FLOW CHARACTERISTICS OVER STEPPED SPILLWAYS

Abstract

Researchers working on stepped spillways have been apprehensive about the damage caused by the impact of water to the the stepped structure. Gabions and Cascading stilling basins can provide some respite by virtue of water pooled on the steps. The present study was, therefore, primarily intended to examine the flow characteristics over Gabions and Cascading stilling basins. Water surface profiles, energy dissipation and aeration aspects have been investigated. Experimental verification of the existing design of cascading stilling basins has been done. Sill heights required, for a particular discharge, for the formation of hydraulic jump, have been determined. It was observed that aeration reaches its maximum on the second step in the basin with three number of falls. Energy dissipation varied between 92% to 96% in case of nappe flow. A computer programme has been developed for the design of cascading stilling basin.