Hydraulic jump downstream of a stepped chute : an experimental study

The number of stepped spillways significantly increased in the past decades. Among other reasons, this is due to their energy dissipation potential leading to a reduction of the residual energy at the toe of the spillway. To date, only fragmentary designed guidelines are available for the stilling basin design in conjunction with stepped chutes. Therefore, tests were carried out on a large-scale physical model of a 30° stepped chute in combination with a classical stilling basin, to study the effect of stepped chute inflow on the hydraulic jump features. Detailed air-water flowmeasurements of the inflow conditions were conducted, as well as of the free surface and dynamic bottom pressures along the hydraulic jump. Specifically results on the free surface, bottom pressure and length characteristics are presented and discussed herein.