Exploring Cascading Failure Dynamics in Multi-Infrastructure Systems: Integrating Network Modeling and Thematic Insights

Interdependent municipal infrastructures, such as road, water, sewer, and drainage systems, form a complex network, in which a repair and maintenance (R&M) activity on an asset can trigger additional R&M activities in the same or colocated assets, ultimately impacting operational efficiency, resilience, and sustainability of the entire system. Most prior studies of integrated multi-infrastructure asset management failed to account for the interdependencies of R&M activities and their cascading impacts. This study used a mixed-method approach, leveraging social network analysis (SNA) to model the causal relationships between various R&M activities and using thematic analysis to capture municipal experts’ insights into the causes and proactive best practices for addressing cascading failures. A total of 115 responses were collected through an online survey of experts working with municipalities. The results of social network analysis revealed that repairing a sinkhole in the street, repairing cracked and collapsed pipes, and digging up the main line to replace old pipes have a higher cascading effect and cause other R&M activities in the network. The thematic analysis yielded a comprehensive framework categorizing the causes of cascading failures into 6 overarching themes with 17 subthemes, and categorizing the proactive best practices for addressing cascading failures into 5 themes encompassing 19 subthemes. This research contributes to the body of knowledge by providing a systematic approach to understanding and addressing cascading failures in multi-infrastructure systems, which will help decision makers develop more effective, evidence-based integrated asset management strategies. The framework developed in this study enables municipalities to proactively address vulnerabilities arising from the cascading failure, enhancing operational efficiency, long-term resilience, and sustainability of their infrastructure systems.