Numerical Investigation of Influences of Drilling Arrangements on the Mechanical Behavior and Energy Evolution of Coal Models

Table 1

Test schemes.

Test scheme	RD (mm)	NH	NR
I	3, 5, 8, 10	1	1
II	3	1, 2, 3, 4	1
III	3	3	1, 2, 3, 4

Note. R_D, N_H, and N_R are the drilling diameter, the number of drilling holes in one row, and the number of drilling rows, respectively.