Application of Water Cycle (WCA) and Weed (IWO) Algorithms to Multi objective Optimization of Stepped Spillway (Case Study: Down Siah Bisheh Dam)

Stepped spillways have received special attention today for their simultaneous operation in energy transfer and dissipation. In designing these spillways, the best way is to achieve a design with the highest amount of energy dissipation in the downstream and the lowest design cost. In this study, a multi-objective optimization model based on weed algorithms (IWO) and water cycle (WCA) is used to design stepped spillways with the aim of minimizing implementation costs and maximizing energy dissipation. The efficiency of the developed model was tested on the spillway of the down Siah Bisheh Dam. The results showed that the IWO algorithm has better accuracy and convergence speed than the WCA algorithm in solving the problem of multi-objective stepped spillway optimization. It was also found that using a multi-objective optimization approach can provide a set of answers to designers who can choose a suitable design for implementation in any situation depending on the amount of cost and energy consumption. Comparison between the responses with the lowest concreting volume provided by the IWO compared to the Spillway plan implemented, reduced the concreting volume by 20% and increased the energy dissipation by 12%. For the WCA, it also reduced the volume of concreting by 10 percent and increased energy dissipation by 4.89 percent.