한국해안·해양공학회논문집 (Journal of Korean Society of Coastal and Ocean Engineers)

  • 제28권4호
  • /
  • Pages.177-190
  • /
  • 2016
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  • 1976-8192(pISSN)
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  • 2288-2227(eISSN)
한국해안·해양공학회 (Korean Society of Coastal and Ocean Engineers)
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불규칙파동장하 잠제 주변지반의 동적거동에 관한 수치해석

Irregular Waves-Induced Seabed Dynamic Responses around Submerged Breakwater

  • 이광호 (가톨릭관동대학교 에너지자원플랜트공학과) ;
  • 류흥원 (한국해양대학교 대학원 토목환경공학과) ;
  • 김동욱 (한국해양대학교 대학원 토목환경공학과) ;
  • 김도삼 (한국해양대학교 건설공학과) ;
  • 김태형 (한국해양대학교 건설공학과)
  • Lee, Kwang-Ho (Dept. of Energy Resources and Plant Eng., Catholic Kwandong University) ;
  • Ryu, Heung-Won (Dept. of Civil and Environmental Eng., Graduate School, Korea Maritime and Ocean University) ;
  • Kim, Dong-Wook (Dept. of Civil and Environmental Eng., Graduate School, Korea Maritime and Ocean University) ;
  • Kim, Do-Sam (Dept. of Civil Eng., Korea Maritime and Ocean Univ.) ;
  • Kim, Tae-Hyung (Dept. of Civil Eng., Korea Maritime and Ocean Univ.)
  • 투고 : 2016.07.01
  • 심사 : 2016.08.04
  • 발행 : 2016.08.31
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초록

잠제와 같은 중력식구조물 하부 해저지반에 고파랑이 장시간 작용하는 경우 토립자내 간극의 체적변화를 일으키는 과정에서 과잉간극수압이 크게 발생될 수 있고, 이에 따른 유효응력의 감소에 의하여 구조물 근방 및 하부의 해저지반에 액상화가 발생될 수 있다. 지반액상화가 발생 및 발달되면 종국적으로 구조물이 파괴될 가능성이 높아진다. 이에 대하여 Lee et al.(2016)은 규칙파를 대상으로 검토하였고, 여기서는 불규칙파랑을 대상으로 규칙파 해석에서 적용된 동일한 수치해석법을 적용하여 불규칙파동장하에서 잠제의 동적변위, 그리고 해저지반내에서 간극수압(진동성분과 잔류성분), 간극수압비 등과 같은 지반거동의 시 공간변화를 규칙파의 경우와 대비하면서 액상화 가능성을 정량적으로 평가한다. 이로부터 한정된 본 계산결과이지만 잠제하의 해저지반내에서 액상화 평가시 불규칙파의 유의파에 해당하는 파랑조건을 규칙파로 해석하는 것이 더욱 안정적인 설계로 된다는 등의 중요한 결과를 도출할 수 있었다.

In case of the seabed around and under gravity structures such as submerged breakwater is exposed to a large wave action long period, the excess pore pressure will be generated significantly due to pore volume change associated with rearrangement soil grains. This effect will lead a seabed liquefaction around and under structures as a result from decrease in the effective stress. Under the seabed liquefaction occurred and developed, the possibility of structure failure will be increased eventually. Lee et al.(2016) studied for regular waves, and this study considered for irregular waves with the same numerical analysis method used for regular waves. Under the condition of the irregular wave field, the time and spatial series of the deformation of submerged breakwater, the pore water pressure (oscillatory and residual components) and pore water pressure ratio in the seabed were estimated and their results were compared with those of the regular wave field to evaluate the liquefaction potential on the seabed quantitatively. Although present results are based on a limited number of numerical simulations, one of the study's most important findings is that a more safe design can be obtainable when analyzing case with a regular wave condition corresponding to a significant wave of irregular wave.

키워드

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피인용 문헌

  1. Numerical Analysis on Liquefaction Countermeasure of Seabed under Submerged Breakwater using Concrete Mat Cover (for Regular Waves) vol.28, pp.6, 2016, https://doi.org/10.9765/KSCOE.2016.28.6.361