Rockburst in Sandstone Containing Elliptic Holes with Varying Axial Ratios

Table 1

Experimental loading plan.

No.	Long axis a (mm)	Short axis b (mm)	Long-short axis ratio	σv0 (MPa)	σh (MPa)
S-1-1	50	50	1	13.6	10.2
S-1-2
S-1-3
S-1.25-1	50	40	1.25	13.6	10.2
S-1.25-2
S-1.25-3
S-1.67-1	50	30	1.67	13.6	10.2
S-1.67-2
S-1.67-3
S-2.5-1	50	20	2.5	13.6	10.2
S-2.5-2
S-2.5-3