Field measurements of wind loads on a low-rise building - Part II: Wind pressure distribution characteristics on gable roof

Wind loads on the gable roof of a low rise building were studied using the pressure data and wind velocity data recorded from a full-scale moveable instrumented low-rise building. The results revealed that high local suctions on the ridge corner and the eaves corner were observed under oblique flows. Probability distributions of the fluctuating pressure in separated flow regions were non-Gaussian. The measured pressure spectra at several locations on the windward ridge corner agreed with the predictions of the quasi-steady theory in low frequencies quite well. However, the predicted spectra decayed significantly faster than the measured pressure spectra in high frequencies. Comparing with those obtained under non-typhoon wind climates, it would appear that building generated or wake turbulences are responsible for the discrepancies from the predictions of the quasi-steady theory. Vertical wind components and pitch angle varied significantly during typhoons, which caused underestimation of fluctuating wind loads.