• Title/Summary/Keyword: Dams

Search Result 1,116, Processing Time 0.028 seconds

Seismic analysis of arch dams including dam-reservoir interaction via a continuum damage model

  • Karaton, M.;Calayir, Y.;Bayraktar, A.
    • Structural Engineering and Mechanics
    • /
    • v.22 no.3
    • /
    • pp.351-370
    • /
    • 2006
  • In this study, the earthquake damage response of the concrete arch dams was investigated including dam-reservoir interaction. A continuum damage model which is a second-order tensor and includes the strain softening behavior was selected for the concrete material. Fluid-structure interaction problem was modeled by Lagrangian approach. Sommerfeld radiation condition was applied to the truncated boundary of reservoir. The improved form of the HHT-${\alpha}$ time integration algorithm was used in the solution of the equations of motion. The arch dam Type 5 was selected for numerical application. For the dynamic input, acceleration records of the 10 December 1967 Koyna earthquake were chosen. These records were scaled with earthquake acceleration scale factor (EASF) and then used in the analyses. Solutions were obtained for empty and full reservoir cases. The effects of EASF and damping ratio on the response of the dam were studied.

A smeared crack model for seismic failure analysis of concrete gravity dams considering fracture energy effects

  • Hariri-Ardebili, Mohammad Amin;Seyed-Kolbadi, Seyed Mahdi;Mirzabozorg, Hasan
    • Structural Engineering and Mechanics
    • /
    • v.48 no.1
    • /
    • pp.17-39
    • /
    • 2013
  • In the present paper, a coaxial rotating smeared crack model is proposed for mass concrete in three-dimensional space. The model is capable of applying both the constant and variable shear transfer coefficients in the cracking process. The model considers an advanced yield function for concrete failure under both static and dynamic loadings and calculates cracking or crushing of concrete taking into account the fracture energy effects. The model was utilized on Koyna Dam using finite element technique. Dam-water and dam-foundation interactions were considered in dynamic analysis. The behavior of dam was studied for different shear transfer coefficients considering/neglecting fracture energy effects. The results were extracted at crest displacement and crack profile within the dam body. The results show the importance of both shear transfer coefficient and the fracture energy in seismic analysis of concrete dams under high hydrostatic pressure.

Fetal growth retardation induced by maternal exposure to phenol in the rat (임신 랫트의 페놀 노출에 따른 태자의 발육 지연효과)

  • Chung, Moon-koo
    • Korean Journal of Veterinary Research
    • /
    • v.34 no.3
    • /
    • pp.601-607
    • /
    • 1994
  • This study was carried out to investigate the potential of phenol to induce embryotoxicity in the Sprague-Dawley rat. Seventy mated rats were distributed among three treated troups, a vehicle control group and a negative control group. Phenol was at dose levels of 20, 60 and 180mg/kg/day adminsistered by gavage to pregnant rats three times per day from days 7 to 12 of gestation. All dams were subjected to the caesarean section on day 20 of gestation. At 120mg/kg, dams exhibited decreased locomotivity. In addition, both weight reduction and retarded ossification of fetuses were observed. There were no signs of maternal toxicity or embryotoxicity at 20 and 60mg/kg. The results show that phenol induces fetal growth retardation at maternally subtoxic dose in rats.

  • PDF