OPTIMAL DESIGN OF SYMMETRICAL BARRAGES/REGULATORS USING SHUFFLED COMPLEX EVOLUTION ALGORITHM.

Background: On the river Nile and its branches, there are more than 360 barrages/regulators, built from nineteenth century to control water discharges used for irrigation, industry and human needs. Barrages/Regulators, generally, consist of the main following parts: intermediate supports, edge supports, upstream and downstream wing walls, the bridge located above the regulator and the floor under the structure with its sheet piles and cut-offs. There is, however, no procedure to fix the basic barrage/regulator parameters; dimensions, material of its elements, types of bridge and hydraulic parameters in a cost-effective manner. Determination of these parameters is not dependant on any standard code; it depends on the designer’s decision. Aim: We aimed at presenting software for the optimal hydraulic and structural design of barrages/regulators based mainly on surface flow and how to reach the most cost-effective technical design. We also aimed at deducing an empirical formula to calculate the barrage elements’ cost. Materials and Methods: Our study has been illustrated using Shuffled Complex Evolution algorithm, developed at the University of Arizona (SCE-UA), as an optimization technique, in which the objective function is the construction cost and the parameters are dimensions, material types, bridge types and hydraulic parameters. The applicability of this approach has been illustrated using seven existing regulators indicating its suitability to evolve a cost-effective design. Results: The reductions of construction costs have been recorded for the selected seven examples and founded to be between 11% and 64% with an average value of 31%. The software illustrates that the slab type is more optimal than arch or beam type for the bridge, plain concrete for abutments and piers is more optimal than reinforced concrete; combining reinforced and plain concrete for the floor is more optimal than either one alone. Conclusion: The software demonstrates the pronounced performance of the developed tool; this program can help decision-makers to know the optimal hydraulic and structural design in addition to the optimal cost of the barrages.