• 제32권5호
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• pp.433-441
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• 2016

Many large dams have been constructed for water supply, irrigation, flood control and hydropower in Korea for the last century. Meanwhile, recent studies indicated that the artificial reservoirs impounded by these dams are major sources of carbon dioxide (CO₂) to the atmosphere and relevant to global budget of green house gases. However, limited information is available on the seasonal variations of CO₂ evasion from the reservoirs located in the temperate monsoon regions including Korea. The objectives of this study were to estimate daily Net Atmospheric Flux (NAF) of CO₂ in Daecheong Reservoir located in Geum River basin of Korea, and analyze the influencing parameters that characterize the variation of NAF. Daily pH and alkalinity (Alk) data collected in wet year (2012) and dry year (2013) were used for estimating the NAFs in the reservoir. The dissolved inorganic carbon (DIC) was computed using the pH and Alk measurements supposing an equilibrium state among the carbonate species. The results showed seasonal variations of NAF; negative NAFs from May to October when the primary production of the reservoir increased with water temperature increase, while positive NAF for the rest of the period. Overall the reservoir acted as sources of CO₂ to the atmosphere. The estimated NAFs were 2,590 and 771 mg CO₂ m^-2d^-1 in 2012 and 2013, respectively, indicating that the NAFs vary a large extent for different hydrological years. Statistical analysis indicated that the NAFs are negatively correlated to pH, water temperature, and Chl-a concentration of the reservoir.

• 환경영향평가
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• 제20권2호
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• pp.107-121
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• 2011

To assess the impact of climate change on water quality in an impounded river basin, this study estimated future air temperature and rainfall in the years of 2020, 2050 and 2080 by statistically downscaling the simulation results from two GCM models combined with two emission scenarios (A2 and B1). Both scenarios were selected from the Special Report on Emission Scenarios (SRES) suggested by IPCC. The A2 scenario represents an extreme condition whereas the B1 scenario represents a clean and energy efficient condition which is similar to that of study basin. With the results of estimated climate factors and land use data, the discharge and the concentrations of BOD, TN and TP in the Andong dam basins were simulated using the SWAT model. The change in BOD concentration for the B1 emission scenario was greater than the A2 scenario in the annual increase range and the pollution level. The concentration of TN was decreased during March? June which is drought period and increased again afterward. In contrast to TN, the concentration of TP was generally decreased. The change in TP concentration was greater for the B1 scenario than the A2 scenario.