Abstract: The smoke exhaustion and disaster prevention and rescue of submarine immersed tunnel with ultralarge crosssection is difficult to carry out. Therefore, a new smoke exhaustion system combining horizontal smoke exhaust connection channel on tunnel top with sidewall smoke exhaust hole is innovatively proposed for immersed tunnel of ShenzhenZhongshan Link under the condition that the full sidewall smoke exhaustion mode cannot meet requirement, which help to solve the smoke exhaust difficulty of superlong and large immersed tunnel. The new smoke exhaustion system is superior to the traditional full sidewall smoke extraction method in terms of use of the smoke flow characteristics, smoke exhaust efficiency, available evacuation time, and the fire safety of superlarge crosssection submarine immersed tunnel. Furthermore, a smoke exhaust scheme for the interconnection area of the underwater hub is proposed based on the characteristics of the interconnection structure of the underwater hub and the characteristics of the ventilation flow field. By adopting the scheme of longitudinal ventilation combined with ceiling exhaust flue in the ramp section of the entrance confluence, and intensive smoke discharge at the bifurcation and confluence positions or the vertical shaft, the fire smoke can be effectively controlled. Under the condition of complete disaster prevention facilities, a technical system for disaster prevention and rescue of immersed tunnel of ShenzhenZhongshan Link is established based on the traffic characteristics of the surrounding road network and the distribution of rescue powers.

Key words: submarine immersed tunnel, underwater hub, river , crossing tunnel, ultrawide cross , section, fire smoke exhaustion, disaster prevention and rescue, smoke exhaustion system