• 한국수자원학회논문집
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• 제55권9호
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• pp.687-700
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• 2022

우리나라 다목적댐과 용수댐에서의 이수능력을 종합적으로 평가하기 위하여 기간신뢰도의 주 지표와 함께 회복도, 무차원 취약도를 포함한 수자원이용률, 비 유입량, 비 공급량을 활용한 통합보조지표를 이수안전도 평가지표로 활용하는 방법론을 제시하였다. 또한 향후 지속가능한 댐 운영 목적에서 이수안전도를 주기적으로 평가하고 평가 결과에 따른 구조적 혹은 비구조적 계획수립을 위한 댐별 우선순위 판단을 위해 이수안전도의 등급화 방안을 함께 제시하였다. 주요 결과로서, 섬진강댐의 경우 기간신뢰도는 99.0%로 1등급이었으나, 통합보조지표는 44점으로 최하인 5등급으로 나타났다. 이는 현재의 높은 신뢰도에도 불구하고, 장래의 기후나 지역적 용수수급의 변화가 이수안전도에 큰 영향을 미칠 수 있음을 의미하는 것이다. 충주댐의 경우는 대조적인 사례로서, 기간신뢰도가 93.0%로 국내 최대 규모의 다목적댐의 위상과는 다르게 전체 다목적댐 중 평균 이하의 성적을 보이는 반면 통합보조지표는 76점으로서 다목적댐 중에서는 소양강댐과 남강댐에 이은 높은 등급을 보인다. 하지만 그럼에도 불구하고 유역 규모상 비 유입량이 185%로서 충분한 유입량이 들어오기 때문에 실제 안정성은 높다는 평가를 할 수 있었다. 단일목적으로 설계된 용수댐은 생·공용수의 비중이 높고 댐의 공급량에 여유가 있기 때문에 이수안전도가 상대적으로 높게 산정되는 경향으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.860-868
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• 2008

Seismic safety analysis of rockfill dams are consist of the stability analysis as an simplifed method and the dynamic analysis as an detailed method. When high risk dams such as Multi-purpose dams were often applied detailed method by dynamic analysis, dynamic properties of dam materials such as shear modulus are considered as most important factor. Dynamic material properties such as shear modulus had to be investigated by cyclic triaxial test et al. during design and construction stage but these were not conducted because of the condition of domestic seismic design technique. MASW and SASW methods had been applied as a non destructive method to investigate dynamic material properties of existing rockfill dam, has no problems in dam safety at present. These methods were usually performed under the assumptions that the subsurface can be described horizontally homogeneous and isotropic layers. Recent studies(Marwin, 1993, Kim, 2001) showed that surface waves generated through inclined structures have different characteristics from those through a horizontally homogeneous layered model. further Kim et al(2005) and Min and Kim(2006) showed that central core type rockfill dam overestimated the shear wave velocities as increasing the depth through the 3D numerical modelling dut to the effect of outer rockfill and geometrical reasons In this study the results of shear wave velocities of seven rockfill dams form comprehensive facility review, was carried out from 2003 to 2007, were collected and analysed to establish the shear wave velocity distribution characteristics in increasing confining stress in rockfill dams and surface wave velocity ranges in rockfill dam through MASW and the limitation in application are discussed to be utilized as an reference value for dynamic analysis.

• Earthquakes and Structures
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• 제17권5호
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• pp.511-519
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• 2019

The concrete gravity dam is one of the most important parts of the nation's infrastructure. Besides the benefits, the dam also has some potentially catastrophic disasters related to the life of citizens directly. During the lifetime of service, some degradations in a dam may occur as consequences of operating conditions, environmental aspects and deterioration in materials from natural causes, especially from dynamic loads. Cumulative Absolute Velocity (CAV) plays a key role to assess the operational condition of a structure under seismic hazard. In previous researches, CAV is normally used in Nuclear Power Plant (NPP) fields, but there are no particular criteria or studies that have been made on dam structure. This paper presents a method to calculate the limitation of CAV for the Bohyeonsan Dam in Korea, where the critical Peak Ground Acceleration (PGA) is estimated from twelve sets of selected earthquakes based on High Confidence of Low Probability of Failure (HCLPF). HCLPF point denotes 5% damage probability with 95% confidence level in the fragility curve, and the corresponding PGA expresses the crucial acceleration of this dam. For determining the status of the dam, a 2D finite element model is simulated by ABAQUS. At first, the dam's parameters are optimized by the Minitab tool using the method of Central Composite Design (CCD) for increasing model reliability. Then the Response Surface Methodology (RSM) is used for updating the model and the optimization is implemented from the selected model parameters. Finally, the recorded response of the concrete gravity dam is compared against the results obtained from solving the numerical model for identifying the physical condition of the structure.

• 생약학회지
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• 제7권1호
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• pp.35-40
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• 1976

The plant distributions in the Na-Ree Dong in Dagelet Island and Baik-Rok Dam in Cheju Island were investigated and 143 genera, 187 species of plants were found in the Na-Ree Dong in Dagelet Island during 15 years from 1961 to 1975. From 1957 to 1975, 113 genera, 174 species of plants were found in Baik-Rok Dam in Cheju Island.

• 환경정책연구
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• 제4권1호
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• pp.21-38
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• 2005

본 연구에서는 댐 건설로 인한 대규모 저수지의 수문기상학적 영향에 대한 공간적인 범위를 분석할 수 있는 모형을 구축하였으며, 구축된 모형을 이용하여 섬진강댐, 소양강댐, 안동댐 충주댐 등의 4개 댐에 대해 분석을 수행하였다. 이러한 분석에는 인공위성 영상을 이용한 토지이용분석과, 아울러 이 결과를 이용한 알베도의 변화추정이 포함된다. 본 연구에서 수행한 모형화 과정 및 적용 결과를 정리하면 다음과 같다. (1) 댐 건설로 인한 알베도의 공간적 변화는 댐의 규모와 크게 관련이 있으며, 섬진강댐은 댐 주변 $10{\sim}20km$, 소양강댐은 40km, 안동댐은 $20{\sim}30km$, 충주댐은 50km 정도까지 알베도의 변화가 나타나는 것으로 파악되었다. (2) 댐 건설 후 댐 주변에서 재순환계수(전체 가용 수분 중 내부 공급이 차지하는 비율)의 변화가 크며(큰 값), 반대로 대상규모가 커질수록 작아지는 것을 파악하였다. (3) 댐의 격자별로 산정된 알베도와 재순환계수의 상관관계는 아주 높은 것으로 나타났다. 따라서, 댐 건설에 따른 토지이용의 변화가 궁극적으로 수분 순환구조에 큰 영향을 미치고 있음을 파악할 수 있었다. (4) 수문기상학적 영향범위를 댐 건설 후 생성되는 수표면적과 비교한 결과, 대략 수표면적이 $50km^2$까지 그 변화의 정도가 민감한 것으로 파악되었다.

• 한국습지학회지
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• 제21권spc호
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• pp.107-116
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• 2019

다목적댐은 생·공용수를 공급하고, 하천유지유량을 방류하는 등 하천관리에 있어 매우 중요한 역할을 한다. 하지만, 최근 발생하고 있는 기상이변은 댐 공급량의 시공간적 변화를 야기하여 댐 용수공급의 취약성이 증대되고 있는 실정이다. 본 연구에서는 기후변화에 따른 국내 6개 다목적댐들의 미래 유입량의 변화를 평가하였다. 평가를 위해, 고해상도 앙상블 기후변화 시나리오를 이용하였으며, 준분포형 강우-유출모형을 통해 댐 유입량을 산정하였다. 평가 결과, 모든 댐과 모든 시나리오에서 홍수량이 크게 증가하는 것으로 나타났다. 하지만, 갈수량의 경우 태백산맥에서 발원되는 소양강댐, 충주댐, 안동댐은 크게 감소하는 것으로 나타났으나, 합천댐은 증가하는 것으로 나타났으며, 대청댐과 섬진강댐은 변화가 거의 없었다. 하지만 합천댐을 제외한 나머지 댐들 모두 갈수량의 범위가 더욱 넓어지고, 갈수량의 최소값은 감소하는 등 기후변화는 댐의 공급능력에 부정적인 영향을 미칠 것으로 분석되었다. 따라서 기후변화를 고려한 극한 물부족 발생 시 대응할 수 있는 물관리 정책수립이 요구된다.

• Structural Engineering and Mechanics
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• 제64권6권
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• pp.793-802
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• 2017

The damage of concrete due to the expansion of alkali-aggregate reaction (AAR) and thermal-chemical reactions affecting the strength of concrete is studied. The empirical equations for the variations of expansion of AAR, compressive strength and degradation of the modulus of elasticity with time, and compressive strength with degradation of the modulus of elasticity are proposed by analysing numerous experimental data. It is revealed that the expansion of AAR and compressive strength increase with time. The proposed combination of the time variations of chemical and mechanical parameters provides a satisfactory prediction of the concrete strength. Seismic analysis of the aged Koyna dam is conceded for two different long-term experimental data of concrete incorporating the proposed AAR based properties. The responses of aged Koyna dam reveal that the crest displacement of the Koyna dam significantly increases with time while the contour plots show that major principal stress at neck level reduces with time. As the modulus of elasticity decreases with ages the stress generated in the concrete structure get reduces. On the other hand with lesser value of modulus of elasticity the structure becomes more flexible and the crest displacement becomes very high that cause the seismic safety of the dam reduce.

• Structural Engineering and Mechanics
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• 제63권5호
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• pp.639-646
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• 2017

According to the multi-index system of dam safety assessment and the standard of safety, a comprehensive evaluation model for dam safety based on a cloud model is established to determine the basic probability assignment of the Dempster-Shafer theory. The Dempster-Shafer theory is improved to solve the high conflict problems via fusion calculation. Compared with the traditional Dempster-Shafer theory, the application is more extensive and the result is more reasonable. The uncertainty model of dam safety multi-index comprehensive evaluation is applied according to the two theories above. The rationality and feasibility of the model are verified through application to the safety evaluation of a practical arch dam.

• 상하수도학회지
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• 제27권1호
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• pp.39-47
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• 2013

This study demonstrates the oxidative degradation of pharmaceutical compounds during ozonation of surface waters in Ulsan. Diclofenac, carbamazepine, bezafibrate, and ibuprofen were selected as surrogate pharmaceutical compounds, and ozonation experiments were performed using raw waters collected from the Sayeon Dam and the Hoeya Dam in Ulsan. Diclofenac and carbamazepine which have high reactivity with molecular ozone showed higher removal efficiencies than bezafibrate and ibuprofen during ozonation. The addition of tert-butanol, a hydroxyl radical scavenger, increased the removal efficiencies of diclofenac and carbamazepine by increasing the ozone exposure. However, the oxidation of bezafibrate and ibuprofen was inhibited by the presence of tert-butanol due to the suppression of the exposure to hydroxyl radical. The elimination of the selected pharmaceuticals could be successfully predicted by the kinetic model base on the $R_{ct}$ concept. Depending on the experimental condition, $R_{ct}$ values were determined to be $(1.54{\sim}3.32){\times}10^{-7}$ and $(1.19{\sim}3.04){\times}10^{-7}$ for the Sayeon Dam and the Hoeya Dam waters, respectively. Relatively high $R_{ct}$ values indicate that the conversion of $O_3$ into $^{\cdot}OH$ is more pronounced for surface waters in Ulsan compared to other water sources.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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• pp.3554-3570
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• 2021

With the rapid development of the Chinese water project, the safety monitoring of dams is urgently needed. Many drawbacks exist in dams, such as high monitoring costs, a limited equipment service life, long-term monitoring difficulties. MEMS sensors have the advantages of low cost, high precision, easy installation, and simplicity, so they have broad application prospects in engineering measurements. This paper designs intelligent monitoring based on the collaborative measurement of dual MEMS sensors. The system first determines the endpoint coordinates of the sensor array by the coordinate transformation relationship in the monitoring system and then obtains the dam settlement according to the endpoint coordinates. Next, this paper proposes a dual-MEMS sensor collaborative measurement algorithm that builds a mathematical model of the dual-sensor measurement. The monitoring system realizes mutual compensation between sensor measurement data by calculating the motion constraint matrix between the two sensors. Compared with the single-sensor measurement, the dual-sensor measurement algorithm is more accurate and can improve the reliability of long-term monitoring data. Finally, the experimental results show that the dam subsidence monitoring system proposed in this paper fully meets the engineering monitoring accuracy needs, and the dual-sensor collaborative measurement system is more stable than the single-sensor monitoring system.