New Integrated Condition-Assessment Model for Combined Storm-Sewer Systems

Abstract

Optimal assessment of the overall state of the degradation affecting sewer systems requires consideration of both the hydraulic and the structural aspects. This work identifies a set of 15 factors—pertaining to both degradation aspects—as primary and constituting the framework for hierarchical structuring of the condition states. The relative importance of these factors was determined by the analytic hierarchy process (AHP). The proposed model was successfully applied to assess the current degradation state of the sewer network in Saint-Hyacinthe, Quebec. The relative significance effect, assessing prevalence of either the hydraulic or the structural criteria in the degradation process, was established through sensitivity analysis. The outcome indicates that hydraulic factors have to be integrated in the pipe-deterioration model as well as the structural factors. With a reference case set at