典型大跨度屋盖结构的风压谱工程简化模型

The present research proposed a simplified engineering model of wind pressure spectra that can describe the characteristics of body-induced turbulence around large-span roofs. The model was based on the spectral analyses on 1 730 cases, 18 048 samples of wind tunnel data on five types of typical large-span roofs including flat, cantilevered, cylindrical, spherical and saddle roofs. Two key parameters, namely, the peak frequency and the coherence index, were introduced to describe the wind pressure spectra and to develop the simplified model. The results show that, the mentioned five types of large-span roofs can be divided into three categories in spectral perspective. Category Ⅰ is bluff body with sharp corners represented by flat and saddle roofs. Category Ⅱ is cantilevered roof characterized as planar flow. Category Ⅲ is curved bluff body represented by cylindrical and spherical roofs. For roof category Ⅰ and Ⅱ, the peak frequencies are concentrated at 0.1-0.2 Hz, while the coherence indexes are concentrated at 2.5 and 3.5, respectively. For roof category Ⅲ, the peak frequencies are below 0.1 Hz, and the mode of coherence index is 4.0. Finally, through statistical analyses, the zone values of spectral parameters are given for engineering reference.