普立特大桥桥位处山区风特性实测研究

为了获取偏远山区的风场特性,以普立特大桥桥位处风场实测项目为研究背景,开发了基于无线传输的高频风速仪数据采集系统,分析了桥位处的平均风特性,并对实测脉动风的非平稳与非高斯特性进行了探讨.研究结果表明:与传统方法相比,新开发的无线传输系统具有实时传输、成本低及无需现场监测等优势;桥位处的大风期主要集中在2~4月份,且大部分发生在西南方向;在选取的强风天气中,出现山区雷暴风的比例约为15%;实测强风的平均风攻角主要在-10~0范围内波动;拟合出的风剖面指数波动范围为0~0.14,且其拟合概率密度分布的均值0.056明显小于规范规定的最小值0.12,说明规范规定的风剖面指数不足以描述山区风;山区风出现了同时具有非平稳与非高斯特性的风速样本,且其瞬时最大风速可达22.0 m/s. 

Field Measurement Study on Wind Characteristics at Puli Great Bridge Site in Mountainous Area

To obtain the wind characteristics in mountainous area, the wind field measurement at Puli Great Bridge site was conducted. A data collection system for high-frequency wind speed based on wireless transmission was developed. The mean wind characteristic was analyzed. The non-stationarity and non-gaussianity of the fluctuating wind were investigated. The results show that the new system has the advantages of real-time transmission, low cost and no field monitoring compared with the traditional method. The majority of strong wind occurs from February to April annually in the southwest direction. The proportion of the thunderstorm is about 15%among the selected strong wind during the field measurement. The wind attack angle varies from -10 to 0 degrees. The wind profile index ranges from 0 to 0.14,and the mean value of the probability density distribution is 0.56 which is less than 0.12, its minimum in the specification. It illustrates that the wind profile in the mountainous area cannot be well described by the specification. The wind speed sample with both non-stationarity and non-guassianity is measured in the mountainous area, and its instantaneous maximum speed can reach to 22.0 m/s.