山区地形复杂多变，风场由此呈现出非定常、非平稳的特性，给桥隧连接段处行车安全带来巨大挑战。为研究复杂山区桥隧连接段风场空间特性变化规律，选取G318与S217交界处直径8 km范围内的山区地形为研究背景，获取研究区域地形的数字高程模型，采用逆向拟合方法建立5种长度桥隧连接段的山体模型。参照标准16方位风向图设置来流工况，利用数值模拟方法，得到不同来流工况下各桥隧连接段处的风场空间分布特性。结果表明，数值模拟结果与现场实测数据的误差基本在20%以内，数值模拟方法具有较高的准确性；在山体坡度近似不变的条件下，受实际复杂地形影响，不同长度的桥隧连接段处的横桥向风速、竖直风剖面与风攻角特性存在一定的差异，但总体趋势相近；来流垂直于桥隧连接段时，受到峡谷加速效应在跨中处风速达到最大，这种加速效应随着桥隧连接段长度的减小而增大，其余工况来流受两侧高陡山体的折减效应而减小，在顺桥隧连接段时风速最小；高陡山体与河道弯曲影响竖直方向横桥向风速分布，在高程较低的峡谷内部，桥隧连接段长度越短，影响越大；风攻角特性也受地形影响变化较大，总体表现出以负攻角为主。复杂山区桥隧连接段风场数值模拟研究得到的变化规律，可为桥隧连接段处的行车安全性研究提供一定的指导和参考作用。

The complex and variable mountainous area causes the wind field to exhibit unsteady and non-stationary characteristics, posing significant challenges to traffic safety at bridge-tunnel connection sections. To study the variation law of the spatial characteristics of the wind field at the bridge-tunnel connection sections in complex mountainous area, this paper takes the mountainous terrain within an 8 km diameter range at the junction of G318 and S217 as the research background. It acquires the digital elevation model (DEM) of the study area’s terrain, and utilizes a reverse fitting method to construct mountain mass models for bridge-tunnel connection sections of five varying lengths. With reference to the standard 16-point wind rose diagram, inflow conditions were configured. The spatial distribution characteristics of wind fields at bridge-tunnel connection sections under various inflow conditions were obtained through numerical simulation. The results show that the error between the numerical simulation results and the on-site measured data is generally within 20%, indicating that the numerical simulation method has high accuracy. Under the condition that the slope of the mountain remains approximately unchanged, affected by the actual complex terrain, cross-bridge wind speeds, vertical wind profiles, and wind attack angles exhibit distinct characteristics at bridge-tunnel connection sections of varying lengths, though they demonstrate similar overall patterns. When the incoming flow is perpendicular to the bridge-tunnel connection section, the wind speed reaches the maximum at the mid-span due to the canyon acceleration effect. This acceleration effect increases as the length of the bridge-tunnel connection section decreases. Under other cases, due to the reduction effect of the high and steep mountains on both sides, the incoming flow decreases and the wind speed is the minimum along the bridge-tunnel connection section. The steep mountainous terrain and river bends significantly influence the vertical cross-bridge wind speed distribution. Within lower-elevation canyons, shorter bridge-tunnel connection sections experience more pronounced effects. Wind attack angles also exhibit substantial terrain-induced variations, predominantly manifesting as negative attack angles overall. The variation laws obtained from the numerical simulation study of the wind field in the bridge-tunnel connection section of complex mountainous areas can provide certain guidance and reference for the study of driving safety at bridge-tunnel connection sections.