Abstract: Herein, the field monitoring method is performed to clarify the distribution of environmental temperature and ventilation flow field in a long and large submarine shield tunnel. Subsequently, the primary heat sources of submarine shield tunnels are identified and a threedimensional numerical model of the temperature field is established. These steps investigate the effects of shield tunneling length, ventilation rate, and wind temperature on the temperature and ventilation blind zone distribution in the tunnel. The primary conclusion points are as follows: (1) The main machine of the shield and equipment on the lower and middle floors of the No. 1 framework are the main heat sources. A large ventilation blind area behind the equipment exhibits a locallyhigh temperature. (2) The return air velocity in the area from the shield main machine to the launching shaft sharply decreases and then gradually increases before stabilizing. Air loss occurs mainly in the postshield support workarea. (3) The wind temperature undergoes a sudden decrease, followed by a gradual decrease and then a gradual increase. (4) When the excavation length of the shield is <6 km, the temperature at the shield main machine exhibits a rapid linear increase, which is followed by a slowdown in the growth rate. (5) The range of the ventilation blind zone increases and decreases exponentially with the increasing tunnel excavation length and ventilation inlet air volume, respectively. Increasing the ventilation volume can effectively minimize the ventilation blind zone.

Key words: submarine shield tunnel, ultralongdistance ventilation, tunnel temperature field, ventilation heat transfer characteristics