Case Study on Long-distance Ventilation of Zhongtianshan Tunnel Driven by TBM

Zhongtianshan tunnel is 22.449 km long.The 13.8 km entrance section of the tunnel is driven by TBM.Long-distance ventilation during tunneling is one of the important factors that affect the construction progress and economic efficiency.Study is made on the ventilation of Zhongtianshan tunnel on basis of the construction method,driving length and construction organization of the tunnel.Comparison and contrast is made between single-direction long-distance ventilation program and gallery-type combined ventilation program,which indicates that the gallery-type combined ventilation program is the optimum ventilation program.The stage division and number of the ventilation fans needed for the gallery-type combined ventilation program are proposed.The ventilation program is further adjusted during tunneling in accordance with the site ventilation monitoring results so as to meet the actual conditions of the site.In the end,the ventilation program adopted guarantees the successful breakthrough of Zhongtianshan tunnel.