Abstract
The integrated and multi-functional pipeline system should require quality, quantity, and reliability in water supply. This paper describes how to redesign the drinking water distribution system including both self-cleaning function and disaster resilience. In this study, distribution network analyses in some Kobe City distribution areas were conducted in case of downsizing and redesigning of water distribution system, and self-cleaning function of pipeline was evaluated by the frequency of pipe flow velocity, because the pipe flow velocity more than 2.0 m/s could prevent degradation of water quality in pipelines such as the composure of suspended substance. Also, disaster resilience was evaluated by recovery resistance curves in water supply and opportunity loss in recovery period. As a result, a trade-off between self-cleaning function and disaster resilience was pointed out. It was shown that earthquake resistance should be reduced, while smaller diameter pipe should improve self-cleaning property due to increasing of pipe flow velocity in the distribution network system. In addition, it was indicated that blocking pipe network would contribute to earthquake-resistant improvement, but its network should make security of self-cleaning function of pipelines difficult. It was said that branch-formed pipe network might improve self-cleaning function, but could decrease earthquake resisting. Consequently, it was indicated that, under a condition not to replace with earthquake-resistant pipeline in restructuring water distribution network system, a redesigning water distribution system would ensure both self-cleaning function and earthquake resilience in its networking system.
