Seismic resilience evaluation of confined masonry school buildings retrofitted by shotcrete method

This study addresses the urgent need for retrofitting masonry schools in Iran, where over 89 % of schools are constructed using masonry (107000 Schools consisted of 563000 classrooms). Focusing on seismic performance evaluation, this research is of paramount importance as the current state of these schools poses a significant risk to the safety of millions of students. Without proper evaluation, the consequences could be catastrophic. To illustrate the significance of this study, a confined masonry school in Tehran was selected as a representative case study. The seismic resilience index was calculated, considering two hazard levels (2 % and 10 %) over a 50-year period, with and without near-fault pulse-type ground motions. Furthermore, a comparative analysis was conducted by modeling the retrofitted structure, which involved the application of shotcrete on walls, to assess the benefits of retrofitting. The seismic resilience index, derived from analytical functions that account for probable hazards and the recovery process, serves as a comprehensive measure of the structure's vulnerability. Through this evaluation, valuable insights into the retrofitting and rehabilitation of confined masonry schools can be gained. The results obtained from this research will aid in informed decision-making regarding the mitigation of seismic risks in similar structures. In conclusion, this paper indicates applying shotcrete to masonry walls can be substantially efficient as the resilience index and functionality of the building increases by a significant margin. Furthermore, the building damage was halved after the retrofitting operation and fragility curves admit it by showing better performance in higher drift ratios.