Influence of turbulence intensity on wind effects toward a high-rise building with curved cross-section at coastal area

Abstract

Although the important role of turbulence intensity (Ti) in wind-induced effects on many civil structures have long been acknowledged, there is a lack of concerns with the Ti influence on high-rise buildings at coastal areas especially under typhoon dominated conditions. Existing results suggest that typhoon wind turbulence may differ from that of conventional wind (e.g., strong monsoon), owing to the existence of complex small-scale eddies/vortexes. Meanwhile, due to the effects of air-sea interaction, marine roughness tends to vary with the strength of upwind wind, and the onshore wind at coastal areas may not be modeled via a single type, e.g., following the way as stipulated in many wind load codes/standards. To this end, this article investigates the Ti-dependence of wind effects toward a super-tall building with curved cross section at a typhoon-prone coastal area, based on combined usage of wind tunnel tests and field measurements. The dependence of Strouhal number, wind pressure, layer force, structural response and equivalent static wind load on Ti in the range from 2.5% to 31.0% is analyzed and further compared with those for circular and square cylinders. The results show that Ti has a significant impact on the wind-induced effects on structures. As Ti increases, the mean and fluctuating pressures on wind structure surfaces keep rising. The frequency of vortex shedding increases with Ti by changing the vortex generation state at shear layer in the wake region. In addition, the global geometric characteristics of cross-section and its local details, especially the location of blunt edges which might lead to flow separation, may play an important role in the effect of Ti on fluid structures around the building. These factors above collectively result in significantly growing fluctuating values of wind loads on the structure as Ti increases. Overall, the structural response of this building gradually increases with the enhance of Ti, although the mean value of layer load may decrease with that.