Civil and Environmental Engineering Publications
An appraisal of tornado-induced load provisions in ASCE/SEI 7-22 and 7-16 for residential low-rise buildings.
In this study, the loads induced by tornado-like vortices on scaled models of eight low-rise residential buildings with real-world shapes in a typical North American community are quantified and compared to the provisions provided by ASCE/SEI 7-16 and 7-22. Physical simulations of the interaction between translating tornado-like vortices representative of EF1-, EF2-and EF3-rated tornadoes and the scaled models were performed in the WindEEE Dome at the University of Western Ontario. Three internal pressure scenarios were numerically simulated. The tornado velocity gust factor was identified as a critical parameter when translating loads from model to full-scale. The load comparison results show that the provisions are safer as the rating of the design tornado increases. The uplift forces on the whole roof in the internal pressure scenarios with one dominant opening are between 44% and 63% higher than the distributed leakage scenario, highlighting the importance of keeping the integrity of the envelope. The ratios of pressures obtained from physical simulation to the ones calculated using the standard are higher on the walls than on the roof. Pressure ratios on the eaves are higher than on the other parts of the roof.