Modeling Pavement Fragility

Pavement performance models are the key to efficient designs and effective management practices. Over the years, a number of researchers have developed reliability models to account for the uncertainty in pavement responses and utilization patterns. However, these efforts were mostly directed toward coupled capacity-demand limit state functions that do not take into account the discontinuities after the application of rehabilitation actions (e.g., overlays). The aim of this paper is to develop a pavement fragility modeling framework that accounts for the effects of the rehabilitation actions. The fragility, defined as the conditional probability of failure given a unit level of utilization, uncouples the reliability function into the capacity and demand functions, which are two separate areas of study in pavement engineering. Closed-form approximations of the fragility curves are developed to illustrate the process and allow for seamless integration in design and management optimization models.