Extreme natural events and bridge collapses: statistical insights in Italy

This study investigates bridge collapses and severe damage events in Italy over the last three decades, focusing on the role of natural hazards under changing climatic conditions. This study was undertaken due to the aging nature of Italy's bridges to assess their vulnerability and understand how to enhance their long-term structural safety. The data used in this assessment consisted of 180 cases, with each event classified by bridge typology, material, damage severity, and most probable triggering cause. 

The results show that 73% of failures were linked to natural hazards, with floods and landslides representing the dominant triggers, while anthropogenic factors accounted for 27%. In particular, floods emerged as the predominant cause of collapse, generally leading to global or partial failures that nevertheless undermines the overall functionality of the structure. Statistical analyses indicate a significant correlation between failures and extreme precipitation, which has increased in frequency in recent years as a consequence of climate change.