INSIDE THE TBM TUNNELING ROBOT’S DEEP DIVE AT HANOI METRO LINE 3

As of August 25, the entire TBM, including the cutterhead and auxiliary equipment, is now fully underground. The machine has excavated approximately 100 meters, installed 7 temporary tunnel segments, and assembled 58 permanent tunnel segments.

Up-Close Look at the TBM Robot Excavating Deep Underground at Hanoi Metro Line 3 (Source: MRB-HGU-FECON)

After nearly a month of TBM operation, the tunneling process encountered challenges due to the machine drilling through stiff clay formations, requiring a reduction in speed. However, after adjusting the soil conditioning agent ratio—a substance sprayed in front of the TBM cutter head to soften the geological layer and facilitate excavation—the TBM’s tunneling speed has returned to normal at approximately 35-40 mm per minute.

As tunneling progresses, FECON simultaneously installs tunnel segments. With its advanced robotic arm, the segment installation process takes around 30 to 35 minutes for each tunnel ring, which consists of six segments. Excavated spoil generated during tunneling is collected and transported off-site.