Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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An Analytical Solution of Dynamic Responses for Seabed under Coexisting Fields of Flow and Partial Standing Wave with Arbitrary Reflection Ratio

흐름과 임의반사율을 갖는 부분중복파와의 공존장하에서 해저지반내 동적응답의 해석해

  • Lee, Kwang-Ho (Dept. of Energy Resources and Plant Eng., Catholic Kwandong Univ.) ;
  • Kim, Dong-Wook (Dept. of Civil and Environmental Eng., Korea Maritime and Ocean Univ) ;
  • Kang, Gi-Chun (Dam & Watershed Maintenance Dept., K-water) ;
  • Kim, Do-Sam (Dept. of Civil Eng., Korea Maritime and Ocean Univ.) ;
  • Kim, Tae-Hyung (Dept. of Civil Eng., Korea Maritime and Ocean Univ.) ;
  • Na, Seung-Min (Dept. of Civil and Environmental Eng., Korea Maritime and Ocean Univ)
  • 이광호 (가톨릭관동대학교 에너지자원플랜트공학과) ;
  • 김동욱 (한국해양대학교 토목환경공학과) ;
  • 강기천 (한국수자원공사 댐.유역관리처) ;
  • 김도삼 (한국해양대학교 건설공학과) ;
  • 김태형 (한국해양대학교 건설공학과) ;
  • 나승민 (한국해양대학교 토목환경공학과)
  • Received : 2015.04.17
  • Accepted : 2015.06.10
  • Published : 2015.06.30
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Abstract

An analytical solution of dynamic responses for seabed in finite and infinite thicknesses including shallow has been developed under flow and partial standing wave with arbitrary reflection ration coexisting field at a constant water depth condition. In the analytical solution, a field was simply transited to a coexisting field of progressive wave and flow when reflection ratio was 0 and to a coexisting field of fully standing wave and flow when reflection ratio was 1. Based on the Biot's consolidation theory, the seabed was assumed as a porous elastic media with the assumptions that pore fluid is compressible and Darcy law governs the flow. The developed analytical solution was compared with the existing results and was verified. Using the analytical solution the deformation, pore pressure, effective and shear stresses were examined under various given values of reflection ratio, flow velocity, incident wave's period and seabed thickness. From this study, it was confirmed that the dynamic response of seabed was quite different depending on consideration of flow, which causes changing period and length of incident and reflection waves. It was also confirmed that dynamic response significantly depends on the magnitude of reflection ratio.

일정수심상에서 임의반사율을 갖는 부분중복파와 흐름이 공존하는 경우 얕은 두께를 포함한 유한두께 및 무한두께의 해저지반내에서 동적응답을 나타내는 해석해를 유도한다. 해석해에서 반사율이 0인 경우는 진행파와 흐름과의 공존장으로, 반사율이 1인 경우는 완전중복파와 흐름과의 공존장으로 간단히 변환된다. Biot의 압밀이론에 기초하여 해저지반은 투과탄성매체로, 간극유체는 압축성으로, 그리고 지반내 간극수의 흐름은 Darcy법칙으로 각각 가정된다. 도출된 해석해는 기존의 해석결과와의 비교 검토로부터 검증되며, 실제 계산에서는 반사율, 흐름속도, 입사파의 주기 및 지반두께 등의 변화에 따른 지반변위, 간극수압, 유효응력 및 전단응력의 변동특성을 면밀히 검토한다. 이로부터 흐름이 존재하는 경우 흐름으로 인한 입사파와 반사파의 주기 및 파장의 변화로 인하여 흐름이 없는 경우의 지반내 동적응답과는 큰 차이를 나타내며, 또한 반사율의 크기에 따라 동적응답에서 큰 차이가 나타난다는 것을 확인할 수 있다.

Keywords

Acknowledgement

Supported by : 한국해양과학기술진흥원

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