山区峡谷桥位处的风场特性非常复杂，成为山区大跨桥梁设计和建造的新难题。为准确获取山区峡谷内的风场特性，并研究风场特性的分布规律，以某待建大跨桥梁所在的山区V形峡谷桥位风场为研究对象，分别进行了均匀来流和边界层湍流风场来流下地形模型风洞试验，研究了不同风向角下桥位的平均风场特性和脉动风场特性，分析了桥塔和主梁位置处的风场特性分布规律。并对比了边界层湍流风场来流下V形峡谷中主梁1/6跨和跨中与来流风特性。结果表明：相关抗风规范中适用于平坦地形的风剖面无法应用于山区峡谷地形，并且峡谷内风攻角变化范围较大，V形峡谷内风攻角取值范围建议-20°~+20°。当来流方向和峡谷走向一致时，湍流强度也较小，而桥梁背风侧湍流强度大，桥梁设计时应对背风侧加固。主梁跨中和桥塔位置的脉动风功率谱均与von Kármán谱吻合。本研究可为类似的山区V形峡谷大跨桥梁的抗风分析和设计提供参考。

Wind characteristics at a bridge site in mountain valley are very complicated, which leads to a new problem for the design and construction of long span bridges. To accurately obtain the wind characteristics in mountain valley and their distribution, the terrain model wind tunnel test of a V-shaped canyon where a long span bridge is going to be built with uniform and atmospheric boundary layer inflow conditions was carried out, and the mean and fluctuating wind characteristics at the bridge site under different wind directions were studied. The distribution of wind characteristics at the location of bridge tower and main girder was analyzed. And the main beam 1/6 span and the midspan of the V-shaped canyon in the boundary layer turbulent wind field under the inflow wind characteristics were compared. The results indicate that the wind profile suitable for flat terrain in the relevant wind resistance specifications cannot be directly applied for mountain area, and the range of wind attack angle changes in the canyon is large. The suggested wind attack angle range for V-shaped valleys is -20° to +20°. When the flow direction and the valley orientation are consistent, the turbulence intensity is also smaller, while the turbulence intensity of the leeward side of the bridge is large, so the leeward side of the bridge should be reinforced during the design. The fluctuating wind power spectra at the middle span of main girder and the pylon are in agreement with the von Kármán spectrum. This study could be provided reference for wind resistance analysis and design of long span bridges in similar V-shaped canyon in mountain areas.