Prediction of Grade Classification of Rock Burst Based on PCA-SSA-PNN Architecture

Table 1

The classification of rock burst grade [42].

Features of rock burst	Rock burst grades
	I	II	III	IV
Sound features	None	Cracking sounds and tearing sounds	The crisp crackling sound	Very loud popping sounds
Movement features	None	Loosen or peel off	Burst, peeled off, and little ejection	Lots of bursts and ejections
Aging features	None	Occurs sporadically and intermittently	Long duration	Occurs in succession and rapidly extends deep
Influence depth	None	<0.5 m	0.5 to 1 m	1 to 3 m
Hazardous degree	None	Little	Relatively large	Serious