为明确蛇型曲线隧道内风流分布特性，掌握其沿程阻力系数变化规律及计算方法，依托跑马山1号隧道工程，采用三维数值计算方法对不同曲率半径、不同反向次数蛇型曲线隧道的风流分布及沿程阻力特征进行研究和分析。研究结果表明： 1)蛇型曲线隧道内，当进入反向曲线隧道时，风流分布和沿程阻力系数均存在一个显著的过渡段，长度约为450 m。2)蛇型曲线隧道过渡段内，断面风速分布从右侧（内侧）偏移逐渐向左侧偏移过渡，过渡段内沿程阻力系数表现为先衰减后增长的趋势。3)隧道曲率半径较小时，蛇型曲线隧道过渡段沿程阻力系数数值计算结果较规范计算结果明显偏小； 当半径大于1 200 m时，过渡段沿程阻力系数数值计算结果与规范计算结果差别较小。

In order to figure out the velocity distribution and resistance loss of serpentine curved tunnel, based on Paomashan No. 1 tunnel project, numerical calculation method is used to simulate the velocity distribution and resistance loss in serpentine curved tunnels with different curvature radius and different inversion. Calculation results show that: (1)There is a significant transition stage of both velocity distribution and resistance loss in serpentine curved tunnel as entering the reverse curved tunnel; the length of transition stage is about 450 m. (2)The velocity distribution shifts from the right side (inside) to the left side in transition stage; the resistance loss of transition stage decreases first and then increases. (3)When the radius is small,the resistance loss calcalated in transition stage is obviously smaller than that in the specification; when the radius is greater than 1 200 m, the two calcalation results show little difference.