为研究高海拔隧道内不同通风参数下流场、氧气质量分数分布的变化规律及优化措施，通过开展隧道内现场试验验证并建立计算流体力学CFD仿真模型，对施工状态下的高海拔隧道各类耗氧边界进行假设与计算，开启组分输运方程模拟TBM隧道内氧气质量分数的分布情况，分析不同出风口风速、面积、氧气质量分数对低氧区域体积占比、变化规律的影响和低氧区域形成原因。对比试验数据与数值模拟结果表明： 1）空气中氧气体积分数主要在内燃机车附近发生骤降，随着到掌子面距离增加呈波动上升趋势； 2）当出风口风速从14 m/s增大到20 m/s时，可有效降低低氧区域在隧道内的占比，提高隧道内氧气质量分数； 3）出风口面积与低氧区域体积百分比成负相关关系，随着出风口面积逐渐增大，低氧的区域面积显著增加，富氧与低氧界面间的氧气质量分数变化梯度也逐渐变大； 4）出风口处的氧气质量浓度为0.275 kg/m³, 以保证不出现低于20%氧气体积分数的空气，满足高海拔隧道施工的需要。

To study the changes in flow fields and oxygen concentration distribution under different ventilation parameters in high-altitude tunnels and to explore optimization measures, on-site experiments for verification were conducted in tunnels and a computational fluid dynamics simulation model was established. Various oxygen consumption boundaries of the high-altitude tunnel under construction conditions were hypothesized and calculated. The component transport equation was activated to simulate the distribution of oxygen concentration in the TBM tunnel. The influence of different air outlet wind speeds, areas, and oxygen mass fractions on the volume proportion and variation pattern of low-oxygen areas, as well as the causes of the formation of low-oxygen areas were analyzed. The comparison between experimental data and numerical simulation results shows the following: (1) Volume fraction of oxygen concentration in the air drops sharply near the diesel locomotive and exhibits a fluctuating upward trend with the increase of the distance to the tunnel face. (2) When the air outlet wind speed increases from 14 m/s to 20 m/s, the proportion of lowoxygen areas in the tunnel can be effectively reduced and the oxygen concentration in the tunnel can be increased. (3) There is a negative correlation between the area of the air outlet and the volume percentage of the hypoxic zone. As the area of the air outlet gradually increases, the area of the hypoxic zone dramatically increases, and the gradient of oxygen content change at the interface between oxygen-rich and hypoxic also gradually increases. (4) Maintaining the oxygen mass concentration at the air outlet at 0.275 kg/m³ can ensure an oxygen volume fraction higher than 20%, meeting the requirements of high-altitude tunnel construction.