Optimal Proportion of Similar Materials and Rockburst Tendency of White Sandstone

Table 3

Design table for orthogonal test covered by the study.

Level	(A) Quartz sand (%)	(B) Iron powder (%)	(C) Plaster : cement	(D) Sand size (mm)
L1	45	0.5	1 : 1	0.25–0.5
L2	45	1	1.5 : 1	0.5–1
L3	45	1.5	2 : 1	1-2
L4	45	2	3 : 1	2–4
L5	50	0.5	1.5 : 1	1–2
L6	50	1	1 : 1	2–4
L7	50	1.5	3 : 1	0.25–0.5
L8	50	2	2 : 1	0.5–1
L9	55	0.5	2 : 1	2–4
L10	55	1	3 : 1	1-2
L11	55	1.5	1 : 1	0.5–1
L12	55	2	1.5 : 1	0.25–0.5
L13	60	0.5	3 : 1	0.5–1
L14	60	1	2 : 1	0.25–0.5
L15	60	1.5	1.5 : 1	2–4
L16	60	2	1 : 1	1-2