6.5K views · 104 reactions | Blasting techniques in rock tunnels...

Pre-splitting blasting technique is a method employed in rock excavation to create a fracture plane ahead of the main blasting zone. It involves drilling a line of closely spaced holes along the desired contour, typically using smaller diameter drill bits. These holes are then charged with explosives, but the detonation sequence is carefully controlled to ensure that the fractures propagate smoothly and evenly along the designated plane. Pre-splitting helps in achieving a smooth excavation face,

Drill and blast method is one of the common tunnelling techniques in hard rock. The principle behind the blasting in tunnel is to create a free face at the centre of the tunnel by means of cut holes and then extending the blasting to the 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. In our online Tunnel Engineering course, you will learn blasting techniques in tu