黄河复杂地形桥位风特性现场实测

FIELD MEASUREMENT OF WIND CHARACTERISTICS OF A BRIDGE SITE WITH COMPLEX YELLOW RIVER TERRAIN

  • 摘要: 结合某拟建黄河大桥,在大桥桥位附近建立一座高85 m的测风塔,分别在测风塔10 m、30 m、50 m及80 m高度处设立观测层对大桥桥位处风特性进行现场实测,实测风速风向数据采用GPRS传输,基于MATLAB开发了相应的数据处理程序对实测风速数据进行处理。结果表明:桥位处平均风速沿高度方向总体服从幂指数分布,大风状况下风剖面指数拟合值为,接近规范推荐的B类地表。大风天气(10 m高度处10 min平均风速大于10 m/s)大风时段10 m高度处风攻角范围为-4.9°~6.7°,80 m高度处风攻角范围为-4.4°~5.3°。桥面高度处脉动风紊流度及风谱等与规范推荐值总体比较接近。

     

    Abstract: Using a bridge across the Yellow River as an example, an 85 m tall wind observation tower was built to measure the wind speed and direction at 10 m, 30 m, 50 m and 80 m high. The measured wind data were transmitted by means of GPRS. A program based MATLAB environment was developed to calculate the wind speed and direction from the measured wind data. The results show that the average wind speeds along height direction generally obey a power-law distribution. The wind profile index fitted value from strong wind data is about 0.167, which is near to a class B roughness surface as recommended by the Wind-Resistant Design Specification for Highway Bridges. The average attack angle of strong wind at 10 meters high (defined as having a wind speed larger than 10 m/s with 10min intervals) is in the range of -4.9° to 6.7°, and the average attack angle of strong wind at 80 meters high is in the range of -4.4° to 5.3°. The turbulent intensity and wind spectrum of the turbulent wind at main deck level are close to the values recommended by the Wind-Resistant Design Specification for Highway Bridges.

     

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