Reliability-based optimization models for scheduling pavement rehabilitation

Deteriorating pavements require timely application of rehabilitation actions. This article presents reliability-based optimization models for scheduling rehabilitation actions for flexible pavements. The pavement reliability and the effect of rehabilitation actions are modeled using parametric fragility curves based on simulated pavement responses. Three models are presented: MIN-C, a model that minimizes the cost where the target reliability is set as a constraint; MAX-R, a model that maximizes the cumulative life-cycle reliability where the budget is set as a constraint; and minimize cost and maximize reliability (MINMAX), a multi-objective model that determines Pareto optimal solutions to reliability-cost trade-off. As the multi-objective optimization model is nonlinear and nonconvex, the solution approach is based on a multi-objective genetic algorithm (MOGA). The results from a numerical example show that the developed optimization model can be used efficiently in determining optimal rehabilitation strategies and cost-reliability trade-offs.