By rosebell
In order to advancing the Yangtze-to-Hanjiang River Water Diversion Project, China Railway Engineering Equipment Group, (CREG), has designed and manufactured three hard rock TBMs.
While using 10 hard rock TBMs for total tunneling length of 123km, the project will supply another three TBMs for the project in the next few months.
As a project with deep overburden, long mileage and a large tunnel diameter, challenges along the alignment is going to include strong rockburst, mud and water intrusion, large faults, soft rock deformation, high temperatures and potentially harmful gases.
With 12.23m diameter and almost 160m length,this single shield TBM, CREC 1463, was the first hard rock machine for the project and has the advantages of probe drilling and intelligent tunneling. The machine is equipped with technologies, such as a comprehensive geological prediction system and cutter condition monitoring system.
The double shield TBM, CREC 1468, which was the second machine to roll off the production line, is 11.93m diameter TBM and around 180m long and considering that it is equipped with the self-developed TBM SMART system in addition to a TBM jamming warning system and cutter condition monitoring system, this SMART system can automatically evaluate geological conditions and machine health, and set the best tunneling parameters for safety and efficiency.
With the aim of adapting to the minimum curve radius of 800m and the maximum gradient of 10%, a second single shield TBM, CREC 1466, has a diameter of 12.23m and total length of 227m and potential construction risks are greatly minimised by adopting a double-speed reducer, shield structure resistance reduction design and TBM jamming warning and evaluation system.
As a follow-up water source project of the South-to-North Water Diversion Middle Route Project, which diverts water from the Three Gorges Reservoir to the Danjiangkou Reservoir, the Yangtze-to-Hanjiang River Water Diversion Project is due to link the South-to-North Water Diversion Project and the Three Gorges project closely, and link the Yangtze River Basin, the Hanjiang River Basin and North China’s Beijing and Tianjin to form a new water network.
