An experimental research on the rock cutting process of the gage cutters for rock tunnel boring machine (TBM)

• We proposed an experimental method to study TBM gage cutter’s rock cutting process.
• The experiments were conducted on a full-scale rotary cutting machine (RCM).
• Wedges were inserted into the space between the cutter base and cutter box.
• The cutting forces of the gage cutters are smaller than the normal cutter.
• The depth of the rock broken zone is smaller than the cutting depth.

This paper proposed an experimental method to investigate the rock cutting process of TBM gage cutters based on the full-scale rotary cutting machine (RCM). The key point of this method is to reconstruct the RCM by inserting three wedges with angles of 10°, 20° and 30° respectively into the space between the cutter base and cutter box. As a result, the rock cutting process of gage cutters with tilt angles of 10°, 20° and 30° can be proceed. Using this method, rock cutting experiments were conducted with penetrations of 2 mm, 4 mm, 6 mm and 8 mm respectively. The testing results were analysed on the rock cutting force, rock debris dimension, specific energy and cutting surface profile, and it was found that: (1) the cutting forces and specific energy of the gage cutter were lower than those of the normal cutter respectively; and (2) the depth of the rock broken zone was smaller than the cutting depth. The testing results can also be used to validate corresponding numerical models and design the layout of gage cutters.