Author(s): B. Ward; D. A. Savic
Linked Author(s):
Keywords: Sewer rehabilitation; Asset management; Investment planning; Multi-objective; Optimisation
Abstract: A new methodology for sewer rehabilitation investment planning has been developed. An optimisation model, founded on standard sewer condition classification grading information from CCTV inspections, is used to evaluate numerous intervention options. The output from the model specifies the nature and extent of the rehabilitation solutions that are suitable for delivery based on a cost vs benefit trade-off. The model evaluates rehabilitation solutions at individual asset level and the combination of these solutions at a catchment level, in-terms of two conflicting objectives which are used to define the solutions optimality: (1) Network improvement and (2) Construction cost. A software platform has been specifically developed to provide an integrative mechanism to achieve this and to allow the evaluation of alternative decisions. The platform uses a multi-objective genetic algorithm to optimise for these competing objectives. To evaluate the effectiveness of the sewer rehabilitation investment model, it was applied to two catchment case studies. Cost savings of 45% and 55% were achieved when compared to the solutions that had previously been developed using traditional techniques.
Year: 2011