• 산업기술연구
• /
• 제26권B호
• /
• pp.43-51
• /
• 2006

Through the result of calculating the deviation between the value calculated from two-dimensional number formula, one-dimensional number interpretation, and curving part water surface type calculation method, we could confirmed that the deviation is reduced more than 50% when we use curving part water surface type calculation method. Also it was confirmed that there occurs the reduction rate of maximum 59% as the result of comparing with one-dimensional number interpretation since the reduction rate of safe room height was 20%, in 500 CMS of flood water quantity when we planted the construction of levee by curving part water surface type calculation method. And therefore, we have confirmed that the curving water surface type calculation method can be used as a simple formula in rivers with water quantity less than 500 CMS that flows in and out in Jess than 90 degree angle.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 추계 학술발표회
• /
• pp.124-143
• /
• 2010

Cofferdam is a temporary levee or dam structure built by using sheet pile or earth materials to prevent water infiltration during construction work of bridge, dam, harbour dock, or hydraulic structures in the river. In this regard, it is required to secure cutoff ability for dry work and workability for rapid installation and removal of the temporary dam or levee structures. In this paper, case studies for design and construction of cofferdam were performed, and water diversion method was briefed with some examples of cofferdam type as well. For the case study details of design and construction were reviewed based on cofferdams under construction related to 16 submerged weirs of "The 4-river restoration project" and dam type cofferdam respectively. From the review, it was known that the method for changing the water flow is selected based on the data from geological and geo-hydraulic site investigation in order to mitigate environmental effects by making sure if the design cross-sectional area of flow and maximum working days are sufficiently guaranteed. Finally, the primary findings and main conclusion derived are summarized that determination of applicable type of cofferdam should be checked by case study and meet design requirements such as water inflow control, constructability.

• 대한토목학회논문집
• /
• 제26권6B호
• /
• pp.605-612
• /
• 2006

본 연구(II)에서는 2002년 8월 집중호우시 낙동강 유역에 대하여 강우예측 신경망 모형을 적용하였다. 예측된 3시간 선행 강우량은 실제 관측된 강우량의 패턴을 잘 따르고 있었으며, 기존의 연구와 비교하여 선행시간을 감안하면 강우예측의 정확성이 향상되었음을 확인할 수 있었다. 또한 동일한 유역의 실제 제방붕괴에 따른 범랑양상을 모의하였다. 이때 예측된 강우량 자료는 유역에서의 홍수량 산정을 위한 기본자료로 이용되었으며, 유역에서의 홍수량은 하도 및 제내지에서의 홍수범람 모의를 위한 경계조건으로 이용되었다. 모의결과는 실제 범람흔적과 하천에서의 홍수위 자료와 비교하여 잘 일치되고 있음을 확인할 수 있었다. 본 연구를 통해서 집중호우나 태풍과 같은 이상강우의 강우예측에 대한 인공위성 자료의 실질적인 활용성을 제공하였으며, 위성자료를 이용한 강우예측 기법과 연계하여 국내 실정에 맞는 홍수유출 및 홍수범람 모형의 개발을 통합함으로써 홍수재해에서의 강우, 유출, 범람에 대한 체계적인 실무적용에 사용될 수 있을 것으로 판단되었다.

• 대한토목학회논문집
• /
• 제30권6B호
• /
• pp.533-540
• /
• 2010

최근, 하천변에 분포된 식생관리는 하천의 안정성 뿐만 아니라 하천복원을 위해서도 매우 중요하다. 통상 하천변에 분포된 식생에 의하여 수리학적 저항이 증가되고 통수능이 감소되어 제방 범람을 초래한다. 본 논문에서는 1차원 및 2차원 수리해석 모형을 활용하여 소양강 댐 하류하천을 대상으로 서로 상이한 식생분포에 해당하는 조도계수를 적용함으로써 식생에 의한 제방월류 가능성을 검토하였다. 본 연구에서는 3가지 상이한 조도계수 즉, 관목부, 교목부, 그리고 주수로 부로 구분하여 해당되는 조도계수를 현장측정을 통해 작성한 식생도를 바탕으로 모형에 반영하여 이들에 의한 영향을 고려하였다. 전체적으로 식생에 의하여 약 0.1 m - 0.7 m 수위가 상승하는 것으로 모의되었으며 월류에 취약한 제방의 경우 범람방지를 위해 적절한 대책이 필요한 것으로 분석되었다.

• 한국지형학회지
• /
• 제27권3호
• /
• pp.13-24
• /
• 2020

This study analyzed the characteristics of the grain size distribution of the sediments obtained from the flooding in Ibang-myeon, Changnyeong-gun, which was caused by the collapse of a embarkment on the Nakdong River on August 9, 2020. As a results, it was found that the mean grain size decreases and the sorting becomes poorer as the distance from the embarkment collapse point increases. This is attributed to the fact that the transport energy of the river decreases when flooding occurs, ensuring that coarse-grained sediments are deposited first. Further, as the transport energy further reduces and becomes dispersed, the sorting for the fine-grained sediments becomes poor. Considering the characteristics of spatial distribution, sediments along the farm road showed the properties of floodplain deposits that transport to natural levee and back swamp due to river flooding. On the other hand, sediments along the irrigation ditch exhibited the properties of the deposits that are carried by the flow backward of ditch from the river after the collapse of the embarkment. The results of this study are significant because characteristics of flood sediments were elucidated for major rivers where flooding rarely occurs due to the recently built artificial structures. In addition, by applying the grain size distribution characteristics of present river flood sediments, it will be able to contribute to clarifying the sedimentary environments of the paleo river flood deposits.

• 한국지반공학회논문집
• /
• 제27권3호
• /
• pp.55-61
• /
• 2011

일반적으로 하천제방 배수통문은 다양한 원인에 의하여 붕괴가 발생하며, 특히 연약지반 상에 말뚝기초를 이용하여 설치된 경우 1) 주변 지반(외부토체)/말뚝기초 처리된 암거 상단(내부토체)의 상대적 침하 차에 의한 배수통문 암거 측벽부의 다짐도 약화, 2) 하이드로릭 플랙처링에 의한 홍수 시 침투수압의 지속적 반복에 의한 측벽부 교란 등에 의해 붕괴가 발생한다. 특히 측벽부는 시공여건상 다짐장비의 접근이 어려운 다짐 취약부이고, 이질재료에 의한 마찰력 감소로 전단저항력이 일반 흙의 전단강도에 비해 1/3 이상 감소하여 발현된다. 이에 본 연구에서는 주변 지반에 인위적인 변형을 발생시키는 방법으로 침하를 모사한 실내 모형실험을 통하여 연약지반 상 말뚝 기초된 배수통문 암거의 상대적 침하에 따른 외부토체/내부토체 발현 메카니즘과 저판확폭에 따른 배수통문 암거 측벽부 다짐도 향상 효과를 비교 분석함으로써 배수통문 저판 확폭을 통한 주변지반 공동 확장 억제기법을 제시하였다.

• 한국수자원학회논문집
• /
• 제47권4호
• /
• pp.321-330
• /
• 2014

본 연구는 국내를 대표하는 모래하천 낙동강에서 하안식생의 분포와 환경요인의 상관관계를 규명하기 위하여 수행하였다. 경상북도 안동시의 낙동강 일대에서 자연제방 5곳을 실험구간으로 선정하고 84개의 방형구를 설치하여 식물상, 식생피도, 평수위기준상대고도, 토양의 수분함량, 유기물함량, pH, 전기전도도 및 토성분석을 실시하였다. 식생단면조사의 피도값과 환경자료를 바탕으로 정준대응분석(Canonical correspondence analysis)을 실시한 결과 각 식물종은 평수위기준상대고도, 유기물함량, 모래함량 등에 의하여 3개의 그룹으로 구분되었으며 하천의 식생분포에 가장 큰 영향력을 끼치는 환경인자는 평수위기준상대고도로 나타났다.

• 한국수자원학회논문집
• /
• 제50권9호
• /
• pp.617-625
• /
• 2017

본 연구에서는 조석의 영향을 주기적으로 받는 임진강 하류부의 계획홍수위를 보다 합리적으로 산정하는 방안을 검토해 보았다. 우선 감조하천의 특성을 감안할 수 있는 부정류모의를 수행하여 홍수위의 변동을 살펴보았고, 수위 계산에 민감한 매개변수인 조도계수를 해당지역의 특성에 맞게 현실화하여 홍수위 변화를 분석하였다. 그 결과를 2011년 임진강하천기본계획보고서에서 고시한 임진강 하구 계획홍수위와 비교하고, 감조구간에서 홍수위 산정시 유의해야 할 점들을 정리하였다. 참고로 2011년에 고시된 계획홍수위는 대규모 하상 준설 단면을 입력자료로 하여 부등류모의를 통해 산정된 바 있다. 본 연구의 결과, 임진강 하구의 경우 홍수위 산정에 있어서 조도계수를 한강하구와 동일한 값으로 할당하고, 하구 조위를 감안할 수 있는 부정류 모의를 수행하면 하상 준설을 하지 않더라도 홍수위가 제방 여유고를 만족함을 알 수 있었다.

• 한국농공학회지
• /
• 제24권2호
• /
• pp.49-55
• /
• 1982

The purpose of this study is to classify the factors influenced on the damages of head works suffered from the storm flood occurred on July 22 1980 in both Musim and Bochong rivers and to find out an integral counter measures against the causes influenced on the disaster of head works in the engineering aspect of planning, design, construction and maintenance. In this survey, number of samples was taken 25 head Works, and the counter measures against the causes of their disasters summarized was as follows, 1. In the aspect of planning a. As the flood water level after the establishment of head works is more increased than the level before setting of head works owing to having more gentle slope of river bed between the head works than nature slope of river bed. Number of head works should be reduced for the appropriate annexation of them b. In the place where head works is established on the curved point of levee, the destruction of levee becomes severe by the strong deflective current. Therefore the setting of head works on the curved point should be kept off as long as possible and in case of unavoidable circumstances the construction method such as reinforced concrete wall or stone wall filed with concrete and anchored bank revetments should be considered. 2. In the aspect of design a. As scoring phenomena at up stream is serious around the weir Where the concentration of strong current is present in such a place, up stream apron having impermeability should be designed to resist and prevent scoring. b. As the length of apron and protected bed is too short to prevent scoring as down stream bed, the design length should be taken somewhat more than the calculated value, but in the case the calculated length becomes too long to be profitable, a device of water cushion should be considered. c. The structure of protected river bed should be improved to make stone mesh bags fixed to apron and to have vinyl mattress laid on river bed together with the improvement for increasing the stability of stone mesh bags and preventing the sucked sand from the river bed. d. As the shortage of cut-off length, especialy in case of the cutoffs conneting both shore sides of river makes the cause of destruction of embankment and weir body, the culculation of cut-off length should be taken enough length based on seepage length. 3. In the aspect of design and constructions a. The overturing destruction of weir by piping action was based on the jet water through cracks at the construction and expansion joints. therefore the expansion joint should be designed and constructed with the insertion of water proof plate and asphalt filling, and the construction joint, with concaved shape structure and steel reinforcement. b. As the wrong design and construction of the weep holes on apron will cause water piping and weir destruction, the design and construction of filter based on the rule of filter should be kept for weep holes. c. The wrong design and construction of bank revetment caused the severe destruction of levee and weir body resulting from scoring and impulse by strong current and formation of water route behind the revetment. Therefore bank revetment should be designod and constructed with stone wall filled with concrete and anchored, or reinforced concrete wall to prevent the formation of water flow route behind the wall and to resist against the scoring and impulse of strong stream. 4. In the aspect of maintenance When the damaged parts occurred at head works the authorities and farmers concerned should find and mend them as soon as possible with mutual cooperation, and on the other hand public citizen should be guided for good use of public property.

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