PSI - Issue 78

Silvia Santarelli et al. / Procedia Structural Integrity 78 (2026) 333–340

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1. Introduction: state of the art and current trends in "community resilience" development Community resilience, understood as the capacity of a social system to absorb disturbances, maintain its functions, and recover rapidly after an adverse event, has become a fundamental pillar in seismic risk management (Fabbricatti et al., 2018; Pinto et al., 2018). Traditionally, the focus was solely on emergency response, delegating coordination and intervention to central authorities. However, the experience of numerous, even recent, seismic events has demonstrated how preparation and active participation of the population are decisive factors in mitigating impacts and accelerating the recovery process (Deeming et al., 2019). Current trends in community resilience development highlight a shift from a top-down approach to a more participatory and holistic one (Contardo et al., 2023; Zeballos-Velarde et al., 2023). It's recognized that resilience isn't a static condition but a dynamic process built over time through education, training, risk perception, preventive planning, and the strengthening of social ties (Kiani et al., 2022). The goal is to create communities capable of self-organizing and adapting, transforming challenges into opportunities for learning and improvement (Cvetković et al., 2024). This implies a significant investment in spreading a culture of safety, encouraging knowledge of risks, adoption of protective behaviors, and participation in drills and simulations (Mavroulis et al., 2025). In Europe, various programs have been launched to promote resilience, emphasizing cross-border cooperation and the exchange of best practices (Musacchio et al., 2023). 2. Secondary transport network resilience: implications in seismic emergencies The functionality of transport networks (road, rail, air, and maritime) is a critical element for the overall resilience of a region in the event of a seismic emergency. A system’s innate capacity to endure natural disruptions relies on pre- and post-event aspects (Faturechi and Miller-Hooks, 2015), this concept is well described in the Disaster Life Cycles, where the disaster management is divided into four phases, two phases (mitigation and preparation) happening before the event and the other two (response e recovery) happening after the event (Khademi et al., 2015). Despite anti-seismic designs, many transport infrastructures, including bridges, viaducts, tunnels, and road sections, are highly susceptible to significant damage or collapse during high-intensity seismic events, severely impeding access for rescue and aid (Borzi et al., 2015). Such disruptions can isolate entire regions, hindering emergency response and the supply of essential goods. The situation in Italy is particularly critical due to the advanced age of its infrastructure; over 50% of its bridges are more than 50 years old, far exceeding the G7 average of 20-30%. Italy's vast road network (approximately 840,000 km, including 21,072 bridges/viaducts and 2,179 tunnels), largely built post-WWII, often lacks modern seismic design and capacity for current traffic demands (Bozza et al., 2023; Fattorini et al., 2022). This obsolescence, combined with material degradation and high seismic risk, increases vulnerability (Zelaschi et al., 2019). While specific figures on directly impacted municipalities are elusive, 8 million Italians and 442 municipalities reside in high-seismic risk areas (Sabetta et al., 2023), often relying on these aging connections, making isolation a significant threat during an earthquake. To ensure resilient transport networks, it's crucial to not only build robust infrastructure but also plan alternative routes (Xu et al., 2021), have special vehicles for debris removal and quick road access restoration available, and integrate real-time monitoring systems to assess damage and coordinate interventions (Iliopoulou et al., 2025). An analysis of the state of the art in Europe reveals significant infrastructure vulnerabilities, particularly in areas with outdated infrastructure or complex geographical contexts. Italy stands out as a prominent example of these challenges. While entities are making ongoing efforts to monitor and improve these infrastructures, the sheer scale

and age of the network present a formidable task. 3. Self-organization without central coordination

The concept of self-organization without central coordination refers to the ability of a complex system, in this case a community, to develop effective responses to a crisis in the absence or delay of coordinated action by external authorities (Ismael, 2011; Tu, 2022). During a large-scale seismic event, communication infrastructures can collapse, and official aid might not be able to reach all affected areas immediately. In these circumstances, the population's