Seismic loss estimation of residential wood-frame structures in south-western British Columbia considering mainshock-aftershock sequences

Earthquakes are rare natural catastrophes, causing severe impacts on society due to loss of lives, damage to built facilities, and business interruptions. After a large earthquake (mainshock), many induced events (aftershocks) may be triggered and cause additional damage or even collapse to mainshock-damaged buildings. To reduce seismic hazard and risk of aftershocks and extend the current performance-based earthquake engineering framework, the effects of aftershocks on the seismic performance of structures should be incorporated. Considering an extensive set of real and artificial mainshock-aftershocks sequences, the vulnerability of residential wood-frame houses in southwestern British Columbia, Canada, is examined analytically using incremental dynamic analysis. Subsequently, seismic loss estimation is conducted for four wood-frame house types with different seismic capacities. The analysis results indicate: (1) moderate effects of aftershocks (5–20%) on maximum structural response and damage extent, and (2) significant impact of structural seismic capacity on estimated seismic loss.