Abstract

The 2016 Mw 7.8 Pedernales earthquake in Ecuador caused significant damage to school infrastructure, raising concerns about the real performance of these essential buildings. This paper evaluates the seismic performance of two reinforced concrete structural systems for low-rise school buildings using a fragility analysis. The first system consists of special moment-resisting frames, which is extensively used in Ecuador and other earthquake-prone countries, while the second system consists of structural walls, which has seen less use in the construction of new school buildings. For this purpose, fragility curves for immediate occupancy (IO), life safety (LS), and collapse (C) were developed for each structural system through incremental dynamic analysis using an analytical model with fiber-type beam-column elements. Using seismic hazard curves for the location of the structures, the mean annual frequency (lambda) and the probability of reaching these limit states in 50 years (P(50)) were obtained. The results show that, for low-rise school buildings, the structural wall system is the most reasonable from the perspective of seismic damage control, due to its lower probability of reaching the IO and LS performance levels in 50 years. Additionally, the deaggregation of lambda at each limit state showed that for the moment frame system, the seismic intensities that dominate lambda depend on the limit state considered. While, for the structural wall system, the intensities that control lambda come from intensities lower than the median intensity regardless of the limit state.