• Title/Summary/Keyword: Dams

Search Result 1,114, Processing Time 0.028 seconds

PERI-NATAL AND POST-NATAL STUDY OF THE RECOMBINANT HUMAN INTERFERON ${\alpha}A\;(rHuIFN-{\alpha}A)$ IN RATS

  • Lee, Yong-Soon;Kim, Yun-Bae;Kim, Hyun-Su;Cho, Nam-Jin;Yoo, Moo-Young
    • Toxicological Research
    • /
    • v.3 no.1
    • /
    • pp.55-63
    • /
    • 1987
  • A Peri-and Postnatal Study was Carried out to examine the effects of rHuIFN-${\alpha}A$, produced by gene-manipulated E. coli, on offsprings of Wistar rats. The substance was administered intraperitoneally to dams at dose levels of $1{\times}10^5$, $4{\times}10^5$ and $1.2{\times}10^6$ I.U/kg/day during the period from day 17 of gestation to day 21 after delivery. All the pregnant dams were allowed to deliver naturally, and the postnatal development of the offsprings was observed. No noticeable toxic effects and pathological changes on dams were observed, and no detectable variations in postnatal development of offsprings occured.

  • PDF

Direct frequency domain analysis of concrete arch dams based on FE-BE procedure

  • Lotfi, Vahid
    • Structural Engineering and Mechanics
    • /
    • v.26 no.4
    • /
    • pp.363-376
    • /
    • 2007
  • A FE-BE procedure is presented for dynamic analysis of concrete arch dams. In this technique, dam body is discretized by finite elements, while foundation rock is handled by three dimensional boundary element formulation. This would allow a rigorous inclusion of dam-foundation rock interaction, with no limitations imposed on geometry of canyon shape. Based on this method, a previously developed program is modified, and the response of Morrow Point arch dam is studied for various ratios of foundation rock to dam concrete elastic moduli under an empty reservoir condition. Furthermore, the effects of canyon shape on response of dam, is also discussed.

Controlling Spillway Gates of Dams Using Dynamic Fuzzy Control

  • Woo, Young-Woon;Han, Soo-Whan;Kim, Kwang-Baek
    • Journal of information and communication convergence engineering
    • /
    • v.6 no.3
    • /
    • pp.337-342
    • /
    • 2008
  • Controlling spillway gates of dams is a complex, nonlinear, non-stationary control process and is significantly affected by hydrological conditions which are not predictable beforehand. In this paper, control methods based on dynamic fuzzy control are proposed for the operation of spillway gates of dams during floods. The proposed methods are not only suitable for controlling spillway gates but also able to maintain target water level in order to prepare a draught. In the proposed methods, we use dynamic fuzzy control that the membership functions can be varied by changing environment conditions for keeping up the target water level, instead of conventional static fuzzy control. Simulation results demonstrate that the proposed methods based on dynamic fuzzy control produce an accurate and efficient solution for both of controlling spillway gates and maintaining target water level defined beforehand.

Risk factor analysis for failure characteristics of fill dam (필댐 파괴 특성에 따른 위험 요소 분석)

  • Lim, Jeong-Yeul;Oh, Seok-Hoon;Jang, Bong-Seok;Kim, Bum-Joo;Lim, Eun-Sang
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2006.03a
    • /
    • pp.794-799
    • /
    • 2006
  • For various historical reasons and some technical reasons, the safety of dams has been controlled by an engineering standards-based approach, which has developed over many years, initially for the design of new dams, but increasingly applied over the past few decades to assess the safety of existing dams. And some countries were asked for risk assessment on existing dam, which included structural, hydraulic safety of dam and social risk. So, Many countries were developed and could be adapted as an additional tool to assist in decision-making for dam safety management.

  • PDF

A Study on Crest Settlement Characteristics of Rockfill Dam (락필댐의 정부침하 거동특성 연구)

  • Park, Han-Gue;Park, Dong-Soon;Kim, Yong-Seong;Lee, Jong-Wook
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2005.03a
    • /
    • pp.1219-1226
    • /
    • 2005
  • In this study, crest settlement characteristics of CFRD (Concrete Faced Rockfill Dam) and ECRD (Earth Cored Rockfill Dam) were analysed through the instrumentation data from representative 7 large dams in Korea. Also, We have studied the effect of valley shape and uniaxial compressive strength of intact rock to better understand the impact of the parent rock strength and the valley shape on the long term crest settlement of CFRDs. From the results, we found that the valley shape and strength of intact rock on crest settlement of dams are an important parameters. As a result, we obtained that the maximum crest settlement of CFRD is larger than that of ECRD and long term crest settlement rate per dam height of rockfill dams is less than 0.60% during service period.

  • PDF

Transient stochastic analysis of nonlinear response of earth and rock-fill dams to spatially varying ground motion

  • Haciefendioglu, Kemal
    • Structural Engineering and Mechanics
    • /
    • v.22 no.6
    • /
    • pp.647-664
    • /
    • 2006
  • The main purpose of this paper is to investigate the effect of transient stochastic analysis on nonlinear response of earth and rock-fill dams to spatially varying ground motion. The dam models are analyzed by a stochastic finite element method based on the equivalent linear method which considers the nonlinear variation of soil shear moduli and damping ratio as a function of shear strain. The spatial variability of ground motion is taken into account with the incoherence, wave-passage and site response effects. Stationary as well as transient stochastic response analyses are performed for the considered dam types. A time dependent frequency response function is used throughout the study for transient stochastic responses. It is observed that stationarity is a reasonable assumption for earth and rock-fill dams to typical durations of strong shaking.

Existing concrete dams: loads definition and finite element models validation

  • Colombo, Martina;Domaneschi, Marco;Ghisi, Aldo
    • Structural Monitoring and Maintenance
    • /
    • v.3 no.2
    • /
    • pp.129-144
    • /
    • 2016
  • We present a methodology to validate with monitoring data finite element models of existing concrete dams: numerical analyses are performed to assess the structural response under the effects of seasonal loading conditions, represented by hydrostatic pressure on the upstream-downstream dam surfaces and thermal variations as recorded by a thermometers network. We show that the stiffness effect of the rock foundation and the surface degradation of concrete due to aging are crucial aspects to be accounted for a correct interpretation of the real behavior. This work summarizes some general procedures developed by this research group at Politecnico di Milano on traditional static monitoring systems and two significant case studies: a buttress gravity and an arch-gravity dam.

A Study of the Seepage through Filter Installed Earth Dams (필타설치흙댐의 침수에 관한 연구)

  • Gang, Gwan-Won;Sin, Bang-Ung;Lee, Jae-Gi
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.19 no.2
    • /
    • pp.4417-4422
    • /
    • 1977
  • This thesis is a result of theoretical and electrical experimental studies for the shape of Seepage on various Earth Dams. The decrement method of seepage through of water amount to earth Dam's was tested by means of experiment by the model constructed in the water tank. A study of the seepage through earth Dam's is necessary for a satisfactory of the same. An attempt was made in these investigations to study the problem of the seepage through homogeneous earth dams with filters located near the axis of the dam and filters extending in to upstream portion of the dam by the electrical analogy method. The experimental results were at variance with the graphical solution given by A Casagrande method. Some of the results were checked by relaxation method and by the circle criterion for drawing flow nets.

  • PDF

A Study of Operation Standard and Method of Small Dams (소규모 댐의 운영기준 및 기법 연구)

  • Kim, Phil-Shik;Kim, Sun-Joo;Lee, Joo-Yong
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2005.10a
    • /
    • pp.260-265
    • /
    • 2005
  • The purpose of this study is to established a storage management method and operation standard for irrigation dams occupying the largest portion of small dams using storage management system. The system can be applied to seongju dam for effective management. The storage management method was established considering hydrology simulation and statistical analysis using the system. This method and operation standard are capable of analyzing additional available water, considering the water demand and supply of basin actually. It can improve the flood control capacity and water utilization efficiency by the flexible operation of storage space.

  • PDF

Characteristics of Abutment Slopes of Four Dams in Korea (우리나라 주요 댐 좌우안 사면의 특징)

  • 신동훈;이종욱
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2000.11b
    • /
    • pp.183-195
    • /
    • 2000
  • Slopes near a dam body can be categorized into 4 groups, such as right and left abutment slopes, reservoir slopes, slopes along the access road and slopes along the relocated road. For each of the geological investigation, the design standards, the evaluation methods of safety and the maintenance methods, both abutment slopes in the four dams have different characteristics from the conventional cut slopes in that they can severely affect the dam safety. From this point of view this study compares and analyzes the geological investigation methods, the status of design and construction, evaluation method of safety, and monitoring & maintaining methods for four major dams in Korea, such as Soyanggang dam, 'Andong dam, Chungju dam and Boryong dam.

  • PDF