Experimental Investigations of Structural Responses of a High-Rise Building Subject to Oblique-Downstream Interference Effects

This study experimentally investigates the aerodynamic mechanisms and dynamic responses of slender high-rise buildings subjected to oblique-downstream interference effects. Using a simulated open-terrain atmospheric boundary layer, a square prismatic principal building (aspect ratio 8.0) was evaluated alongside an identical interfering building. High-frequency force balance and aeroelastic vibration tests were conducted across four Scruton numbers (Scr). Aerodynamic damping was quantified using the random decrement technique and a trial-and-error approximation. Results show pronounced resonant amplification under strict conditions. Specifically, at a low Scr (1.12), a reduced velocity (Ur) of 5.5, and an interference location of x/B,y/B=−1.5, 1.5, the principal building exhibits an inclined elliptical trajectory, driven by a negative aerodynamic damping effect of approximately −2%. Higher Scr values attenuate displacement, but rooftop acceleration amplifications persist, reaching an interference factor of 2.0. Ultimately, the synchronized rhythmic channeling required to excite the principal building necessitates a minimum wake width from the interfering structure (breadth-to-depth ratio > 0.5), highlighting critical aeroelastic instabilities in dense high-rise clusters.