Seismic risk assessment based on seismic resilience for mid-rise CFS structures considering multiple uncertainties

With the development of society and the improvement of living standards, seismic resilience has gradually become a research hotspot in the field of engineering seismic resistance. This paper focuses on the shortcomings of Chinese standard GB/T 38591-2020, combines the multi-parameter seismic resilience evaluation index of mid-rise cold-formed steel (CFS) structures, takes into full consideration of the uncertainties brought by recordto-record, structural design parameters and modelling in the seismic resilience assessment process, and establishes the seismic resilience assessment system of mid-rise CFS structure considering multiple uncertainties. Through a representative and universal 6-story CFS structure, the ranges of uncertainty indexes are obtained through several comprehensive calculation examples, and the recommended values of the indexes are obtained by comparing and analysing the results with those obtained by the performance-based seismic design (PBSD) method. The results of the seismic resilience assessment are combined with seismic hazard analysis to perform the seismic risk assessment based on seismic resilience for a 6-story CFS structure example. It is shown that the seismic risk assessment method based on seismic resilience established in this paper can quantitatively distinguish the seismic resilience of buildings, and provide comprehensive engineering guidance for researchers. The modelling uncertainty has the greatest impact on the 50-year seismic risk assessment results, which is 2.1-2.6 times the probabilities determined when only considering the uncertainties of record-to-record and structural design parameters. The impacts brought by the various uncertainties should be fully considered in the seismic risk assessment, otherwise, the potential risk of the structure may be underestimated. The seismic risk assessment method based on seismic resilience considering multiple uncertainties proposed in this paper can provide a reference for the development of seismic resilience design method for other buildings, and the analysis results can serve the research on seismic resilience and risk assessment of mid-rise CFS structures.