Optimum flow depths prediction along the convergent stepped spillways side walls

Abstract

Stepped spillway designs are popularly adopted in dam systems due to their distinct advantage of enhanced energy dissipation of flow. Several references and literature are available for the design of stepped chute with straight side walls. For spillway modification works or due to site-specific situations, spillways may sometimes be provided with convergent training walls. But very few literature references are available on spillways having stepped chute provided with convergent side walls instead of straight side walls. The outcome of comprehensive experimental investigations carried out on spillway experimental set up with 0.7H:1V (i.e. θ = 55°) slope of stepped chute and side walls with 15° convergence on both sides is presented. This paper described expressions for estimation of optimum depth of flow and decide the height of sidewall in spillways having stepped chute required to be provided with symmetrically converging side walls.