Research and Application of Integrated Presplitting Blasting in Nonpillar Mining Technology

Figure 9

Roof lithology description and nonpillar mining design parameters. (a) The lithology within 15 m of the roof of 1306 working face was drilled and photographed to form the lithology geological section map, which is the most important basis for the design of key parameters. (b) Two parameters are designed according to the roof lithology. The constant resistance anchor cable is designed in three columns and 12.3 m long. The blast hole length of the directional cutting roof is 10 m and the drilling angle is 75°.

(a)

(b)