Numerical Simulation of the Stress Field in Repeated Mining of Coal Seams Based on In Situ Stress Measurement

Table 2

Rock mass strength estimation and measured maximum principal stress.

Drilling number	Lithology	Depth (m)	σci (MPa)	σ1m (MPa)	CRP (%)	GSI	mi	σcm (MPa)	σcm/σ1m	Em (GPa)
BK212	Coarse sandstone	102	9.28	5.17	49	55	15	2.18	0.42	4.06
	Medium sandstone	203	6.14	3.81	28	50	15	1.30	0.34	2.48
	Sandy mudstone	304	7.96	3.32	82	70	15	2.63	0.79	8.92
	Fine sandstone	406	21.41	9.64	27	50	15	4.53	0.47	4.63
	Fine sandstone	510	43.44	14.46	99	80	21	21.24	1.47	37.06
	Fine sandstone	590	40.45	13.66	93	90	21	26.90	1.97	63.60
BK209	Sandy mudstone	222	12.52	4.90	89	75	13	4.46	0.91	14.92
	Fine sandstone	330	23.53	8.77	88	75	21	10.10	1.15	20.46
	Fine sandstone	403	26.27	12.10	90	90	21	17.47	1.44	51.25
	Siltstone	497	36.39	13.48	62	65	18	11.57	0.86	14.31
BK213	Fine sandstone	300	22.91	5.74	59	60	21	7.02	1.22	8.51
	Siltstone	400	34.22	10.86	89	75	18	13.80	1.27	24.67
	Siltstone	469	33.04	11.91	89	75	18	13.33	1.12	24.24
	Fine sandstone	532	128.94	15.62	73	60	21	39.52	2.53	17.78
BK207	Coarse sandstone	100	48.62	5.54	64	60	18	13.86	2.50	12.40
	Coarse sandstone	201	12.91	5.84	88	75	18	5.21	0.89	15.15
	Coarse sandstone	260	18.86	16.64	44	65	21	6.00	0.36	10.30
	Siltstone	301	33.18	9.97	92	80	18	15.33	1.54	32.39
	Medium sandstone	362	116.25	17.97	55	60	18	33.14	1.84	17.78
	Siltstone	400	51.64	18.19	98	80	21	25.25	1.39	40.41
	Siltstone	449	65.46	17.97	54	60	21	20.06	1.12	14.39
BK220	Coarse sandstone	83	46.62	4.72	44	50	17	10.49	2.22	9.11
	Coarse sandstone	150	5.67	4.89	92	80	21	2.77	0.57	13.39
	Coarse sandstone	285	77.92	10.78	96	70	17	27.11	2.51	27.91
	Medium sandstone	375	90.85	12.97	99	70	17	31.61	2.44	30.14
	Coarse sandstone	430	22.44	10.05	75	60	21	6.88	0.68	8.42
	Sandy mudstone	562	51.40	19.57	95	95	21	23.27	1.19	40.32
	Medium sandstone	603	84.64	17.04	65	60	21	25.94	1.52	16.36