Tornado fragility and risk assessment of an archetype masonry school building

Tornadoes are a low-occurrence high-consequence hazard and not only threaten the life safety of building occupants but have recently resulted in billions of dollars in direct and indirect damages for single events. Design codes do not consider tornado loads for building and other structures (with the exception of nuclear facilities) because the occurrence rate has historically been considered too low. The advent of performance-based seismic design has revolutionized the engineering thought process and as a result building owners can consider performance objectives that enable a building to perform better in an extreme hazard than observed with current design code. In this paper, the performance of a masonry school building subjected to tornado wind loads is investigated using a fragility methodology. The tornado fragility assessment methodology is described along with proposed damage states for consideration in loss estimation. An array of masonry material types are considered based on the Masonry Standards Joint Committee (MSJC) code to enable applicability of the fragilities developed herein for a range of designs throughout the United States.