# Post-Earthquake Fire Resistance in Structures: A Review of Current Research and Future Directions
## 7 Influence of Different Structural Systems  
Studying the behavior of various structural systems under post-earthquake fire (PEF) conditions is vital due to the distinct vulnerabilities and damage patterns associated with each system. This knowledge is crucial for developing effective design strategies that enable engineers to create targeted solutions, enhancing fire resistance and preventing collapse under such extreme conditions [3; 65; 73; 74]. For instance, understanding that irregular buildings are more prone to earthquake damage and, consequently, have reduced fire resistance can guide design choices to improve PEF performance [50; 68]. Incorporating PEF considerations into performance-based design paradigms is also essential. This approach transcends traditional design methods that address individual hazards like fires or earthquakes separately and instead focuses on their combined effects, ensuring a comprehensive assessment of structural integrity under multiple hazards [68]. Evaluating how earthquake-induced damage impacts fire resistance is fundamental to this holistic design approach [3]. Enhancing post-disaster safety is another critical aspect of this research. Understanding how different structural systems behave in PEF scenarios helps predict potential damage patterns and collapse modes, which is invaluable for informing post-disaster response and recovery efforts [54]. Such insights are particularly beneficial for fire and rescue services, as they improve preparedness and response strategies. Furthermore, a deep understanding of the influence of different structural systems on PEF response is crucial for developing accurate risk assessment models and informing effective mitigation strategies [51]. Various studies have examined the PEF performance of different structural systems, including steel structures, reinforced concrete structures, and concrete-filled steel tube (CFST) structures. Research on steel structures, for example, has explored the PEF behavior of steel moment-resisting frames, taking into account factors such as fire scenarios, gravity loads, connection damage, and the effectiveness of fireproofing materials [62; 73; 75]. These studies highlight the vulnerability of steel structures to PEF and emphasize the critical role of effective fireproofing in enhancing fire resistance [74]. For reinforced concrete structures, research has focused on the impact of earthquake-induced damage on fire resistance, considering factors such as concrete spalling, reinforcement exposure, and varying levels of damage [15; 51; 76]. Similarly, studies on CFST structures have investigated the PEF performance of CFST columns and connections, analyzing aspects like residual stress, deformation, and temperature gradients [31; 77]. However, there are still significant gaps in the research that need to be addressed. Most existing studies have concentrated on individual structural elements or 2D frame analyses, highlighting the need for more research on full-scale structures and the interactions between different structural systems under PEF conditions [15; 78]. Developing more advanced modeling techniques is also necessary. This includes incorporating more realistic damage representations, accounting for uncertainties in structural analysis--such as variations in geometric parameters, fire location, and spread--and considering the dynamic nature of fire spread to enhance the accuracy of PEF simulations [2; 31; 79]. Additionally, addressing gaps related to the long-term effects of PEF on structural performance is crucial. Further investigation is needed into the long-term effects of concrete properties, such as creep and shrinkage, on PEF response, which will improve the realism of sequential analysis [65]. By addressing these research gaps and deepening the understanding of how different structural systems behave under PEF conditions, the structural engineering community can make significant strides toward developing more resilient and safer buildings in earthquake-prone regions.