Recovery and reconstruction of schools after M 7.3 Ezgeleh-Sarpole-Zahab earthquake; part II: Recovery process and resiliency calculation

Abstract

After presenting a taxonomy of schools in part one and their modes of behavior during the Ezgeleh earthquake in November 2017, this paper quantifies the seismic resilience index of Iranian school buildings, including post-recovery and retrofitting processes. Six schools having different structural properties as being representative of the 3029 Iranian school buildings in the affected area were chosen for resilience evaluation. Field observations were made at the selected schools and the collected data on the earthquake recovery process were used to calculate the seismic resilience index for the different types of school buildings. Functionality curves were developed to illustrate the process of recovery three years after the event. The Ezgeleh earthquake caused slight to moderate damage to masonry schools that otherwise had acceptable levels of resilience. School buildings that had been retrofitted before the Ezgeleh earthquake remained intact and showed a high level of resilience and robustness. Those which had been slated for retrofitting but had not been reinforced suffered serious structural and nonstructural damage. The school buildings which recorded the lowest resilience values required reconstruction after the earthquake. Comparison of the resilience parameters of school buildings, including robustness, rapidity, recovery time, resilience index, and delay time indicated that buildings that were retrofitted earlier recorded the highest resilience factors.