Optimum design of the intake tower of reservoir, 1; with application of working stress design method

The purpose of the present study is to set up an efficient optimum design method for the large-scale reinforced concrete cylindrical shell structures like intake tower of reservoir and to establish a solid foundation for the automatic optimum structural design combined with finite element analysis. The major design variables are the dimensions and steel areas of each member of the structures. The construction cost which is composed of the concrete, steel, and form work costs, respectively, is taken as the objective function. The constraint equations for the design of intake-tower are derived on the basis of the working stress design method. The corresponding design guides including the standard specification for concrete structures have been also empolyed in deriving the constraint conditions. The present nonlinear optimization problem is solved by SUMT method. The reinforced concrete intake-tower is composed by three major substructures. The optimization is then conducted for both the whole structure and the substructures. The following conclusions can be drawn from the present study. The basis of automatic optimum design of reinforced concrete cylindrical shell structures which is combined with finite element analysis was established. The efficient optimization algorithms which can execute the automatic optimum design of reinforced concrete intake-tower based on the working stress design method were developed. Since the objective function and design variables were converged to their optimum values within the first or second iteration, the optimization algorithms developed in this study seem to be efficient and stable. The difference in construction cost between the optimum designs with the substructures and with the entire structure was found to be small and thus the optimum design with the substructures may conveniently be used in practical design