配水管網拡張時の最適設計法

抄録

Recently, design problems of water distribution networks are getting larger and more complicated. To cope with difficulty of the problems, the authors have developed a method for designing newly-constructed networks, ones for irrigation which need to be more precisely and carefully designed than ones for city-water service. One of the prominent features of the method is that it enables us to consider explicitly the trade-off between enhancement of the distribution security (or reliability) and reduction of the construction cost. It has already been used for practical design of large networks, and has proved its excellent capability compared with conventional techniques
Based upon the fundamental idea of the above method, the present paper develops a design method for enlargement of existing networks. This is motivated by the fact that, nowadays in Japan, most of the city-water service networks are constructed by enlarging the old ones. Mathematically the problem is formulted into a nonlinear programming type. By choosing proper decision variables, mesh flow volumes, in the formulation and by noticing a feature of the problem structure, we present an efficient solution procedure which has sound feasibility even for large-scale networks. As the method inherits the fundamental virtues of the method previously mentioned, the concept of trade-off between security and cost is kept well in the design procedure.