Table 1.

Physical and mechanical parameters of coal and rock.

Rock layers	Thickness/m	Buried depth (m)	Test weight (kg·m− 3)	Volume force (kN/m³)	Elastic modulus (MPa)	Internal friction angle (°)
Loess	39.50	39.50	1 600	16.00	300	15
Mudstone, conglomerate	169.30	178.85	2 220	22.20	2 790	38
Sandy mudstone	46.25	225.00	2 220	22.20	2 790	35
Conglomerate	8.47	233.47	2 220	22.20	2 790	35
Silty mudstone	14.77	248.24	2 530	25.30	1 740	28
Mudstone	14.52	262.76	2 530	24.20	1 400	31
Fine sandstone	16.45	279.21	2 420	26.40	4 130	26
Argillaceous siltstone	7.68	286.89	2 640	25.30	1 740	25
Silty mudstone	19.68	306.57	2 530	25.30	1 740	26
Argillaceous siltstone	14.35	320.92	2 530	25.30	1 740	36
Medium-grained sandstone	36.98	356.90	2 530	23.60	5 200	32
3# coal seam	0.88	357.78	1 300	13.00	800	35
Fine sandstone	10.43	368.21	2 640	26.40	4 130	35
Mudstone	2.76	372.42	2 420	24.20	1 400	36
Coarse sandstone	12.14	384.56	2 410	24.10	2 860	25
Fine sandstone	13.85	398.41	2 640	26.40	4 130	35
Silty mudstone	18.75	417.16	2 530	25.30	1 740	35
Fine sandstone	37.66	454.82	2 640	26.40	4 130	25
Siltstone	18.28	473.10	2 530	25.30	1 740	32
Silty mudstone	4.50	477.60	2 530	25.30	1 400	32
5# coal seam	33.48	507.60	1 300	13.00	800	35
Coarse sandstone	9.12	516.72	2 630	23.60	2 860	35