Smooth Blasting in Hard Rock tunnel Using an Automatic Drilling Machine

This study was made to minimize overbreak and underbreak of the design excavation face by conducting various analyses of data obtained from the automatic drilling robot in a hardrock tunnel. At the site, it is difficult to minimize overbreak and underbreak, so trial and error must be repeated. We conducted a 3-stage blasting experiment using the numerically controlled drilling robot (automatic drilling machine) and tunnel measuring equipment and found that a proper drilling plan and its execution are very important in minimizing overbreak and underbreak in hardrock tunnels. In the near future, the drilling robot will be used widely for tunnel excavation because it is not affected by the technique or skill of the workers.