超高层建筑脉动风压的非高斯特性

Non-Gaussian feature of wind-induced pressure on super-tall building

对带切角的菱形超高层建筑进行风洞试验,将试验得到的风压时程数据进行时域、幅域信息分析,研究该类体形超高层建筑表面风压的非高斯分布特性.基于在各风向角下风压系数的3阶、4阶矩统计量,对高层建筑各立面风压进行高斯与非高斯分布的分区,发现侧面的前缘气流分离区、背风面以及迎风面切角区域的脉动风压存在显著的非高斯特性.对高斯区和非高斯区设计风压系数的峰值因子取值问题和估算方法进行讨论,发现在实际应用中对非高斯区的峰值因子取值偏小.

Wind tunnel tests were conducted on a diamond-shaped super-tall building with corner cuts. The non-Gaussian features of the wind-induced pressure on the building were analyzed through the wind pressure data analysis both in time domain and amplitude domain. Based on the third and the fourth order statistical moments of wind pressure coefficients, the Gaussian and non-Gaussian regions of the wind pressure at a given wind direction were identified on the surface of the super-tall building, respectively. The non-Gaussian features were prominently exhibiting at the leading edge separation on the side face, lee ward side and the windward corner cuts. The determination method of peak factor for the design wind pressure coefficient at the Gaussian and non-Gaussian regions was discussed. Results show that the current code-specified values of peak factor are riskily used at the non-Gaussian region in some wind engineering practices.