Location: Yongji County, Jilin City, Jilin Province, China
Customer: China Railway 18 Bureau Group Company
Being the longest water delivery line in the history of Jilin province, transferring water from Songhua River into Central Jilin Province will transfer the largest capacity of water and cover the largest areas. The water diversion line is 371.54 km long and the total period of construction is 6 years. An open-type TBM produced by CRCHI is used to excavate a tunnel from the Fengman Reservoir to the left bank of Wende River.
The tunnel is 19797 meters long. The first construction phase is 8298 meters and the second construction phase is 11499 meters. The tunnel slope is 1/4300. The maximum depth is 536.8 meters.
Among the surrounding rocks, II surrounding rock accounts for 32.8%, III surrounding rock accounts for 56%, IV and V surrounding rock accounts for 11.2%. Tuff and granite are the main rocks. Compressive strength was measured to be within 74-169 MPa initially, while the maximum compressive strength during the construction reached 200 MPa.
Key features of Open-type TBM produced by CRCHI
- Main parameters of the Open-type TBM: excavation diameter is 7.93 meters.
- The whole machine is 185 meters long and its weight is 1500 tons.
- Installed power is 5000 kW.
- The maximum advance rate is more than 120mm/min.
- A research theory of disc cutter wear mechanism has been established by combining simulation analysis and engineering practice.
- Sensor for cutter wear monitoring has been developed using wire grid and resistor array.
- New ways of testing cutter wear have been created.
- Ways of designing drive system under strong vibration have been mastered.
- Problems in correcting TBM posture have been addressed through simulation analysis.
- The effect of vibration on pose measurement has been reduced to zero through technological innovation.
- It is verified that inclinator data can be preprocessed by wavelet synthesized filtering algorithm, and measurement accuracy of inclinator has been effectively improved.
CRCHI leads a task of “Big-diameter TBM and Major Engineering Machinery” from National 863 Plan of “Key Technologies and Application of Big-diameter Hard-rock TBM”. This is China’s first Open-type TBM whose purchase contract was signed in June of 2014. It took seven months to design and manufacture the TBM and one month to transport it to the customer. It took two months for installation, conditioning and shield stepping. The TBM was launched on March 26th of 2015. The maximum daily advance reached up to 86.5 meters, creating a new record in China. Monthly advance reached more than 920 meters in May and June when the TBM tunneled in III surrounding rocks.
From July 2015, the TBM started to excavate hard rocks whose compressive strength was above 200 MPA and encountered fracture zones. Monthly advance got to 550 meters in July 2016; 558 meters in August; 509 meters in September; 736.5 meters in October; 851 meters in November; and 1209.8 meters in December. In short, since March 2015, the total advance of TBM was 6865 meters and the average monthly advance was 725 meters, creating a new record in China.