Semi-theoretical approach to optimisation of gate ratio for small concrete dams and weirs

Abstract

In hydropower projects, the geological, topographical and economical aspects favour building of small concrete dams or weirs which may have a gated spillway to discharge the flood water. As the dimension of the gate influences in the volume of concrete used for the dam, this obviously reflects in the overall cost of the structure.A study was carried out by taking eight different river cross sections and assuming four different elevations for the dam for each case to get the optimum ratio of the gate height to the structure height. A relation was developed between the physical and geometrical characteristics of the valley and the ratio of the gate height for the weirs to the total height of the structure on the basis of the optimum cases using linear genetic programming technique. The results showed that the proposed approach can successfully be applied in identifying the gate ratio and can be a solid base for preliminary decision for defining the ratio from the physical and geometrical characteristics of the valley. This study proposes decreasing the iterations required for deciding the height of the gates and expediting the process of the design decision in the early stages of the hydropower design projects.