Analysis on the Influence of Natural Wind on the Ventilation Performance of Multi-entrances and Exits Underground Roads

With the development of urban construction, multi-entrances and exits urban underground roads have become a new trend of urban underground traffic development planning. Based on the network ventilation theory and the ventilation design standard, a one-dimensional pressure balance model in the tunnel is established. The influence of natural wind on the ventilation performance of multi-entrances and exits underground road combined with the urban underground road project in Wuhan city is studied. It is found that the safety of tunnel equipment configuration can't be completely improved if the ventilation equipment is configured according to the natural wind speed recommended by the design specification. In the operation of tunnel, it is necessary to control the operation of ventilation equipment in combination with the change of tunnel natural wind speed and average vehicle flow speed. Under the typical natural wind speed, the length change of ramp and main line has a significant impact on the off-ramp ventilation, but has a little effect on the on-ramp ventilation. The relevant conclusions provide reference for ventilation design and tunnel operation of similar projects.