Empirical tornado resilience model for light-framed wood residential buildings

An empirical tornado resilience model based on structural functionality, a metric with clearly defined physical states, is developed for light-framed wood residential buildings using field observations of damage and recovery following the February 2017 tornado in Naplate, IL. The resilience model is composed of independent damage and recovery models that serve as a complete resilience model for residential buildings measured with the metric of structural functionality. Structural functionality is the most basic function of a building, the ability to safely provide shelter, and includes both the structural system and the building envelope. This model may be integrated into external resilience models that include measurements of other functionality components, such as lifeline services and building services, to construct a model of total functionality that includes all functionality components necessary for occupancy. The empirical tornado resilience model for light-framed wood residential buildings is an observation-based resilience model for residential buildings subject to tornado damage. It addresses the overlapping critical research needs for studies of tornado hazard, studies of residential resilience, and studies that provide a basis for validation, without replicating the existing body of resilience analysis frameworks. The included analysis using the indicators of structural functionality for wind-damaged structures reveals that some buildings trend toward zero functionality (demolition) during community-level recovery and that clear differences exist in the recovery behavior of buildings with similar post-storm structural functionality. Exponential structural functionality recovery functions are found to be appropriate for most levels of damage. Heavily damaged buildings are observed to follow a normal/s-shaped recovery.