• Journal of Wetlands Research
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• v.15 no.1
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• pp.149-157
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• 2013

The weirs built so far are mainly overflow type weirs overflowing to the upstream. Main advantages of overflow type weirs are, effective water resources management and easy design, construction and maintenance due to many accumulated studies. However, due to the special feature of the overflow type weir where water overflows through the upstream of the weir, the silt coming from the upstream is not discharged to the downstream of the weir. This increases the river bed and reduces the reservoir capacity, and as a result, the weir loses its function. A underflow type weir with a water gate has been implemented in order to solve such sediment deposit and weir maintenance problems. However due to the design problem of recently constructed underflow type weirs, the river bed of the downstream of a weir has been scoured. And this leds to a structural problem. In this study, the flow characteristics of overflow type weirs and underflow type weir, hydraulic jump length analysis depending on change of water depth and the amount of specific energy loss generated per unit length depending on a weir type have been compared and analyzed, for the effective design and management of the weirs. The experiment results show that, when identical upstream conditions of underflow type weir and an overflow type weir were maintained, the hydraulic jump length was up to twice longer with Fr(Froude number) 3.5 of the hydraulic jump length at the underflow type weir, and the hydraulic jump length gradually decreased as the downstream water depth increased. The comparative analysis result of the amount of specific energy loss generated per unit length showed that the amount of energy loss per unit length was twice higher for an overlfow type weir than a underflow type weir. Therefore, in case of a underflow type facility, an additional energy reduction facility is determined to be necessary for safety of water construction structures.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.309-313
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• 2005

한강 하류부의 잠실 및 신곡 수중보가 흐름에 미치는 영향을 적절히 모의할 수 있도록 FLDWAV 모형을 수정, 개선하였다. 고정좌 측에서 발생하는 월류형 흐름에 대해서는 월류 유량 관계식을, 가동보 측에서의 하도형 흐름에 대해서는 Manning 형의 유량관계식을 각각 적용함으로써 복합적인 형태의 수중보 흐름을 모의하도록 하였다. 월류 유량식으로는 수중 위어형 및 자유 월류형 흐름에 대한 식들이 적용 가능하며, 가동보 개방 시 또는 미개방 시의 흐름을 모두 모의할 수 있다. 모형의 적용성을 검증하기 위하여 수중보 지점에서의 다양한 조건에 대하여 계산을 수행한 결과, 각 경우에 대한 배수효과가 잘 모의되었다. 평수시 흐름에 대한 모의 기능을 검사한 결과, 수중보의 존재로 인한 수위의 불연속성이 잘 모의되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.453-457
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• 2004

본 연구에서는 WES의 표준 월류형 여수로에 대한 동수역학적인 흐름거동을 FLOW-3D 모형을 이용하여 해석하였다. 월류수두에 따른 월류유량, 월류흐름의 수면곡선, 여수로 표면에서의 압력분포와 같은 모의결과는 WES의 실험자료와 잘 일치하였다. 그리고 월류수두가 여수로 설계수두의 1.33배인 경우의 유속과 압력의 연직분포를 검토하였다. 검토결과, 웨어마루를 통과하면서 저층의 유속이 먼저 가속되며 점차 하류로 이동하면서 수표면의 유속이 가속되어 거의 균일한 유속분포를 보였으며, 압력의 연직분포는 웨어마루 상류에서는 수표면에서 내기압을 보이고 점차 수심이 길어짐에 따라 정수압분포와 유사한 분포를 보이나, 여수로 표면에 접근함에 따라 급격하게 압력이 감소하면서 부압이 발생하였다. 웨어마루 하류에서는 여수로 표면에서의 압력이 점차 대기압으로 접근함에 따라, 거의 전 수심에 걸쳐 대기압과 유사한 분포를 보였다.

• Journal of Korea Water Resources Association
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• v.40 no.2 s.175
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• pp.135-146
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• 2007

FLDWAV model was modified such that it can adequately simulate the effect of Jamsil and Singok submerged weirs in the main reach of the Han River. The enhanced model combines weir-type discharge equations for overflow at fixed weir and Manning equation for fluvial-type flow at the movable weir. Equations for weir overflow include those for submerged weir flow and free overflow. Gates of the movable weir may be open or closed for the simulation. In order to test the simulation capabilities, the enhanced model was applied for various flow conditions at submerged weirs. Backwater effect due to Jamsil and Singok submerged weirs were well simulated. Simulations were carried out for spring and neap tides extracted from artificial tide generated by combining $M_2\;and\;S_2$ tidal constituents. Simulation results cleared indicated that tidal effect extends further upstream as the flood discharge decreases. Low flow simulation capabilities of the enhanced model was tested. Discontinuities of water surface elevation due to the submerged weirs were successively simulated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6B
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• pp.541-550
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• 2011

This study sets the goal to improve effectively water quality of stream by complementing the weak points of the gravel contact oxidation process to use the inverted siphon curved channel system in free overfall of serial contact materials. The size of the current system can be diminished by expanding contact time, and the materials' replacement can be made easier when their gap are closed through the filtering boxes of contact materials. This system also has been developed into a construction method in which mixed and serial contact materials can be employed by using just the conventional single contact materials. It was verified the improvement ability of water quality of this system, during the simulation test at Tandong stream in Daejeon. The results of the verification of water quality improvement through several experiments in field were measured as follows : it showed to reduce about the averaged 55~83% higher than 60~75%, the internal planned goal of water quality improvement facilities.