Recently, good news has come from the open-type tunnel boring machine (TBM) independently developed by CRCC Heavy Industry and applied at the Yangcheng Coal Mine of Jining Energy in Shandong. In July and August, it achieved a cumulative monthly advance of over 400 meters for two consecutive months. Among these, the cumulative advance in August reached 416 meters, with a daily advance exceeding 22.5 meters and a per-shift advance exceeding 11 meters.

The TBM was officially lowered into the shaft for installation on November 12, 2022. During this period, multiple challenges were overcome, including the cage transport of large equipment and long-distance underground roadway transport. The total installation length of various equipment components exceeded 80 meters, and installation and commissioning were successfully completed in 38 days. On January 15 of this year, the TBM started excavation. From a first-month advance of 190 meters to the current monthly advance of 416 meters, the excavation efficiency has reached about 4 times that of traditional excavation efficiency, providing safer and faster equipment support for coal mine roadway construction.

During excavation, the TBM successively overcame multiple unfavorable factors such as crossing coal seams, water inflow, roof falls and rib spalling, soft rock fracture zones, high ground pressure, clogging of the cutterhead, and jamming of the shield body. CRCC Heavy Industry's on-site service personnel overcame harsh working conditions such as high underground temperatures, dust, water inflow, and long working hours. They provided round-the-clock on-machine maintenance, handled problems immediately when they arose, and continuously optimized the equipment to minimize the equipment failure rate.

In response to the problem of slow TBM excavation in soft rock fractured strata, on-site service personnel communicated and held discussions with the mining area many times. They analyzed, tested, and summarized measures from aspects such as roof support, prevention of roof falls and rib spalling, cutterhead cleaning, equipment failure control, and changing the excavation route, and adopted targeted measures that achieved good results. Through sincere cooperation between both parties, the seeds of effort have finally borne gratifying fruit.