Study on Roof-Coal Caving Characteristics with Complicated Structure by Fully Mechanized Caving Mining

Table 1

Hard coal failure factor i and soft coal failure factor in hard coal gangue.

σc	30	35	40	45	50	55	60
	1.3	1.11	0.98	0.87	0.78	0.71	0.65
	10	8	7	6	5	4	3
	3.9	4.88	5.57	6.5	7.8	9.75	13