Research and Application of Integrated Presplitting Blasting in Nonpillar Mining Technology

Figure 4

Principle of integrated presplitting technology. (a) Fragmentation blasting. The shallow hole blasting is to fragmented regional roof, which is to create cracks in the roof and weaken the strength of the roof, and reduce the span of the roof and the pressure when it collapses. (b) Directional cutting roof blasting. This roof-cutting blasting uses special PVC pipes (energy gathering pipe) to form a directional cutting surface, and the result of cutting the roof can be realized.