• Water for future
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• v.11 no.2
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• pp.43-53
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• 1978

Synopsis: This study has systemized the results of construction and classification with 656 large dams in Korea which were defined in ICOLD provision. Especially, checking up the drainage capability of large capacity outlets and its of spillway, this paper suggests the planning of outflow discharge with large capacity outlets and spillway in future. The results of this study are following as; 1. The classification by purposes in Korea shows that irrigation dams are 94% in rate(607 dams), jydropower and multipurpose dams are 2% (14 dams), municipal and industrial water supply dams are 4% (26 dams). 2. In design of proposed outflow discharge, spillways of irrigation dams were selected outflow discharge on 100 years return period, those of municipal and industrial water supply dmas 200 years and those of hydropower and multipurpose dams 500 years or 1000 years. 3. Emergency spillway should be considered in the fields of disaster prevention engineering and the rank of return periods for the emergency proposed out flow discharge was suggested. 4. Some of problems are suggested for this subject in future.

• The Korean Journal of Ecology
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• v.27 no.1
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• pp.9-13
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• 2004

Dams are distributed widely in all over the world. China is one of the countries which have the most dams in the world. The construction of dams promotes consumedly to the development of economy and society, at the same time, brings many ecological and social problems. In China, the landscape ecological changes are caused by the construction of dams. These changes are long term or short term, and some of these changes are positive, others are negative. Solving these issues need do a lot of circumspect work in location choosing, planning and designing, practicing and protection of the up reservoir basin and the whole basin and so on. The construction of dams should be implemented by reasonable landscape planning, ecological environment protection in order to realize sustainable development.

• Computers and Concrete
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• v.27 no.2
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• pp.143-152
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• 2021

Large dams are a part of the infrastructure of any society, and a huge amount of resources are consumed to build them. Among the various types of dams, the optimum design of concrete gravity dams requires special attention because these types of dams require a huge amount of concrete for their construction. On the other hand, concrete gravity dams are among the structures whose design, regarding the acting forces, geometric parameters, and resistance and stability criteria, has some complexities. In the present study, an optimization methodology is proposed based on Sequential Quadratic Programming (SQP), and a computer program is developed to perform optimization of concrete gravity dams. The optimum results for 45 concrete gravity dams are studied and regression analyses are performed to obtain some explicit formulas for optimization of the gravity dams. The optimization of concrete gravity dams can be provided easily using the developed formulas, without the need to perform any more optimization process.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.4
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• pp.201-209
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• 2016

Damages of large embankment dams by recent strong earthquakes in the world highlight the importance of seismic security of dams. Some of recent dam construction projects for water storage and hydropower are located in highly seismic zone, hence the seismic performance evaluation is an important issue. While state-of-the-art numerical analysis technology is generally utilized in practice for seismic performance evaluation of large dams, physical modeling is also carried out where new construction technology is involved or numerical analysis technology cannot simulate the behavior appropriately. Geotechnical centrifuge modeling is widely adopted in earthquake engineering to simulate the seismic behavior of large earth structures, but sometimes it can't be applied for large embankment dams due to various limitations. This study proposes a dynamic centrifuge testing method for large embankment dams and evaluated its applicability. Scaling relations for a case which model scale and g-level are different could be derived considering the stress conditions and predominant period of the structure, which is equivalent to previously suggested scaling relations. The scaling principles and testing method could be verified by modified modeling of models using a model at different acceleration levels. Finally, its applicability was examined by centrifuge tests for an embankment dam in Korea.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.2
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• pp.75-82
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• 2008

There are almost 18,000 dams including about 1,200 large dams in Korea. The large dams are well operated and maintained by KWATER(Korea Water Resource Corporation), KRC(Korea Rural Community & Agriculture Corporation) and KHNP(Korea Hydro & Nuclear Power Co., Ltd.). Several research reports concern with the safety of these large dams are presented but there is no paper concerned with small dams which has diversion tunnel through the dam body. The purpose of this study is to show the common defects of small dams according to various cases of degradation of dams and the repair and retrofit methods which applied to the damaged dams. And this study performed resistivity survey to evaluate the effect of retrofitting dam. Also, this study tries to present the solution which concerned with these common defects in maintenance and design steps.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.2
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• pp.27-35
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• 2006

Large dams are managed with operation standard and flood forecasting systems, while small dams do not have management method generally. Shortage of water resources and natural disasters due to drought and flood raised public concerns for management of small dams. Most of small dams are irrigation dams, which need diversified water uses. However, the lack of systematic management of small dams have caused serious water wastage and increased natural disasters. Storage management method and system were developed to solve these problems in small dams. The system was applied to Seongju dam for effective management. The storage management method was established considering hydrology simulation and statistical analysis using the system. This method can bring additional available water, even in the same conditions of the water demand and the supply conditions of watershed. It can improve the flood control capacity and water utilization efficiency by' the flexible operation of storage space.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.190-198
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• 2010

This study was conducted to examine the effects of dams on benthic macroinvertebrate communities in Korean streams and rivers. Four low-head dams and three large dams were studied throughout South Korea. Sampling was taken at immediately upper (impoundment), lower (riffle area), and control (riffle area) sites from the dams during 2004-2007. The upper sites, of which substrate heterogeneity and velocity were relatively low, showed a lower degree of species richness, density, and diversity indices, which is very different from the lower and control sites. Heavily polluted streams showed a lesser degree of community differences between the upper and lower sites. In the large dams, the upper and lower sites showed very low values of species diversity indices and very high values of dominance indices compared to the control sites. In the low-head dams, however, the difference of degree of the values was relatively smaller. Compositions of the functional feeding groups and the habitat orientation groups were relatively simpler at the upper sites than at the lower sites and the degree of difference was greater in the large dams. Species richness and community indices of benthic macroinvertebrates were more significantly affected by habitat characteristics than water quality at the upper sites; however, those were more significantly related with water quality at the lower sites. In conclusion, large and low-head dams could simplify stream habitats particularly at the upper sites (impoundment), and they negatively affected on the benthic macroinvertebrate communities inhabited the habitats. The impact was larger in the large dams than in the low-head dams.

• Computers and Concrete
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• v.13 no.2
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• pp.209-220
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• 2014

Vibration based damage detection is very popular in the civil engineering area. Especially, special structures like dams, long-span bridges and high-rise buildings, need continues monitoring in terms of mechanical properties of material, static and dynamic behavior. It has been stated in the International Commission on Large Dams that more than half of the large concrete dams were constructed more than 50 years ago and the old dams have subjected to repeating loads such as earthquake, overflow, blast, etc.,. So, some unexpected failures may occur and catastrophic damages may be taken place because of theloss of strength, stiffness and other physical properties of concrete. Therefore, these dams need repairs provided with global damage evaluation in order to preserve structural integrity. The paper aims to show the effectiveness of the model updating method for global damage detection on a laboratory arch dam model. Ambient vibration test is used in order to determine the experimental dynamic characteristics. The initial finite element model is updated according to the experimentally determined natural frequencies and mode shapes. The web thickness is selected as updating parameter in the damage evaluation. It is observed from the study that the damage case is revealed with high accuracy and a good match is attained between the estimated and the real damage cases by model updating method.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.2
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• pp.11-20
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• 2016

Korea has 17,500 irrigation dams and facing variety of causes that jeopardize dam safety. With limited resources available to manage large inventory, a portfolio risk analysis application method for numerous irrigation dam safety is essential. The purpose of this study is to find an optimum way to adopt the risk analysis to the large number of irrigation dams in Korea and to propose the portfolio risk analysis process for irrigation dams. In this study, the necessity of the risk analysis for reservoirs safety has been suggested and a phased process using pre-screening and screening methodology has been proposed. This proposed procedure will help to effectively introduce the risk analysis for reservoirs safety in Korea.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.3
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• pp.15-25
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• 2005

Ninety tow percent of over 1,800 gate controlled dams in Korea are classified as small dams. The primary purpose of these small dams is to supply irrigation water. Therefore, while large dams can store as much as 80 percent of precipitation and thus are efficient to control flood, small dams are often lack of flood control function resulting in increased susceptibility drought and flood events. The purpose of this study is to develope a storage management model for irrigation dams occupying the largest portion of small dams. The proposed Storage Management Model (STMM) can be applied to the Seongju dam for efficient management. Besides, the operation standard is capable of analyzing additional available water, considering water demand and supply conditions of watershed realistically. And the model can improve the flood control capacity and water utilization efficiency by the flexible operation of storage space. Consequently, if the small dams are managed by the proposed Storage management model, it is possible to maximize water resources securance and minimize drought and flood damages.