Experimental Study on Influence of Borehole Arrangement on Energy Conversion and Acoustic Characteristics of Coal-Like Material Sample

Figure 7

Typical curve of stress-time-AE energy evolution of coal-like material samples under different borehole arrangements. (a) Scheme I 03: complete samples. (b) Scheme II 02: samples with boreholes. (c) Scheme III 02: samples with borehole with stepwise increased borehole depth. (d) Scheme IV 01: samples with borehole with stepwise increased borehole diameter. (e) Scheme V 03: samples with borehole with stepwise increased borehole depth and borehole diameter.

(a)

(b)

(c)

(d)

(e)