• Title/Summary/Keyword: 공진주기파

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A Time Domain Analysis of Moored Ship Motions with Resonant Period of a Tsunami (쓰나미의 공진주기파를 고려한 항내 계류선박의 시계열 해석)

  • Cho Ik-Soon;Lee Yun-Sok;Lee Choong-Ro
    • Journal of Navigation and Port Research
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    • v.30 no.6 s.112
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    • pp.433-438
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    • 2006
  • Recently, the earth scale disaster is occurring frequently. Under the effects of global warming, the weather has become unseasonable worldwide. Hence, the earth is experiencing unstable condition with many disasters such as storms and flood damages as well as earthquake. Therefore, it is necessary to consider what we am do to prevent disasters. Consequently, recent warnings indicate that there is a potential risk of massive earthquakes. Consideration of the effects of tsunami to the moored ship is very important. Operational problems such as moored ship motions sometimes become remarkable with large amplitude and long periods in harbor. Moored ship motions may cause the breakage of mooring systems such as mooring lines, fenders or quay. Large and long period moored ship motions are caused by resonant effects. In this paper, the moored ship motions within a harbor by the large-scale tsunami and the effects on the motions and mooring loads with resonant effects are investigated by numerical simulations.

Numerical Simulation on Control of Tsunami by Resonator (I) (for Imwon and Mukho ports) (공진장치에 의한 지진해일파의 제어에 관한 수치시뮬레이션(I) (임원항과 묵호항에 대해))

  • Lee, Kwang-Ho;Jeon, Jong-Hyeok;Kim, Do-Sam;Lee, Yun-Du
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.32 no.6
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    • pp.481-495
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    • 2020
  • After the resonator on the basis of the wave-filter theory was designed to control the waves with a specific frequency range surging into the harbor, the several case with the use of resonator have been reported in some part of sea, including the port of Long Beach, USA, and yacht harbor at Rome, Italy in order to control the long-period wave motion from the vessels. Recently, the utility and applicability of the resonator has been sufficiently verified in respect of the control of tsunami approximated as the solitary wave and/or the super long-period waves. However, the case with the application of tsunami in the real sea have not been reported yet. In this research, the respective case with the use of existing resonator at the port of Mukho and Imwon located in the eastern coast of South Korea were studied by using the numerical analysis through the COMCOT model adapting the reduction rate of 1983 Central East Sea tsunami and 1993 Hokkaido Southwest off tsunami. Consequently, the effectiveness of resonator against tsunami in the real sea was confirmed through the reduction rate of maximum 40~50% at the port of Mukho, and maximum 21% at the port of Imwom, respectively. In addition, it was concluded that it is necessary to study about the various case with application of different shape, arrangement, and size of resonator in order to design the optimal resonator considering the site condition.