Field measurement study on near ground wind characteristics and wind pressure of instrumented low rise building during typhoons

A full-scale instrumented moveable low-rise building was constructed and used to monitor wind velocity field and associated building surface pressures during typhoons. The major objective of the field study was to further understand typhoon-generated wind characteristics and wind pressure on the low-rise building under extreme wind conditions during typhoon landfalls. The field measurements of wind speed velocity and wind pressure on the low rise building were carried out during typhoons based on the field instrumented building system. This paper focuses on field study of wind characteristics in surface boundary layer and wind pressure distribution on roof corer zones. Wind turbulence characteristics such as turbulence intensities, gust factors and turbulence integral length scales were investigated relative to different terrain roughness regimes. Turbulence intensities increase with increasing surface roughness. The mean values of the longitudinal turbulence intensities (TI) are 0.13, 0.21 and 0.32 for the coastal terrain, open land terrain and suburban terrain, respectively. Gust factor increases with turbulence intensity increasing for three special roughness regimes. Turbulence integral scales are expected to decrease with increasing turbulence intensity. The spectra for longitudinal components of the typhoon and monsoon show similar energy distribution, whereas, the spectra for lateral wind component for winds within eye-wall region has significantly higher energy than those for monsoon. The observed spectrum for longitudinal component of the typhoon within eye wall region is close to the Von Karman's model and Harris's model in the lower and in the middle frequency regions. Moreover, detailed analysis of the mean, peak and standard deviation of pressures measured on a roof corner zone is conducted to investigate the pressure distribution characteristics on the roof corner zone. The windward leading edge on the corner is consistently subjected to the most severe suction pressures and fluctuation pressures for quartering winds. The minimum negative peak pressure coefficient is -13.5.