Remaining fire resistance of steel frames following a moderate earthquake – A case study

Post-earthquake damage in cementitious passive fire protection (PFP) systems is a serious fire safety hazard in steel frame structures, because it is unaccounted for at the design stage. This is of greatest concern after small to moderate earthquakes as modern structural components are designed to resist them with no damage. However, PFP systems are not currently subjected to any design regulations for seismic loading and therefore their performance cannot be quantified. Additionally, the inaccessibility of cementitious coatings hampers the evaluation of their remaining fire resistance capacity following earthquakes by means of visual inspections. This paper proposes an integrated multi-hazard framework using finite element analysis (FEA) for assessing the remaining fire resistance capacity of PFP protected steel frame structures subjected to moderate earthquakes. This multi-hazard framework is presented in the open source software environment OpenSEES, and provides structural engineers with a practical solution to access the fire safety concern associated with the PFP damage. •Proposal of indices for post-earthquake damage assessment in cementitious PFP.•Comparison study on the impact of different seismic frame designs on the PFP damage.•Guideline on finite element model choice for PFP damage assessment.•A multi-hazard framework for remaining structural fire resistance capacity assessment.•Raise of fire safety concern of PFP damage resulted from moderate earthquakes.