ripper TBM is usually applied to bore hard rock. As it is equipped with steel rib erector, shotcrete anchor and effective supports, gripper TBM can also be used in soft-rock tunnel. Gripper TBM is suitable for rocks with UCS 50-300MPa, RQD 10%-100% and joint exceeding 0.6.
Jilin Yinsong Water Diversion Tunnel Project, China
CREG supplied an 8.03m gripper TBM to Lot 4 of Jilin Yinsong Water Diversion Project. This TBM is equipped with integrated multiple system coordination and control technology, high-efficiency rock-breaking cutterhead with non-linear layout and small cutter spacing, with efficient, safe and fast support system and geology forecast/ detection with 3D induced polarized probe. Out of the 22.955km tunnel, the TBM needs to bore through 7km karst cluster, fractured zones and soft ground. CREG TBM adapts well to this geology with average equipment availability exceeding 95% (weekly) (highest 99.1%).
Greater Beirut Water Supply Project, Lebanon
In July 2015, CREG and Italian Contractor CMC signed contract for supplying two hard rock TBMs to Greater Beirut Water Supply Project in Lebanon. Excavation diameter of the two double X gripper TBMs is 3.53m. The small diameter makes the TBM more sophisticated. CREG engineers successfully applied back-loaded cutting tools technology on the TBM (for the first time in the world for such small diameter), and also adopted small cutter spacing and non-linear cutter arrangement to enhance TBM excavating capacity and support ability in adverse geologies.