This study focuses in the Probabilistic
Performance Assessment for Masonry Structures of School Buildings in El
Salvador, through analytical fragility functions and its application to seismic
risk analysis, following the Performance-based Earthquake Engineering (PBEE)
methodology developed by PEER Center. Three combinations of two-story masonry
buildings with openings (A: Mixed, B: Reinforced Concrete Masonry Infill and C:
Confined Masonry Walls) were taken as target structures, based on configurations
commonly found in the school’s portfolio of the country. Updated results of a
Probabilistic Seismic Hazard Assessment and soil amplification effects of El
Salvador, were used. Similarly, both the variation of seismic demand response
as the deformation capacities of each structure, have been taken into account.
Three performance levels, known as Immediate Occupancy (IO), Life Safety (LS)
and Collapse Prevention (CP) limit states, were deemed, on which the Seismic
Demand and Damage Fragility Functions were built, along with the calculation of
the Failure Probabilities in terms of Mean Annual Frequencies (MAFs) of each
combination. Results indicate that for IO and LS limit states, the Combination
B has the highest structural reliability (best seismic performance) for both
intensity measures [PGA and Sa (T1, 5%)], due to its low failure probabilities
obtained concerning the other combinations. For the CP limit state, the
combination C provides the greater structural reliability for both intensity measures.
Nevertheless, none of the combinations managed to meet the acceptable MAFs at
the less frequent seismic hazard levels of 475 and 975 years of return period.
Keywords: Confined Masonry, Masonry Infill, Limit States, Fragility Function, Failure Probability.