Vulnerability assessment of road logistics and transportation network sections under seismic hazard

In recent years, the frequent occurrence of geological disasters has severely damaged the infrastructure of highway logistics transportation networks, leading to road fractures, bridge collapses, and roadbed subsidence. The sudden increase in the vulnerability of segments in the highway logistics network results in traffic disruptions and congestion, significantly affecting the timely transportation of goods and the continuity of supply chains, causing economic losses and delays in rescue operations. Therefore, studying how to mitigate the vulnerability of highway logistics networks under seismic disasters can help enhance the risk resilience of these networks and reduce the economic and social impacts of earthquakes. To address these issues, this paper constructs a vulnerability evaluation model for highway logistics network segments, considering the probability of network failures and their consequences. Using the Dijkstra algorithm, it searches for the normal shortest paths between nodes and the alternative paths after segment failures due to seismic disasters. It calculates the vulnerability value for each segment and classifies and ranks them using the K-means algorithm. According to the results, the vulnerability is categorized into four levels: no alternative path, severely vulnerable, moderately vulnerable, and slightly vulnerable. Corresponding pre-disaster preparedness and post-disaster emergency strategies are proposed for each vulnerability level to improve and reduce segment vulnerability.