Congratulations on the completion of Qinling Water Diversion Tunnel of Hanjiang to Weihe River Project!

On February 22, 2022, with the hard rock tunnel boring machine cutterhead broke out of the rock, the 98.3km Qinling Water Diversion Tunnel of Hanjiang to Weihe River Project has been completed.

Hanjiang to Weihe River Project spans the two major basins of the Yellow River and the Yangtze River and crosses the Qinling Mountains to realize the connection of the two rivers.

The Qinling Water Diversion Tunnel has a maximum burial depth of 2,012 meters. The stratum is mainly composed of quartzite, granite and diorite. The average compressive strength of the rock is 194 MPa, and the highest hardness is 316 MPa. The geological conditions of the tunnel crossing area are extremely complex, and many experts evaluate it as "rare in the world of comprehensive difficulty".  Restricted by geological and topographical conditions, the Qinling Water Conveyance Tunnel adopts the drilling & blasting method and TBM combined construction, of which the drilling & blasting method is 63.3 kilometers and the TBM construction is 35 kilometers.

Litian began to provide rock drilling tools (threaded button bits, drill rods, shank adapter, coupling sleeves) for the drilling and blasting construction of the project in June 2014. In the aspect of TBM construction, due to the high hardness and wear resistance of rock, the consumption of TBM disc cutter is large and the wear of disc cutter ring is serious. Frequent disc cutter replacement seriously affects the tunnelling speed of TBM. Under the circumstance that the original manufacturer's disc cutter ring was no longer competent, Litian was asked to provide TBM cutters and cutter rings for the project on January 1^st, 2016, which solved the urgent needs of the project, such as frequent disc cutter changes, delays in the excavation period and high costs. It ensures the normal operation of the Tunnel boring machine.

It is the first time in the history of human engineering that the water tunnel from The bottom of the Qinling Mountains was completed, and it has created the world's first records of ultra-long deep burial and continuous tunnelling by a single TBM.  We are honoured to be able to participate in this great project!