Reliability-based layout design of sewage collection systems in flat areas.

The sewer layout in flat areas significantly influences the final design which is desired to be optimized for the construction and operational costs. This study introduces a model for designing the layout of sewer networks considering their reliability. A reliability criterion is introduced and optimized using a simple simulated annealing scheme. The best layout with the maximum reliability represents an optimum sewer layout in which clogging in a sewer has the least effect on its upstream lines. A case study is solved using the proposed model. Then, for the obtained layout, the sewer specifications are designed using a dynamic programming model. The reliability somehow reflects the operational costs that can be taken into account in the system design by the proposed model. Furthermore, it is concluded that the network's reliability and construction cost are in conflict with each other such that more reliable layouts lead to more expensive designs. [ABSTRACT FROM PUBLISHER]