Analysis of Failure Characteristics and Strength Criterion of Coal-Rock Combined Body with Different Height Ratios

Table 2

Test results of coal and rock pure samples and coal-rock combined samples.

Samples		(MPa)	Elastic modulus (GPa)	Peak stress (MPa)	Residual strength (MPa)	Axial strain (10^−3)	Circle strain (10^−3)	Volume strain (10^−3)
ROCK	0	0	6.88	53.32	0.85	9.04
		5	7.7	66.20	6.32	8.93	–0.79	7.35
		10	9.11	90.93	14.71	8.44	–0.59	7.26
RCB-1-3	0.75	0	1.44	5.61	0.75	6.22
		5	3.37	10.9	6.51	5.06	–3.74	–2.42
		10	3.74	18.71	12.09	7.79	–8.64	–9.49
RCB-1-2	0.67	0	1.54	6.36	1.23	5.89
		5	3.38	12.33	7.02	5.55	–4.35	–3.15
		10	3.52	24.57	18.08	8.83	–7.14	–5.45
RCB-1-1	0.5	0	2.48	7.93	1.95	6.27
		5	3.58	14.12	7.20	5.28	–2.67	–0.06
		10	3.89	29.51	22.7	9.05	–7.1	–5.15
RCB-2-1	0.33	0	2.19	9.72	1.21	6.68
		5	4.48	17.92	8.13	6.32	–3.9	–1.48
		10	4.63	33.92	23.32	8.92	–6.41	–3.9
Coal	1	0	1.22	6.38	1.8	7.98
		5	2.07	10.03	2.21	6.88	–3.33	0.22
		10	2.29	17.1	7.85	9.39	–7.58	–5.77