• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.541-544
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• 2008

Generally numerical analysis of tunnel lining, under dynamic loading condition, performed not considering pore pressure. But if tunnel excavated under the surface of water, such as bottom of the sea, the river bed, tunnel lining can take pore water pressure. It may be different from evaluated numerical analysis not considering pore pressure. Therefore tunnel design should consider effect of water pressure acting on tunnel lining.

• 동굴
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• 제8호
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• pp.19-42
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• 1998

The Bullock Creek Caves are located adjacent to the usually dry river bed of Bullock Creek, which reaches the sea about a kilometer north of Punakaiki. The caves have been comprehensively written up by Rodgers(972). Under conditions of normal water flow Bullock Creek submerges where the stream meets limestone on the west side of their Punakaiki syncline. In flood conditions it overflows the first submergence and progressively floods a series of smaller submergences down valley until it comes to the caves shown on the map. All these with the exception of Wazpretti Cave and Dry Valley Cave are probably more or less flooded during and after heavy rain.(omitted)

• Journal of Positioning, Navigation, and Timing
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• 제5권4호
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• pp.221-233
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• 2016

This paper deals with performance assessment of the kinematic network-based GPS positioning technique with a view to using it for ellipsoidally referenced bathymetric surveys. To this end, two field trials were carried out on a land vehicle and a surveying vessel. Single-frequency GPS data acquired from these tests were processed by an in-house software which equips the network modeling algorithm with instantaneous ambiguity resolution procedure. The results reveals that ambiguity success rate based on the network model is mostly higher than 99.0%, which is superior to that of the single-baseline model. In addition, achievable accuracy of the technique was accessed at ${\pm}1.6cm$ and 2.7 cm with 95% confidence level in horizontal and vertical component respectively. From bathymetric survey at the West Nakdong River in Busan, Korea, 3-D coordinates of 2,011 points on its bed were computed by using GPS-derived coordinates, attitude, measured depth and geoid undulation. Note that their vertical coordinates are aligned to the geoid, the so-called orthometric height which is widely adopted in river engineering. Bathymetry was constructed by interpolating the coordinate set, and some discussion on its benefit was given at the end.

• 한국산학기술학회논문지
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• 제14권2호
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• pp.911-918
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• 2013

2차원 RMA2 모형을 이용하여 방류조건에 따른 댐하류 하천의 홍수위, 유속분포 및 하상변동을 분석하였다. 수위분석결과 200년빈도에 의한 영향은 주암댐에서 광천교까지 구간(1.27km)에서 나타났고, 여유고는 댐 직하류 좌안제방 300m 구간에서 0.7m 부족하였다. PMF 방류시는 보성강 전구간에서 제방을 월류하는 것으로 분석되었다. 침수범람구역은 200년 빈도에서는 하천합류부의 일부지점에서 발생하였고, PMF 방류시에는 제방월류로 침수구역이 확대되었다. 하도내의 유속은 교량 및 하도의 폭이 좁은 구간에서 비교적 유속이 크게 나타나 하상저하가 발생하였다.

• 한국환경복원기술학회지
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• 제10권3호
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• pp.71-87
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• 2007

In order to improve and manage rationally for Youngdam creek in Haman-gun, the channel change, water quality and ecological adaptation etc. were evaluated by monitoring during three years. The distinct differences of channel characteristics appeared in the extents of bed excavation and the revetment methods because overall reconstruction was occurred intense disturbance of width expansion and levee construction etc. The scour and deposition were caused according to channel characteristics of ripple and pool, and the adaptation of vegetation was distinguished from each revetment methods clearly. Water quality was maintained first class on the basis of BOD as 0.5~1.5mg/${\ell}$. The vegetation appeared in 380 species close-to-nature river improvement before, but 64 species it after one year, 159 species it after two year and 158 species it after three year. The animal life appeared in 123 species of close-to-nature river improvement before, but 103 species it after one year, 116 species it after two year and 119 species it after three year.

• 한국환경복원기술학회지
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• 제9권4호
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• pp.1-12
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• 2006

The usages of urban riverine areas for the Gapchoen and Yudungcheon in Daejoen City were evaluated by analyzing riverbed characteristics and water quality and by surveying the status of the floodplain usage including questionnaires of people visiting the rivers. Both rivers appear to be stable with insignificant bed changes as the riverbeds are dominated by gravels. Water qualities of both rivers have been improved significantly over the past decade although there are quite large seasonal fluctuations, which is common in most rivers in Korea. The results of floodplain usage analyses show that Gapcheon is dominated with static uses (>70%) such as promenades and resting facilities, while Yudungcheon by dynamic uses (>44%) such as sports facilities. Overall, both rivers require better plans for riverine area usage management considering a balance between the dynamic uses and the static uses such as natural observation places for education and habitats for birds and fish in the rivers. The questionnaire survey results indicate that overall the present status of both rivers are satisfactory and that water quality improvement is one of the key factors to enhance the value of the riverine areas. Future river restoration should be conducted by taking into account the characteristics of urban rivers in harmony with surrounding natural sceneries.

• Water Engineering Research
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• 제3권1호
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• pp.45-55
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• 2002

The Szentgotthard Flood Protection Project is located in the southeasters part of Austria, very close to the Hungarian border and to the Hungarian town of Szentgotthard situated near the Junction of the rivers Lafnitz and Raab. During heavy rainstorms, this area has always been liable to severe floodings, affecting the town itself and upstream reaches, where major industrial and commercial development is planned. In order to solve these problems, several solutions have been developed by means of a series of model tests performed at the hydraulic laboratory of the Technical University of Graz, Austria. The model was constructed to scales 1:75 (lengths) and 1:25 (heights). This trebled scale allowed greater accuracy in the measurement of discharge depths. The results from the model tests have led to the following proposals: - Construction of a flood relief trough with an inflow section 3.5 km upstream of the junction of the rivers Lafnitz and Raab. - Use of a former river bed for the flood relief trough. - Design of a lowered embankment crest section to pass one-third of the maximum flood flow of the river Lafnitz. - Connection of the flood relief trough to the Lahnbach stream, a tributary of the river Raab.

• 한국수산과학회지
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• 제1권1호
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• pp.31-43
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• 1968

낙동강 하구산 재첩 (Corbicula elatior)을 채취구의 찬택성이 다른 이종의 채취구로서 채집하여 표본의 각고류도의 확률도에 따라 각년령군으로 분리하여 성장과 연령조성을 추정하고 연간 평균생잔률을 추산하였다.

• 한국농공학회논문집
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• 제48권1호
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• pp.27-38
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• 2006

In this study, we developed a program to estimate discharge efficiently considering major hydraulic characteristic including water level, river bed, water slope and roughness coefficient in a natural river. Stream discharge was measured at Gongju gauge station located in the down stream of the Daechung Dam during normal and dry seasons from 2003 to 2004. The developed model was compared with the results from the existing rating curve at T/M gage stations, and was used for runoff analyses. Evaluating the developed river discharge estimation program, it was applied during 1983-2004 that base flow separation method and RRFS (Rainfall Runoff Forecasting System) which is based on SSARR (Streamflow Synthesis And Resevoir Regulation). The result presents the stage-discharge curve creator range at the Gong-ju is overestimated by approximately $10-20\%$, especially at the low stage. It is attributed to the hydraulic characteristics at the study. The discharge simulated by the RRFS and base flow separation, which is calibrated using the measurement at the early spring and late fall season during relatively d]v season, shows the least errors. The coefficient of roughness at Gongju station varied with the high and low water level.

• 한국방재학회 논문집
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• 제6권4호통권23호
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• pp.29-36
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• 2006

최근 이상기후 및 집중호우로 인해 낙동강유역의 많은 지역이 재산 및 인명손실을 크게 입고 있으며 제방축조 재료의 획득 및 운송비등의 증가로 인해 재해방지차원의 제방축조에 여러 가지 어려움을 겪고 있는 실정이다. 본 연구에서는 낙동강 하상의 모래를 이용하여 소량의 시멘트를 혼합한 시멘트혼합토에 대해 삼축압축실험을 통해 시멘트혼합율에 따른 특성을 규명하고자 한다. 이를 위하여 낙동강유역 하상 모래와 시멘트의 혼합율을 변화시키면서 실내시험을 실시하였다. 제체재료의 적합성 검토, 설계 및 해석에 필요한 기초자료를 제공하기위해 다짐시험 및 표준삼축압축시험을 실시하여 시멘트혼합율에 따른 강도, 변형에 따른 응력 및 거동특성 등을 분석하였다.