为分析多点进出结构的城市地下道路空气流动特性，以长沙市营盘路湘江隧道为原型，通过现场实测、缩尺模型试验以及CFD软件数值模拟方法，对分（合）匝道通风阻力特性进行了研究，考察了雷诺数、风量比、分岔角度对分（合）流匝道阻力特性的影响规律。研究结果表明： 1）主隧道与匝道风量比、主隧道与匝道夹角是影响分（合）流匝道局部阻力系数的关键因素； 2）城市地下道路分（合）流匝道局部阻力变化特性，不宜简单套用通风管道的三通构件的参数； 3）结合最小二乘法和Matlab软件对计算结果进行多因素回归分析，给出了基于长沙营盘路湘江隧道的分（合）流匝道主隧道和匝道的局部阻力系数关联式。研究结果可为复杂结构城市地下道路通风系统阻力特性分析及通风工程优化设计提供方法参考。

The ventilation resistance characteristics of confluence and distributary ramps of Xiangjiang Rivercrossing Tunnel on Yingpan Road in Changsha is studied by field monitoring, scale model experiment and software CFD numerical simulation; and then the influences of Reynolds number, air volume ratio and bifurcation angle on resistance characteristic of confluence and distributary ramps of the tunnel are analyzed so as to know the air flowing characteristics of urban underground passageway with bifurcated ramps. The results show that: 1) The air volume ratio and bifurcation angle are the key factors on the local resistance coefficients of confluence and distributary ramps. 2) The parameters of triplet joint component of ventilation pipe cannot be applied to characterize the variation of local resistance of confluence and distributary ramps. 3) The multiplefactor regression analysis of calculation results is carried out by least square method and software Matlab, which provides the expression equation of local resistance coefficient of confluence and distributary ramps of Xiangjiang Rivercrossing Tunnel on Yingpan Road in Changsha. The study results can provide reference for analysis of resistance characteristics of ventilation system and optimization of ventilation engineering design of urban underground passageway with complex structure.