Strata Caving and Gob Evolution Characteristic in Longwall Mining

Table 1

Properties of coal and rock block in the BBM.

Lithology	Density (kg/m^3)	E (GPa)		C (MPa)	φ (°)	σt (MPa)
Mudstone	2570	5.12	0.36	1.38	34.90	0.43
Siltstone	2610	6.14	0.20	1.60	38.57	0.84
Coal	1360	1.05	0.36	0.36	34.45	0.23
Clasolite	2640	2.07	0.22	1.27	38.10	0.40
Fine sandstone	2530	13.48	0.15	2.84	35.89	2.03
Mudstone	2570	5.12	0.26	1.38	34.90	0.43
Coal (excavation)	1360	1.05	0.36	0.36	34.45	0.23
Mudstone	2570	5.12	0.26	1.38	34.90	0.43
Coal	1360	1.05	0.36	0.36	34.45	0.23