Comparison of load characteristics of high-rise buildings under synoptic and non-synoptic wind profile

Tornadoes are among the most destructive wind disasters in severe convective weather systems. Their tangential wind speed exhibits a “strong at lower levels, weak at upper levels” vertical distribution, which fundamentally differs from the atmospheric boundary layer (ABL) profile adopted in current wind-resistant design codes. However, existing studies have coupled multiple mechanisms such as three-dimensional rotation, pressure drop, and translation effects, leaving the independent loading effect of this non-synoptic profile unclear. To address this issue, this study uses a multi-fan actively controlled wind tunnel to independently simulate a non-synoptic profile that retains only the vertical distribution characteristics of tornado tangential wind speed. A systematic comparison of wind pressure distribution, spectral characteristics, and overall wind forces on a high-rise building is conducted among this profile, the ABL profile, and uniform flow. Results show that under the non-synoptic profile, the maximum positive pressure shifts from the building top to mid-height. The downwash effect at the bottom corner of the side face increases the extreme negative pressure by more than 20% compared with the ABL condition. Spectral analysis reveals that fluctuating energy is stably concentrated in the 0.1–0.5 Hz range and does not broaden with increasing turbulence intensity. The building surface is divided into impingement, downwash, and vortex shedding zones based on physical mechanisms. Overall force analysis shows that the relative height of the resultant force action point remains stable within 0.52–0.54 for all three profiles. This study confirms that the non-synoptic profile itself is an independent loading factor, and its low-frequency concentration in local wind pressures implies potential implications for structural response assessment. The findings provide a reference for tornado load modeling from the perspective of vertical wind profile effects.