广西跨海大桥桥位区风场特征实测分析  

Field Measurement and Analysis of Wind Characteristics at Site of Sea-crossing Bridge in Guangxi

作　　者：何如[1,2] 谢敏[2] 周绍毅[1,2] 孙明[3] 苏志[1,2] 李强[1,2] 

机构地区：[1]广西壮族自治区气象服务中心,南宁530022 [2]广西壮族自治区气候中心,南宁530022 [3]广西壮族自治区气象减灾研究所,南宁530022

出　　处：《热带地理》2016年第6期952-959,共8页Tropical Geography

基　　金：广西自然科学基金项目(2015GXNSFBA139189);广西自然科学基金项目(2014GXNSFBA118216);华南区域气象中心科技攻关项目(GRMC2014Z03)

摘　　要：为了全面准确地掌握广西跨海大桥的风环境和风特性参数,2012年在桥位区设立了一座高度为55 m的测风塔,安装了梯度风和超声风观测仪器对其近地风场环境进行了连续1 a的现场观测,分析大桥桥位区实测的平均风场特征和湍流脉动风场特征,并推算了桥位区设计风速,结果表明:1)桥位区平均风速垂直变化曲线符合幂指数规律,大风状况时的风切变指数为0.062,平均风速上半年>下半年,累年平均和秋、冬、春季主导风向较稳定且均为偏北风;2)在台风"启德"过程观测到的风攻角基本不超过规范用于抗风性能检验规定的±3°范围,脉动风湍流表现为均匀平稳的湍流变化过程,三维方向的湍流强度变化趋势基本一致、湍流积分尺度随时间的变化不大,湍流功率谱在惯性副区内基本符合Kolmogrove谱-5/3律;3)大桥桥面高度处的设计风速50 a一遇为39.7 m/s,100 a一遇为42.7 m/s。In order to learn the wind environment and the parameters of the wind environment at the sea-crossing bridge in Guangxi, the characteristics of the mean wind （mean wind velocity and directions, maximum wind velocity and instantaneous maximum wind velocity） and the fluctuation wind （the wind attack angel, turbulence versus, turbulence integral scale and turbulence power spectrum） are presented at site of the bridge, on the basis of the field measurements of the near-ground wind environment using the observation instruments of gradient wind in a wind measurement tower, which is 55m in height, at 10, 33, 38, 48, 53 m and ultrasonic anemometer at the bridge surface height （43 m） during the whole year 2012. The designing wind velocity by using the wind observation data of Fangcheng reference meteorological station is calculated for different reappearing period at site of the bridge. The results show that： 1） The change of horizontal mean wind velocity followed the power exponent law, and the vertical wind shear indexes of complete wind sample and strong wind sample were 0.148 and 0.062, respectively. The observed maximum wind speed and instantaneous maximum wind speed were 26.0 and 29.3 m/s, respectively, and both of them appeared at the height of 53 m. The mean wind velocity in the first half of the year was greater than that in the second half. The annual dominant wind direction of mean wind field was partial to N, and so was in autumn, winter and spring, while it was partial to S in summer. 2） The wind attack angel of Typhoon Kai-tak was almost ＋3~, which did not exceed the test range for wind resistance performance in specification. It reflected that the terrain of the site of the bridge was relatively flat. The turbulence variation was even and stable in the observed process of Typhoon Kai-tak. The change of turbulence versus changing in 3D direction had the same trend. The 3D turbulence versus had small fluctuation in strong wind period, and the value was small too. The turbulence integral sc

关 键 词：跨海大桥 现场观测 平均风场 脉动风场 设计风速 广西 

分 类 号：TU312.1[建筑科学—结构工程]