# Post-Earthquake Fire Resistance in Structures: A Review of Current Research and Future Directions
## 1 Introduction  
Post-earthquake fire (PEF) presents a significant secondary hazard following seismic events, often leading to extensive damage and casualties. Characterized as a widespread and imminent threat, PEF ignition probability surges immediately after an earthquake, with approximately 70% of ignitions occurring within one day of the main event [1]. This cascading hazard exacerbates existing earthquake damage, increasing community vulnerability. PEF ignition stems from both external and internal sources. External causes primarily involve damage to utility systems, such as gas pipelines and electrical networks, resulting in gas leaks and electrical sparks. Internal ignition sources include overturned flammable contents, damaged electrical appliances, and compromised internal gas piping within structurally damaged buildings [2]. Historical accounts, particularly from Japan and the United States, underscore the significant role of PEF in post-earthquake damage, as exemplified by the 1995 Kobe earthquake. While early research focused on community-level impacts and fire spread modeling, recent studies have shifted towards building-level analysis and themechanical aspects of PEF [3]. This evolving research landscape emphasizes the need for a probabilistic understanding of earthquake-fire sequences to facilitate a comprehensive assessment of hazard risk. The cascading progression of earthquake-induced fire ignition, structural damage, and economic loss is effectively depicted in Figure 1, which illustrates the interconnected nature of these hazards in post-earthquake scenarios. Despite this progress, significant challenges remain. Knowledge gaps persist regarding performance-based assessment procedures and evaluation methods specific to PEF scenarios, hindering effective structural design and performance evaluation. Furthermore, limitations in data availability necessitate reliance on expert opinions for structural fragility assessment and impede accurate quantification of PEF ignition probability, particularly for internal causes. Current methodologies often oversimplify fire intensity, neglecting crucial aspects like uneven fire distribution. Addressing these challenges necessitates a multi-hazard design approach, incorporating advanced analytical tools, expanded experimental research, and the integration of PEF considerations into building codes. Future research priorities include investigating the complex interplay between earthquake damage and fire behavior, and developing sophisticated risk prediction models to enhance structural resilience and inform decision-making in multi-hazard scenarios.  
Research indicates that traditional design methodologies often treat seismic and fire hazards independently. This compartmentalized approach overlooks the synergistic effects of fire following an earthquake, posing a significant risk to structures in earthquake-prone regions. Performance-based design, which integrates both seismic and fire loads, is essential to ensure structural resilience in the context of PEF scenarios.  
Figure 1: Post-earthquake fire impact.