Classification and Application of Roof Stability of Bolt Supporting Coal Roadway Based on BP Neural Network

Table 3

The roof stability type and the standardized data of each index evaluating gene.

Evaluation factor	L	D	σc	B	N	H
Stable (class I)	0	>1.00	0.75∼1.00	<0.53	0∼0.25	<0.33
Medium stable type (class II)	0∼0.46	1.00∼0.77	0.50∼0.75	0.53∼0.61	0.25∼0.50	0.33∼0.53
Falling type (class III)	0.46∼1.00	0.77∼0.43	0.38∼0.50	0.61∼0.71	0.50∼0.75	0.53∼1.00
Easy to fall type (class IV)	>1.00	<0.43	<0.38	0.88∼1.00	0.75∼1.00	>1.00