Fire Risk Assessment in railway tunnels based on human safety assessment criteria in Korea

This study critically examined the ASET/RSET(point) method currently applied in the Republic of Korea's railway tunnel fire safety guidelines and compared evaluation results through simulations that applied the ASET/RSET(map) method and various FED thresholds. The analysis revealed that the estimated number of fatalities varied significantly depending on the assessment method, confirming that the outcomes are highly sensitive to the selected evaluation criteria. While the ASET/RSET(point) method has the advantage of procedural simplicity, it may overestimate fatalities as it does not reflect spatial and behavioral complexities. In contrast, the ASET/RSET(map) method enables a more realistic and accurate assessment by simultaneously considering smoke propagation and evacuee distribution, making it more suitable for the structural characteristics of railway tunnels. This study also emphasizes the necessity of considering irritant gases. While a conservative analysis excluding such gases may still be valid under the FED <0.3 threshold, a more realistic evaluation that accounts for evacuation delays and behavioral impairments caused by sensory irritation suggests the potential appropriateness of applying a dual-criteria framework of FED <1.0 and FIC ≤ 3–5.