Exploring the Feasibility of Ventilation without Shafts for an Ultralong Subsea Tunnel in the Bohai Strait Channel

Table 1

Ventilation of extralong tunnels around the world.

Name	Country	Length (km)	Type	Max ventilation length (m)	Ventilation pattern
Laerdal tunnel	Norway	24.5	Bidirectional 1 tube with 2 lanes	6510	Segmented longitudinal
Gotthard Road tunnel	Switzerland	16.9	Bidirectional 1 tube with 2 lanes	5658	Semitransverse
Frejus tunnel	Italy	12.9	Bidirectional 1 tube with 2 lanes	∼4000	Semitransverse/longitudinal
Zhongnanshan tunnel	China	18.02	2 tubes with 2 lanes per direction	5494	Segmented longitudinal
Kanetsu tunnel	Japan	11.055 + 11.926	2 tubes with 2 lanes per direction	3738	Longitudinal with electrostatic precipitator
Plabutsch tunnel	Austria	10.085 + 9.913	2 tubes with 2 lanes per direction	∼2500	Transverse