Minimization the construction cost of stepped spillway using Gravitational Search Algorithm

In this paper one of the newest meta-heuristic algorithms named Gravitational Search Algorithm (GSA) is used to optimal design of stepped spillway with minimizing cost. Generally, dam construction projects classify as expensive projects in which the related high costs should be reduced. Dams consist of different structures. One of these structures is energy dissipater structure. Generally, different structure such as spillway have been used for energy dissipation. Here, stepped spillway is considered as an energy dissipater structure. Therefore, GSA is used here for optimizing the excavation and concrete costs and reducing the final costs of this structure. With the use of MATLAB software for GSA coding, the Tehri dam in India is considered here as a case study and the construction cost is reduced using GSA so that all of the hydraulic constraints will be satisfied. In the following, the obtained results of GSA are compared with the results of Genetic Algorithm (GA) and Vittal and Porey (VP) approach. Comparing the results of VP approach with two used algorithms indicates that when the spillway has four steps, the results of GA and GSA are improved respectively 6% and 7.6% than the results of VP and the results of GSA are improved 1.8% than the results of GA.