چكيده لاتين :
In the past years considerable research was done on stepped spillways. Investigations were conducted
to understand the hydraulics on the stepped face of Roller Compacted Concrete (RCC) dams and
overlays for embankment dams. Also a number of embankments were designed with concrete
overtopping protection shaped in a stepped fashion. During large overflows on stepped chutes, there is
no skin friction between mainstream and steps, and flow resistance is basically form drag. Significant
energy losses occur along the stepped chute so that the energy dissipation structure, e.g. the stilling
basin, becomes smaller and more economic. In addition, in design conditions when discharge, slope
of the normal ground and the height of spillway are available, there are so many combinations of
width and the number of steps, which leads to different head losses. In each feasible case the remained
head should be dissipate by the energy dissipaters in down stream, which are much cost consuming.
So the cost of project which is consist of spillway and it’s down stream dissipaters should be
minimized. In this study, the Genetic Algorithm has been applied to find the best combination of
design variables to minimizing the total cost of both structures. The results show the efficiency of GA
in this field of application. Furthermore, GA has a very rapid convergence to feasible and sufficient
optimum.
