The Study on Large-Diameter Drilling Prevention Method of Rock Burst in the Xinxing Coal

Table 2

Physical and mechanical parameters of 65-layer coal and rock samples.

Coal and rock sample	Sample No.	Specimen size	Cross-sectional area; cm^2	Damage; Load; kN	Uniaxial compressive strength; MPa	Average uniaxial compressive strength; MPa	Apparent density; kg/m^3
Roof	1		19.6	207.20	105.712	101.0744
	2		19.6	190.43	97.156
	3		19.6	196.26	100.132
	4		19.6	214.47	109.425
	5		19.6	182.18	92.947
Coal	1		19.6	42.45	21.659	18.003
	2		19.6	33.94	17.318
	3		19.6	32.32	16.488
	4		19.6	30.14	15.375
	5		19.6	37.59	19.177
Bottom plate	1		19.6	213.66	109.011	102.0526
	2		19.6	207.11	105.668
	3		19.6	200.60	102.349
	4		19.6	193.62	98.784
	5		19.6	185.12	94.451