Abstract
The purpose of this study is to propose an optimization method using genetic algorithm (GA) for selecting appropriate pipe diameter in the replacement planning of water distribution network. Firstly, we formulated the mathematical programming problem to minimize the pipeline replacement cost under the hydraulic constraints such as flow velocity in each pipe and water pressure at each node. In addition to the economical perspective, we considered the stability of flow velocity in pipes as another objective function of the multipurpose programming problem. Secondly, we made GA model combined with hydraulic pipe network analysis, which is referred to as HGA model. Finally, we conducted a case study to show the validity of our proposed model. As a result, it was revealed that our multipurpose HGA model was useful for the optimization of pipeline replacement planning.
