丘陵地区深切峡谷风特性现场实测研究

Study on Field Measurement of Wind Properties near a Canyon Deep-cut to Hilly Land

根据测风塔和当地气象站数据,对江底河大桥桥址处深切峡谷的风场特性进行研究.基于数据统计分析得到桥址处风场的平均风速、风向、湍流强度、湍流积分尺度和湍流的功率谱密度函数.结果表明:该桥所在的深切峡谷地形对风向有锁定作用、对风速有加速作用、并且对各个风向下的湍流特性有明显的影响;深切峡谷顺风向湍流强度与平均速度的关系用反比例型函数拟合,拟合效果良好且高风速下接近规范值;竖风向湍流强度明显高于规范推算值.顺风向实测风谱与Kaimal谱相差较大而与von Karman谱吻合较好;竖风向实测风谱明显大于Panofsky风谱而与von Karman谱比较接近.横风向实测风谱与Panofsky谱、von Karman谱都比较接近.

Based on the data obtained from a tower and a local meteorological station, the wind properties at the Jiangdihe Bridge site, located at a deep-cut valley,were investigated. According to statistical data processing, the mean wind properties, wind directions, turbulence integral scales, as well as wind spectra were obtained. The results show that the deep canyon terrain in which the bridge is located plays roles in locking the wind direction and accelerating the wind speed, and shows obvious influence on the turbulence characteristics. The relationship between the turbulent intensity and mean wind speed was obtained by fitting with inverse example functions, resulting in good fitting effect and high wind speed close to the standard value. The vertical turbulence intensities are much higher than those values specified in the China wind-resistant design specification for highway bridges. The wind spectra from the measured wind are quite different from the Kaimal spectrum, but in good agreement with the von Karman spectrum. The wind spectra of the vertical wind fluctuations are obviously larger than the Panofsky wind spectrum, but close to the von Karman spectrum. The measured across-wind spectra are quite close to both the Panofsky spectrum and the von Karman spectrum.