Principle and optimal design of smoke extraction system of shield tunnel

The selection of the smoke control system for the river-crossing shield tunnel in Qingchun Road is discussed. In the preliminary design, a semi-transverse smoke control plan is earlier proposed. However, the early plan tends to result in great difficulty on construction and negative effects on the durability of tunnel system. The worldwide tunnel cases are extensively investigated, and various aspects on vertical and semi-transverse smoke extraction systems are compared. Finally, the longitudinal smoke extraction system is recommended.