Wind loading on a stepped roof building: Comparison of field measurements, wind tunnel data, and standard provisions

Abstract

This study investigates wind loads on stepped roof buildings measured in the field and in an atmospheric boundary layer wind tunnel to verify the suitability of the North American codes and standards for the design of stepped roofs. Good agreement has been generally found between field and wind tunnel results. The field measurements and wind tunnel results were compared with the NBCC 2020 and ASCE/SEI 7–22 (2022) provisions. It was found that the Edge provisions of NBCC 2020 are currently underestimated and need to be increased. The study suggests merging the Corner and Edge zones into a single “Perimeter” zone in NBCC 2020 as this would resolve the current underestimation of the NBCC Edge wind loads and add simplicity to the Code provisions. Peaks of ASCE/SEI 7–22 (2022) were found conservative, except for the zone near the step wall on the lower roof; ASCE/SEI 7–22 (2022) positive peaks seem to be underestimated.