Field measurements of extreme pressures on a flat roof of a low-rise building during typhoons

Abstract

A full-scale moveable instrumented low-rise building has been built and implemented to monitor wind velocity field and associated building surface pressures during typhoon landfalls. The major objective of the comprehensive field study is to further understand typhoon-generated wind characteristics and wind loads on the low-rise building under extreme wind conditions. This paper presents the field measurement results of turbulent wind characteristics and extreme suction pressures on a roof corner zone of the instrumented building during Typhoon Chanthu. The surface level wind turbulence characteristics such as gust factor, turbulence intensity and turbulence integral length scale are investigated relative to different terrain roughness regimes, various stages of the typhoon and approaching wind speed strengths. Detailed analysis of the mean, fluctuating and negative peak pressures measured on the roof corner zone is conducted to investigate the pressure characteristics in conical vortex region under wind actions with oblique directions. The results reveal that the windward leading edges on the corner area are consistently subjected to the most severe suction pressures for quartering winds. Moreover, extreme value analysis is performed using an automated procedure to determine the peak suction pressure coefficients on the roof corner. The measured and estimated extreme peak pressures are compared with those stipulated by ASCE 7–10 standard. It is found that the measured and estimated extreme peak pressures at the windward leading edge areas are significantly larger in absolute value than those determined by ASCE 7–10. The findings of this study provide useful information on the wind-resistant design of low-rise buildings in typhoon-prone regions.