Effects of Unidirectional In Situ Stress on Crack Propagation of a Jointed Rock Mass Subjected to Stress Wave

Table 2

Emission energy of ZDF-3 electric spark (2500 V).

In situ stress (MPa)	Number	Charging voltage (V)	Residual voltage (V)	Actual voltage (V)	Emission energy (J)	Average emission energy (J)
0.5	1	2500	640	1860	726.5	734.4
0.5	2	2500	650	1850	718.7
0.5	3	2500	600	1900	758.1
1.0	1	2500	600	1900	758.1	745.0
1.0	2	2500	600	1900	758.1
1.0	3	2500	650	1850	742.2
2.0	1	2500	620	1880	742.2	742.4
2.0	2	2500	650	1850	718.7
2.0	3	2500	590	1910	766.1
3.0	1	2500	640	1860	726.5	746.3
3.0	2	2500	/	/	/
3.0	3	2500	590	1910	766.1
4.0	1	2500	710	1790	672.9	665.5
4.0	2	2500	700	1800	680.4
4.0	3	2500	750	1750	643.1
5.0	1	2500	700	1800	680.4	719.0
5.0	2	2500	620	1880	742.2
5.0	3	2500	630	1870	734.3

Note: “/” indicates that no data has been collected.