Seismic risk assessment of Tehran masonry school buildings and prioritizing them for seismic retrofitting using reliability methods

This paper aims to evaluate the seismic risk of the masonry school buildings located in the Tehran metropolis over the next 50 years and to prioritize them for seismic retrofitting toward optimal seismic risk mitigation. Tehran ranks among the world's largest cities facing a significant seismic hazard, and masonry buildings are identified as among the structural types exhibiting the poorest seismic performance. In addition, school buildings, due to their population density, are considered important buildings by many seismic codes; Consequently, it is vital to conduct a comprehensive seismic risk analysis for these buildings and strategically allocate limited resources to their seismic retrofitting. Sensitivity analysis is conducted to rank school buildings here. The sensitivity measures are the derivative of the risk measures with respect to the building retrofit cost. These risk measures are the moments of the probability distribution of the structural and non-structural costs of the building portfolio following risk-neutral and risk-averse decision-making. The risk and sensitivity analyses are conducted employing reliability methods and Rtx software which includes assembling a chain of probabilistic models to represent an earthquake's hazard, the damage caused by it, and the ensuing costs.