Bed-load transport flume experiments on steep slopes

Experiments were conducted over uniform gravel bed materials to obtain 143 friction factor values under bedload equilibrium flow conditions in an attempt to add to the scarce data available on slopes between 1% and 9% for Shields numbers between 0.08 and 0.29. Analyses showed that when only flows over flat beds are considered, a distinction must be made between flows with and without bedload. More particularly, fitting flow resistance equations indicated that the roughness parameter increases by a factor of 2.5 from clear water flow to intense bedload transport. Between these two states, the flow resistance can be approximated by a constant for a given slope. / Cet article présente les résultats d'expériences de transport solide menées à forte pente (1 à 9%). 143 jeu de données sont publiées. Il est montré que le charriage augmente la résistance à l'écoulement.