The critical factor in blasting in tunnels is the lack of an available free surface towards which breakage can occur (only the tunnel heading itself). The principle behind tunnel blasting is to first create an opening by means of a cut, usually at the centre, which provides a breaking surface for the surrounding holes.On the other hand, a common misconception is that the only step required to control blasting damage is to introduce pre-splitting or smooth blasting techniques. However, controllin

Drill and blast method is one of the common tunnelling techniques in hard rock. The principle behind the blasting in tunnel is to create free face at the centre of tunnel by means of cut holes and then extending the blasting to full face of tunnel. In simple words, blasting relies on two main factors: 1. shock wave to create cracks in the rock 2. Expansion of gas to move into the cracks to crush the rock. #tunnelengineering #tunnelengineer #blasting #drillandblast #mechanizedtunnelling #blast #d