Wind Performance Enhancement Strategies for Residential Wood-Frame Buildings

Abstract

Extreme winds such as tornadoes and hurricanes are relatively common natural hazards in the United States and can result in fatalities as well as damaging physical and socioeconomic infrastructure. Buildings are a critical sector within the built environment of a community and studying their performance under natural hazards is a major step for the risk and resilience assessment of a community. More than 8% of the total building stock in the United States and more than 9% of the residential buildings in North America are wood-frame construction; a construction type that is vulnerable to wind damage because they are light and typically are not engineered, only prescriptive in their design. Performance enhancement strategies for wood-frame residential buildings were investigated in this study by exploring combinations of roof coverings, roof sheathing nailing patterns, and roof-to-wall connection types. In this regard, a total of nine construction product combinations were considered. Further, recent changes to the wind standards were also explored. Specifically, the damage fragilities of five wood-frame building archetypes are considered for four damage states defined based on the performance of the building envelope, including roof coverings, doors and windows, roof sheathing, and roof-to-wall connections. The fragility curves are explained at the component level and then the building level for one archetype as an example, and the building fragility parameters are provided for all archetypes and for all construction product combinations. Comparison between fragilities developed using the last two versions of the wind standards are also presented. Then, an existing approach that amplifies the wind pressures in the wind standards to represent a tornado load is also compared. The fragility curves provided in this study can be used to represent residential buildings within a community for risk or resilience assessment/mitigation under hurricane or tornado loading.