• Title/Summary/Keyword: Dam failure

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A Study of the Management of Groundwater Reservoir by Numerical Three Dimensional Flow Model (3차원 흐름모델을 이용한 지하저수지의 관리에 대한 연구)

  • 신방웅;김희성
    • The Journal of Engineering Geology
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    • v.5 no.3
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    • pp.289-300
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    • 1995
  • At the initial stage of the underground reservoir design one should thoroughly consider surface and subsurface hydrology, hydrogeologic characteristics of aquifer system, and the function of cut - off wall because it is linked to the effective management. In this study, three dimensional finite difference model was applied to analyse the function of Ian underground reservoir at Kyungbuk Province. The steady and unsteady state conditions after construction of the underground dam were simulated through the model, and from these results the groundwater budget and the safe yield were determined. The model simulation indicates the infiltration of irrigation water to be one of the major factors of seasonal fluctuation of groundwater level. The recharge rates of irrigation water were estimated as 4.3mm/d during May and June, and 1.7mm/d during July and Agust. Groundwater recharge from the watershed area estimated to about $0.04m^3/s$, almost consistent through the year. In 1984, groundwater discharge through the transverse section of the dam was $0.002m^3/s$ and the optimum yield for two momths(July and Aguest)was $254000m^3$, however, the discharge became $0.013m^3/s$ in1993, implying the failure of cut -off function. without appropaiate of the cut - off wall, optiumum yield during the irrigaton period would be $93, 000m^3$.

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Measurement of Joint-Orientation and Monitoring of Displacement in Tunnel using 3D Laser Scanning System (3차원 레이저 스캐닝 시스템을 이용한 불연속면의 방향성 측정과 터널 변위 모니터링)

  • Shon, Ho-Woong;Oh, Seok-Hoon;Kim, Young-Kyung
    • Journal of the Korean Geophysical Society
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    • v.9 no.1
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    • pp.47-62
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    • 2006
  • More than 70% of Korean Peninsula is consisted of mountains, so that lots of roads, rail-roads and tunnel,which play a pivotal role in the industry activity, are existed along the rock-slope and in the rock-mass. Thus,it is urgent that tegration of management system through the optimum survey and design of rock-slope excavation, proper stabilization method and database of rock-slope. However, conventional methods have shortcoming with the economy of survey time and human resources, and the overcome of difficulties of approach to the in-situ rock-slope. To overcome the limitation of conventional method, this paper proposed the development of remote measurement system using Terrestrial Laser Scanning System. The method using Terrestrial 3D Laser Scanning System, which can get 3D spatial information on the rock-slope and2)Dept. Geosystem Engineering, Kangwon National University, Korea tunnel, has an advantage of reduction of measurement time and the overcome of difficulties of approach to the in-situ rock-slope/dam/tunnel. In the case of rock-slope, through the analysis of 3D modeling of point-cloud by Terrestrial Laser Scanning System, orientation of discontinuity, roughness of joint surface, failure shape and volume were successively achieved. in the case of tunnel face, through reverse-engineering, monitoring of displacement was possible.

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Optimal Reservour Operation for Flood Control Using a Hybrid Approach (Case Study: Chungju Multipurpose Reservoir in Korea) (복합 모델링 기법을 이용한 홍수시 저수지 최적 운영 (사례 연구 : 충주 다목적 저수지))

  • Lee, Han-Gu;Lee, Sang-Ho
    • Journal of Korea Water Resources Association
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    • v.31 no.6
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    • pp.727-739
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    • 1998
  • The main objectives o reservoir optimal operation can be described as follows : maximization of the benefits through optimal allocation of the limited water resources for various purpose; minimization of t도 costs by the flood damage in potential damaging regions and risk of dam failure, etc. through safe drainage of a bulky volume of excessive water by a proper reservoir operation. Reviewing the past research works related to reservoir operation, we can find that the study on the matter of the former has been extensively carried out in last decades rather than the matter of the latter. This study is focused on developing a methodology of optimal reservoir operation for flood control, and a case study is performed on the Chungju multipurpose reservoir in Korea. The final goal of the study is to establish a reservoir optimal operation system which can search optimal policy to compromise two conflicting objectives: downstream flood damage and dam safety-upstream flood damage. In order to reach the final goal of the study, the following items were studied : (1)validation of hydrological data using HYMOS: (2)establishment of a downstream flood routing model coupling a rainfall-runoff model and SOBEK system for 1-D hydrodynamic flood routing; (3)replication of a flood damage estimation model by a neural network; (4)development of an integrated reservoir optimization module for an optimal operation policy.

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Strength and Permeability Characteristics of Soil-Bentonite Mixture (Soil-Bentonite 혼합토의 강도 및 투수 특성)

  • Jin, Guangri;Im, Eunsang;Kim, Kiyoung;Sin, Donghoon
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.4
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    • pp.5-12
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    • 2010
  • Soil mixture using bentonite as a cutoff material is used a lot for various structures such as landfills, banks and dams as cutoff materials. But seepage water is expected to seep since shear failure of filter layer occurs due to external load, embankment load when constructed. Generally, only coefficient of permeability of Soil Mixture is considered irrespective of the changes of intensity on amount of additives. This research is to study on how the changes of amount of bentonite affects permeability and strength of soil mixture. So successive experiments for measuring permeability and strength were conducted as the amount of bentonite changes from 0 to 4%, mixing with the bed material and then making specimens. Around construction site of B dam. As a result, 2.085E-07 cm/sec was shown when the amount of Soil Mixture was 4%. It is proved that unconfined compressive strength and tensile strength increase as the amount of bentonite increases, but saturation shear strength of bentonite soil mixture from the CD experiment is hardly influenced by the amount of bentonite.

Performance Evaluation of the Cast-in-place Anchor Bolt in Non-cracked Concrete used in Power Plant Facilities (비균열 콘크리트에 매립된 발전설비 정착부 선 설치 앵커의 구조성능 평가)

  • Kim, Dong-Ik;Jong, Woo-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.11
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    • pp.250-258
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    • 2019
  • The seismic performance and stability of operating facilities installed in domestic power plants need to be verified because of the increased incidence of earthquakes resulting in power plant damage due to the overturning failure of electric operating facilities. In this study, a structural performance evaluation of the anchor bolts constructed to setup the operating facilities on concrete slabs was carried out through an on-site inspection of power plants, called Daechung-Dam. M10 J hook and M12 J hook anchor bolts were installed in the field unit. According to the ASTM E 488-96 specifications, anchor bolt pullout and shear tests were carried out and compared with the anchor-bolt design standards. The results from the tension and shear pullout tests showed that the M10 and M12 J hook anchor bolts had higher performance than the required design load. Thus, they were found to be safe enough. Nevertheless, more research in the field of analytical study will be needed in the near future.

Study on the Soil Compaction (Part 4) -The Influence of Soil Compadtion on Unconfined Compressive Strength and Coefficient of Permeability- (흙의 다짐에 관한 연구(제4보) -흙의 다짐이 -축골조강동 및 투수계수에 미치는 영향-)

  • 강예묵
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.12 no.3
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    • pp.2003-2012
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    • 1970
  • In order to the influence of grain size distribution on compressive strength and coefficient of permeability, unconfined compression test and permeability test were performed for seventy samples that have various grain-size distributions. Its results are as follows: 1. Maximum unconfined compressive strength appears at the dry side of optimum moisture content. 2. Unconfined compressive strength is proportional to the increase of percent passing of No. 200 sieve. 3. Precent of deformation in failure increases in proportion to the increase of percent passing of No. 200 sieve, and modulus of No. 200 sieve, and modulus of deformation also increases in proportion to percent passing of No. 200 sieve. 4. Unconfined compressive strength increases in proportion to uniformity coefficient, liquid limit and plastic index, but it decreases gradually according to the increase of coefficient of grading and classification area. 5. Maximum dry density decreases according to the increase of void ratio. 6. Coefficient of permeability decreases according to the increase of percent passing of No. 200 sieve, and when percent of No. 200 sieve, and when percent passing of No. 200 enlarged more than 40%, it becomes less than $10^{-6}cm/sec$ which is the limit of coefficient of permeability of core material for earth dam proposed by Lee. 7. Coefficient of permeability increases according to the increase of coefficient of grading, classification area and index of Talbot formula r, but it was rather decrease by the increase of uniformity coefficient. 8. Coefficient of permeability seems to depend on the size and the shape of the flow path which is a series of void to be concerned by the size and the proprton of soil grain, even though void ratios are same.

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The Analysis of Flood Propagation Characteristics using Recursive Call Algorithm (재귀호출 알고리듬 기반의 홍수전파 특성 분석)

  • Lee, Geun Sang;Jang, Young Wun;Choi, Yun Woong
    • Spatial Information Research
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    • v.21 no.5
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    • pp.63-72
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    • 2013
  • This paper analyzed the flood propagation characteristics of each flood elevation due to failure of embankment in Muju Namdae Stream using recursive call algorithm. A flood propagation order by the flood elevation was estimated by setting destruction point at Beonggu and Chasan small dam through recursive call algorithm and then, the number of grids of each flood propagation order and accumulated inundation area were calculated. Based on the flood propagation order and the grid size of DEM, flood propagation time could be predicted each flood elevation. As a result, the study could identify the process of flood propagation through distribution characteristic of the flood propagation order obtained from recursive call algorithm, and could provide basic data for protection from flood disaster by selecting the flood vulnerable area through the gradient pattern of the graph for accumulated inundation area each flood propagation order. In addition, the prediction of the flood propagation time for each flood water level using this algorithm helped provide valuable information to calculate the evacuation path and time during the flood season by predicting the flood propagation time of each flood water level.

The Effects of Hominis Placenta Hydrate (HPH) on the Bone Marrow Failuer Induced by 5-Fluorouracil

  • Shin, Jang-Woo;Cho, Jung-Hyo;Son, Chang-Gue;Lee, Yong-Yeon;Lee, Yeon-Weol;Yoo, Hwa-Seung;Lee, Nam-Heon;Yun, Dam-Hee;Cho, Chong-Kwan;Choi, Chang-Woo
    • The Journal of Internal Korean Medicine
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    • v.27 no.2
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    • pp.327-335
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    • 2006
  • Aim: To examine the efficacy of Hominis Placenta Hydrate (HPH) on the hemopoiesis in a myelosuppression model system. Methods: Mice were injected with 5-Fluorouracil (5-FU) intraperitoneally and were administered with 200 mg/kg and 1000 mg/kg of HPH. Peripheral blood was analyzed at 5, 9, and 13 days. Histopathologic examination of bone marrow was performed at 5 days after 5-FU injection. The expression of cytokine involved in hemopoiesis was examined by using ELISA kit. Results: The hematology data demonstrated that the treatment of all the agents augmented monocytes and leucocytes counts in the peripheral blood WBC and platelet in HPH treated group were significant increased compared with control group. Also, cell numbers of RBC and Hb were restored. In HPH treated group, expression of IL-3, GM-CSF was significant increased But not TPO. Conclusions: Based on the above results, it is suggested that Hominis Placenta Hydrate is an effective remedy for the bone marrow failure and myelosuppression occurring during chemotherapy.

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Infiltration Analysis for Surficial Stability Evaluation of Two-layered Slopes (2층 지반의 표면파괴에 대한 안정성 평가를 위한 침투거동 해석)

  • Cho Sung-Eun
    • Journal of the Korean Geotechnical Society
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    • v.21 no.8
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    • pp.45-53
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    • 2005
  • Shallow slope failures in residual soil during periods of prolonged infiltration are common over the world. Therefore, this study examines an approximate method to estimate the influence of infiltration on surficial stability of slopes by one-dimensional infiltration model. Modified GAML model based on the Green-Ampt model was extended to predict the infiltration behavior of two-layered slope. Then, the model has been considered to evaluate the likelihood of shallow slope failure which is induced by a particular rainfall event that accounts for the rainfall intensity and duration for various return periods in two-layered soil profile. The results obtained from the approximate method were compared with those obtained from numerical analyses. According to the results, with the use of properly estimated input parameters, the proposed method was found to give good results that agree reasonably well to those of the more rigorous finite element analyses.

Slope Failure Surface Using Finite Element Method

  • Ahn, Tae-Bong
    • Journal of the Korean Geotechnical Society
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    • v.15 no.3
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    • pp.27-40
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    • 1999
  • In limit equilibrium methods(LEM), all methods employ the same definition of the safety factor as a ratio of the shear strength of the soil to the shear stress required for equilibrium, employing certain assumptions with regard to equilibrium. In addition, in the conventional finite element method of analysis, the minimum safety factor is obtained assuming certain slip surfaces after the state of stress are found. Although the stress states are obtained from the finite element method(FEM), the slope stability analysis follows the conventional method that assumes a potential slip surface. In this study, a slope stability analysis based on FEM is developed to locate the slip surface by tracking the weakest points in the slope based on the local safety factor considering the magnitude and direction of the shear stresses. It has also been applied to be compared with the slip surfaces predicted by LEM. A computer program has been developed to draw contour lines of the local safety factors automatically. This method is illustrated through a simple hypothetical slope, a natural soil slope, and a dam slope. The developed method matches very well with the conventional LEM methods, with slightly lower global safety factors.

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