The total length of the diversion tunnel in the third stage is 24.3km, the diameter of TBM excavation is 7.9m, and utilize the reverse slope excavation method. The main excavation work of TBM began on March 12, 2015 and was completed on May 4, 2018. In the process of construction, the project has encountered many geological hazards, such as bad geological fault belt sticking, sudden water gushing, arch sinking and so on. It achieved the highest daily tunneling feet of 75m, the average monthly footage of 1080m, and the highest monthly footage of 1423.5m, which set the record of the highest monthly footage of Open Type TBM of the same grade in China. At present, the concrete lining work is being carried out in a tense and orderly manner.
The total length of the construction drainage hole is 14.9km, and the excavation diameter of TBM is 7.2m. Deep burial, complex geological conditions. In the process of construction, there are many problems such as rock burst and water gushing. The project started in March 2007 and the tunnel holing-through in 2011. In such complex geological conditions, TBM still created a monthly footage of 753m, which was a new record of TBM construction in China in areas of extremely high ground stress and large water gusher.
