• 한국방재학회 논문집
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• 제4권1호
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• pp.1-14
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• 2004

본 연구의 목적은 무엇보다도 콘크리트중력식 댐의 내진안전성 평가방법을 정립하는 데에 있다. 그렇게 하기 위하여 지진시 구조물의 거동을 파악하고 내진성능을 평가해야 한다. 본 연구에서는 구조해석 프로그램을 사용한 동적해석을 통하여 지진시의 피해상황을 알아보았다. 물의 중량으로 인하여 댐에 가해지는 동수압은 부가질량법을 이용하여 계산하였다. 본 연구에서 알아낸 바에 의하면 지반상태에 따라 경계조건을 부여해 주는 것이 필요하며 특히 댐의 모양이 불균일하거나 갑작스런 기하학적인 변화가 있을 때에는 댐의 상하류방향 지진 만이 아닌 댐축방향 지진에 대한 해석이 반드시 필요하다는 것이 밝혀졌다.

• Biomolecules & Therapeutics
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• 제4권1호
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• pp.59-67
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• 1996

A new composite antibiotic, SM-101(sulbactam·metampicillin), was at dose levels of 0, 375, 750 and 1500 mg/kg/day administered intravenously to pregnant Sprague-Dawley rats during the organogenetic period. Two-third of dams per group were subjected to caesarean section on day 20 of pregnancy and the remaining 10 dams per group were allowed to deliver. Effects of test substance on dams, embryonal development of F1 fetuses, as well as growth, behaviour and mating performance of F1 offspring were examined. In dams, two deaths occurred at 375 and 1500 mg/kg, respectively. The decrease in the weight of adrenal glands of the 1500 mg/kg group was observed. The prolongation of pregnancy period was found at 1500 mg/kg. F1 fetuses showed no changes related to the treatment of SM-101. In F1 offspring, the increase in spleen weight was seen at all doses treated. No treatment-related abnormalities were observed in each treated group in terms of development, behaviour and reproductive performance. In F2 fetuses, no drug-induced abnormalities occurred at all doses. The results show that the no-effect dose levels (NOELS) for dams and Fl offspring are under 375 mg/kg/day and NOELs for F1/F2 fetuses are over 1500 mg/kg/day.

• Advances in concrete construction
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• 제9권5호
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• pp.503-510
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• 2020

Concrete dams are important structures due to retaining amount of water on their reservoir. So such kind of structures have to be designed against static and dynamic loads. Especially considering on critical importance against blasting threats and environmental safety, dams have to be examined according to the blast loads. This paper aims to investigate structural response of concrete gravity dams under blast loads. For the purpose Sarıyar Concrete Gravity Dam in Turkey is selected for numerical application with its 85 m of reservoir height (H), 255 m of reservoir length (3H), 72 m of bottom and 7 m of top widths. In the study, firstly 3D finite element model of the dam is constituted using ANSYS Workbench software considering dam-reservoir-foundation interaction and a hydrostatic analysis is performed without blast loads. Then, nearly 13 tons TNT explosive are considered 20 m away from downstream of the dam and this is modeled using ANSYS AUTODYN software. After that explicit analyses are performed through 40 milliseconds. Lastly peak pressures obtained from analyses are compared to empirical equations in the literature and UFC 3-340-02 standard which provide unified facilities criteria for structures to resist the effects of accidental explosions. Also analyses' results such as displacements, stresses and strains obtained from both hydrostatic and blasting analysis models are compared to each other. It is highlighted from the study that blasting analysis model has more effective than the only hydrostatic analysis model. So it is highlighted from the study that the design of dams should be included the blast loads.

• Geomechanics and Engineering
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• 제9권6호
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• pp.709-727
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• 2015

The main aim of this study is to introduce optimal design of homogeneous earth dams with oblique and horizontal drains based on particle swarm optimization (PSO) incorporating weighted least squares support vector machine (WLS-SVM). To achieve this purpose, the upstream and downstream slopes of earth dam, the length of oblique and horizontal drains and angle among the drains are considered as the design variables in the optimization problem of homogeneous earth dams. Furthermore, the seepage through dam body and the weight of dam as objective functions are minimized in the optimization process simultaneously. In the optimization procedure, the stability coefficient of the upstream and downstream slopes and the seepage through dam body as the hydraulic responses of homogeneous earth dam are required. Hence, the hydraulic responses are predicted using WLS-SVM approach. The optimal results of illustrative examples demonstrate the efficiency and computational advantages of PSO with WLS-SVM in the optimal design of homogeneous earth dams with drains.

• Advances in concrete construction
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• 제11권5호
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• pp.397-407
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• 2021

This paper investigates the optimal sensor placements and capabilities of this procedure for dynamic characteristics identification of arch dams. For this purpose, a prototype arch dam is constructed in laboratory conditions. Berke arch dam located on the Ceyhan River in city of Osmaniye is one of the highest arch dam constructed in Turkey is selected for field verification. The ambient vibration tests are conducted using initial candidate sensor locations at the beginning of the study. Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification methods are used to extract experimental dynamic characteristics. Then, measurements are repeated according to optimal sensor locations of the dams. These locations are specified using the Effective Independence Method. To determine the optimal sensor locations, the target mode shape matrices which are obtained from ambient vibration tests of the selected dam with a large number of accelerometers are used. The dynamic characteristics obtained from each ambient vibrations tests are compared with each other. It is concluded that the dynamic characteristics obtained from initial measurements and those obtained from a limited number of sensors are compatible with each other. This situation indicates that optimal sensor placements determined by the Effective Independence Method are useful for dynamic characteristics identification of arch dams.

• 한국환경과학회지
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• 제31권2호
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• pp.195-213
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• 2022

This research summarizes the generating factors of greenhouse gas (carbon dioxide, methane, nitrous oxide) in hydropower dams and related domestic/foreign researches. Microorganisms and eutrophication are the main factors in greenhouse gases in hydropower dam reservoirs. The greenhouse gas emission from the hydropower dam is affected by meteorological factors and dam operation periods, and greenhouse gases are also emitted from the outlets. The fluxes of greenhouse gas emission from the hydropower dams were -926~180,806 mg CO₂ m^-2d^-1, -0.19~3800 mg CH₄ m^-2d^-1, and 0.01~16.1 mg N₂O m^-2d^-1. In South Korea, the study on the greenhouse gas emission from Korean hydropower dams has been rarely, and therefore it is inquired. This research suggested the methods on the greenhouse gas emission from Korean hydropower dams and flux calculation.

• 생태와환경
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• 제43권2호
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• pp.190-198
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• 2010

본 연구는 우리나라의 하천과 강에 설치된 댐(보)이 저서성 대형무척추동물 군집에 미치는 영향을 알아보고자 전국의 대표적인 하천과 강에 설치된 4개의 소형 보와 3개의 대형 댐을 대상으로 댐의 상류(저수역: impoundment), 하류(유수역) 및 대조지점(유수역)에서 2004~2007년에 걸쳐 저서성 대형무척추동물의 군집을 조사하였다. 바닥물질이 단순하고 유속이 상대적으로 낮은 상류지점은 종풍부도, 개체수밀도 및 다양도지수가 상대적으로 낮았으며, 하류지점과는 큰 차이를 보였다. 수질오염이 심한 도시하천에서는 보의 상류와 하류지점 간의 군집의 차이가 거의 없었다. 대형 댐의 상류와 하류지점은 대조지점에 비해 다양도지수가 훨씬 낮았고, 우점도지수는 훨씬 높았다. 반면, 소형 보의 하류지점은 대조지점과 유사하였다. 서식 및 섭식 기능군은 상류지점이 하류지점에 비해 더욱 단순하였으며, 대형 댐의 상류지점은 소형 보의 상류지점에 비해 더욱 단순하였다. 저서성 대형무척추동물의 종풍부도와 군집지수는 상류지점에서는 수질오염보다는 서식처 특성에 더 큰 영향을 받는 것으로 나타났으며, 하류지점에서는 수질오염과 더 높은 상관성을 보였다. 결론적으로, 하천과 강에 설치된 보와 댐은 상류지점(저수역)의 서식처를 단순화시켜 저서성 대형무척추동물 군집에 부정적인 영향을 미치며, 규모가 큰 댐이 소형보에 비해 더 큰 악영향을 미칠 수 있음을 시사하였다.

• Structural Engineering and Mechanics
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• 제21권4호
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• pp.423-435
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• 2005

A modal approach is proposed for dynamic analysis of concrete arch dam-reservoir systems in frequency domain. The technique relies on mode shapes extracted by considering the symmetric parts of total mass and stiffness matrices. Based on this method, a previously developed program is modified, and the response of Morrow Point arch dam is studied for various conditions. The method is proved to be very effective and it is an extremely convenient modal technique for dynamic analysis of concrete arch dams.

• Computers and Concrete
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• 제1권3호
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• pp.285-302
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• 2004

A FE-(FE-HE)-BE procedure is presented for dynamic analysis of concrete arch dams. In this technique, dam body is discretized by solid finite elements, while the reservoir domain is considered by a combination of fluid finite elements and a three-dimensional fluid hyper-element. Furthermore, foundation rock domain is handled by three-dimensional boundary element formulation. Based on this method, a previously developed program is modified, and the response of Morrow Point arch dam is studied for various conditions. Moreover, the effects of canyon shape on response of dam, is also discussed.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2001
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• pp.216-223
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• 2001

The necessity of the seismic capacity evaluation of existing concrete gravity dams i: through the Izmit, Turkey and JiJi, Taiwan earthquake in 1999. In this study, the method seismic capacity evaluation of existing concrete gravity dams in U.S. A., Japan and Canada reviewed, applied them to the concrete gravity dam in use. Evaluation of the seismic ca approach using three levels that are level 1 - Screening, level 2 - Pseudostatic Metho level 3 - Dynamic Analysis, Method.