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.