Estimation methods of maximum scour depth in steep gravel-bed bend channel
Jaewoong Choa,b A-Reum Namc Tae Young Wood Sang Deog Parka,*
aDept. of Civil Eng., Gangneung Wonju National University bDept. of Disaster Prevention, National Disaster Management Research Institute cRiver&Tech Co., 1113-ho, Doosan Venture Digm dDept. of Institute of Technology, BAU Consultant Co., LTD
The existing methods to estimate the maximum scour depth in the bend of steep gravel bed channel have been evaluated by the hydraulic movable-bed experiments. In the 90° bend steep-slope channel paved with the fluvial gravels which are uniform in size and have a mean diameter of 43mm, the maximum scour depths due to the flow discharge and the gradient of bed slope have been investigated and compared with the scour depth computed from the equations. The local scour has occurred in conditions that the bed slope is steeper than 0.02 and the Fr is greater than 0.95. Except Lacey’s equation and Zeller’s equation, the existing methods computing the maximum scour depth overestimate the maximum scour depth in the steep channel with the very coarse gravel bed. However, Lacey’s equation with the bed material size and Zeller’s equation considering the approach channel gradient and the bend angle may be relatively used to estimate the scour depth in bend of the steep gravel-bed river.
8. Leopold, L.B., and M.G. Wolman (1960), River Meanders, Geologic Society of America Bulletin, v. 32, pp. 769-794.