An extreme value estimation method of wind pressures based on change point theory

Abstract

Estimating the extreme wind pressure accurately on the roofs of low-rise buildings is crucial for wind-resistant design in wind engineering. This study proposes a new method for extreme value estimation, where change-point theory is incorporated into selecting thresholds to determine the optimal threshold and the wind pressure coefficient is converted into an intermediate exponential variable. The measured wind pressure data collected from the roof of a low-rise building at the Pudong experimental base of Tongji University during Typhoon Ampil is used as the sample of the extreme value estimation. Referring to the position of change point, the interpolation method assists in finding the most appropriate threshold for the wind pressure coefficient. The number of independent peaks in a standard wind pressure sample is reduced from 204 to 30, applying the optimal threshold while considering the correlation. This processing is crucial to reducing the estimation error. Then, the error rates of the proposed method are below 5 % at quantile p = 0.95 and the mean error rate of the proposed extreme value estimation method is within (−0.1, 0) for the whole roof regions. For comparison, the upper limit of the mean error rate for the modified Hermite model based on zero-crossing theory reaches 0.41 and that of Quan's method based on classical extreme value theory is 0.28. These results demonstrate the superiority of the proposed method. Meanwhile, the relevant estimation results show that the proposed method's extreme wind pressure values meet engineering requirements at the specified percentile.