Behavior of Earthquake Damage Steel Structures in Fire

Fire following an earthquake (FFE) has become a major threat for building, particularly in seismic areas. Many FFE events have caused a high level of damage and casualties. On the other hand, current design codes do not support a specific loading case for FFE. Moreover, the modern design philosophy for seismic design allows a certain level of damage that may affect the structure's vulnerability during a post-earthquake fire. Many previous studies have investigated the structural behavior of the building under FFE. This study is intended to showcase, theoretically and practically, the numerical analysis methods used in previous studies. The main objective is to improve the understanding of the performance of steel structures under a post-earthquake fire. A brief historical review of the numerical analysis methods is presented. It is observed that there are four stages of analyses adopted in the previous studies, which are structure system, earthquake analysis, fire analysis, and evaluation. However, different concepts and methods have been used in every stage. This study discusses the advantages and disadvantages of the design concept and the numerical analysis method. It was found that the key aspect of fire following an earthquake analysis is interpreting earthquake damage as an initial condition for the subsequent fire action. The 3D model is required since the composite slabs have a significant role in the frame's survival through tensile membrane action. Furthermore, several parametric fires must be considered to simulate a fire event after an earthquake.