2019 CSCE Annual Conference - Laval (Greater Montreal) Conference
Dr. Luis E Amador-Jimenez , Concordia University
North America’s infrastructure is at risk. Water and combined sewer and stormwater systems, representing an important part of the cities’ urban infrastructure, are in dire condition state. According to the latest Canadian Infrastructure report card, one-third of the pipes are in fair condition state and below, which requires further attention. Furthermore, more than half of the linear stormwater assets are facing the risk of overflooding due to the increased flow demand/capacity ratio. Even though some scholars developed management systems for pipes to optimize the maintenance and replacement and improve network condition, they ignored the growing effect of urban growth and climate change (i.e. intense and frequent rainfall cause flooding) on the pipes’ deterioration. Accordingly, this paper proposes a scheduling and optimization framework that optimizes the pipes’ replacement decisions to increase their resiliency while considering the annual expenditures, urban growth and its’ future impact on the demand. The framework revolves through five core models: (1) urban and climate change models that simulates the impact of the urban growth and climate change on water and combined sewer pipes; (2) capacity performance model that predicts the future flow demand-capacity ratios based on the estimated population growth, land use changes, and climate change; (3) pipes’ deterioration model that calculates the pipes’ condition across their service life; (4) financial model that computes the life-cycle costs; and (5) multi-objective optimization model that schedules the replacement decisions to minimize the network’s demand-capacity ratio and maximize its condition, while respecting the available budget. The system was applied to the water and combined sewer and stormwater network of Kindersley town, Saskatchewan, Canada. The results showed an optimal intervention schedule with a total of 500 intervention actions across the 25 years planning horizon. Furthermore, it showed an EUAC of $1.7 million and an average condition state of 69% with resilience preparedness of 59% for both networks at the end of the planning horizon. In conclusion, the pipes’ resiliency to flooding could be drastically improved while minimizing the life-cycle costs through maintaining acceptable pipes’ condition states and demand-capacity ratios, identifying condition/capacity deficient pipes, and taking prompt recovery measures.