U形峡谷桥址区风特性实测研究

Study of Wind Environment Characteristics for Bridge across U-type Canyon

山区桥梁桥址区风场特性相比平原地区更加复杂,具有强烈的地形效应。针对某U形峡谷中三塔斜拉桥的中塔建立了高度方向的多个测点,测得了不同高度处的风速时程,通过统计分析得到桥位的平均风参数和脉动风参数及其统计规律。分析结果表明,该峡谷桥址区的平均风速剖面受地形影响大而且形式复杂,风攻角比规范推荐值大,顺、横、竖风向的湍流度比值与规范值的差异明显,湍流积分尺度、脉动风功率谱与规范相比也有所区别。

The wind field characteristics of bridge sites in mountainous areas are more complex than those in plain areas,which is strongly affected by the geography.In the paper several measuring points at different heights of the middle tower of a cable-stayed bridge with tree towers are established,and the wind speed time series are obtained,then the mean wind characteristics and fluctuating wind characteristics of the wind field are studied.The results show that the mean wind profile curve is more complicated because of the terrain,the wind attack angle is larger than the recommended values in the Chinese specification,the ratio of turbulence intensity among the downwind,crosswind and vertical direction of wind,turbulence integral scale and the turbulence wind speed power spectrums of the mountain bridge site are also very different from those in the Chinese specification.