Master of Engineering Science
Civil and Environmental Engineering
Dr. G. A. Kopp
Tornadoes can produce some of the strongest winds on earth; these highly localized storms can cause massive damage. Assessments of tornado wind speeds are done using post-event observations of damage via the Enhanced Fujita Scale.
A very commonly observed failure occurs at the roof-to-wall connection where the roof breaks up or flies away, typically leaving the walls in place. However, once the roof is gone the walls are more vulnerable to the wind. If a wall subsequently fails, it increases the risk of injury or death for occupants. Significant research has been done for failures of roof-to-wall connections and roof failure wind loads. In contrast, little work has been done pertaining to how the walls perform when there is no roof in place.
In the current study, experiments were performed on a full-scale, two storey residential structure with no roof. The objectives of the study were (i) to determine the wind loads and wind speeds required to cause exterior wall failure after the roof-to-wall connections had already failed, and (ii) to develop low-cost recommendations for strengthening wood-frame houses and, thereby, reducing risk to occupants during severe storms such as tornadoes.
It was found that the capacity of the walls of the test house significantly exceeded Canadian (Ontario) design loads when clad in brick veneer. The interior wall placement and connections between the exterior and interior walls are shown to have a significant effect on overall capacity. For vinyl-clad houses, increasing the stiffness of the corners of the walls will also increase capacity – which appears to be the primary structural benefit of brick cladding.
Stedman, Derek A., "Full-Scale Tests of a Wood-Frame Structure under Extreme Wind Loads" (2014). Electronic Thesis and Dissertation Repository. 1977.