Evaluation Method of Floor Heave Damage Degree and a Case Study in Zaoquan Coal Mine, China

Table 5

Grading judgment table of each index of floor heave damage degree.

Index		Classification of floor heave
		Light type	Obvious type	Severe type	Destructive type	Extremely severe type
		I	II	III	IV	V
Direct index	D (%)	100∼200	200∼300	300∼500	500∼700	>700
	V (m·s^−1)	0∼2000	2000∼2500	2500∼4000	4000∼5000	5000∼7500
Indirect index	P (m)	0∼3	3∼5	5∼7	7∼9	9∼11
		<4		4∼7		>7
	Rc (MPa)	1∼5	5∼15	15∼30	30∼60	>60