Journal of Korea Water Resources Association (한국수자원학회논문집)

Korea Water Resources Association (한국수자원학회)
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A Numerical Model for Bed Elevation Change and Bed Material Sorting in the Channel of Non-uniform Sediment

혼합사로 구성된 하천에서 하상변동 및 유사의 입도분포 계산을 위한 수치모형 개발

  • 장창래 (한국수자원공사 수자원연구원 수자원시스템 연구소) ;
  • 정관수 (충남대학교 토목공학) ;
  • 김재한 (충남대학교 토목공학과)
  • Published : 2004.05.01
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Abstract

A computer model was proposed to simulate channel changes and bed material sorting of the meandering channels with different grain size in time and space simultaneously. The bed at the outside of the meandering channel with mixed sediments was scoured deeply and composed of coarser materials, and at the inside was aggradated and composed of finer materials. The sorting process started at the upstream inflection point and was finished at the downstream inflection point. At the natural with complicated boundaries and non-uniform grain sizes, the bed near the outside at the bend and narrow width was scoured deeper with coarse materials than in the channel with uniform grain sizes. The point bars showed lip at the inside near the bend and the bed materials were finer The bed at the outside near the bend and in the narrow width was scoured deeply with the coarser materials.

본 논문에서는 하상변동 및 유사입자의 시간적 공간적 분포를 동시에 모의할 수 있는 2차원 수치모형을 제시하였다. 사행수로의 하상변동은 만곡부의 외측에서는 하상이 세굴되고 훨씬 더 거친 입경의 재료로 구성되며, 만곡부의 내측에서는 하상이 상승하고, 세립토로 구성되었다. 또한 사행하천에서 흐름의 방향에 대한 입자분포 과정은 상류의 변곡점에서 시작하여, 하류 변곡점에서 마치게 되는 것을 보여주었다. 하천의 경계가 불규칙하고 복잡한 하천에서는 혼합사호 형성된 하천에서보다 균일사로 이루어진 하천에서 하상이 깊게 세굴되는 현상을 보여준다. 혼합사로 이루어진 하천에서의 공간적 입도 분포는 사행하천에서와 마찬가지로 하상이 퇴적되는 사행의 내측에서는 세립토로 구성되고 하상이 세굴되는 외측에서는 굵은 입자로 구성되는 것을 보여주었으며, 하천 폭이 좁은 부분에서는 하상의 세출 및 하상재료가 굵게 변화되는 것을 보여주었다.

Keywords

References

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