Numerical Analysis of the Behavior of Bars in a Compound Channel with a Drop Structure

낙차공이 있는 복단면 수로에서 사주거동의 수치분석

Kim, Gi-Jung;Jang, Chang-Lae

  • Received : 2016.02.05
  • Accepted : 2016.03.20
  • Published : 2016.03.31


This study investigated the behavior of sediment bars in a compound channel with a drop structure. Flow was separated into side banks by alternate bars, and flow was concentrated into the downstream of bar fronts. The bed downstream of a drop structure degradated due to the concentrated flow from it. Bar shapes were kept by the influence of their shapes upstream. Alternate bars, central bars, and multiple bars were developed as the width to depth ratio increased, and the number of bars increased. The bar in the downstream of a drop structure decreased in length due to the concentration of flow and its disturbance.


Bed change;Drop structure;Numerical model;Sediment bars


  1. Ashida, K. and Michiue, M. 1972. Study on hydraulic resistance and bed-load transport rate in alluvial streams. Journal of Civil Engineering, Japan Society of Civil Engineers 206: 59-69. (in Japanese)
  2. Blondeaux, P. and Seminara, G. 1985. A unified bar-bend theory of river meanders. Journal of Fluid Mechanics 157: 449-470.
  3. Ikeda, S. and McEan, I.K. 2009. Flow and Sediment Transport in Compound Channels: The Experience of Japanese and UK Research. International Association of Hydraulic Engineering and Research, IAHR, CRC Press, New York, USA.
  4. Ikeda, S., Parker, G. and Sawai, K. 1981. Bend theory of river meanders. Part 1. Linear development. Journal of Fluid Mechanics 112: 363-337.
  5. Jang, C.-L. 2013. Dynamic characteristics of multiple bars in the channels with erodible banks. Journal of Korea Water Resources Research 46: 25-34. (in Korean)
  6. Jang, C.-L. and Shimizu, Y. 2005. Numerical simulations of the behavior of alternate bars with different bank strength. Journal of Hydraulic Research 43: 596-612.
  7. Kuroki, M. and Kishi, T. 1984. Regime criteria on bars and braides in alluvial straight channels. Proceedings of Japan Society of Civil Engineers 342: 87-96. (in Japanese)
  8. Shimizu, Y., Fujita, M. and Hirano, M. 1999. Calculation of flow and bed deformation in compound channel with a series of vertical drop spillways. Annual Journal of Hydraulic Engineering, Japan Society of Civil Engineers 43: 683-688. (in Japanese).
  9. Shimizu, Y. Takuyam, I. Michihiro and H. Toshiki, I. 2011. Nays2D Solver Manual of iRIC Software.


Supported by : 국토교통부