Physics-based resilience assessment of interdependent civil infrastructure systems with condition-varying components: A case with stormwater drainage system and road transport system

Despite an abundance of frameworks and toolkits for assessing resilience performance of interdependent infrastructure systems in recent years, they are generally underpinned by the topological-based approaches with limited consideration on commodities being flowed and supplied to consumers through the entire system. Besides, previous studies on resilience assessment have failed to consider the pre-event component condition of infrastructure systems by implicitly regarding the condition of components as pristine without any deterioration. These could lead to undermine the accuracy of resilience assessment results. To fill these research gaps, the paper synthetically assesses the resilience performance of interdependent infrastructure systems with the condition-varying components leveraging the physics-based approaches to delineate the intricate operating scheme of each infrastructure system. A case study strives to investigate the pre-event resilience performance of interdependent stormwater drainage system and road transport system in Hong Kong against heavy rainfall. The results show that the component deterioration in the stormwater drainage system could cause incremental amount of inundated rainwater in certain manholes and thus lead to substantial degradation in traffic performance in the vicinity when compared to the scenario without considering the pre-event component condition. Simultaneously, certain intersections of the network as well as the spatially subordinated small-scaled network do not seem to be affected while the traffic performance could even be advanced at those intersections. This phenomenon explains the heterogeneity of spatial and temporal traffic patterns within the same network. The results should help guide decision-makers identifying the vulnerabilities, planning pre-event mitigation strategies, and prioritizing recovery resources actions in case hazards occur.