Abstract:

Inclined shaft is often used to increase working faces and thus to speed up the construction progress of long and large tunnels, but with multiple working faces, ventilation becomes an important factor affecting excavation speed. Based on the inclined shaft work area project of Jinjiazhuang spiral tunnel, air cabin ventilation is proposed since forced ventilation used in leftline working faces exists the problems of low air flow and poor ventilation. And then threedimensional numerical model is used to calculate and analyze the "fanwind pipetunnel" systems of the two schemes, and the numerical results are verified by the current measured data. The calculation results show that: (1) For existing forced ventilation, both the air flow of wind pipe outlet and wind speed inside the tunnel can not meet the requirement of tunnel construction; (2) After adopting air cabin ventilation, the air flow of wind pipe outlet can be better controlled and meet the requirement of construction; (3) Air cabin ventilation is flexible, and the fan inside cabin can be adjusted to control the air flow; (4) Air cabin ventilation can reduce the length and angle of wind pipe, therefore, the air leakage and wind pressure loss of wind pipe also can be reduced, and air flow can be better provided for the working face.The research results can provide reference for similar projects and have practical engineering significance.

Key words: tunnel, construction ventilation, air cabin ventilation, numerical calculation, air flow of wind pipe