On November 25th, 2019, a CRCHI hard-rock tunnel boring machine (TBM) was launched in Inner Mongolia Autonomous Region, China, which is used for the Chaor River-Xiliao River Water Diversion Project.
The project consists of hydro-junction construction and water diversion construction, being the biggest scale ever in Inner Mongolia. The water-conveyance tunnel with a total length of 183 kilometers adopts mechanized tunneling methods including drilling-blasting equipment and TBM. CRCHI develops five TBMs for this project.
The TBM has a diameter of 4.75 m, a total length of 295 m, a total weight of 1000 t and installed power of 3300 kW. For the project, long-distance excavation and risks of sudden water inflow or mud inflow result in high requirements on equipment reliability; fault fracture zones or other unstable grounds lead to high demands on TBM’s fast supporting capability. Therefore, CRCHI organized design liaison meetings for several times to continuously optimize the technical proposal and overcame technical difficulties, such as system integration of small diameter TBM, fast excavation in unfavourable geologies, layout of personnel and logistics channels, ventilation in long-distance and small-section tunnelling, cutter layout for small diameter TBM.
The project contractor-CRCC 18th Bureau Group-started TBM assembly on December 4th, started commissioning on December 17th and finished commissioning on November 22nd. Assembly and commissioning were completed within two months, ensuring construction as scheduled.